Abstract
Disorders of sudomotor function are common and diverse in their presentations. Hyperhidrosis
or hypohidrosis in generalized or regional neuroanatomical patterns can provide clues
to neurologic localization and inform neurologic diagnosis. Conditions that impair
sudomotor function include small fiber peripheral neuropathy, sudomotor neuropathy,
myelopathy, α-synucleinopathies, autoimmune autonomic ganglionopathy, antibody-mediated
hyperexcitability syndromes, and a host of medications. Particularly relevant to neurologic
practice is the detection of postganglionic sudomotor deficits as a diagnostic marker
of small fiber neuropathies. Extensive anhidrosis is important to recognize, as it
not only correlates with symptoms of heat intolerance but may also place the patient
at risk for heat stroke when under conditions of heat stress. Methods for assessing
sudomotor dysfunction include the thermoregulatory sweat test, the quantitative sudomotor
axon reflex test, silicone impressions, and the sympathetic skin response.
Keywords
hypohidrosis - hyperhidrosis - small fiber neuropathy - thermoregulation
