Lior Ungar
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Lior Ungar has a total of 21 co-authors. Here are the top co-authors by number of shared publications:
- Paz Kelmer
Department of Neurosurgery, Sheba Medical Center, Ramat Gan 52621, Israel
9 shared publications - Shachar Zion Shemesh
Department of Neurosurgery, Sheba Medical Center, Ramat-Gan, Israel
9 shared publications - Jose Asprilla
Department of Neurosurgery, Sheba Medical Center, Ramat Gan 52621, Israel
5 shared publications - Omri Cohen
Department of Neurosurgery, Sheba Medical Center, Ramat Gan 52621, Israel
4 shared publications - Itay Goor-Aryeh
Pain Center, Sheba Medical Center, Ramat Gan 5262100, Israel
3 shared publications - Zvi R. Cohen
Department of Neurosurgery, Sheba Medical Center, Ramat Gan 52621, Israel
3 shared publications
Latest Publications
- 30 August 2026
- Published by Taylor & Francis in Neurocase
- Vol. 32 (5) , 202-208
Severe amnestic-cognitive syndrome after right-sided resection in a patient with bilateral trigonal choroid plexus xanthogranulomas: illustrative case
Xanthogranulomas (XGs) of the choroid plexus are uncommon benign inflammatory lesions, usually discovered incidentally within the ventricular system. Although most remain asymptomatic, larger lesio...
- 30 August 2026
- Published by Taylor & Francis in Neurocase
- Vol. 32 (5) , 202-208
Severe amnestic-cognitive syndrome after right-sided resection in a patient with bilateral trigonal choroid plexus xanthogranulomas: illustrative case
Xanthogranulomas (XGs) of the choroid plexus are uncommon benign inflammatory lesions, usually discovered incidentally within the ventricular system. Although most remain asymptomatic, larger lesio...
- Open Access
- 8 July 2026
- Published by MDPI AG in Clinical and Translational Neuroscience
- Vol. 10 (3) , 21
The ABCDE Preoperative Framework for Functional Neurosurgery: A Structured Workflow Model Associated with Fewer Late-Stage Surgical Cancellations in a Single-Center Before-and-After Study
Background: Same-day or post-admission cancellation of elective surgery is associated with inefficient operating room utilization, patient distress, and disruption of coordinated perioperative care. Functional neurosurgery is particularly vulnerable to late-stage cancellation because procedural readiness depends on parallel clinical, anatomical, medication-related, device-related, and systemic considerations. Objective: This paper aims to describe the implementation of a structured preoperative review framework for functional neurosurgery and to evaluate its association with late-stage surgical cancellation after patient admission. Methods: We performed a retrospective single-center before-and-after study of consecutive functional neurosurgical procedures scheduled at Sheba Medical Center between January 2020 and December 2025. The ABCDE framework was introduced in 2023 as a structured workflow model organized around five domains: Anatomy, Bacteria, Clotting, Devices, and Elsewhere. Included procedures were deep brain stimulation, vagus nerve stimulation, focused ultrasound, intrathecal pump implantation or replacement, implantable pulse generator replacement, spinal cord stimulation, peripheral nerve stimulation, and other palliative neuromodulation procedures. The primary endpoint was late-stage cancellation, defined as cancellation after hospital admission and initiation of operative preparation. The primary comparison was between 2020–2022 and 2023–2025. A sensitivity analysis excluded 2020 because of pandemic-era disruption. Results: A total of 867 procedures were scheduled. Late-stage cancellation occurred in 16 of 407 pre-implementation procedures and 5 of 460 post-implementation procedures, corresponding to rates of 3.9% and 1.1%, respectively. The absolute risk difference was −2.8 percentage points (95% CI, −5.2 to −0.8), and the relative risk for cancellation after implementation was 0.28 (95% CI, 0.10 to 0.75). A two-sided Fisher’s exact test comparing cancellation versus non-cancellation across the pre-implementation and post-implementation periods was statistically significant (16/407 vs. 5/460; p = 0.0074). After excluding 2020, the direction of effect remained similar, but the difference was not statistically significant: 8 of 302 procedures in 2021–2022 were canceled compared with 5 of 460 in 2023–2025 (2.6% vs. 1.1%; p = 0.15). Detailed source-level attribution was incomplete for 10 of 21 cancellation events, and domain-level analyses should therefore be interpreted descriptively. Conclusions: Implementation of the ABCDE framework was associated with fewer late-stage surgical cancellations in this single-center before-and-after study. Because the design is observational, the number of events is small, and the study period overlaps with pandemic-era disruption and post-pandemic service stabilization, the findings should be interpreted as hypothesis-generating rather than causal. The framework may provide a practical structure for standardizing preoperative review in functional neurosurgery, but prospective studies with formal adherence tracking and procedure-specific analyses are needed.
- 8 July 2026
- Published by MDPI AG in Clinical and Translational Neuroscience
- Vol. 10 (3) , 21
Open AccessThe ABCDE Preoperative Framework for Functional Neurosurgery: A Structured Workflow Model Associated with Fewer Late-Stage Surgical Cancellations in a Single-Center Before-and-After Study
Background: Same-day or post-admission cancellation of elective surgery is associated with inefficient operating room utilization, patient distress, and disruption of coordinated perioperative care. Functional neurosurgery is particularly vulnerable to late-stage cancellation because procedural readiness depends on parallel clinical, anatomical, medication-related, device-related, and systemic considerations. Objective: This paper aims to describe the implementation of a structured preoperative review framework for functional neurosurgery and to evaluate its association with late-stage surgical cancellation after patient admission. Methods: We performed a retrospective single-center before-and-after study of consecutive functional neurosurgical procedures scheduled at Sheba Medical Center between January 2020 and December 2025. The ABCDE framework was introduced in 2023 as a structured workflow model organized around five domains: Anatomy, Bacteria, Clotting, Devices, and Elsewhere. Included procedures were deep brain stimulation, vagus nerve stimulation, focused ultrasound, intrathecal pump implantation or replacement, implantable pulse generator replacement, spinal cord stimulation, peripheral nerve stimulation, and other palliative neuromodulation procedures. The primary endpoint was late-stage cancellation, defined as cancellation after hospital admission and initiation of operative preparation. The primary comparison was between 2020–2022 and 2023–2025. A sensitivity analysis excluded 2020 because of pandemic-era disruption. Results: A total of 867 procedures were scheduled. Late-stage cancellation occurred in 16 of 407 pre-implementation procedures and 5 of 460 post-implementation procedures, corresponding to rates of 3.9% and 1.1%, respectively. The absolute risk difference was −2.8 percentage points (95% CI, −5.2 to −0.8), and the relative risk for cancellation after implementation was 0.28 (95% CI, 0.10 to 0.75). A two-sided Fisher’s exact test comparing cancellation versus non-cancellation across the pre-implementation and post-implementation periods was statistically significant (16/407 vs. 5/460; p = 0.0074). After excluding 2020, the direction of effect remained similar, but the difference was not statistically significant: 8 of 302 procedures in 2021–2022 were canceled compared with 5 of 460 in 2023–2025 (2.6% vs. 1.1%; p = 0.15). Detailed source-level attribution was incomplete for 10 of 21 cancellation events, and domain-level analyses should therefore be interpreted descriptively. Conclusions: Implementation of the ABCDE framework was associated with fewer late-stage surgical cancellations in this single-center before-and-after study. Because the design is observational, the number of events is small, and the study period overlaps with pandemic-era disruption and post-pandemic service stabilization, the findings should be interpreted as hypothesis-generating rather than causal. The framework may provide a practical structure for standardizing preoperative review in functional neurosurgery, but prospective studies with formal adherence tracking and procedure-specific analyses are needed.
