Background: Hereditary Sensory Motor Neuropathy (HSMN) 1A and Multiple Sclerosis (MS) are distinct demyelinating disorders affecting the peripheral and central nervous systems, respectively. We present a case of simultaneous occurrence of both conditions, exploring the clinical presentation, diagnostic workup, and potential interplay between these diseases. Case presentation and clinical approach: A 49-year-old male with a history of optic neuritis presented with progressive numbness, weakness, and sensory loss in all extremities over four years. Neurological examination revealed distal weakness, sensory deficits in a stocking-glove distribution, pes cavus, and hammer toes. Nerve conduction studies and electromyography confirmed sensory motor demyelinating polyneuropathy. The patient’s lack of response to intravenous immunoglobulin therapy suggested hereditary neuropathy as an etiology. Genetic testing identified a PMP22 gene duplication, confirming HSMN 1A. Elevated cerebrospinal fluid protein level and oligoclonal bands, combined with magnetic resonance of the brain showing multiple T2 hyperintense lesions in the brain and spinal cord, fulfilled the diagnostic criteria for MS. Discussion: This case of co-existing HSMN 1A and MS highlights a rare overlap of peripheral and central demyelination. While HSMN 1A results from PMP22 gene duplication, primarily affecting peripheral myelin, MS is driven by immune-mediated central myelin attacks. The co-existence of these disorders suggests potential shared mechanisms, such as immune dysregulation. Some evidence suggests that overexpression of PMP22 in HSMN 1A may disturb immune tolerance, possibly triggering autoimmune responses linked to MS. Further research is needed to explore the genetic and autoimmune interplay between these two diseases, expanding our understanding of demyelinating disorders.

Background: This study examined the impact of age-adjusted cerebrospinal fluid (CSF) protein levels on clinical characteristics, disease severity, and outcomes in Guillain–Barré Syndrome (GBS) patients. Methods: This retrospective study included 71 GBS patients at UTMB Galveston. Albuminocytologic dissociation (ACD) was defined as CSF–total protein (CSF-TP) >0.45 g/L with a cell count of 0.45 g/L) and age-adjusted upper limits (URLs) for CSF-TP levels, comparing clinical, CSF, and electrophysiological characteristics across groups. Results: The mean age was 50 years (SD = 14.5). The mean age of patients with a CSF-TP > 45 g/L was higher (53 vs. 39 years, p = 0.000), whereas no such difference was noted using age-dependent URLs. Using age-adjusted CSF-TP URLs reduced the sensitivity for detecting ACD by 20%. CSF-TP > age-adjusted URLs were associated with lower MRC sum scores (39 vs. 47.43, p = 0.000), higher ICU admission rates (34% vs. 20%, p = 0.003), and the need for second-line treatment (41% vs. 17%, p = 0.049), and the trends were not observed with the conventional cutoff of 0.45 g/L. CSF-TP was an independent predictor of lower MRC sum scores (p = 0.009, 95% CI −0.058, −0.009) and higher GBS disability scores (p = 0.015, 95% CI 0.000, 0.004). Conclusions: ACD is a common finding in GBS, but normal protein levels do not exclude the diagnosis. Using age-adjusted URLs might improve specificity but reduce sensitivity for ACD detection, potentially increasing false negatives. CSF-TP levels exceeding age-adjusted URLs were more strongly associated with greater disease severity and poorer outcomes compared to the conventional cutoff of 0.45 g/L.

Background/Objectives: Optic neuritis is associated with demyelinating diseases such as multiple sclerosis (MS), but atypical presentations, particularly bilateral optic nerve involvement or coexisting systemic symptoms, necessitate broader diagnostic consideration. Case presentation: This case report describes a 50-year-old male with untreated, active hepatitis C virus (HCV) infection who presented with bilateral optic neuritis. Cerebrospinal fluid (CSF) analysis revealed elevated myelin basic protein, positive oligoclonal bands, an elevated immunoglobulin G index, and an HCV viral load of 9.3 million international units/milliliter (IU/mL). Magnetic resonance imaging (MRI) of the orbits showed bilateral optic neuritis with perineuritis. The patient had no history of interferon therapy and lacked markers of cryoglobulinemia, making this a rare case of optic neuritis possibly associated with chronic hepatitis C viral infection. The patient was treated with intravenous immunoglobulin (IVIG) without corticosteroids, with some improvement in vision. Conclusions: This case adds to the expanding spectrum of multiple sclerosis (MS) mimics and underscores diagnostic challenges associated with atypical optic neuritis presentations, particularly in the setting of coexisting systemic viral infections.

Optic neuritis is associated with demyelinating diseases such as multiple sclerosis (MS), but atypical presentations, particularly bilateral optic nerve involvement or coexisting sys-temic symptoms, warrant broader diagnostic consideration. This case report describes a 50-year-old male with untreated, active Hepatitis C virus (HCV) infection who presented with bilateral optic neuritis. Cerebrospinal fluid analysis revealed elevated myelin basic protein, oligoclonal bands, and a high IgG index and an elevated Hepatitis C viral load of 9.3 million IU/mL. MRI orbit showed bilateral optic neuritis/perineuritis. The patient had no history of interferon therapy and lacked markers of cryoglobulinemia, making this a ra-re case of optic neuritis likely related to chronic HCV infection. Treatment was complicated by concerns of exacerbating infection, leading to administration of IVIG without cortico-steroids. This case contributes to the expanding spectrum of multiple sclerosis (MS) mimics and highlights the diagnostic challenges in atypical optic neuritis presentations, especially in the setting of systemic viral infections.