[Inverse ocular bobbing associated with cerebral embolism and diabetes insipidus--a case report]

Inverse ocular bobbing (IOB) is an uncommon abnormal eye movement. Its characteristics are slow downward eye movement with rapid upward return, a nadir at the extreme of downgaze position and horizontal roving eye movement. We present a case of IOB associated with cerebral embolism and diabetes insipidus. A 69 year-old right-handed woman was admitted because of a consciousness disturbance. She had been well until November 10, 1983, when she was found dysarthric and left hemiplegic. On admission, she was stuporous. There were conjugate deviation to the right, central left facial and hypoglossal palsy, left hemiplegia with spasticity, left hyperreflexia with positive pathologic reflex and anosognosia. A CT scan performed on November 11 showed extensive hypodense area in the region supplied by the right middle cerebral artery. A right carotid angiography revealed multiple occlusions in the top of the right internal carotid artery with poor collateral circulation. After admission, the level of consciousness gradually deteriorated and became comatose on November 18, when the following abnormal eye movements were observed. Following spontaneous horizontal roving eye movement, both eyes deviated downward slowly from midposition, taking 1 to 2 seconds to reach the nadir. The eyes then remained in the position for 1 to 15 seconds, followed by a rapid return to the midposition. These abnormal eye movements are compatible with inverse ocular bobbing (IOB) described by Knobler. Electronystagmography detected typical IOB and spontaneous upward nystagmus. There was no evidence of hypoxia when these abnormal eye movements were present.(ABSTRACT TRUNCATED AT 250 WORDS)