ROSS SYNDROME: CLINICAL AND LABORATORY EVALUATION OF TWO CASES

Abstract

We describe two males, aged 41 and 55, come to our observation complaining of heat intolerance, abnormal increase in body temperature with minimal exercising, reduced sweating and, generalized fatigability; one of them had distal paresthesias. Neurologic evaluation showed bilateral Adie's tonic pupil and an absence of deep‐tendon jerks. A diagnosis of Ross' Syndrome was advanced. Autonomic tests, nerve conduction study, H‐reflex, computerized termoregulatory and pain thresholds, laser CO2 cortical evoked potentials, and skin biopsy were performed. One of them performed a histamine test and hand photopletismography resulted positive for sympathetic impairment, and pilocarpine pupil test that showed a parasympathetic denervation hypersensitivity.The following tests gave the same results in both patients: parasympathetic and most sympathetic tests were normal. Sympathetic skin response was absent and Minor test showed an almost complete absence of sweating. Sweating was possible only in two or three small areas. Positive pilocarpine test suggested a postganglionic involvement of sympathetic nervous system. Sensitive and motor nerve conduction velocities were normal, while H‐reflex was not detectable. Termoregulatory and pain thresholds were abnormal. Laser CO2 cortical evoked potentials showed the absence of C fibre potentials, whereas A‐δ fibres response was abnormal in one of them. Hairy skin biopsy showed a definite reduction of sweat glands and of small vessel innervation; glabrous skin biopsy performed in one of them showed a reduced number of Meissner corpuscles. These findings suggest that in Ross' Syndrome the degenerative process can involve, besides the autonomic fibres, myelinated somatosensory fibres also.