Perception of the acoustic environment and neuroimaging findings: a report of six cases with a history of closed head injury.
CONCLUSIONS
The main finding was the relation between difficulty in determining the direction of movement of a sound source and frontal lesions and poor working memory. Poor correspondence in some cases between functional findings and imaging findings can be due to the possibility of axonal degeneration as well as plastic reorganization.


OBJECTIVE
The purpose of the present investigation of six cases was to identify auditory, cognitive and neuroimaging long-term sequelae of closed head injury (CHI) with particular focus on environmental sound recognition and moving sound sources.


METHODS
Six subjects who had experienced CHI were investigated with auditory tests. Four subjects also completed cognitive testing. CT and MRI were performed.


RESULTS
There was a large individual variability of the test results with respect to morphological findings. In five cases with central auditory processing disorders morphological brain damage was demonstrated. Two cases with shortcomings on cognitive testing and with frontal brain lesions demonstrated problems in determining the direction of movement of a sound source. The results may indicate that basal frontal lobe structures play a role in following and determining the direction of movement of a sound source. Two cases had problems with environmental sound recognition; in one left temporal brain lesions were demonstrated.
Bergemalm
Per-Olof
PO
Ahlsén Research Institute, Orebro University Hospital, SE-701 85 Orebro, Sweden. Perolof.bergemalm@orebroll.se
Hennerdal
Sture
S
Persson
Birger
B
Lyxell
Björn
B
Borg
Erik
E
D000293:Adolescent; D000328:Adult; D001309:Auditory Threshold / Q000502:physiology; D002648:Child; D003072:Cognition Disorders / Q000175:diagnosis / Q000503:physiopathology; D005500:Follow-Up Studies; D005625:Frontal Lobe / Q000293:injuries / Q000503:physiopathology; D016489:Head Injuries, Closed / Q000175:diagnosis* / Q000503:physiopathology; D046088:Hearing Loss, Unilateral / Q000175:diagnosis / Q000503:physiopathology; D006320:Hearing Tests / Q000379:methods; D006801:Humans; D007805:Language Development Disorders / Q000175:diagnosis* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008570:Memory, Short-Term / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D038223:Post-Concussion Syndrome / Q000175:diagnosis* / Q000503:physiopathology; D012016:Reference Values; D012887:Skull Fractures / Q000175:diagnosis* / Q000503:physiopathology; D013017:Sound Localization / Q000502:physiology; D014057:Tomography, X-Ray Computed; D055815:Young Adult