Identifying idiopathic intracranial hypertension in a hospital-based chronic headache population: Utility of magnetic resonance imaging, magnetic resonance venography and trans-orbital sonography.

BACKGROUND

One of the most underestimated types of chronic headaches is headaches as a result of cerebro-spinal fluid dysregulation disorders. Idiopathic intracranial hypertension (IIH) presents with headache and visual symptoms and usually is associated with papilledema. We identified patients with IIH in a chronic headache population presenting to a hospital-based headache clinic, and studied its associations with clinical, sonographic and magnetic resonance imaging (MRI) findings.

METHODS

Of 168 patients, 141 chronic headache patients were identified and completed the study procedures (semi-structured medical interview, fundus examination, MRI brain with magnetic resonance venography (MRV) and trans-orbital sonography (TOS)). Patients with abnormal findings underwent lumbar puncture for opening pressure.

RESULTS

The prevalence of IIH was 27%. IIH patients were of higher age, had gnawing/throbbing headache in the vertex in most cases, and had higher body mass index. Fundus examination had a sensitivity of 79% and a specificity of 98% for the detection of IIH cases. Approximately 23% of IIH patients had no papilledema. The most sensitive MR sign was found to be transverse sinus stenosis. TOS showed optic nerve sheath dilation in 35.7% of IIH without papilledema cases.

CONCLUSIONS

The prevalence of IIH is high in the chronic headache population and should be suspected in the headache clinic setting, particularly because there is significant overlap with migraine symptomatology. MRI/MR venography and TOS can be useful adjunct tests to identify IIH patients.