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

Abstract

Aims and Objective: Giddiness is one of the commonest presenting complaints to the emergency physicians. Differentiation between ‘peripheral’ and ‘central’ etiologies is important to avoid unnecessary investigations and avoid missing a potentially serious diagnosis such as an ischemic stroke. Isolated nodular infarction can present with clinical signs that mimic a peripheral vestibular cause. We present the clinical findings in 14 cases of isolated nodular infarction and discuss their differentiating features. Study Design: Retrospective case series. Place and Duration: Tertiary care university hospital in Singapore between January 2007 to September 2012. Methods: We evaluated the clinico-radiological findings of all the patients diagnosed with isolated nodular infarction at our center during the study period. Their clinical presentations were extracted from the case records. We combined our cases to an existing series of 8 patients from Korea to strengthen the findings. Results: Of the 286 acute posterior circulation ischemic stroke patients admitted to our tertiary care center during the study period, 6 (2.1%) were found to have isolated nodular infarction. They typically presented with acute severe giddiness. Nystagmus was seen in all, which was unidirectional and beating towards the side of the lesion with no latency or fatigability. Walking was usually severely impaired due to imbalance and all patients had a negative head impulse test. All patients at our center achieved complete recovery at 3-months. Conclusions: We present the clinical spectrum of isolated nodular infarction. In addition to a high index of suspicion in patients with multiple vascular risk factors, a negative head impulse test despite severe vertigo and imbalance can help in establishing the correct diagnosis.