A 67-year-old man presented with headache and gait disturbance. On admission, he was mildly confused but aroused by verbal stimulus, with normal motor function. A CT scan showed bilateral subdural hematomas (right >> left) and a midline shift to the left. One hour after admission, he suddenly became somnolent and developed right hemiparesis. While repeated CT examinations failed to reveal new findings, coronal MRI clearly depicted the left cerebral peduncle pressed against the free edge of the tentorium. Craniotomy was immediately performed to remove the right chronic subdural hematoma. Soon after the operation, neurological functions were markedly improved. When paradoxical (ipsilateral to the lesion) motor deficit is observed in patients with head injuries, including cases of chronic subdural hematomas, coronal MR imaging and magnetic resonance angiography should be immediately performed to detect Kernohan\u27s notch and to rule out other possible complications, such as diffuse axonal injury or cerebral stroke
