Involvement of the autonomic nervous system in patients with syringomyelia--a study with the sympathetic skin response.

In order to determine the function of the autonomic nervous system in syringomyelia, the sympathetic skin response (SSR) was performed in 13 patients with syringomyelia and 20 healthy controls. SSR was recorded from both palms and soles. In patients with syringomyelia, we found absent responses, prolonged latencies and reduced amplitudes. SSRs could be recorded in 15 out of the examined 26 upper extremities. The latencies were prolonged in 12 of these cases. In the lower limbs, 11 SSRs could be obtained. In 4 of these cases the latencies were prolonged. The SSR latencies recorded from the palms and soles were both significantly prolonged (p < 0.05) and the amplitudes were reduced (p < 0.05) as compared to normal persons. Our data strongly suggest involvement of the autonomic nervous system in syringomyelia as assessed by the SSR response (in upper and lower extremities). In our patients, the extent of autonomic dysfunction was not related to the stage or the duration of disease.