[Parkinsonism secondary to chronic subdural hematoma. A case report].

We described a case of secondary parkinsonism due to chronic subdural hematoma (CSH). An 83-year-old man developed memory impairment and gait disturbance gradually since one year ago, and these symptoms subacutely deteriorated after he fell down and hit his head. On admission he had moderate cognitive impairment, gait disturbance (wide-based, small steps and initial freezing), postual instability, akinesia and right-sided rigidity. He did not have resting tremor. A CT scan showed a right-sided CSH with marked compression on the left hemisphere, and remarkable decrease of the blood flow in the left cerebral hemisphere was revealed by single photon emission computed tomography. His neurological condition improved gradually through the decrease of the CSH, which suggested the diagnosis of secondary parkinsonism due to CSH. We thought that the CSH in the right hemisphere caused right-sided parkinsonism through mechanical compression to the left hemisphere, which was shown in the SPECT image, in this case. Elderly people suffering from subacute progressive parkinsonism, should undergo CT studies be to differentiate the parkinsonism secondary to CSH.