Foville Syndrome Associated With Cerebellar Arteriovenous Malformation Resection

Foville syndrome, also known as dorsolateral pontine syndrome, is a rare condition of the brain stem. Clinical findings include disrupted innervation to the eye and adnexa.^1-5 The syndrome classically involves the trigeminal nerve (cranial nerve [CN] V), abducens nerve (CN VI), facial nerve (CN VII), and vestibulocochlear nerve (CN VIII) and causes oculosympathetic paresis.^1-5 This article describes a case of Foville syndrome with ipsilateral cerebellar ataxia secondary to cerebellar arteriovenous malformation (AVM) resection.

CASE PRESENTATION

A 59-year-old White woman presented with a 1-month history of horizontal diplopia and vertigo. She reported undergoing an intracranial procedure in the same timeframe to repair a large cerebellar AVM.

The patient stated that, immediately before the discovery of her AVM, she had experienced a severe headache and an acute mental status change, which led to emergent hospitalization. At the hospital, the patient was found to have poorly controlled hypertension and a large, cerebellar AVM on CT and angiography (Figures 1 and 2). The AVM included both the left superior cerebellar artery and the left anterior inferior cerebellar artery.

Neurosurgical clipping of the AVM the next day was successful (Figure 3). Immediately after surgery, the patient experienced the onset of horizontal diplopia, left-sided facial numbness and weakness, left-sided hearing loss, and left-sided ataxia (Table).

On examination, the patient’s VA was 6/6 OU. Visual field testing was within normal limits in each eye. Pupil size was equal in bright and dim light, and no afferent pupillary defect was observed. Extraocular motility was normal in the right eye, but restricted abduction in attempted left gaze was observed in the left eye. The patient’s esotropia in primary gaze worsened in attempted left gaze, consistent with left abducens nerve palsy (Figure 4). Additional CN testing confirmed numbness of the left cheek and jawline (CN V2 and V3), left hemifacial motor weakness (CN VII), left hearing loss (CN VIII), and left-sided ataxia (cerebellar involvement). The remainder of the examination was unremarkable in each eye.

The patient was diagnosed with Foville syndrome, and the clinical findings were discussed with her neurosurgeon, who recommended standard conservative postsurgical management. Four months after the AVM resection, the patient’s diplopia and facial weakness resolved, but her other ocular findings remained the same.

DISCUSSION

Ischemia is the most common cause of Foville syndrome.^1-5 Interestingly, the patient discussed here did not have anisocoria, anhidrosis, or ptosis indicative of oculosympathetic paresis, but she did have an additional finding of cerebellar ataxia. It therefore might be best to describe her condition as a variant of Foville syndrome.

Cerebellar AVM occurs in approximately 15% of patients with brain AVM.⁶ Cerebellar AVM affects men and women approximately equally, but women are more likely (90%) to experience hemorrhagic conversion (ie, leakage of blood from weakened blood vessels to surrounding tissues).⁶ Neurosurgical complications have been reported with attempted AVM repair. These include associated pontine infarcts, subsequent facial weakness, and other hemisensory defects.⁶ Cerebellar ischemia can also cause ipsilateral ataxia, as in this case.⁷

Because two cerebellar arteries (superior cerebellar artery and anterior inferior cerebellar artery) were involved in the patient’s AVM, it might appear difficult to determine which artery or arteries were responsible. A review of brain stem anatomy, however, showed that the anterior inferior cerebellar artery was most likely involved because it feeds the lower pontine structures and cerebellum, which is where the CNs involved in this case are located (Figure 5).^1-9