- Open Access
- 23 June 2026
- Published by MDPI AG in Biomedicines
- Vol. 14 (7) , 1422
Pain Phenotypes, Treatment Patterns, and Utilization Burden Among Patients with Inflammatory Bowel Disease Referred to a Tertiary Pain Clinic: A Retrospective Cohort Study
Background: Pain is a prominent and disabling manifestation of inflammatory bowel disease (IBD), including abdominal, pelvic, musculoskeletal, axial, and neuropathic pain phenotypes. Patients referred to pain clinics represent a selected subgroup with clinically meaningful, persistent, refractory, or diagnostically complex pain. Objective: To characterize pain phenotypes, treatment patterns, interventional pain-care exposure, and utilization burden among patients with IBD evaluated in tertiary pain-clinic settings and to explore differences between Crohn’s disease and ulcerative colitis patients. Methods: We performed a retrospective electronic medical-record cohort study of patients with documented IBD who were evaluated in pain-clinic settings between 24 October 2010 and 14 May 2026. Repeated clinical entries were aggregated into unique visit dates and patient-level variables. IBD diagnosis, pain phenotypes, treatment documentation, interventional procedures, and pain-clinic utilization were summarized descriptively using counts, percentages, means, medians, interquartile ranges, and ranges as appropriate. Crohn’s disease and ulcerative colitis subgroups were compared using univariable odds ratios with 95% confidence intervals and two-sided p-values. Because repeated clinical entries could belong to the same patient, the primary analytic unit was the patient rather than the individual note. Results: The source dataset included 19,615 clinical entries representing 7053 unique pain-clinic visits among 596 unique patients with IBD. The cohort included 314 patients with Crohn’s disease (52.7%), 247 with ulcerative colitis (41.4%), and 35 with IBD-unclassified (5.9%). The mean number of pain-clinic visits per patient was 11.8, with a median of four visits (interquartile range, 1–11). The dominant patient-level pain phenotypes were limb or peripheral joint pain (395/596, 66.3%), back or axial spine pain (358/596, 60.1%), and abdominal or pelvic pain (246/596, 41.3%). Overall, 437 patients (73.3%) had documentation of at least one interventional pain procedure. Compared with ulcerative colitis, Crohn’s disease was associated with higher documentation of abdominal or pelvic pain (148/314, 47.1% vs. 82/247, 33.2%; odds ratio, 1.79; 95% confidence interval, 1.27–2.53; p = 0.001) and fibromyalgia-like or widespread pain (83/314, 26.4% vs. 39/247, 15.8%; odds ratio, 1.92; 95% confidence interval, 1.25–2.93; p = 0.0027). In contrast, radiofrequency procedures (59/314, 18.8% vs. 78/247, 31.6%; odds ratio, 0.50; 95% confidence interval, 0.34–0.74; p = 0.0005) and facet or medial branch procedures (79/314, 25.2% vs. 87/247, 35.2%; odds ratio, 0.62; 95% confidence interval, 0.43–0.89; p = 0.012) were less frequently documented in Crohn’s disease than in ulcerative colitis. Conclusions: Among patients with IBD referred to tertiary pain-clinic evaluation, pain was heterogeneous and predominantly musculoskeletal, axial, neuropathic, and procedurally targetable rather than exclusively visceral. These findings support structured, mechanism-based pain assessment integrated with gastroenterology, rheumatology, and pain-medicine care.
- 23 June 2026
- Published by MDPI AG in Biomedicines
- Vol. 14 (7) , 1422
Open AccessPain Phenotypes, Treatment Patterns, and Utilization Burden Among Patients with Inflammatory Bowel Disease Referred to a Tertiary Pain Clinic: A Retrospective Cohort Study
Background: Pain is a prominent and disabling manifestation of inflammatory bowel disease (IBD), including abdominal, pelvic, musculoskeletal, axial, and neuropathic pain phenotypes. Patients referred to pain clinics represent a selected subgroup with clinically meaningful, persistent, refractory, or diagnostically complex pain. Objective: To characterize pain phenotypes, treatment patterns, interventional pain-care exposure, and utilization burden among patients with IBD evaluated in tertiary pain-clinic settings and to explore differences between Crohn’s disease and ulcerative colitis patients. Methods: We performed a retrospective electronic medical-record cohort study of patients with documented IBD who were evaluated in pain-clinic settings between 24 October 2010 and 14 May 2026. Repeated clinical entries were aggregated into unique visit dates and patient-level variables. IBD diagnosis, pain phenotypes, treatment documentation, interventional procedures, and pain-clinic utilization were summarized descriptively using counts, percentages, means, medians, interquartile ranges, and ranges as appropriate. Crohn’s disease and ulcerative colitis subgroups were compared using univariable odds ratios with 95% confidence intervals and two-sided p-values. Because repeated clinical entries could belong to the same patient, the primary analytic unit was the patient rather than the individual note. Results: The source dataset included 19,615 clinical entries representing 7053 unique pain-clinic visits among 596 unique patients with IBD. The cohort included 314 patients with Crohn’s disease (52.7%), 247 with ulcerative colitis (41.4%), and 35 with IBD-unclassified (5.9%). The mean number of pain-clinic visits per patient was 11.8, with a median of four visits (interquartile range, 1–11). The dominant patient-level pain phenotypes were limb or peripheral joint pain (395/596, 66.3%), back or axial spine pain (358/596, 60.1%), and abdominal or pelvic pain (246/596, 41.3%). Overall, 437 patients (73.3%) had documentation of at least one interventional pain procedure. Compared with ulcerative colitis, Crohn’s disease was associated with higher documentation of abdominal or pelvic pain (148/314, 47.1% vs. 82/247, 33.2%; odds ratio, 1.79; 95% confidence interval, 1.27–2.53; p = 0.001) and fibromyalgia-like or widespread pain (83/314, 26.4% vs. 39/247, 15.8%; odds ratio, 1.92; 95% confidence interval, 1.25–2.93; p = 0.0027). In contrast, radiofrequency procedures (59/314, 18.8% vs. 78/247, 31.6%; odds ratio, 0.50; 95% confidence interval, 0.34–0.74; p = 0.0005) and facet or medial branch procedures (79/314, 25.2% vs. 87/247, 35.2%; odds ratio, 0.62; 95% confidence interval, 0.43–0.89; p = 0.012) were less frequently documented in Crohn’s disease than in ulcerative colitis. Conclusions: Among patients with IBD referred to tertiary pain-clinic evaluation, pain was heterogeneous and predominantly musculoskeletal, axial, neuropathic, and procedurally targetable rather than exclusively visceral. These findings support structured, mechanism-based pain assessment integrated with gastroenterology, rheumatology, and pain-medicine care.
