Cerebellar haemorrhage mimicking acute peripheral vestibulopathy: the role of the video head impulse test in differential diagnosis

Abstract

Dizziness and vertigo without neurological signs are typically due to a peripheral vestibular disease. Although the most common causes are benign, differential diagnosis must include potentially life-threatening central diseases such as cerebrovascular pathologies. A systemic clinical approach needs a careful work-up, bedside examination and appropriate instrumental investigation. The head impulse test (HIT) allows qualitative clinical assessment of canalar function; it has some limitations such as subjective evaluation, mainly in patients with a spontaneous nystagmus. A new device has been recently developed consisting of an infrared video camera (video-HIT) to provide quantitative instrumental assessment of the high-frequency vestibular-ocular reflex (VOR) gain. By reporting a case of cerebellar haemorrhage mimicking an acute peripheral vestibulopathy, the authors suggest that video-HIT may be considered a useful tool in differential diagnosis between vestibular neuritis and cerebellar vascular disease in patients with severe acute vertigo without central signs.

Keywords: Central vertigo; Cerebellar haemorrhage; Head impulse test; Peripheral vertigo; Vestibular neuritis.

Fig. 1.

Bithermal caloric testing shows a leftward directional preponderance (absolute preponderance, 5.6°/sec; relative preponderance, 94%) without significant hypovalence (10% on the right side).

Fig. 2.

Video-HIT shows normal function of the six semi-circular canals. The semi-circular canals are displayed as a six branch star called the "canalogram". Displayed in the top-left corner of the screen, it expresses the percentage of canal paresis. Branch orientation is in relation to canal anatomical array. The canalogram represents the patient facing the examiner, and therefore the left branch of the canalogram are on the patient's right SCC. The green zone of the canalogram is the statistically normal zone. The dots identify the results of measurement of the head impulse test. The position of the dot indicates that the canal deficit is within normal limits (values: from 0% to 35% for the lateral canal and from 0% to 40% for vertical ones) or pathological. The operator stimulates a specific canal, and the results will be immediately displayed if the tested canal is damaged and indicate to what proportion. The canalogram displays the results of involvement by a single canal or multiple canals.

Fig. 3.

Axial image of cerebral non-contrast CT shows a left anterior-inferior cerebellar haematoma in the parafloccular region, measuring about 2.5 cm in its largest diameter, with a mild "mass effect", brainstem distortion and shift of the fourth ventricle to the contralateral side.

Fig. 4.

T1-weighted sagittal image of brain MRI shows a cerebellar haematoma with a hemosiderin ring suggesting subacute haemorrhage.