Abstract
Introduction: Morvan syndrome is a rare autoimmune/paraneoplastic disorder involving antibodies to the voltage-gated potassium channel complex. It is defined by subacute encephalopathy, neuromuscular hyperexcitability, dysautonomia, and sleep disturbance. It may present a diagnostic dilemma when trying to differentiate from amyotrophic lateral sclerosis with frontotemporal dementia. Methods: A 76-year-old man with a history of untreated prostate adenocarcinoma was evaluated for subacute cognitive decline, diffuse muscle cramps, and hyponatremia. Results: MRI demonstrated atrophy most prominent in the frontal and temporal regions. Electromyography (EMG) demonstrated diffuse myokymia/neuromyotonia. Polysomnography lacked REM and N3 sleep. Paraneoplastic panel detected antibodies to voltage-gated potassium channel complex (CASPR2 subtype). Conclusions: It is difficult to differentiate between Morvan syndrome and amyotrophic lateral sclerosis with frontotemporal dementia with examination and neuroimaging alone. There may be a link between Morvan syndrome and prostate adenocarcinoma which could help with screening/diagnosis. The authors found that laboratory and neurophysiological tests are indispensable in diagnosing and treating Morvan syndrome.
Original language | English (US) |
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Pages (from-to) | 207-211 |
Number of pages | 5 |
Journal | Journal of Clinical Neuromuscular Disease |
Volume | 17 |
Issue number | 4 |
DOIs | |
State | Published - Jun 1 2016 |
Keywords
- Morvan syndrome
- amyotrophic lateral sclerosis
- frontotemporal dementia
- myokymia
- neuromyotonia
- voltage-gated potassium channel
ASJC Scopus subject areas
- Neurology
- Clinical Neurology