Nam-Hee Kim

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system, driven by immune-mediated myelin damage. Unlike neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease, which are diagnosed via serological testing, MS lacks biomarkers, relying on magnetic resonance imaging (MRI)-based spatial and temporal lesion dissemination per the 2017/2024 McDonald criteria. Perivenular lesions, a hallmark of MS, first described by James W. Dawson in 1916, are now visualized noninvasively using advanced MRI. Emerging biomarkers -central vein sign and paramagnetic rim lesions- demonstrate high specificity, improving diagnostic accuracy. Artificial intelligence innovations enhance biomarker detection and monitoring, enabling personalized therapies. This review highlights key MRI biomarkers, clinical interpretation, and recent advancements in MS diagnostics.

손이슬, et al. J Korean Soc Radiol. 2025 Jul;86(4):483-500. https://doi.org/10.3348/jksr.2024.0107

Kim SH, et al. J Clin Neurol. 2025 Mar;21(2):131-136. https://doi.org/10.3988/jcn.2024.0485

Background: Myotonic dystrophy type 1 (DM1) is a multisystemic disorder caused by CTG repeat expansion in the DMPK gene. Brain involvement in DM1 has been reported, but quantitative imaging data is limited. This study aimed to characterize and quantify brain structural abnormalities in DM1 using MRI and DUIH-Image software.Methods: Sixteen patients with classic DM1 (10 male, 6 female; age range 17–68 years) underwent genetic testing, neuropsychologic assessment, and brain MRI. FLAIR images were analyzed using DUIH-Image software to quantify brain lesions and create probabilistic lesion maps.Results: FLAIR imaging revealed hyperintensities predominantly in periventricular and subcortical white matter. Probabilistic lesion maps highlighted the subcortical white matter near the anterior horn as the most affected site, with additional involvement of the posterior horn, frontal, insular, parietal, and temporal cortices. Neuropsychological testing identified frontal lobe dysfunction as the most common deficit, correlating with brain involvement. No significant correlations were found between lesion load, CTG repeat number, and disease duration.Conclusions: This study demonstrates significant periventricular and subcortical white matter involvement in DM1, with the anterior subcortical white matter being the most affected site. Frontal lobe dysfunction was a frequent finding. Brain involvement did not correlate with CTG repeat number or disease duration, suggesting complex pathophysiology in DM1-related brain abnormalities.

Tolosa-Hunt syndrome (THS) is a rare neurological disorder characterized by painful ophthalmoplegia due to idiopathic granulomatous inflammation of the cavernous sinus or orbital apex. This review aims to summarize recent advances in the etiology, diagnosis, and management of THS.

Postherpetic neuralgia (PHN) is a chronic neuropathic pain syndrome that persists for more than three months after the resolution of herpes zoster rash. This condition affects approximately 30% of the population, primarily the elderly and immunocompromised individuals. PHN can be severely debilitating and often proves challenging to treat effectively. Recent advances in prevention and treatment have improved the management of PHN. The introduction of herpes zoster vaccines has shown promise in reducing the incidence of both herpes zoster and PHN. Current treatment guidelines recommend a multimodal approach, with effective therapies including tricyclic antidepressants, topical lidocaine, gabapentin, pregabalin, opioids, and topical capsaicin. This review focuses on optimizing treatment strategies and developing novel therapies to further enhance PHN management.

Critical illness neuromyopathy (CINM) is a common yet frequently overlooked complication in intensive care units (ICU). CINM often results in prolonged ventilator dependence and persistent limb weakness, significantly impacting patient recovery and long-term quality of life. CINM can be categorized into two primary subtypes: critical illness polyneuropathy (CIP) and critical illness myopathy (CIM). These conditions frequently arise in the context of severe sepsis, multiple organ failure, or as adverse effects of certain medications used in the ICU. This review aims to provide a concise overview of CINM, focusing on its pathophysiology, diagnostic approaches, and current clinical management strategies.

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune astrocytopathy caused by the autoantibody of aquaporin-4 (AQP4). Herein, we report a case of Tolosa-Hunt syndrome presenting with abducens palsy and AQP4 antibodies. This was a rare case of AQP4-immunoglobulin G seropositivity in a patient with Tolosa-Hunt syndrome. Our findings may expand the clinical phenotype of NMOSD and indicate that clinicians should consider testing for AQP4 antibodies in patients with Tolosa-Hunt syndrome.

Invasive fungal infection remains a major cause of morbidity and mortality in immunocompromised patients. Invasive fungal sinusitis can present as a Tolosa-Hunt syndrome (THS) or orbital apex, leading to frequent misdiagnosis. Accurate diagnosis of fungal infection invading the cavernous sinus or orbital apex is essential to reduce mortality through early antifungal treatment and reduce the risk of worsening with steroid treatment due to misdiagnosis of THS. Herein, we report a case of invasive fungal sinusitis mimicking THS.

Background: The younger generation in Korea easily exposed to nitrous oxide (N2O) under the name “Happy Balloon” may abuse it. N2O can irreversibly oxidize vitamin B12 and cause abnormal hematopoiesis or nervous system toxicity such as subacute combined degeneration (SCD). The objective of this study was to assist in early diagnosis of N2O-induced SCD of spinal cord by characterizing its clinical manifestations.Methods: Four patients with myelopathy after abusing N2O were enrolled. To characterize N2O-induced myelopathy, previously reported cases of N2O-induced SCD were searched through PubMed and KoreaMed. Collected cases and our four patients were analyzed.Results: A total of 30 patients with N2O-induced myelopathy (26 males and 4 females with mean age of 24 years) were analyzed. These patients took a median dose of 650 canisters for a median duration of 3.5 months. All patients presented sensory disturbances, which involved the lower extremities more frequently (100%) than the upper extremities (63.3%). Gait ataxia (76.7%), weakness in the upper (23.3%) and lower (36.7%) extremities, bladder symptoms (26.7%), Rhomberg sign (43.3%), and Lhermitte’s phenomenon (10.0%) were observed. Serum vitamin B12 levels were decreased in many (63.3%) patients and homocysteine levels were elevated in all. Of 20 patients who underwent magnetic resonance imaging (MRI) of the spine, 19 had abnormal findings. Three patients presented with contrast enhancement in lesions.Conclusions: We strongly recommend that history of N2O abuse should be asked for young patients with suspected myelopathy, especially those presenting with gait ataxia and sensory disturbances suggesting posterior column dysfunction and those presenting long-segment lesion involving the upper cervical cord on MRI.