[Intermittent paraparesis as manifestation of a bilateral chronic subdural hematoma]

Chronic subdural haematomas are mainly related to slight or moderate head trauma with consecutive lesion of bridge or cortical veins and bleeding in the subdural space. Further predisposing factors are known impairment of coagulation (coagulopathies, treatment with anticoagulants, alcohol abuse), risk factors for degenerative disease of the arteries (diabetes mellitus, arterial hypertension), and development of pressure gradients (hydrocephalus, epileptic seizures, lumbar puncture, CSF drainage and cerebral atrophy). Chronic subdural haematomas appear bilaterally in 20 to 25% of cases. We report on a 69-year-old male with a 4-day history of intermittent, proximal, painless paraparesis (BMA grade M2-5) without a trigger event. Sensibility was normal in all qualities and vigilance was not disturbed. Computed tomography of the neurocranium revealed a bitemporally located chronic subdural haematoma with extension to parietal on both sides. Trepanation was performed over the tuber parietale and temporoparietally on both sides, with release of 150 ml fluid. The neurologic deficits regressed totally within 12 hours postoperatively. To the best of our knowledge, we are the first to describe the clinical paradox of intermittent, painless paraparesis with preserved sensibility and without disturbances of vigilance, as manifestation of a chronic subdural haematoma possibly leading to impairment of cerebral blood flow in the area of the middle cerebral artery. Small changes in systemic blood pressure lead to changes in cerebral perfusion pressure due to vessel compression by the haematoma, thus explaining the intermittent character of the clinical presentation.