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Dartos reflex: A sympathetically mediated scrotal reflex
Author(s) -
Yilmaz Ugur,
Yang Claire C.,
Berger Richard E.
Publication year - 2006
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.20476
Subject(s) - scrotum , reflex , reflex arc , medicine , cremaster muscle , anatomy , efferent , axon reflex , efferent nerve , anesthesia , afferent , microcirculation
The dartos muscle is a sympathetically innervated dermal muscle layer within the scrotum, distinct from the somatically innervated cremasteric muscle. We electrophysiologically demonstrate the presence of a dartos reflex (DR), which can be used to evaluate the thoracolumbar sympathetic and genitofemoral nerve pathways. In 20 healthy men, we evoked the DR by cutaneous stimulation of the thigh and recorded the resultant scrotal skin contraction. We recorded hand, foot, and perineal sympathetic skin responses (SSRs) as controls. The DR was reliable and reproducible, as were the SSRs. The mean left DR latency was 4.8 s (SD, 2.7 s) and right DR latency was 5.4 s (SD, 3 .4), both of which were longer than the mean hand, foot, and perineal SSRs ( P < 0.05). An intact reflex arc reflects the integrity of the afferent and efferent branches of the genitofemoral nerve (T12–L2). The DR test can also be used to assess scrotal autonomic innervation. Abnormalities of dartos innervation may impact testis thermoregulation and spermatogenesis. Muscle Nerve, 2006