Developmental venous anomaly responsible for hemifacial spasm

Microvascular decompression for developmental venous anomaly causing hemifacial spasm: illustrative case

BACKGROUND

Developmental venous anomaly (DVA) is a rare cause of hemifacial spasm (HFS). The treatment of HFS caused by a DVA varies in the literature and includes medication management, botulinum toxin injections, and microvascular decompression (MVD).

OBSERVATIONS

A 64-year-old woman presented with right-sided HFS. Preoperative magnetic resonance imaging showed a DVA in the right inferior pons, with an enlarged segment compressing the facial nerve at its root detachment point prior to drainage into the superior petrosal sinus. MVD was performed, and the facial nerve was decompressed without sacrifice of the vein. Immediately following the procedure, the patient had significantly reduced spasms. The patient became spasm-free 3 months after MVD and maintained spasm freedom for 3 months. Six months after MVD, the patient had a partial return of spasms. At 8 months, the patient continued to have reduced and intermittent spasms in the right orbicularis oculi muscle.

LESSONS

MVD for HFS caused by a DVA is a safe procedure and can be effective at reducing spasm frequency and severity.

Double Crush Syndrome as a Cause of Hemifacial Spasm

Hemifacial spasm is a rare but debilitating disorder of vascular compression of the facial nerve at the root exit zone causing repetitive, uncontrolled spasm of one half of the face. Usually, compression is caused by a pulsatile artery and less often by venous. Rarely, however, is hemifacial spasm caused by simultaneous compression by two formally named blood vessels. Here, we report a case of hemifacial spasm caused by simultaneous compression of the facial nerve root exit zone by the anterior inferior cerebellar artery and the superior petrosal vein. We describe the operative technique utilized to decompress the facial nerve and discuss the consequences of venous sacrifice in this scenario.

Hemifacial spasm caused by the brainstem developmental venous anomaly: A case report and review of the literature

Background:

Hemifacial spasm (HFS) is usually caused by vascular compression of the root exit zone (REZ) of the facial nerve. Dual compression of the REZ by veins and arteries is also associated with HFS, but venous origin alone is rarely reported. We present a rare case of HFS caused by the brainstem developmental venous anomaly (DVA) treated with microvascular decompression (MVD).

Case Description:

A 30-year-old women presented with the left-sided HFS since the age of 18 years. The brainstem DVA was diagnosed by magnetic resonance imaging (MRI) and followed by two attempts of MVD at some other clinics without any improvement. At our hospital, MVD was performed through a left retromastoid craniotomy. Intraoperatively, after detaching the strong adhesions between the cerebellar hemisphere, petrosal dura and lower cranial nerves, and removing the Teflon sponge inserted during the previous operations, the compressing large vein was found, separated from facial nerve REZ and MVD was completed. The postoperative computed tomography angiography and MRI showed the thrombosis of the main trunk of DVA and decompression of the facial nerve REZ. Complete cessation of HFS with hearing preservation was observed with only slight weakness of mimic muscles which disappeared within 3 months after surgery.

Conclusion:

HFS associated with brainstem DVA is a very rare condition. MVD of the facial nerve REZ with transposition of the large draining vein should be considered as an effective treatment option.

Symptomatic developmental venous anomalies

Cerebral developmental venous anomalies (DVAs) are variations of venous vascular anatomy related to an underdevelopment of either the superficial or deep venous emissary system, resulting in a dilated transmedullary vein fed by multiple smaller venous radicles responsible for drainage of normal brain parenchyma. While typically benign and found incidentally on imaging studies, DVAs can rarely be symptomatic. The radiographic appearance of DVAs, as well as their symptomatic manifestations, is diverse. Herein, we will discuss the pathophysiology of symptomatic DVAs while providing illustrative case examples depicting each of their pathogenic mechanisms.

Presurgical evaluation of hemifacial spasm and spasmodic torticollis caused by a neurovascular conflict from AICA with 3T MRI integrated by 3D drive and 3D TOF image fusion: A case report and review of the literature

Background:

Hemifacial spasm (HS) and spasmodic torticollis (ST) are well-known disorders that are caused by a neurovascular conflict. HS is characterized by irregular, involuntary muscle contractions on one side of the face due to spasms of orbicularis oris and orbicularis oculi muscles, and is usually caused by vascular compression of the VII cranial nerve. ST is an extremely painful chronic movement disorder causing the neck to involuntary turn to the side, upward and/or downward. HS is usually idiopathic but it is rarely caused by a neurovascular conflict with the XI cranial nerve.

Case Description:

We present a case of a 36-year-old woman with a 2-year history of left hemifacial spasm and spasmodic torticollis. Pre-surgical magnetic resonance imaging MRI examination was performed with 3TMRI integrated by 3Ddrive and 3DTOF image fusion. Surgery was performed through a left suboccipital retrosigmoid craniectomy. The intraoperative findings documented a transfixing artery penetrating the facial nerve and a dominant left anteroinferior cerebellar artery (AICA) in contact with the anterior surface of the pons and lower cranial nerves. Microvascular decompression (MVD) was performed. Postoperative course showed the regression of her symptoms.

Conclusions

Transfixing arteries are rarely reported as a cause of neurovascular conflicts. The authors review the literature concerning multiple neurovascular conflicts.