Abstract: Objective To study the clinical presentations of Kennedy disease (KD) and compare the neurophysiological features
between KD and amyotrophic lateral sclerosis(ALS). Methods Nine 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. Results The 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). Conclusion 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.