Jahard Aliaga-Arias

Background/Objectives: The purpose of this study was to investigate preoperative interhemispheric differences of the FAT in relation to the onset of postoperative SMA syndrome. Methods: This was a single-center retrospective analysis of patients who underwent surgical resection of diffuse gliomas involving the SMA between 2018 and 2022. Inclusion criteria were availability of preoperative and postoperative Magnetic Resonance Imaging, no previous surgery, and no neurological deficits at presentation. Diffusion-weighted data were processed by spherical deconvolution (SD) and diffusion tensor imaging tractography algorithms, and TrackVis was used to dissect the FAT of both hemispheres. The FAT data were analyzed for correlation with postoperative SMA syndrome onset. Results: N = 25 cases were included in the study, among which n = 23 had preoperative bilaterally identifiable FAT by SD. N = 12 developed an SMA syndrome, 6 demonstrated a motor-only syndrome, 4 had a verbal-only syndrome, and 2 had mixed verbal and motor features. The SMA syndrome incidence was significantly more frequent in lower-grade gliomas (p = 0.005). On the tumor side, the FAT identified by SD was smaller than the contralateral (mean volume 6.53 cm³ and 13.33 cm³, respectively, p < 0.001). In the 6 cases that developed a verbal SMA syndrome, a normalized FAT volume asymmetry (FAT-VA) demonstrated an asymmetry shifted towards the non-dominant side (mean FAT-VA = −0.68), while the cases with no postoperative verbal impairment had opposite asymmetry towards the dominant side (mean FAT-VA = 0.42, p = 0.010). Conclusions: Preoperative interhemispheric FAT volume asymmetry estimated according to functional dominance can predict postoperative onset of verbal SMA syndrome, with proportionally smaller FAT on the affected dominant hemisphere.

Background: Repetitive transcranial magnetic stimulation (rTMS) is established for depression and rehabilitation after stroke and is emerging for cognitive rehabilitation. We sought to evaluate patient and carer perceptions toward rTMS for rehabilitation after neurosurgery. Methods: Two surveys were undertaken. Group 1: Patients who received 7 days of rTMS for motor or language rehabilitation for severe postoperative deficits following lesional resection were prospectively surveyed on the last day of their rTMS treatment, as well as their next of kin. Group 2: Patients who had previously been diagnosed with glioma but did not receive rTMS were retrospectively surveyed through two brain tumor charities, including next of kin. Results: Group 1: Twenty-one responses. Eleven patients, 10 next of kin. The commonest pathology was WHO Grade 4 glioma (n = 3). Group 2: 24 responses. Sixteen patients, 8 next of kin. The commonest pathology was WHO Grade 2 glioma (n = 7). Most Group 1 respondents reported a positive experience of rTMS (15/21). Patients experienced subjective improvements in gross motor functions of arm and leg weakness and purposeful movement (9/11). Lack of subjective motor improvement was associated with adverse symptoms (e.g., headaches; p = .01). Group 2 respondents were supportive of rTMS. Key priorities included motor and cognitive rehabilitation. They were accepting of longer and more frequent rTMS sessions than Group 1 (p = .028 and <.001, respectively). Commonest concerns pertained to side effects are seizures and headaches. Conclusions: rTMS for rehabilitation was well-tolerated by patients with side effects being commoner in those with no subjective motor improvements. Nontreated patients and their next of kin would find longer and more sessions acceptable but have concerns about potential side effects.

BACKGROUND: Navigated transcranial magnetic stimulation (nTMS) is a well-established preoperative mapping tool for motor-eloquent glioma surgery. Machine learning (ML) and nTMS may improve clinical outcome prediction and histological correlation. METHODS: This was a retrospective cohort study of patients who underwent surgery for motor-eloquent gliomas between 2018 and 2022. Ten healthy subjects were included. Preoperative nTMS-derived variables were collected: resting motor threshold (RMT), interhemispheric RMT ratio (iRMTr)—abnormal if above 10%—and cortical excitability score—number of abnormal iRMTrs. World Health Organization (WHO) grade and molecular profile were collected to characterize each tumor. ML models were fitted to the data after statistical feature selection to predict tumor grade. RESULTS: A total of 177 patients were recruited: WHO grade 2—32 patients, WHO grade 3—65 patients, and WHO grade 4—80 patients. For the upper limb, abnormal iRMTr were identified in 22.7% of WHO grade 2, 62.5% of WHO grade 3, and 75.4% of WHO grade 4 patients. For the lower limb, iRMTr was abnormal in 23.1% of WHO grade 2, 67.6% of WHO grade 3%, and 63.6% of WHO grade 4 patients. Cortical excitability score (P = .04) was statistically significantly related with WHO grading. Using these variables as predictors, the ML model had an accuracy of 0.57 to predict WHO grade 4 lesions. In subgroup analysis of high-grade gliomas vs low-grade gliomas, the accuracy for high-grade gliomas prediction increased to 0.83. The inclusion of molecular data into the model—IDH mutation and 1p19q codeletion status—increases the accuracy of the model in predicting tumor grading (0.95 and 0.74, respectively). CONCLUSION: ML algorithms based on nTMS-derived interhemispheric excitability assessment provide accurate predictions of HGGs affecting the motor pathway. Their accuracy is further increased when molecular data are fitted onto the model paving the way for a joint preoperative approach with radiogenomics.

Hypertrophic pachymeningitis is a rare disorder of the dura mater of the spine or brain. It can be caused by inflammatory, infective or neoplastic conditions or can be idiopathic. We report a man with hypertrophic pachymeningitis and bilateral chronic subdural haematoma caused by IgG4-related disease. We highlight the diagnostic challenges and discuss possible underlying mechanisms of subdural haematoma formation in inflammatory conditions. Isolated IgG4-related hypertrophic pachymeningitis with chronic subdural haematoma is very rare; previously reported cases have suggested a possible predilection for men in their sixth decade, presenting with headache as the dominant symptom. Given the rarity and complexity of the condition, it should be managed in a multidisciplinary team setting.