TUBEROUS SCLEROSIS - EARLY DIAGNOSIS BY T ESTING RESPONSES OF THE AUTONOMOUS NERVOUS-SYSTEM IN HYPOPIGMENTED MACULES

The earliest clinical sign for the diagnosis of tuberous sclerosis (TS ) is the presence of cutaneous hypopigmented macules. However, there a re no clinical, histopathological or functional criteria to discrimina te between hipopigmented macules of TS and those without associated pa thology. In this prospective study, the responses of the autonomous ne rvous system, erythema and sweating induced through iontophoresis with pilocarpine, were studied in three groups of patients (20 with TS, 10 with hipomelanosis of Ito, and 10 with hipopigmented macules without associated pathology). In hipopigmented macules without associated pat hology, the responses were similar to those observed in normal skin. I n TS erythema and sweating were significantly diminished (p = < 0.001) . In hypomelanosis of Ito the descrease in erythema and sweating were not statistically significant. In TS the degree of decrease of erythem a and sweating correlated positively with the severity of the neurolog ical alterations. Light and electronmicroscopic studies of the hypopig mented macules in the three groups showed morphologically normal sweat glands and neves. The latter suggests a disfunction of the sweat glan ds in TS as a cause of their abnormal behavior. We conclude that sweat testing in hypopigmented macules is a useful mean for the early diagn osis of ET.