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RESEARCH PRODUCT

The so-called one-and-a-half syndrome, type II: a new syndrome?

subject

description

Objective: The term one-and-a-half syndrome, type II, was recently coined and has been applied to two somewhat different eye movement disorders: the loss of voluntary horizontal eye movements except for adduction in one eye (one patient with two lesions, one in the cerebral hemisphere and the other in the cavernous sinus) and the loss of all voluntary horizontal eye movements with adduction nystagmus in the right eye on attempted gaze to the left and preserved abduction in both eyes with the doll’s head maneuver (one patient with infarction of the midbrain). The justification of the term ‘one-and-a-half syndrome, type II’ is questioned. Design: Retrospective analysis of 9000 consecutive electro-oculographic recordings (EOG) with respect to combined abnormalities of conjugated horizontal eye movements to one side and abduction to the other. Results: Only one patient had loss of horizontal eye movements sparing adduction in one eye on clinical examination. In eight patients with clinically unilateral abduct...