Distinguishing clinical and electrodiagnostic features of X-linked bulbospinal neuronopathy

✍ Scribed by Matthew N. Meriggioli; Julie Rowin; Donald B. Sanders

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 86 KB
• Volume: 22
• Category: Article
• ISSN: 0148-639X
• DOI: 10.1002/(sici)1097-4598(199912)22:12<1693::aid-mus11>3.0.co;2-s

✦ Synopsis

X-linked bulbospinal neuronopathy (XLBSN) or Kennedys disease is a rare inherited neuromuscular disease characterized by adultonset muscle weakness, usually in a limb-girdle distribution. It is frequently misdiagnosed despite a distinctive clinical presentation, usually due to the absence of a clear family history, and perhaps also due to failure of recognition. Accurate diagnosis is crucial for genetic counseling purposes and because alternative diagnoses usually carry a poorer prognosis. We evaluated 4 patients with XLBSN and one symptomatic female heterozygote patient. Based on our clinical observations in these patients and a systematic review of previously reported cases, the following clinical and electrophysiologic features when present in the setting of adult-onset muscle weakness, are strongly suggestive of the disorder: 1) facial weakness, 2) facial twitching or fasciculations, 3) tongue weakness and atrophy, 4) postural hand tremor, 5) hypo-or areflexia, and 6) absent or low-amplitude sensory nerve action potentials despite clinically normal sensation. We also hypothesize regarding the possibility of partial expression of the abnormal XLBSN gene in a symptomatic heterozygote female patient.