Hemifacial spasm: magnetic resonance angiography

Area of Science:

• Neurology
• Neurosurgery
• Radiology

Background:

• Hemifacial spasm (HFS) is a neurological disorder characterized by involuntary contractions of facial muscles.
• The presumed cause of HFS is neurovascular compression of the facial nerve root.
• Identifying the specific causative vascular structures is crucial for effective treatment.

Purpose of the Study:

• To investigate the relationship between the vertebrobasilar circulation and the facial nerve in patients with hemifacial spasm.
• To evaluate the utility of magnetic resonance angiography (MRA) in diagnosing neurovascular compression in HFS.
• To correlate imaging findings with clinical presentation and discuss treatment implications.

Main Methods:

• A cohort of 23 consecutive patients with hemifacial spasm was prospectively studied.
• Magnetic resonance imaging angiography (MRA) of the brain was performed in 20 patients and 15 age- and sex-matched controls.
• Angiograms were independently reviewed by two blinded observers to identify arterial contact with the intracranial facial nerve root.

Main Results:

• Ipsilateral arterial contact with the facial nerve root was identified in 85% (17/20) of HFS patients.
• In contrast, only 7% (2/30) of control half-brains showed similar arterial contact.
• The most frequent contact involved arteries of the vertebrobasilar system.

Conclusions:

• The study strongly confirms that contact between an artery and the facial nerve root is the predominant cause of hemifacial spasm.
• MRA is a valuable non-invasive tool for identifying neurovascular compression in HFS.
• Findings support the use of MRA for preoperative evaluation and research in HFS, and MRI for excluding other pathologies.