Prevalence and impact of diffuse axonal injury in patients with moderate and severe head injury: a cohort study of early magnetic resonance imaging findings and 1-year outcome.
OBJECTIVE
In this prospective cohort study the authors examined patients with moderate to severe head injuries using MR imaging in the early phase. The objective was to explore the occurrence of diffuse axonal injury (DAI) and determine whether DAI was related to level of consciousness and patient outcome.


METHODS
One hundred and fifty-nine patients (age range 5-65 years) with traumatic brain injury, who survived the acute phase, and who had a Glasgow Coma Scale (GCS) score of 3-13 were admitted between October 2004 and August 2008. Of these 159 patients, 106 were examined using MR imaging within 4 weeks postinjury. Patients were classified into 1 of 3 stages of DAI: Stage 1, in which lesions were confined to the lobar white matter; Stage 2, in which there were callosal lesions; and Stage 3, in which lesions occurred in the dorsolateral brainstem. The outcome measure used 12 months postinjury was the Glasgow Outcome Scale-Extended (GOSE).


RESULTS
Diffuse axonal injury was detected in 72% of the patients and a combination of DAI and contusions or hematomas was found in 50%. The GCS score was significantly lower in patients with "pure DAI" (median GCS Score 9) than in patients without DAI (median GCS Score 12; p < 0.001). The GCS score was related to outcome only in those patients with DAI (r = 0.47; p = 0.001). Patients with DAI had a median GOSE score of 7, and patients without DAI had a median GOSE score of 8 (p = 0.10). Outcome was better in patients with DAI Stage 1 (median GOSE Score 8) and DAI Stage 2 (median GOSE Score 7.5) than in patients with DAI Stage 3 (median GOSE Score 4; p < 0.001). Thus, in patients without any brainstem injury, there was no difference in good recovery between patients with DAI (67%) and patients without DAI (66%).


CONCLUSIONS
Diffuse axonal injury was found in almost three-quarters of the patients with moderate and severe head injury who survived the acute phase. Diffuse axonal injury influenced the level of consciousness, and only in patients with DAI was GCS score related to outcome. Finally, DAI was a negative prognostic sign only when located in the brainstem.
Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway. toril.skandsen@ntnu.no
Toril
T
Skandsen
Kjell Arne
KA
Kvistad
Ole
O
Solheim
Ingrid Haavde
IH
Strand
Mari
M
Folvik
Anne
A
Vik
D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology; D001930:Brain Injuries / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D015331:Cohort Studies; D003243:Consciousness; D006259:Craniocerebral Trauma / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D020833:Diffuse Axonal Injury / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D020127:Recovery of Function; D012720:Severity of Illness Index; D013997:Time Factors; D055815:Young Adult