[A study of autonomic dysfunction and sympathetic skin response in motor neuron disease]

To explore the symptoms of autonomic dysfunction and sympathetic skin response (SSR) abnormality in patients of motor neuron disease (MND).

The clinical features of autonomic dysfunction were collected as follows: dermal numbness or pruritus, parahidrosis, xerostomia, salivation, abnormal skin temperature, orthostatic hypotension, mydriasis, ptosis or abnormal pupillary light reflex, constipation, voiding dysfunction and sexual dysfunction. SSR was performed and the results were judged according to the normal range of our laboratory. Abnormality rate in MND patients was calculated. The relationship between clinical symptoms and SSR parameters were analyzed statistically.

Among a total of 142 MND patients, the symptom incidences of autonomic dysfunction were as follows: dermal numbness (53.5%), dermal pruritus (15.5%), parahidrosis (10.6%), xerostomia (9.1%), salivation (2.1%), abnormal skin temperature (14.8%), orthostatic hypotension (2.1%), constipation (16.2%), voiding dysfunction (9.9%) and sexual dysfunction (1.4%). Abnormal SSR was found in 51/142 (35.9%) patients, including 12(8.5%) in palmar and 47(33.1%) in plantar. The features of abnormal SSR included delayed latency of palmar (P < 0.05) and decreased amplitudes of both palmar and plantar compared with normal ranges (P < 0.01 respectively). The group of patients with lumbosacral onset had a higher abnormal rate of SSR than those of other onset sites. There was no significant correlation between clinical symptoms and abnormal SSR parameters.

The patients of MND exhibit autonomic dysfunctions of skin, gland secretion, cardiovascular system and sphincters. Some of them show abnormal SSR with prolonged latency and decreased amplitude. The abnormalities of SSR are not related to clinical features of autonomic dysfunction. Those with an onset of lower limbs have a higher rate of abnormal SSR.