Idiopathic Intracranial Hypertension in a 24-Year-Old Woman

Refractory Cases

A patient who fails conservative treatment should be referred to a neurosurgeon for placement of a CSF shunt, optic nerve sheath fenestration, or placement of a venous sinus stent.²³

Case Conclusion

After a noncontrast CT of the head was interpreted as completely normal, an LP was performed with the patient in the left lateral recumbent position. The opening CSF pressure exceeded 55 cm H₂O (the upper limit of the manometer). The CSF was clear, and opening pressure was rechecked after each 5 mL draw. After 15 mL had been removed, the patient reported a sudden, dramatic disappearance of her headache and clearing of her vision. After 19 mL of CSF had been removed, the CSF pressure had dropped into the normal range (<20 cm H₂O), and the procedure was ended.

To definitively rule out venous sinus thrombosis, a CT venogram was performed in the ED, and interpreted as normal. All other CSF results (cell count, protein, glucose, and gram stain) were normal. After complete resolution of the patient’s symptoms, she was discharged home with a prescription for acetazolamide 500 mg twice daily and instructions to follow-up with a neurologist within 48 hours. At discharge, the patient also received weight-loss counseling and was instructed to return immediately to the ED if her headache recurred or if she experienced any new neurological symptoms.

Summary

Idiopathic intracranial hypertension, also referred to as pseudotumor cerebri, is a rare but potentially vision-threatening cause of headache. Patients with signs and symptoms of IIH often initially present to the ED for evaluation and management. While the etiology of IIH is poorly understood, its clinical picture is unique: elevated ICP (sometimes markedly so) with no other significant findings on noncontrast head CT or CSF analysis. Venous sinus thrombosis, a life-threatening mimic of IIH, must always be included in the differential diagnosis.

Idiopathic intracranial hypertension is initially treated with rapid weight loss and acetazolamide. Many patients experience instant, though sometimes only transient, symptom relief from LP. No definitive studies to support any specific approach, including “therapeutic lumbar punctures.” The condition is rarely fulminant, and hospital admission is not typically required as long as urgent outpatient neurology follow-up is available.