OBJECTIVETo study the clinical presentations of Kennedy disease (KD) and compare the neurophysiological features between KD and amyotrophic lateral sclerosis(ALS).

METHODSNine patients with KD, 13 patients with ALS and 26 normal control subjects were recruited. The clinical presentations of KD were analyzed, and the results of nerve conduction studies and electromyography were compared among the 3 groups.

RESULTSThe rates of tongue atrophy and facial fasciculation were 100% and 88.9%, respectively, in the early course and mid-course of KD, sensory damages might be perceived. 2)The sural nerve sensory nerve action potential (SNAP) was not elicited in 56.3% of the patients with KD, and sural nerve SNAP amplitudes were significantly lower in KD (7.9. ± 3.4 µV) than in ALS patients (20.0 ± 5.2 µV) and normal control subjects (26.1 ± 16.8 µV) (P<0.05).

CONCLUSIONB The onset of clinical presentations mimicking motor neuron disease, appearance of tongue atrophy and facial fasciculation in the early and mid-course, and presence of sensory impairment with a decreased sural nerve SNAP amplitude may suggest the diagnosis of KD and should prompt a genetic test for KD.