2009 年 20 巻 7 号 p. 383-389
Diffuse axonal injury (DAI) commonly causes immediate loss of consciousness after head injury. We report the case of a 20-year-old man who was involved in a motor vehicle accident, which his estate car ran into a truck from behind. Although he was alert on arrival at the hospital, his conscious level deteriorated approximately 7 hours after the accident. At this time point, he had a generalized tonic seizure and decorticate posturing of his arms with a Glasgow coma scale (GCS) score of 5. MRI revealed findings consistent with DAI. On the 14th day, his conscious level improved to a GCS of 9 and MRI showed chronic DAI. The patient recovered well with only mild memory deficit at discharge. There are few reports of delayed onset DAI, but in terms of its neuropathology, it is possible for it to occur after the time of injury. DAI is the result not only of direct injuries to the axon membrane and axonal sheath due to shearing force, but also of secondary injury by loss of axon transport. In the emergency department, a diagnosis of DAI should be considered in any patient who has suffered head injury by rotational forces even if there is no loss of consciousness on arrival at the hospital.