- Open Access
- 8 June 2026
- Published by MDPI AG in International Journal of Environmental Research and Public Health
- Vol. 23 (6) , 772
Temporal Increase in Strict Spontaneous Intracerebral Hemorrhage Admissions During the First March Following Direct Israel–Iran Hostilities: Preliminary Single-Center Findings from a Decade-Referenced Neuroscience Services Cohort
Objective: On 28 February 2026, Israel entered direct large-scale hostilities with Iran under Operation Roaring Lion. The opening phase was characterized by repeated missile alerts, civilian protected-space instructions, and rapid reorganization of hospital activity into protected areas. We observed an apparent increase in strict spontaneous intracerebral hemorrhage admissions during March 2026 within our linked neurology/neurosurgery services dataset. The aim of this preliminary single-center study was to determine whether March 2026 was temporally associated with a higher proportional burden of strict spontaneous intracerebral hemorrhage admissions compared with March cohorts from the preceding decade and whether this pattern was also observed for acute ischemic stroke or non-traumatic subarachnoid hemorrhage. Methods: We performed a retrospective observational cohort study of all unique March admissions captured within a linked neurology/neurosurgery services dataset from 2016 through 2026. Hospitalizations were deduplicated by admission number. March 2026 was treated as the first full March occurring after the onset of direct Israel–Iran hostilities on 28 February 2026. Strict spontaneous ICH was defined using diagnosis-text phenotyping that included intraparenchymal or intracerebral hemorrhage terminology while excluding trauma, subarachnoid hemorrhage, subdural hematoma, aneurysm, arteriovenous malformation, tumor-related hemorrhage, cavernoma, venous sinus thrombosis, dissection, and other clearly secondary etiologies. Comparator phenotypes included acute ischemic stroke and non-traumatic subarachnoid hemorrhage (SAH). Results: Across 3855 unique March admissions, 68 met criteria for strict spontaneous ICH. In March 2026, 9 of 223 admissions (4.0%) were classified as strict spontaneous ICH, compared with 59 of 3632 admissions (1.6%) across March 2016–2025, yielding a rate ratio of 2.48 (95% CI 1.25–4.94; p = 0.015). Patients with strict spontaneous ICH in March 2026 were older (mean age 72.3 vs. 65.8 years), and 7 of 9 cases (77.8%) occurred in patients aged ≥70 years compared with 25 of 59 (42.4%) historically (p = 0.073). Acute ischemic stroke did not increase in March 2026 (7.6% vs. 9.4%; p = 0.475), and non-traumatic SAH showed only a non-significant numerical increase (2.7% vs. 1.4%; p = 0.147). Sensitivity analyses showed a directionally consistent but statistically non-significant increase when March 2026 was compared with March 2025 alone (4.0% vs. 1.2%; rate ratio 3.36, 95% CI 0.92–12.27; p = 0.076) and with a rolling 3-year March baseline from 2023 through 2025 (4.0% vs. 2.1%; rate ratio 1.93, 95% CI 0.88–4.23; p = 0.143). In-hospital mortality among strict spontaneous ICH patients was 1 of 9 (11.1%) in March 2026 versus 4 of 59 (6.8%) in March 2016–2025. Conclusions: In this preliminary single-center neurology/neurosurgery services cohort, March 2026 showed a higher proportional burden of strict spontaneous intracerebral hemorrhage admissions than March cohorts from the preceding decade, while acute ischemic stroke did not increase. Sensitivity analyses using March 2025 alone and a rolling 3-year March baseline were directionally consistent but did not reach statistical significance. These findings should therefore be interpreted as a hypothesis-generating temporal association rather than evidence of causality or population-level incidence. Wartime-related psychological stress, sleep disruption, altered healthcare access, blood pressure dysregulation, and medication nonadherence are biologically plausible contributors, but individual-level blood pressure, medication exposure, body mass index, time-to-admission, direct stress exposure, and detailed outcome data were not available in the present dataset. Multicenter, hospital-wide, and registry-based validation with seasonal and systems-level sensitivity analyses is required.
