Introduction: Charcot-Marie-Tooth disease (CMT) is a rare inherited peripheral neuropathy characterized by muscle atrophy, sensory malfunction, and pes cavus. Diagnosis can be challenging due to clinical and radiologic overlap with inflammatory neuropathies such as Chronic Inflammatory Demyelinating Polyneuropathy (CIDP), making differentiation essential to avoid misdiagnosis and inappropriate treatment. In this case, we describe a patient with findings initially suggestive of CIDP, later confirmed as CMT1A. Notably, imaging revealed bilateral trigeminal nerve involvement. Although cranial nerve involvement is rarely described in CMT1A, this case highlights it as a possible radiologic finding.
Description: A 78-year-old African American man with a history of a spinal nerve root tumor with debulking at C6-7 in 2011, presented with two months of progressive weakness, functional decline, and increasing confusion. Neurologic examination showed fluctuating orientation, moderate weakness and atrophy, reduced sensation in all extremities, bilateral pes cavus, and absent reflexes. Spine MRI showed enlargement and enhancement of the cervical, thoracic, and lumbosacral roots with spinal cord compression at the C6-7 level, without spinal cord lesions. Brain MRI revealed severe cortical atrophy with enlargement and enhancement of the bilateral trigeminal nerves. CSF showed protein >200 mg/dL, without pleocytosis. Electrodiagnostic studies exhibited severe sensory and motor axonal loss with active denervation in the distal lower extremities. The patient was diagnosed with CIDP and treated with IVIg and steroids without clinical improvement. A more detailed history uncovered a chronic progressive course suggestive of an inherited neuropathy. Sural nerve biopsy revealed demyelination with onion-bulb formations, and genetic testing confirmed a diagnosis of CMT1A.
Discussion: This case highlights the challenge of distinguishing CMT1A from CIDP and other inflammatory neuropathies. Though cranial nerve involvement is rare in CMT1A, our patient exhibited bilateral trigeminal nerve involvement, without corresponding clinical symptoms. These findings broaden the recognized clinical and anatomical features of CMT1A and emphasize the importance of careful clinical and radiologic evaluation for accurate diagnosis.
