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Re: Minor trauma and arachnoid cysts: remember subdural haematoma

Dear Editor

The report by De et al.[1] correctly highlights the need for an index of suspicion of a haemorrhage into an arachnoid cyst even after minor trauma. The majority of such cysts are incidental findings and the variety of symptomatology may not make their consideration all too clear. It is important therefore to consider the need for early CT scanning in new or recent onset persistent and localised headaches that may be accompanied by falls, mild personality changes or unsteadiness, especially (but not exclusively) in the young. The history of a recent head trauma, even minor, may be an important clue. The need for surgical intervention for an intracystic haemorrhage and the relief of any resultant midline shift cannot be overemphasised; CT scanning in emergency departments should be readily available in cases so suspected.

Equally important is the possibility of a subdural haematoma (SDH), which must be borne in mind especially in sports related (minor or not) trauma. SDHs are a recognised association of arachnoid cysts, mainly of the middle fossa, but have also been the presenting feature of previously undiagnosed arachnoid cysts. The patient’s complaints may be more vague than in a case of intracystic haemorrhage and may build up over a longer period of time. The injury may be much milder, such as heading a football[2] or being hit during ball games.[3] Given that SDH may anyway occur in sports injuries even in the absence of arachnoid cysts[4] the diagnosis of the latter has serious implications in sports medicine. Should an arachnoid cyst be an absolute or relative contraindication for contact/collision sports? Should such athletes not be screened for arachnoid cysts given the life-threatening possible complications?

References

(1) De K, Berry K, Denniston S. Haemorrhage into an arachnoid cyst: a serious complication of minor head trauma. Emerg Med J 2002;19(4):365-6.

(2) Kawanishi A, Nakayama M, Kadota K. Heading injury precipitating subdural hematoma associated with arachnoid cysts: two case reports. Neurol Med Chir (Tokyo) 1999;39(3):231-3.

(3) Prabhu VC, Bailes JE. Chronic subdural hematoma complicating arachnoid cyst secondary to soccer-related head injury: case report. Neurosurgery 2002;50(1):195-7.

(4) Keller TM, Holland MC. Chronic subdural haematoma, an unusual injury from playing basketball. Br J Sports Med 1998;32(4):338-9.