- 8 June 2026
- Published by MDPI AG in International Journal of Environmental Research and Public Health
- Vol. 23 (6) , 772
Open AccessTemporal Increase in Strict Spontaneous Intracerebral Hemorrhage Admissions During the First March Following Direct Israel–Iran Hostilities: Preliminary Single-Center Findings from a Decade-Referenced Neuroscience Services Cohort
Objective: On 28 February 2026, Israel entered direct large-scale hostilities with Iran under Operation Roaring Lion. The opening phase was characterized by repeated missile alerts, civilian protected-space instructions, and rapid reorganization of hospital activity into protected areas. We observed an apparent increase in strict spontaneous intracerebral hemorrhage admissions during March 2026 within our linked neurology/neurosurgery services dataset. The aim of this preliminary single-center study was to determine whether March 2026 was temporally associated with a higher proportional burden of strict spontaneous intracerebral hemorrhage admissions compared with March cohorts from the preceding decade and whether this pattern was also observed for acute ischemic stroke or non-traumatic subarachnoid hemorrhage. Methods: We performed a retrospective observational cohort study of all unique March admissions captured within a linked neurology/neurosurgery services dataset from 2016 through 2026. Hospitalizations were deduplicated by admission number. March 2026 was treated as the first full March occurring after the onset of direct Israel–Iran hostilities on 28 February 2026. Strict spontaneous ICH was defined using diagnosis-text phenotyping that included intraparenchymal or intracerebral hemorrhage terminology while excluding trauma, subarachnoid hemorrhage, subdural hematoma, aneurysm, arteriovenous malformation, tumor-related hemorrhage, cavernoma, venous sinus thrombosis, dissection, and other clearly secondary etiologies. Comparator phenotypes included acute ischemic stroke and non-traumatic subarachnoid hemorrhage (SAH). Results: Across 3855 unique March admissions, 68 met criteria for strict spontaneous ICH. In March 2026, 9 of 223 admissions (4.0%) were classified as strict spontaneous ICH, compared with 59 of 3632 admissions (1.6%) across March 2016–2025, yielding a rate ratio of 2.48 (95% CI 1.25–4.94; p = 0.015). Patients with strict spontaneous ICH in March 2026 were older (mean age 72.3 vs. 65.8 years), and 7 of 9 cases (77.8%) occurred in patients aged ≥70 years compared with 25 of 59 (42.4%) historically (p = 0.073). Acute ischemic stroke did not increase in March 2026 (7.6% vs. 9.4%; p = 0.475), and non-traumatic SAH showed only a non-significant numerical increase (2.7% vs. 1.4%; p = 0.147). Sensitivity analyses showed a directionally consistent but statistically non-significant increase when March 2026 was compared with March 2025 alone (4.0% vs. 1.2%; rate ratio 3.36, 95% CI 0.92–12.27; p = 0.076) and with a rolling 3-year March baseline from 2023 through 2025 (4.0% vs. 2.1%; rate ratio 1.93, 95% CI 0.88–4.23; p = 0.143). In-hospital mortality among strict spontaneous ICH patients was 1 of 9 (11.1%) in March 2026 versus 4 of 59 (6.8%) in March 2016–2025. Conclusions: In this preliminary single-center neurology/neurosurgery services cohort, March 2026 showed a higher proportional burden of strict spontaneous intracerebral hemorrhage admissions than March cohorts from the preceding decade, while acute ischemic stroke did not increase. Sensitivity analyses using March 2025 alone and a rolling 3-year March baseline were directionally consistent but did not reach statistical significance. These findings should therefore be interpreted as a hypothesis-generating temporal association rather than evidence of causality or population-level incidence. Wartime-related psychological stress, sleep disruption, altered healthcare access, blood pressure dysregulation, and medication nonadherence are biologically plausible contributors, but individual-level blood pressure, medication exposure, body mass index, time-to-admission, direct stress exposure, and detailed outcome data were not available in the present dataset. Multicenter, hospital-wide, and registry-based validation with seasonal and systems-level sensitivity analyses is required.
- Open Access
- 29 May 2026
- Published by MDPI AG in Diagnostics
- Vol. 16 (11) , 1674
Post-Dental and Alveolar Nerve-Related Trigeminal Pain in Patients Referred with Trigeminal Neuralgia Terminology: A Retrospective Tertiary-Center Diagnostic Pathway Study
Background: Trigeminal neuralgia (TN), a facial pain disorder classically characterized by recurrent brief electric-shock-like paroxysms in one or more trigeminal divisions, frequently traverses dental pathways before specialist evaluation. Conversely, dental extraction, endodontic treatment, implant procedures, and third-molar surgery may injure the inferior alveolar, superior alveolar, mental, or lingual nerves and generate painful post-traumatic trigeminal neuropathy. We sought to define the diagnostic interface between classical TN and post-dental/alveolar nerve-related trigeminal pain in a tertiary referral cohort. Methods: We performed a retrospective single-center diagnostic-pathway study using a clinical dataset comprising 672 unique patients. A dental-interface trigeminal candidate cohort was assembled from aggregated patient-level source notes and adjudicated into five prespecified phenotypes: confirmed alveolar neuropathy, post-extraction neuropathic onset, odontogenic diagnostic misclassification, mixed/uncertain dental-interface pain, and clean classical TN. Extracted variables included demographics, trigeminal branch documentation, sensory deficit, dental procedure history, post-extraction onset, MRI and neurovascular conflict language, secondary structural disease, TN-directed medication exposure, invasive treatment exposure, documented outcomes, and time from first specialist documentation to first dated invasive treatment. Results: Among 201 dental-interface trigeminal candidates, 19 patients (9.5%) had confirmed alveolar neuropathy, 31 (15.4%) had post-extraction neuropathic onset, 20 (10.0%) represented odontogenic diagnostic misclassification, 115 (57.2%) remained mixed/uncertain, and 16 (8.0%) fulfilled a clean classical TN phenotype. Overall, 114 patients (56.7%) carried explicit TN terminology somewhere in the chart. Non-classical alveolar/post-dental syndromes comprised 70 patients (34.8%). Compared with clean classical TN, this non-classical group had higher rates of documented oral sensory deficit (38.6% vs. 0.0%, p = 0.002), post-extraction onset (52.9% vs. 0.0%, p < 0.001), extraction history (61.4% vs. 0.0%, p < 0.001), and secondary structural disease (22.9% vs. 0.0%, p = 0.035). Neurovascular conflict or vascular-loop language did not distinguish non-classical alveolar/post-dental syndromes from clean classical TN (38.6% vs. 37.5%, p = 1.000). Conclusions: A substantial minority of tertiary dental-interface trigeminal referrals represented alveolar/post-dental syndromes rather than clean classical TN, even while carrying TN labels and accumulating TN-directed treatment exposure. Post-extraction onset, lower-lip/chin or intraoral sensory change, and pain persisting despite extraction should prompt careful phenotyping before classical TN-directed escalation. The alveolar–trigeminal interface can be operationalized as a recognizable diagnostic pathway with direct implications for multidisciplinary facial-pain evaluation.
