Cerebellar Infarctions Mimicking Acute Peripheral Vertigo.

Objective: 1) To determine the true incidence of cases of missed cerebellar stroke mimicking acute peripheral vertigo (APV), the so-called pseudo-APV without additional symptoms. 2) To identify the clinical indicators useful for differentiating APV from cerebellar infarction presenting isolated vertigo. Method: We conducted a retrospective chart review of cases of missed cerebellar infarction over the past 3 years. All patients had first undergone a neurological evaluation and CT scan of the brain in the emergency unit, before performing a complete bedside examination in the Dizziness Unit of our tertiary referral center. Results: We identified 11 patients with cerebellar infarction mimicking APV (2.8% of all the cases presenting to the dizziness unit complaining of acute vertigo). Spontaneous horizontal nystagmus (of central type in 2 cases) was recorded in all patients. Head Impulse Test (HIT) was negative in 10 cases. MRI showed 9 cases of infarction in the posterior-inferior cerebellar artery territory; in 2 patients an involvement of the anterior-inferior cerebellar artery territory was recorded. The duration of vertigo lasted more than 72 hours in 8 patients. In 4 patients acute vertigo was followed by delayed neurological signs 2-3 days after the onset. Conclusion: Pseudo-APV is not an uncommon diagnosis in otoneurological practice. HIT, a careful evaluation of spontaneous nystagmus, persistence of vertigo, and imbalance more than 72 hours from the onset are useful clinical indicators for recognizing a cerebellar ischemic origin in cases of acute vertigo, especially in patients with vascular risk factors.