Evidence for cellular damage in normal-appearing white matter correlates with injury severity in patients following traumatic brain injury: A magnetic resonance spectroscopy study

• Published in: Brain (London, England : 1878) Vol. 123; no. 7; pp. 1403 - 1409
• Main Authors: GARNETT, M. R, BLAMIRE, A. M, RAJAGOPALAN, B, STYLES, P, CADOUX-HUDSON, T. A. D
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.07.2000; Oxford Publishing Limited (England)
• Subjects: Adolescent; Adult; Aged; Amnesia - pathology; Aspartic Acid - analogs & derivatives; Aspartic Acid - metabolism; Axons - pathology; Biological and medical sciences; Brain Chemistry - physiology; Brain Injuries - metabolism; Brain Injuries - pathology; Cerebral Cortex - injuries; Cerebral Cortex - metabolism; Cerebral Cortex - pathology; Choline - metabolism; Creatine - metabolism; Female; Glasgow Coma Scale; Humans; Injuries of the nervous system and the skull. Diseases due to physical agents; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Male; Medical sciences; Middle Aged; Traumas. Diseases due to physical agents; Human; Nervous system diseases; Craniocerebral; Diseases of the osteoarticular system; NMR spectrometry; Nuclear magnetic resonance imaging; White matter; Trauma; Cerebral disorder; Central nervous system disease; Skull disease; Proton; Medical imagery; Severity score; Comparative study; Brain (vertebrata)
• ISSN: 0006-8950; 1460-2156; 1460-2156
• DOI: 10.1093/brain/123.7.1403

Neuropsychological studies in patients who have suffered traumatic brain injury show that the eventual clinical outcome is frequently worse than might be predicted from using conventional (CT or T(1)/T(2)-weighted MRI) imaging. Furthermore, patients who have sustained an initial mild or moderate injury may show long-term disability. This implies that there may be abnormalities in areas of the brain that actually appear normal on conventional imaging. Proton magnetic resonance spectroscopy studies have shown that N-acetylaspartate and choline-containing compounds can provide measures of cellular injury. We report MRI and proton magnetic resonance spectroscopy studies of 19 head-injured patients performed once the patients were clinically stable (mean 11 days after injury, range 3-38 days). Proton magnetic resonance spectra were acquired from frontal white matter that on conventional MRI appeared normal. The brain N-acetylaspartate/creatine ratio was reduced [patients (mean +/- standard deviation), 1.28 +/- 0.25; controls, 1.47 +/- 0. 24; P = 0.04] and the choline/creatine ratio was increased (patients, 0.85 +/- 0.18; controls, 0.63 +/- 0.10; P < 0.001) compared with controls. When the severity of the injury was assessed using either the Glasgow coma scale or the length of post-traumatic amnesia, the increase in the choline/creatine ratio was significant even in the mildly injured group (P = 0.008 and P = 0.04, respectively). Furthermore, there was a significant correlation (P = 0.008) between the severity of head injury and the N-acetylaspartate/choline ratio. We conclude that there is an early reduction in N-acetylaspartate and an increase in choline compounds in normal-appearing white matter which correlate with head injury severity, and that this may provide a pathological basis for the long-term neurological disability that is seen in these patients.