BACKGROUND AND PURPOSE: The previous studies described phenotype-associated imaging findings in amyotrophic lateral sclerosis (ALS) with a prior categorization of patients based on clinical characteristics. We investigated the natural segregation of patients through a radiologic cluster-based approach without a priori patient categorization using 3 well-known prognostic MR imaging biomarkers in ALS, namely bilateral precentral and paracentral gyrus cortical thickness and medulla oblongata volume. We aimed to identify clinical/prognostic features that are cluster-associated. MATERIALS AND METHODS: Bilateral precentral and paracentral gyri and medulla oblongata volume were calculated using FreeSurfer in 90 patients with amyotrophic lateral sclerosis and 25 healthy controls. A 2-step cluster analysis was performed using precentral and paracentral gyri (averaged pair-wise) and medulla oblongata volume. RESULTS: We identified 3 radiologic clusters: 28 (31%) patients belonged to “cluster-1”; 51 (57%), to “cluster 2”; and 11 (12%), to “cluster 3.” Patients in cluster 1 showed statistically significant cortical thinning of the analyzed cortical areas and lower medulla oblongata volume compared with subjects in cluster 2 and cluster 3, respectively. Patients in cluster 3 exhibited significant cortical thinning of both paracentral and precentral gyri versus those in cluster 2, and this latter cluster showed lower medulla oblongata volume than cluster 3. Patients in cluster 1 were characterized by older age, higher female prevalence, greater disease severity, higher progression rate, and lower survival compared with patients in clusters 2 and 3. CONCLUSIONS: Patients with amyotrophic lateral sclerosis spontaneously segregate according to age and sex-specific patterns of neurodegeneration. Some patients with amyotrophic lateral sclerosis showed an early higher impairment of cortical motor neurons with relative sparing of bulbar motor neurons (cluster 3), while others expressed an opposite pattern (cluster 2). Moreover, 31% of patients showed an early simultaneous impairment of cortical and bulbar motor neurons (cluster 1), and they were characterized by higher disease severity and lower survival.

Background/Objectives: Autoimmune nodopathies are a distinct subgroup of immune-mediated peripheral neuropathies caused by antibodies targeting nodal and paranodal proteins, including contactin-1 (CNTN1). These disorders are frequently misclassified as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), despite fundamental differences in pathophysiology, clinical course, and treatment response. Growing evidence indicates that systemic manifestations, such as proteinuria, may represent relevant diagnostic red flags. We report a case of anti-CNTN1 autoimmune nodopathy with renal involvement and long-term follow-up after rituximab therapy. Methods: We describe the longitudinal clinical, electrophysiological, laboratory, and therapeutic features of a patient presenting with an acute/subacute sensory ataxic neuropathy evolving into a chronic immune-mediated disorder. Serial nerve conduction studies were performed during multiple hospital admissions and follow-up visits. Autoantibody testing for nodal/paranodal antigens was undertaken, and systemic biomarkers were monitored over time. Results: The patient initially exhibited a robust response to intravenous immunoglobulin (IVIg), consistent with an acute inflammatory neuropathy. Subsequent relapse was characterized by cranial nerve involvement, worsening sensory ataxia, peripheral edema, albuminocytologic dissociation on cerebrospinal fluid analysis, proteinuria, and an inverted albumin/gamma globulin ratio, redirecting the diagnostic hypothesis toward CIDP. The detection of anti-CNTN1 antibodies ultimately established the diagnosis of autoimmune nodopathy. Owing to poor durability of IVIg, rituximab was initiated, resulting in sustained clinical improvement and near-complete recovery of motor and sensory nerve conduction parameters at one-year follow-up (November 2025). Conclusions: This case emphasizes the diagnostic relevance of extraneurological biomarkers, including proteinuria and peripheral edema, in autoimmune nodopathies and supports early nodal/paranodal antibody testing in atypical demyelinating neuropathies. Prompt B-cell-directed therapy may enable functional recovery of nodal integrity and improve long-term outcomes. Further studies are needed to clarify potential immunological triggers, including anti-IL-23 therapies, in the pathogenesis of anti-CNTN1 autoimmune nodopathy.