Abstract
Neurophysiology studies in a 50-year-old man with slowly progressive weakness of the left upper limb revealed conduction block in the ulnar nerve above the elbow. His weakness remained stable with regular subcutaneous immunoglobulin, but he noted gradual hemibody hair depigmentation. Examination also revealed unilateral left hand leukonychia (figure). MRI of the brain and cervical spine was normal.
Neurophysiology studies in a 50-year-old man with slowly progressive weakness of the left upper limb revealed conduction block in the ulnar nerve above the elbow. His weakness remained stable with regular subcutaneous immunoglobulin, but he noted gradual hemibody hair depigmentation. Examination also revealed unilateral left hand leukonychia (figure). MRI of the brain and cervical spine was normal.
Figure. Unilateral leukonychia and hemibody hair depigmentation.
Patient (viewed from the front) shows unilateral left upper limb leukonychia with depigmentation of chest and abdominal hair and a clear midline demarcation. The left arm appears hyperemic in comparison. The hair depigmentation did not extend to the head or legs.
Multifocal motor neuropathy with conduction block is a rare autoimmune motor neuropathy typically presenting with asymmetric distal upper limb weakness without sensory loss.1 Unilateral nail changes have been described in the context of posttraumatic reflex sympathetic dystrophy.2 The hair depigmentation is unexplained.
Footnotes
Study funding: No targeted funding reported.
Disclosure: The author reports no disclosures relevant to the manuscript. Go to Neurology.org for full disclosures.
References
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