The post-concussional state: neurophysiological aspects.
BACKGROUND
Twenty-six young men admitted to an Accident and Emergency Department for observation following a minor closed head injury (post-traumatic amnesia (PTA) less than 12 hours) were investigated within 24 hours of admission (day 0) and followed up at 10 days, 6 weeks and 1 year after the trauma.


METHODS
Investigations at day 0 included physical examination, completion of post-concussional symptom and stress-arousal checklists, computerised EEG (CEEG) and auditory brainstem evoked potential (BAEP) recordings. These were repeated at ten days and six weeks. At 12 months follow-up, the Present State Examination (PSE) was carried out and a further post-concussional symptom checklist completed.


RESULTS
Post-concussional symptomatology declined progressively from day 0 but half had residual symptoms at 1 year. Seventy-two per cent ran an acute course with recovery by 6 weeks, 8% chronic unremitting course and 20% initially improved but had an exacerbation of symptoms between 6 weeks and 12 months. The CEEG alpha-theta ratios decreased significantly between days 0 and 10, reaching a baseline thereafter. Measures of CEEG recovery from all channels correlated with symptom counts at six weeks; the slower the recovery the greater the symptoms. A relative delay in left temporal recovery was associated with residual psychiatric morbidity (PSE ID scores) at 12 months. Prolonged central brainstem conduction times occurred in 27% of patients at day 0. These correlated positively with PTA and degree of psychiatric morbidity (PSE ID scores) at 12 months.


CONCLUSIONS
Symptom chronicity was accompanied by continuing brainstem dysfunction, while the degree of transient cortical dysfunction appeared to have a direct influence in the intensity of early organic symptom reaction to the trauma. Levels of perceived stress at the time of the injury, or afterwards, were not related to symptom formation.
Watson
M R
MR
Holywell Hospital, Antrim.
Fenton
G W
GW
McClelland
R J
RJ
Lumsden
J
J
Headley
M
M
Rutherford
W H
WH
D000293:Adolescent; D000328:Adult; D001143:Arousal / Q000502:physiology; D001924:Brain Concussion / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D001925:Brain Damage, Chronic / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D001933:Brain Stem / Q000503:physiopathology; D002540:Cerebral Cortex / Q000503:physiopathology; D004292:Dominance, Cerebral / Q000502:physiology; D004569:Electroencephalography; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D019965:Neurocognitive Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology; D012815:Signal Processing, Computer-Assisted