- 29 May 2026
- Published by MDPI AG in Diagnostics
- Vol. 16 (11) , 1674
Open AccessPost-Dental and Alveolar Nerve-Related Trigeminal Pain in Patients Referred with Trigeminal Neuralgia Terminology: A Retrospective Tertiary-Center Diagnostic Pathway Study
Background: Trigeminal neuralgia (TN), a facial pain disorder classically characterized by recurrent brief electric-shock-like paroxysms in one or more trigeminal divisions, frequently traverses dental pathways before specialist evaluation. Conversely, dental extraction, endodontic treatment, implant procedures, and third-molar surgery may injure the inferior alveolar, superior alveolar, mental, or lingual nerves and generate painful post-traumatic trigeminal neuropathy. We sought to define the diagnostic interface between classical TN and post-dental/alveolar nerve-related trigeminal pain in a tertiary referral cohort. Methods: We performed a retrospective single-center diagnostic-pathway study using a clinical dataset comprising 672 unique patients. A dental-interface trigeminal candidate cohort was assembled from aggregated patient-level source notes and adjudicated into five prespecified phenotypes: confirmed alveolar neuropathy, post-extraction neuropathic onset, odontogenic diagnostic misclassification, mixed/uncertain dental-interface pain, and clean classical TN. Extracted variables included demographics, trigeminal branch documentation, sensory deficit, dental procedure history, post-extraction onset, MRI and neurovascular conflict language, secondary structural disease, TN-directed medication exposure, invasive treatment exposure, documented outcomes, and time from first specialist documentation to first dated invasive treatment. Results: Among 201 dental-interface trigeminal candidates, 19 patients (9.5%) had confirmed alveolar neuropathy, 31 (15.4%) had post-extraction neuropathic onset, 20 (10.0%) represented odontogenic diagnostic misclassification, 115 (57.2%) remained mixed/uncertain, and 16 (8.0%) fulfilled a clean classical TN phenotype. Overall, 114 patients (56.7%) carried explicit TN terminology somewhere in the chart. Non-classical alveolar/post-dental syndromes comprised 70 patients (34.8%). Compared with clean classical TN, this non-classical group had higher rates of documented oral sensory deficit (38.6% vs. 0.0%, p = 0.002), post-extraction onset (52.9% vs. 0.0%, p < 0.001), extraction history (61.4% vs. 0.0%, p < 0.001), and secondary structural disease (22.9% vs. 0.0%, p = 0.035). Neurovascular conflict or vascular-loop language did not distinguish non-classical alveolar/post-dental syndromes from clean classical TN (38.6% vs. 37.5%, p = 1.000). Conclusions: A substantial minority of tertiary dental-interface trigeminal referrals represented alveolar/post-dental syndromes rather than clean classical TN, even while carrying TN labels and accumulating TN-directed treatment exposure. Post-extraction onset, lower-lip/chin or intraoral sensory change, and pain persisting despite extraction should prompt careful phenotyping before classical TN-directed escalation. The alveolar–trigeminal interface can be operationalized as a recognizable diagnostic pathway with direct implications for multidisciplinary facial-pain evaluation.
- Open Access
- 25 May 2026
- Published by Journal of Neurosurgery Publishing Group (JNSPG) in Journal of Neurosurgery: Case Lessons
- Vol. 11 (21)
Resolution of chronic refractory migraine and development of burning mouth syndrome after focused ultrasound thalamotomy: illustrative case
BACKGROUND: Chronic migraine is a highly disabling neurological disorder. A subset of patients develop chronic daily headaches refractory to all standard therapies. MR-guided focused ultrasound (MRgFUS) ventral intermediate nucleus (VIM) thalamotomy is an incisionless treatment for medication-refractory essential tremor (ET). OBSERVATIONS: A 76-year-old woman with a 40-year history of chronic migraine with near-daily attacks, characterized predominantly by right-sided headaches and unresponsive to multiple preventive and acute treatments, underwent MRgFUS VIM thalamotomy for severe ET. After the procedure, her tremor resolved, and her chronic migraines were no longer reported during long-term follow-up. Shortly after the procedure, she developed burning mouth syndrome (BMS), characterized by bilateral oral burning dysesthesias with left-sided predominance involving the lips and oral mucosa. She was treated with gabapentin and amitriptyline, with partial symptomatic improvement. Postprocedure MRI confirmed the intended VIM lesion with slight medial extension toward the adjacent ventral posteromedial nucleus (VPM) of the thalamus, which relays trigeminal somatosensory input. LESSONS: This unique case illustrates that ablative neuromodulation of thalamic networks may be followed by marked improvement or remission of chronic refractory migraine, further supporting a possible role for the thalamus in migraine pathophysiology and pain transmission. It also highlights a potential trade-off: lesion extension toward nearby sensory nuclei, including the VPM, may be associated with focal central pain manifesting as BMS. https://thejns.org/doi/10.3171/CASE251040
- 25 May 2026
- Published by Journal of Neurosurgery Publishing Group (JNSPG) in Journal of Neurosurgery: Case Lessons
- Vol. 11 (21)
Open AccessResolution of chronic refractory migraine and development of burning mouth syndrome after focused ultrasound thalamotomy: illustrative case
BACKGROUND: Chronic migraine is a highly disabling neurological disorder. A subset of patients develop chronic daily headaches refractory to all standard therapies. MR-guided focused ultrasound (MRgFUS) ventral intermediate nucleus (VIM) thalamotomy is an incisionless treatment for medication-refractory essential tremor (ET). OBSERVATIONS: A 76-year-old woman with a 40-year history of chronic migraine with near-daily attacks, characterized predominantly by right-sided headaches and unresponsive to multiple preventive and acute treatments, underwent MRgFUS VIM thalamotomy for severe ET. After the procedure, her tremor resolved, and her chronic migraines were no longer reported during long-term follow-up. Shortly after the procedure, she developed burning mouth syndrome (BMS), characterized by bilateral oral burning dysesthesias with left-sided predominance involving the lips and oral mucosa. She was treated with gabapentin and amitriptyline, with partial symptomatic improvement. Postprocedure MRI confirmed the intended VIM lesion with slight medial extension toward the adjacent ventral posteromedial nucleus (VPM) of the thalamus, which relays trigeminal somatosensory input. LESSONS: This unique case illustrates that ablative neuromodulation of thalamic networks may be followed by marked improvement or remission of chronic refractory migraine, further supporting a possible role for the thalamus in migraine pathophysiology and pain transmission. It also highlights a potential trade-off: lesion extension toward nearby sensory nuclei, including the VPM, may be associated with focal central pain manifesting as BMS. https://thejns.org/doi/10.3171/CASE251040
- Open Access
- 21 May 2026
- Published by MDPI AG in Neurology International
- Vol. 18 (5) , 99
Real-World Diagnostic Phenotypes and Treatment Pathways in Trigeminal Pain: A Retrospective Tertiary-Center Cohort—Diagnostic Phenotypes in Trigeminal Pain
