Assessment of mitochondrial impairment in traumatic brain injury using high-resolution proton magnetic resonance spectroscopy

Abstract

Using (1)H-MR spectroscopy, it is possible to detect the posttraumatic neurochemical damage of the injured brain when conventional neuroimaging techniques reveal no abnormality. Reduction of NAA levels is a dynamic process, evolving over time, decreasing and remaining low throughout the involved tissue in patients with poor outcomes. Recovery of NAA levels in patients with favorable outcomes suggests marginal mitochondrial impairment and possible resynthesis from vital neurons.

Long-term global and regional brain volume changes following severe traumatic brain injury: A longitudinal study with clinical correlates

“…In humans, using diffusion tensor imaging, we recently found that diffusion abnormalities following severe TBI, supposedly reflecting disruption of axonal microarchitecture, partly normalise during clinical recovery, particularly in patients with good outcome (Sidaros et al, 2008). Metabolite abnormalities, as measured by MR proton spectroscopy, also have been found to recover over time to near normal levels in good outcome patients (Holshouser et al, 2006;Signoretti et al, 2008).…”

Multifunctional Drugs for Head Injury

“…Indeed, compared with patients with marginal mitochondrial impairment, who demonstrate a good outcome, TBI patients with profound mitochondrial impairment have a poor prognosis. 17 Following injury, this organelle has been shown to undergo a mitochondrial permeability transition, 18 with the permeabilization of the inner mitochondrial membrane being associated with excessive calcium accumulation. 19,20 Mitochondrial permeability transition results in the release of cytochrome c, which is integrally involved in apoptotic cell death, as well as in uncoupling and inhibition of oxidative phosphorylation and the generation of mitochondrial reactive oxygen species (ROS).…”

Limbic Metabolic Abnormalities in Remote Traumatic Brain Injury and Correlation With Psychiatric Morbidity and Social Functioning

“…NAA loss in the frontal lobes is also a dynamic process, with recovery in patients with good outcome and persistent low levels in patients with poor outcome. 29 Our finding of reduced left frontal white matter choline was associated with a non-significant trend toward reduction of the remaining metabolite peaks. Increased water content, which was used as the internal signal standard, in the preferentially injured left frontal lobe might account for these metabolic changes.…”

“…2 TBI is a heterogeneous condition featuring spatially and temporally disseminated necrotic and apoptotic cell death. 3 Apoptosis, 4 excitotoxicity, and mitochondrial impairment play a decisive role, 5 and the time scale of these changes has been reported to span several months. Delayed neuronal death occurs in vulnerable sites such as the hippocampus, 6,7 whose damage is considered a key factor responsible for cognitive and affective alterations secondary to TBI.…”