HPI

• 50 year old woman with a history of RA comes to the ED for headache
• Intermittent headaches for 3 months, worsening over 10 days
• She now has occasional spots in her vision
• HA worse with movement, especially bending forward

Physical Examination

Vitals: 139/84 HR 78 T 97.8F. RR 16 SpO2 100%

• CN are intact including visual fields
• Strength and sensation are intact
• Normal finger to nose and rapid/alternating movements
• Fundscopic exam inconclusive
• Patient ambulates with a slow but steady gait 

Differential Diagnosis

• Primary headache (tension, migraine, cluster): These account for the vast majority of cases encountered in the ED
• Space occupying lesion: tumor
• Subarachnoid hemorrahge: Possible given severity and atypical nature of headache, though no classic "thunderclap" onset
• Idiopathic intercranial hypertension
• Cerebral venous sinus thrombosis

Management 

• CT head without contrast prior to LP
• LP in the lateral decubitus to measure opening pressure-this patient had an elevated opening pressure of 26 cm H20
• Neurology consult: reccomoend MRI brain with and without contrast

Radiology read this as: no acute intracranial abnormalities with partially empty sella and slight prominence of the subarachnoid space that can be seen in the setting of IIH.

Diagnostic Criteria for Idiopathic Intracranial Hypertension

• Papilledema
• Normal neuro examination except 6th nerve palsy
• Normal neuroimaging with partial or completely empty sella
• Normal CSF
• Elevated opening pressure >25cm CSF

Take Home Points

• IIH occurs more frequently in women of childbearing age with elevated BMI 
• Patients present complaining of headache with visual symptoms and sometimes "pulsatile tinnitus"
• Long term treatment with weight loss reduction has been shown to be effective in improving vision and headache symptoms
• Initial medical therapy = acetazolamide to decrease CSF production
• All patients require ophthalmology follow-up to screen for papilledema and for visual field testing
• Rapidly progressive vision loss may require VP shunting
• Undiagnosed IIH may lead to permanent vision loss

Sources

Mollan SP, Davies B, Silver NC, et al. Idiopathic intracranial hypertension: consensus guidelines on management. J Neurol Neurosurg Psychiatry. 2018;89(10):1088-1100. doi:10.1136/jnnp-2017-317440