Background: Trigeminal neuralgia (TN) is clinically defined, but patients presenting to tertiary practice with trigeminal-region pain are often diagnostically heterogeneous and may follow prolonged medication, dental, imaging, and procedural pathways before a stable phenotype is established. We aimed to characterize diagnostic phenotypes, secondary causes, and treatment-escalation patterns in a large retrospective tertiary-center trigeminal pain cohort derived from routine free-text clinical documentation. Methods: We conducted a retrospective single-center cohort study based on a clinical dataset containing 18,007 note fragments linked to 672 unique patient records between 12 October 2010 and 21 April 2026. A rule-based natural-language-processing-assisted chart review framework was used to identify patients with trigeminal pain and to extract documentation-derived demographic features, pain distribution, secondary causes, dental pathway variables, imaging signals, medication exposure, procedures, and outcome language. Patients were grouped into primary/classical TN, secondary TN/trigeminal pain, and dental-first or mimic pathways using predefined operational criteria. Results: A total of 455 patients met criteria for the analytic trigeminal pain cohort; 311 (68.4%) carried explicit TN terminology. Mean age was 58.7 years, median age 60 years, and 267 of 428 patients with recoverable sex data (62.4%) were women. Trigeminal branch involvement could be extracted in 351 patients (77.1%), with V2 involvement documented in 256 (56.3%), V3 involvement in 218 (47.9%), and V1 involvement in 138 (30.3%). The final NLP-derived phenotypic distribution comprised 201 primary/classical TN cases (44.2%), 146 secondary TN/trigeminal pain cases (32.1%), and 108 dental-first or mimic presentations (23.7%). MRI was documented in 384 patients (84.4%), neurovascular conflict or vascular loop in 253 (55.6%), multiple-sclerosis-related disease in 69 (15.2%), and tumor-related trigeminal involvement in 84 (18.5%). Prior dental evaluation was identified in 169 patients (37.1%), and prior dental procedures in 114 (25.1%). Carbamazepine exposure was documented in 367 patients (80.7%), pregabalin in 221 (48.6%), gabapentin in 150 (33.0%), oxcarbazepine in 116 (25.5%), and phenytoin in 73 (16.0%). At least one invasive or image-guided procedure was documented in 390 patients (85.7%), including nerve blocks/injections in 355 (78.0%), radiofrequency procedures in 126 (27.7%), balloon compression in 90 (19.8%), microvascular decompression in 113 (24.8%), and stereotactic radiosurgery in 55 (12.1%). Dental-first patients were significantly more likely to have undergone prior dental procedures (65.7% vs. 3.5% in primary/classical TN and 24.7% in secondary TN; p < 0.001), whereas secondary TN/trigeminal pain was associated with higher use of radiofrequency procedures (36.3%; p = 0.017), higher use of stereotactic radiosurgery (19.9%; p = 0.002), higher recurrence documentation (70.5%; p = 0.001), and a higher rate of complete pain relief documented at last follow-up (46.6%; p = 0.004). Conclusions: In tertiary practice, trigeminal pain is substantially broader than a formal TN label. Secondary disease and dental-first pathways account for a large fraction of referrals, and management is characterized by heavy medication burden, frequent escalation, and recurrent retreatment. A structured phenotyping approach may help convert routine clinical documentation into a clinically meaningful framework for diagnostic triage and treatment selection, although imaging and outcome variables require cautious interpretation when derived from retrospective free text.
- 21 May 2026
- Published by MDPI AG in Neurology International
- Vol. 18 (5) , 99
Open AccessReal-World Diagnostic Phenotypes and Treatment Pathways in Trigeminal Pain: A Retrospective Tertiary-Center Cohort—Diagnostic Phenotypes in Trigeminal Pain
Background: Trigeminal neuralgia (TN) is clinically defined, but patients presenting to tertiary practice with trigeminal-region pain are often diagnostically heterogeneous and may follow prolonged medication, dental, imaging, and procedural pathways before a stable phenotype is established. We aimed to characterize diagnostic phenotypes, secondary causes, and treatment-escalation patterns in a large retrospective tertiary-center trigeminal pain cohort derived from routine free-text clinical documentation. Methods: We conducted a retrospective single-center cohort study based on a clinical dataset containing 18,007 note fragments linked to 672 unique patient records between 12 October 2010 and 21 April 2026. A rule-based natural-language-processing-assisted chart review framework was used to identify patients with trigeminal pain and to extract documentation-derived demographic features, pain distribution, secondary causes, dental pathway variables, imaging signals, medication exposure, procedures, and outcome language. Patients were grouped into primary/classical TN, secondary TN/trigeminal pain, and dental-first or mimic pathways using predefined operational criteria. Results: A total of 455 patients met criteria for the analytic trigeminal pain cohort; 311 (68.4%) carried explicit TN terminology. Mean age was 58.7 years, median age 60 years, and 267 of 428 patients with recoverable sex data (62.4%) were women. Trigeminal branch involvement could be extracted in 351 patients (77.1%), with V2 involvement documented in 256 (56.3%), V3 involvement in 218 (47.9%), and V1 involvement in 138 (30.3%). The final NLP-derived phenotypic distribution comprised 201 primary/classical TN cases (44.2%), 146 secondary TN/trigeminal pain cases (32.1%), and 108 dental-first or mimic presentations (23.7%). MRI was documented in 384 patients (84.4%), neurovascular conflict or vascular loop in 253 (55.6%), multiple-sclerosis-related disease in 69 (15.2%), and tumor-related trigeminal involvement in 84 (18.5%). Prior dental evaluation was identified in 169 patients (37.1%), and prior dental procedures in 114 (25.1%). Carbamazepine exposure was documented in 367 patients (80.7%), pregabalin in 221 (48.6%), gabapentin in 150 (33.0%), oxcarbazepine in 116 (25.5%), and phenytoin in 73 (16.0%). At least one invasive or image-guided procedure was documented in 390 patients (85.7%), including nerve blocks/injections in 355 (78.0%), radiofrequency procedures in 126 (27.7%), balloon compression in 90 (19.8%), microvascular decompression in 113 (24.8%), and stereotactic radiosurgery in 55 (12.1%). Dental-first patients were significantly more likely to have undergone prior dental procedures (65.7% vs. 3.5% in primary/classical TN and 24.7% in secondary TN; p < 0.001), whereas secondary TN/trigeminal pain was associated with higher use of radiofrequency procedures (36.3%; p = 0.017), higher use of stereotactic radiosurgery (19.9%; p = 0.002), higher recurrence documentation (70.5%; p = 0.001), and a higher rate of complete pain relief documented at last follow-up (46.6%; p = 0.004). Conclusions: In tertiary practice, trigeminal pain is substantially broader than a formal TN label. Secondary disease and dental-first pathways account for a large fraction of referrals, and management is characterized by heavy medication burden, frequent escalation, and recurrent retreatment. A structured phenotyping approach may help convert routine clinical documentation into a clinically meaningful framework for diagnostic triage and treatment selection, although imaging and outcome variables require cautious interpretation when derived from retrospective free text.
