Orthostatic Hemifacial Spasm in Idiopathic Intracranial Hypertension: A Case Series and Proposed Mechanism
Madison Patrick1, Galen Postma1, Brenda Trokthi1, Andrew Carey2, Charles Maitland1
1Florida State University College of Medicine, 2Wilmer Eye Institute, Johns Hopkins University School of Medicine
Objective:
This case series reviews the few reports of hemifacial spasm (HFS) in idiopathic intracranial hypertension (IIH) and proposes a mechanism for spasm occurrence.
Background:
Among the multiplicity of symptoms seen in IIH, HFS is a rare finding. We treated two patients with unique IIH presentations wherein spasms were exacerbated by orthostatic changes or following lumbar puncture.
Design/Methods:
Chart review identified two cases of IIH presenting with HFS at our two institutions.
Results:
Case 1: A woman in her mid-40’s with previously controlled IIH developed right-sided hemifacial spasm, daily headache, pulsatile tinnitus, and trigeminal paresthesias arising exclusively when moving from a sitting to a standing position. Opening pressure (OP) on lumbar puncture (LP) was 46 cmH2O with normal CSF components. HFS episodes continued following LP. Acetazolamide dose was increased to 1.5 g/day; symptoms resolved completely at follow up.
Case 2: A woman in her late 40’s presented with left-sided hemifacial spasm, pulsatile tinnitus, and severe daily headache following weight gain. OP on LP was 32 cmH2O with normal CSF components. HFS continued following LP. Based on clinical findings, she was diagnosed with IIH at this time. Acetazolamide treatment was initiated at 1 g/day. Repeat LP at follow up showed improved OP of 25.5 cmH2O. Symptoms were fully resolved at that time.
Conclusions:
Earlier suggested mechanisms of HFS are based on elevated intracranial pressure (ICP) shifting the facial nerve into proximity with a vascular structure. HFS appearing upon standing and continuing after lumbar puncture, and thus at lower ICPs, contradicts this. We propose a mechanism based on the degree of ICP change. This theory is grounded in the lack of intracranial compliance in IIH, wherein substantial pressure changes occur following unsubstantial volume changes.