Case report

A 69-year-old man presented with progressive headache and nausea. Ten days earlier, he had developed an acute neck pain after a workout on his home trainer. Three days later, he had hit his head on a door, and later developed a frontal headache that increased during exercise. His neurological examination was normal, but CT scan of the head showed bilateral subdural haematomas of mixed density. He was admitted for observation, and managed conservatively. An unenhanced MR scan of the brain confirmed subdural collections, but also showed an abnormal configuration of the midbrain, which was swollen and elongated with severe brain sagging (figure 1).

Over the next few days, he became increasingly somnolent and bradyphrenic. After 3 days, he developed anisocoria. He was taken immediately to the operating room, and had two skull burr holes, releasing ‘crankcase oil-coloured’ fluid under low pressure. He improved immediately after surgery. However, when walking with the physiotherapist, he developed impaired arousal that resolved when he lay flat. We tested his mental status in both the Trendelenburg posture and upright posture (see figure 2 and online supplementary video S1); in just 5 min, his consciousness changed from full alertness to coma. A contrast-enhanced MR myelogram (T1-weighted) showed a …