10 - MRS in traumatic brain injury

Summary

Key points

• TBI is a major cause of morbidity in young adults and children.

• Low levels of NAA and, if seen, increased lactate, in the early stage of injury are prognostic of poor outcome.

• Other common metabolic abnormalities in TBI (most of which also correlate with poor outcome) include increased levels of choline, myo-inositol, and glutamate plus glutamine.

• Metabolic abnormalities are observed with MRS in regions of the brain with normal appearance in conventional MRI.

• MRI and MRS are difficult to perform in acutely ill TBI patients: MRS may be more feasible in mild TBI patients for the purpose of predicting long-term cognitive deficits.

• The role of MRS in guiding TBI therapy is unknown.

• The comparative value of MRS compared to other advanced imaging modalities remains to be determined.

Introduction

Traumatic brain injury (TBI) is a leading cause of death and lifelong disability among children and young adults across the developed world. TBI is estimated to result in greater than $60 billion in direct and indirect annual costs due to health care and work loss disability. The Centers for Disease Control and Prevention (CDC) estimate that each year approximately 1.4 million Americans survive a TBI, among whom approximately 235,000 are hospitalized. Approximately 80,500 new TBI survivors are left each year with residual deficits consequent to their injury, which lead to long-term disabilities that may or may not be improved through rehabilitation. In 2001, 157,708 people died from acute traumatic injury, which accounted for about 6.5% of all deaths in the United States.