Traumatic extradural haematoma in factor XI deficiency within pre-existing arachnoid cyst

ABSTRACT

Posterior fossa epidural haematoma [PFEH] is potentially a lethal complication of head injury. Factor XI [FXI] deficiency is a rare autosomal disorder that can manifest first as a bleeding or as an incidental laboratory abnormality. Reporting here a case of PFEH associated with arachnoid cyst and FXI deficiency. Twenty-year-old Moroccan man was admitted to our Neurosurgery Department due to occipital headache, vomiting, diplopia and decrease in consciousness. Seven days later the patient had a fall with occipital impact and he presented to emergency room. The neurological examination and the x-ray was normal. The patient returned to his home. Five days later the patient became symptomatic with occipital headache, vomiting, diplopia, deterioration of consciousness and nuchal stiffness. Cranial CT scan showed a huge unsuspected bilateral epidural haematoma with mass effect on the 4[th] ventricle and brainstem, with a hypodense area on left pontocerebellar angle suggestive to arachnoid cyst. Emergency preoperative blood crasis study showed prolonged activated partial thromboplastin time [aPTT] more than 120 milliseconds three times. A sub-occipital craniectomy on prone position was performed. An organized and collected "placenta like" epidural haematoma was evacuated. No source of bleeding was identified, only diffuse bleeding of dura was noted. The postoperative recovery unremarkable. The patient was alert with disappearance of symptoms and no neurological deficit was noted. The patient denied any recent self-medication. Lab study of blood erase showed prolonged aPTT. The level of FXI showed a severe deficiency of 3.1%. The level of factor XII, VIII and IX were normal. No other biologic abnormality was identified. This case confirms that FXI deficiency and arachnoid cyst are a risk factor of posterior fossa epidural haematoma