- Open Access
Neuropathic Cranial Pain Phenotypes After Craniotomy: A Large, Single-Center Retrospective Cohort Study
Background and Objectives: Chronic headache after craniotomy is common and may include neuropathic subtypes (scar neuroma pain, occipital neuralgia). However, no large series has quantified these phenotypes. We conducted a single-center retrospective review (n = 5624 adult craniotomy patients) to estimate the prevalence of post-craniotomy neuropathic pain and to describe its characteristics. Materials and Methods: Institutional records were screened to identify craniotomy patients referred to a multidisciplinary pain clinic (n = 272). Eligible cases were reviewed in tiers: (1) exclusion of primary headache and noncranial pain; (2) identification of “probable neuropathic cranial pain” based on documented neuropathic features (lancinating/scalp pain, trigger tenderness, dermatomal distribution); and (3) subgroup categorization into occipital neuralgia-like, supraorbital/supratrochlear neuralgia-like, and scar-site neuropathic pain phenotypes. The supraorbital/supratrochlear subgroup was defined by frontal or frontotemporal postoperative pain in the supraorbital region, local tenderness or Tinel-like hypersensitivity over the supraorbital/supratrochlear course, and/or response to supraorbital–supratrochlear nerve block. Data extracted included demographics, timing (surgery to pain referral), pain characteristics, and treatments (blocks, radiofrequency, medications). Results: Of 5624 craniotomy patients, 272 (4.8%) had pain clinic encounters. The initial review identified 124 cases with chronic post-craniotomy headache requiring follow-up; after detailed chart classification, probable neuropathic cranial pain was present in 111 cases (2% of the cohort). Among the 111 probable neuropathic cranial pain cases, the dominant regional phenotype was occipital neuralgia-like pain. In addition, eight patients (7.2%) demonstrated a supraorbital/supratrochlear neuralgia-like phenotype, predominantly after frontal or frontotemporal craniotomies. Scar-site neuropathic pain frequently coexisted with both regional phenotypes, supporting a partially overlapping spectrum rather than mutually exclusive categories. The median time from surgery to pain referral was several months (≈12–18 months). Management commonly included occipital nerve blocks (±steroid); some patients received pulsed radiofrequency ablation of the occipital nerves, and most were trialed on neuropathic analgesics (gabapentinoids, SNRIs, etc., according to neuropathic pain guidelines). Conclusions: A clinically meaningful subset of post-craniotomy patients develops chronic neuropathic cranial pain, most commonly with occipital, supraorbital/supratrochlear, or scar-related features. Because most postoperative headaches are managed through neurosurgical follow-up and improve without pain clinic referral, the present cohort likely underestimates the true burden of neuropathic post-craniotomy pain while enriching for its most refractory neuralgic presentations. This is nevertheless the subgroup that must be recognized, discussed with patients, studied prospectively, and targeted in future prevention strategies.
Open AccessNeuropathic Cranial Pain Phenotypes After Craniotomy: A Large, Single-Center Retrospective Cohort Study
Background and Objectives: Chronic headache after craniotomy is common and may include neuropathic subtypes (scar neuroma pain, occipital neuralgia). However, no large series has quantified these phenotypes. We conducted a single-center retrospective review (n = 5624 adult craniotomy patients) to estimate the prevalence of post-craniotomy neuropathic pain and to describe its characteristics. Materials and Methods: Institutional records were screened to identify craniotomy patients referred to a multidisciplinary pain clinic (n = 272). Eligible cases were reviewed in tiers: (1) exclusion of primary headache and noncranial pain; (2) identification of “probable neuropathic cranial pain” based on documented neuropathic features (lancinating/scalp pain, trigger tenderness, dermatomal distribution); and (3) subgroup categorization into occipital neuralgia-like, supraorbital/supratrochlear neuralgia-like, and scar-site neuropathic pain phenotypes. The supraorbital/supratrochlear subgroup was defined by frontal or frontotemporal postoperative pain in the supraorbital region, local tenderness or Tinel-like hypersensitivity over the supraorbital/supratrochlear course, and/or response to supraorbital–supratrochlear nerve block. Data extracted included demographics, timing (surgery to pain referral), pain characteristics, and treatments (blocks, radiofrequency, medications). Results: Of 5624 craniotomy patients, 272 (4.8%) had pain clinic encounters. The initial review identified 124 cases with chronic post-craniotomy headache requiring follow-up; after detailed chart classification, probable neuropathic cranial pain was present in 111 cases (2% of the cohort). Among the 111 probable neuropathic cranial pain cases, the dominant regional phenotype was occipital neuralgia-like pain. In addition, eight patients (7.2%) demonstrated a supraorbital/supratrochlear neuralgia-like phenotype, predominantly after frontal or frontotemporal craniotomies. Scar-site neuropathic pain frequently coexisted with both regional phenotypes, supporting a partially overlapping spectrum rather than mutually exclusive categories. The median time from surgery to pain referral was several months (≈12–18 months). Management commonly included occipital nerve blocks (±steroid); some patients received pulsed radiofrequency ablation of the occipital nerves, and most were trialed on neuropathic analgesics (gabapentinoids, SNRIs, etc., according to neuropathic pain guidelines). Conclusions: A clinically meaningful subset of post-craniotomy patients develops chronic neuropathic cranial pain, most commonly with occipital, supraorbital/supratrochlear, or scar-related features. Because most postoperative headaches are managed through neurosurgical follow-up and improve without pain clinic referral, the present cohort likely underestimates the true burden of neuropathic post-craniotomy pain while enriching for its most refractory neuralgic presentations. This is nevertheless the subgroup that must be recognized, discussed with patients, studied prospectively, and targeted in future prevention strategies.
- Open Access
- 2 February 2026
- Published by MDPI AG in Dentistry Journal
- Vol. 14 (2) , 81
Burning Mouth Syndrome as a Central Pain Disorder: A Case Study Demonstrating Response to Occipital Nerve Block Treatment
Background: Burning Mouth Syndrome (BMS) is a chronic orofacial pain condition characterized by a burning sensation in the oral cavity without identifiable lesions. It predominantly affects women (especially postmenopausal) but can occur in men. BMS is considered a multifactorial neuropathic pain disorder involving both peripheral small-fiber neuropathy and central dysregulation, often accompanied by taste alterations (dysgusia) and xerostomia despite normal oral exams. Treatment is challenging, with modest responses to agents like clonazepam, tricyclic antidepressants, or gabapentinoids. Observations: We present a 67-year-old male with recalcitrant primary BMS who showed complete remission temporally associated with occipital nerve blockade, likely affecting central trigeminocervical pathways. Initial therapy with amitriptyline (25 mg) and gabapentin (900 mg/day) yielded ~30% pain relief. Given suspected central sensitization, greater and lesser occipital nerve (GON) blocks were administered in series. After the first, second, and third ON blocks, pain was reduced by ~50%, 80%, and 100%, respectively. Remission persisted at one-year follow-up under continued medications. A mild recurrence (~20% of baseline pain) responded fully to a fourth GON block, maintaining another year of pain-free status. Lessons: This case underscores the complex central mechanisms in BMS and illustrates that modulating central pain circuits via occipital nerve blockade, through trigeminocervical convergence mechanisms, without direct trigeminal intervention. We discuss the diagnostic challenges of BMS, the rationale of occipital neuromodulation, and how this novel therapeutic strategy compares with current literature, supporting the hypothesis of central sensitization in BMS.
