Idiopathic intracranial hypertension

Background

• Also known as pseudotumor cerebri/benign intracranial hypertension (BIH)
• Cause is idiopathic, but believed be due to impaired CSF absorption at arachnoid villi
• Associated with OCPs, vitamin A, tetracycline and thyroid disorders

Work-Up

1. CT scan (negative or slit-like ventricles)
2. LP (Opening pressure >25)
3. MR venogram (to r/o cerebral venous sinus thrombosis)

Clinical Features

1. Headache
2. Nausea and Vomiting
3. Vision blurring

Diagnosis

1. Young, obese women
2. Headache (worse in AM / with manuvers increasing ICP)
3. Papilledema (optic atrophy/vision loss)
   1. can be visualized with ultrasound
4. Neuro Exam frequently normal
   1. May have cranial nerve palsies in severe, most often CN 6

Differential Diagnosis

• Aneurysm rupture and Subarachnoid Hemorrhage
• Brain tumor
• Encephalitis
• Head Injury
• Hydrocephalus (increased CSF)
• Hypertensive brain hemorrhage
• Intraventricular hemorrhage
• Cerebral venous sinus thrombosis
• Meningitis
• Subdural Hematoma
• Status epilepticus
• Stroke

Treatment

1. Repeat LPs (decrease CSF pressure) - large volume LPs on the order of 30-40 cc of CSF
2. Acetazolamide 500mg BID (decrease CSF production)
3. Furosemide 20 mg PO BID, give potassium supp as needed
4. Weight loss
5. CSF Shunt
6. Optic nerve sheath fenestration

Disposition

• Admit for:
  • Severe pain
  • Focal findings
  • Vision changes
• Otherwise, discharge w/ ophtho f/u for formal visual field monitoring

Source

Tintinalli