Rt. 6th Nerve Palsy Induced by Benign Idiopathic Intracranial Hypertension Without any Signs

Abstract

Background & Significance: Idiopathic intracranial hypertension (IICH) is the clinical syndrome induced by increased intracranial pressure for which no causative factor can be identified. Common clinical signs and symptoms of IICH include headache, papilledema, transient visual obscurations, diplopia, ocular motor disorders, tinnitus, vomiting and mental irregularities. Headache is the most common symptom. Visual disturbance is also common but not diplopia and photopsia. All the cases with ocular motor disorder are reported to be combined with papilledemia. However, there is no report about sixth nerve palsy induced by IICH without any signs including papilledema. Herein, we report a case of IICH presenting with right sixth nerve palsy without papilledema. Case: A 43-year-old right-handed woman was admitted to our hospital with headache, nausea and diplopia. One month before, she had felt headache on right frontotemporal area and the headache had been aggravated gradually. There was no abnormal finding in her vital sign and laboratory findings but her body mass index was 30.7. On neurologic examination, there were no definite abnormal neurological sign except right sixth nerve palsy. Brain magnetic resonance imaging were performed. It revealed no abnormalities. And the results of CSF study showed very high intracranial pressure (270 mmCSF) and others within normal limits. Four days after the admission, we performed the ophthalmologic examination including visual field test and fundus examination, and the result was normal. The headache and diplopia were gradually improved with oral acetazolamide treatment and she was discharged in fully recovery state 11 days after the admission. Conclusions or Commentes: We reported a patient presenting with headache and diplopia without any other signs including papilledema. Althought papilledema was shown in the patients of IICH with sixth nerve palsy, this case suggest that oculomotor disorder can be developed in the patients of IICH without papilledema.