Isolated Nodular Ischemic Infarcts: A Central Lesion That Presents as Peripheral Vertigo

Abstract

Background and Aim: Giddiness is a common neurological conditions and differentiation between 'peripheral' and 'central etiologies' remains the first aim of a treating physician to avoid unnecessary investigations as well as 'not missing' a potentially serious diagnosis such as ischemic stroke. Nodulus is a small area of cerebellum, just adjacent and posterior to the 4th ventricle and plays an important role in maintaining balance. Isolated Nodular infarction can present with clinical signs that mimic a peripheral vestibular cause. Methods: We present a case series to reflects the clinical spectrum of isolated Nodular infarction. Results: Of the 286 patients admitted to our tertiary center with acute vertigo, 6 (2.1%) suffered from acute Nodular infarction. Similar to other ischemic strokes, nodular infarcts occurred in all age-groups (mean age 66.5 years; range 37-88) and most cases suffered from various cardiovascular risk factors. All cases presented with severe giddiness of sudden-onset and walking was severely impaired due to imbalance. Most of the cases demonstrated nystagmus at rest that became worse on head-shaking. None of the patients suffered from hearing difficulties, tinnitus, pain or ear discharge. Absence of dysarthria, cranial nerve palsy, long tract signs and truncal ataxia were the striking features. Importantly, dysmetria or other cerebellar signs were not seen in any case. Magnetic resonance angiography did not reveal any signficant arterial stenosis in the vertebro-basilar circulation. All cases in our series recovered completely at 3 months from symptomonset. Conclusions: Sudden onset of giddiness is the commonest presentation of isolated ischemic infarction of the Nodulus. In presence of multiple cardiovascular risk factors, a high index of suspicion for the diagnosis of nodular infarct is needed in patients presenting with severe vertigo if the head impulse test is negative.