Acute extradural haematoma occurring during twistdrill craniostomy for chronic subdural haematoma

The incidence of chronic subdural haematoma (SDH) is 1–2 per 100,000 population per year.1 There are some sporadic case reports of unexpected postoperative complications, like acute SDH,2 and more often intracranial haematomas,3 probably induced by rapid decompression of chronic SDHs. Acute extradural haematoma (EDH) developing during twist-drill craniostomy is an extremely rare event, and only one case report of this complication is published in the literature.4 We report one additional case report, and discuss the possible mechanism of this uncommon entity. Early detection and treatment led to a successful clinical outcome. A 22-year-old male was admitted 4 weeks after minor head trauma caused by a motor vehicle accident. He had complained of progressive bifrontal headache. CT of the head revealed a right-sided SDH (Fig. 1). Neurological examination showed no abnormality. Because of severe headache, a twistdrill craniostomy was planned at the parietal eminence, and during insertion of a brain canula some resistance was encountered, before entering the subdural space. A dark altered coloured fluid was evacuated. Immediately after the procedure, the patient complained of headache, which rapidly increased over the next hour together with vomiting and altered consciousness. Urgent CT revealed a large acute extradural haematoma on the same side (Fig. 2). The haematoma was evacuated through a craniotomy. The patient was discharged after 10 days with no neurological deficit.