Clinical History
Our patient suffered from progressive confusion and headache after minor head trauma. Initial CT showed right-sided subdural haematoma. Burr hole drainage of the haematoma with placement of a subduro-external drain was performed. Perioperatively there was extensive drainage of blood and CSF. Post-operatively the patient developed a new type of headache.
Imaging Findings
The postoperative CT examination showed a correct placement of the subdural drain and partial regression of the haematoma with normalisation of the midline, but also revealed a new acute bilateral cerebellar haemorrhage remote from the trepanation site (Fig. 1). These haemorrhages had a curvilinear pattern with superficial parenchymal location (in the superior and inferior semilunar lobule and also in the gracile lobule) and smaller subarachnoid components layered along the folia. There was mild perilesional oedema with no significant mass effect. An additional MRI of the brain (not shown) confirmed these findings. There was no evidence for a vascular malformation or a venous sinus thrombosis.
Because of the absence of neurological deficits the patient was treated conservatively and the symptoms regressed spontaneously. A repeat CT examination 2 weeks after the patient’s discharge showed regression of the haemorrhages (Fig. 2).
Discussion
Remote cerebellar haemorrhage (RCH) is a rare complication following supratentorial or spinal surgery. It has an estimated incidence of 0.08 – 0.6% of supratentorial procedures and is more frequently reported after aneurysmal clipping, tumour resection and lobectomy for focal epilepsy [1, 2]. RCH is often an incidental finding on the routine postoperative CT examination, and occurs within hours to 1 day post-operatively in the majority of cases [1, 2, 3]. When symptomatic, the clinical symptoms include headache, altered neurological state, postoperative seizures and/or delayed awakening from anaesthesia [1, 2, 3, 4]. Cerebellar signs can be seen in an extensive primary haemorrhage or secondary cerebellar herniation [2]. The cause of RCH is thought to be peroperative (as in our case) or postoperative excessive leakage of cerebrospinal fluid. Consequently, an inferior displacement of the cerebellum causes kinking, stretching and shearing of the vermian veins and tributaries, resulting in subarachnoid and peripheral parenchymal haemorrhage [1, 2].
The best diagnostic clue on CT and MR imaging is a typical bleeding pattern called “the zebra sign”, i.e. a layering of blood in a streaky pattern along the cerebellar folia in and over the cerebellar hemispheres and/or vermis [1, 2, 3]. The sign is seen in 65% of patients, is bilateral in 33% of cases and is characterised with a good clinical outcome [2, 3]. Blooming artefacts on susceptibility-weighted images or T2* gradient echo images confirm the haemorrhage [3].
In many cases RCH is asymptomatic and self-limiting, though there are published cases with a lethal outcome [2]. Based on expert opinion, RCH only requires surgical intervention in case of hydrocephalus or progressive deterioration of consciousness. Prolonged clinical surveillance is required to identify cases that may evolve and potentially result in severe neurological impairment [2].
Differential Diagnosis List
Remote cerebellar haemorrhage following a supratentorial burr hole trepanation.
Hypertensive haemorrhage (the patient had no hypertensive periods during admission or a previous history of hypertension)
Coagulopathy-related spontaneous haemorrhage (the patient had no coagulation deficit)
Neoplasm with haemorrhage (no evidence on CT or MRI examinations)
Vascular malformation (no evidence on CT or MRI examinations)
Cerebral amyloid angiopathy (no dementia; rarely cerebellar location)
Final Diagnosis
Remote cerebellar haemorrhage following a supratentorial burr hole trepanation.