- 2 February 2026
- Published by MDPI AG in Dentistry Journal
- Vol. 14 (2) , 81
Open AccessBurning Mouth Syndrome as a Central Pain Disorder: A Case Study Demonstrating Response to Occipital Nerve Block Treatment
Background: Burning Mouth Syndrome (BMS) is a chronic orofacial pain condition characterized by a burning sensation in the oral cavity without identifiable lesions. It predominantly affects women (especially postmenopausal) but can occur in men. BMS is considered a multifactorial neuropathic pain disorder involving both peripheral small-fiber neuropathy and central dysregulation, often accompanied by taste alterations (dysgusia) and xerostomia despite normal oral exams. Treatment is challenging, with modest responses to agents like clonazepam, tricyclic antidepressants, or gabapentinoids. Observations: We present a 67-year-old male with recalcitrant primary BMS who showed complete remission temporally associated with occipital nerve blockade, likely affecting central trigeminocervical pathways. Initial therapy with amitriptyline (25 mg) and gabapentin (900 mg/day) yielded ~30% pain relief. Given suspected central sensitization, greater and lesser occipital nerve (GON) blocks were administered in series. After the first, second, and third ON blocks, pain was reduced by ~50%, 80%, and 100%, respectively. Remission persisted at one-year follow-up under continued medications. A mild recurrence (~20% of baseline pain) responded fully to a fourth GON block, maintaining another year of pain-free status. Lessons: This case underscores the complex central mechanisms in BMS and illustrates that modulating central pain circuits via occipital nerve blockade, through trigeminocervical convergence mechanisms, without direct trigeminal intervention. We discuss the diagnostic challenges of BMS, the rationale of occipital neuromodulation, and how this novel therapeutic strategy compares with current literature, supporting the hypothesis of central sensitization in BMS.
- Open Access
- 22 November 2025
- Published by MDPI AG in Journal of Clinical Medicine
- Vol. 14 (23) , 8314
Identifying S3 and S2 as Key Pain-Sensitive Targets in High-Frequency Ultrasound Therapy for Sacroiliitis
Background/Objectives: Sacroiliitis is a painful inflammatory disorder of the sacroiliac joint, estimated to account for up to 25% of chronic low back pain. Treatment options are often limited, and many patients continue to experience symptoms despite conservative or interventional management. High-Intensity Focused ultrasound (HIFU) has emerged as a novel noninvasive neuromodulation technique. However, the contribution of individual lumbosacral nerve branches (L5–S3) to pain generation during such interventions remains unclear. This study aimed to characterize the distribution of pain-related interruptions during HIFU procedures, with a particular focus on identifying the most pain-sensitive targets. Methods: Eight patients with clinically confirmed sacroiliitis underwent HIFU ablation targeting the L5–S3 branches. Procedural data, including the total number of sonications and interruptions due to pain, were prospectively recorded. Statistical analyses were performed using chi-square tests, including overall distribution testing, pairwise branch comparisons, and an aggregated comparison of S3 versus all other branches combined. Effect sizes were calculated using Cohen’s w. Results: Across 243 sonications, 162 interruptions (66.7%) occurred due to pain. Interruptions were unevenly distributed: 81% occurred at S2 and S3, with S3 alone accounting for 42%. S3 showed significantly more interruptions than L5 (p = 0.0022), S1 (p = 0.0150), S2 (p = 0.0055), and all other branches combined (p < 0.001; w = 0.58, large effect). S2 also demonstrated greater sensitivity than L5 (p = 0.003) and S1 (p = 0.001). Subdivision analysis revealed uniformly high sensitivity across S3, whereas S1 and S2 displayed heterogeneous patterns. Conclusions: HIFU stimulation revealed disproportionate pain sensitivity in sacral branches, with S3—and to a lesser extent S2—emerging as dominant contributors. These findings provide new insight into sacroiliitis pathophysiology and suggest prioritization of S3 in targeted interventional management.
- 22 November 2025
- Published by MDPI AG in Journal of Clinical Medicine
- Vol. 14 (23) , 8314
Open AccessIdentifying S3 and S2 as Key Pain-Sensitive Targets in High-Frequency Ultrasound Therapy for Sacroiliitis
Background/Objectives: Sacroiliitis is a painful inflammatory disorder of the sacroiliac joint, estimated to account for up to 25% of chronic low back pain. Treatment options are often limited, and many patients continue to experience symptoms despite conservative or interventional management. High-Intensity Focused ultrasound (HIFU) has emerged as a novel noninvasive neuromodulation technique. However, the contribution of individual lumbosacral nerve branches (L5–S3) to pain generation during such interventions remains unclear. This study aimed to characterize the distribution of pain-related interruptions during HIFU procedures, with a particular focus on identifying the most pain-sensitive targets. Methods: Eight patients with clinically confirmed sacroiliitis underwent HIFU ablation targeting the L5–S3 branches. Procedural data, including the total number of sonications and interruptions due to pain, were prospectively recorded. Statistical analyses were performed using chi-square tests, including overall distribution testing, pairwise branch comparisons, and an aggregated comparison of S3 versus all other branches combined. Effect sizes were calculated using Cohen’s w. Results: Across 243 sonications, 162 interruptions (66.7%) occurred due to pain. Interruptions were unevenly distributed: 81% occurred at S2 and S3, with S3 alone accounting for 42%. S3 showed significantly more interruptions than L5 (p = 0.0022), S1 (p = 0.0150), S2 (p = 0.0055), and all other branches combined (p < 0.001; w = 0.58, large effect). S2 also demonstrated greater sensitivity than L5 (p = 0.003) and S1 (p = 0.001). Subdivision analysis revealed uniformly high sensitivity across S3, whereas S1 and S2 displayed heterogeneous patterns. Conclusions: HIFU stimulation revealed disproportionate pain sensitivity in sacral branches, with S3—and to a lesser extent S2—emerging as dominant contributors. These findings provide new insight into sacroiliitis pathophysiology and suggest prioritization of S3 in targeted interventional management.