Diminished emotional sweating in patients with limbic encephalitis.

OBJECTIVE

Sweating on the palms of the hands and soles of the feet, so-called emotional sweating, is considered to be mediated by the limbic system, including the amygdala and anterior cingulate cortex. To reveal involvement of the limbic system in emotional sweating, we evaluated emotional sweating on the palms in patients with limbic encephalitis.

METHODS

Sweat and skin vasoconstriction responses to arousal stimuli were recorded on the palms of 7 patients with limbic encephalitis caused by viral infection (n=3) or immune-mediated encephalitis (n=4). All patients had amnesia, and magnetic resonance imaging revealed mesial temporal lobe lesions, including those on the amygdala, in 6 of these patients.

RESULTS

Sweat responses were absent or markedly reduced in patients with limbic encephalitis compared to normal controls following deep inspiration (p<0.05), mental arithmetic (p<0.01), exercise (p<0.05), and tactile stimulation (p<0.01). Skin vasoconstriction responses in these patients were also impaired, but the extent of such impairment was mild compared to that of the sweating reductions.

CONCLUSION

Sweating on the palm was significantly impaired in patients with mesial temporal lesions. Sweating on the palm could be a useful index of limbic function.