Segmental anhidrosis with hyporeflexia associated with congenital spinal deformity: a Ross's syndrome variant or inverse Horner's syndrome?

A 39-year-old soldier presented with anhidrosis affecting both upper extremities below the shoulders, the right side of the trunk below the third rib in front and the third vertebra on the back, and the left lower extremity below the inguinal ligament since 1992. Ten years later in 2002, he was also found to have bilateral absence of Achilles reflex and decreased right knee jerk. In addition, the patient was found to have congenital spinal abnormalities in the form of block of vertebrae C3-C4; decreased disc space C4-C5; and break in pars interarticularis L5-S1 with decreased disc space. A total of seven cases of Ross syndrome, Holmes-Adie syndrome (tonic pupil with lost tendon jerks) with segmental anhidrosis, have been described in the literature. Our case, however, did not have any pupillary abnormality. A case of progressive isolated segmental anhidrosis has also been described. The association of congenital spinal abnormality, which may be pathognomonic in the causation of this progressive sudomotor degeneration, is quite interesting in our case. The distribution of anhidrosis on the right side is just below the level of sweating loss sometimes described in lesions of superior sympathetic cervical ganglion in Horner's syndrome.