Abstract for presentation at 6th World Congress on Brain Injury

PB is a 45 year old man with a significant history of depression who attempted suicide by using a nail gun to shoot himself in the right temporal region. There was no loss of consciousness but PB presented as confused with no recall of the incident. The 8cm nail lodged in his brain remained undetected for several hours until a CT brain scan revealed its presence. PB presented initially with severe and almost global cognitive impairment including dense anterograde and retrograde amnesia. He suffered a psychotic episode, depressed mood and exacerbation of pre-existing obsessive compulsive traits. Serial neuropsychological testing over 12 months following the injury showed significant improvements in general intellectual functioning and ability to access semantic knowledge, some recovery of autobiographical knowledge and minimal improvement in ability to learn new information. Depression symptoms resolved but there was significant ongoing inertia and somnolence. Follow up MRI brain scans indicated a small lesion to the right thalamus and a left thalamic contusion. The differing rates of recovery of PB’s ability to recall semantic, autobiographical and newly presented information are discussed in relation to models of memory functioning and the role of the thalamus. PB’s ongoing anterograde amnesia appears to be providing a protective function against recurrence of his depressed mood. PB presented as a rehabilitation challenge due to his poor learning and inertia but did make some gains via procedural learning.