Remote cerebellar haemorrhage after placement of an external ventricular drainage for acute hydrocephalus: A case report.

INTRODUCTION: Remote cerebellar haemorrhage (RCH) is a rare complication following a craniotomy. This generally benign phenomenon is an identifiable complication of supratentorial craniotomies and should not be mistaken with other pathologies. The most common presenting symptom is a decrease in the level of consciousness but in some cases the RCH may be asymptomatic and accidentally discovered in follow-up CT scans.

CASE REPORT: A 70-year-old man was admitted to our emergency department with sudden mental status deterioration. A head CT scan was carried out and an acute hydrocephalus was diagnosed. The patient was transferred to the operating room for external ventricular drainage (EVD) placement via a frontal burr-hole. At 24hours, the patient made a complete neurological recovery. On third postoperative day, a follow-up CT scan showed an asymptomatic right remote cerebellar haemorrhage. The MRI assessment confirmed the diagnosis. The EVD was removed on the 6th postoperative day and the patient was discharged after one week with no further symptoms.

DISCUSSION: This case report is the first documented case, to our knowledge, of a remote cerebellar haemorrhage after placement of external ventricular drainage via a frontal burr-hole. The precise aetiology of remote cerebellar haemorrhage remains unclear. One of the most accepted theories is the "cerebellar sag" explanation, which defends hypothesis that peri-operative over drainage of cerebrospinal fluid (CSF) is the main mechanism involved. Further investigation is required to understand the pathogenesis and risk factors for the occurrence of this phenomenon.