Magnetic resonance spectroscopy in the evaluation of treatment efficacy in unipolar major depressive disorder: a review of the literature.

More and more neuroimaging studies are using in vivo proton magnetic resonance spectroscopy (1H-MRS) to explore correlates of response to therapy in major depressive disorder (MDD). Their aim is to further understanding of the effects of neurotransmitter changes in areas involved in MDD and the mechanisms underlying a good treatment response. We set out to summarise the literature from the past fifteen years on biochemical correlates of treatment response in MDD patients, reflected in pre- and post-therapy changes in 1H-MRS measurements. Our literature search identified fifteen articles reporting 1H-MRS studies in MDD treatment; no study used 1P-MRS. Despite the wide diversity of 1H-MRS methods applied, brain regions studied, and metabolite changes found, there emerged strong evidence of a correlation between changes in neurometabolite concentrations, in particular glutamate, N-acetylaspartate and choline, and a good treatment response to pharmacotherapy or antidepressant stimulation techniques.

Spinal cord calcification in an early-onset progressive leukoencephalopathy.

Spinal cord calcifications are an unusual finding in pediatric neurology. We here describe a young child who presented severe psychomotor delay, tetraplegia, deafness, and anemia. Neuroradiological investigations revealed severe leukodystrophy and unusual calcifications in the cerebral white matter and all along the medullary pathways. Common infectious and metabolic diseases were ruled out. A mild reduction in the activity of several respiratory chain complexes was documented on muscle biopsy. Of interest, we found an intronic variant in DARS2, a gene involved in mitochondrial DNA translation, responsible for the syndrome of leukoencephalopathy with brainstem and spinal cord involvement and high brain lactate. In our opinion, our case, and probably 2 previously reported Japanese siblings with a picture very similar to that of our patient, could represent a new, progressive leukoencephalomyelopathy.

Complications in major depressive disorder therapy: a review of magnetic resonance spectroscopy studies.

Advanced magnetic resonance imaging techniques, such as proton magnetic resonance spectroscopy (H-MRS), have helped to further understanding of the pathophysiology of major depressive disorder (MDD) and to shed light on mechanisms underlying the therapeutic response. Potential complications of MDD therapy constitute an important area of research. Interruption of the absorption of serotonin reuptake inhibitors (SSRIs) is associated with discontinuation syndrome, while electroconvulsive therapy (ECT) can lead to transient and persistent anterograde amnesia. This paper reviews studies, since 1994, that have used H-MRS to evaluate adverse effects and complications of MDD treatment, either with ECT or SSRIs. Three articles have been published on adverse effects and complications of MDD treatment and H-MRS. Two focused on the ECT-induced memory deterioration and showed no sign of hippocampal atrophy in MDD patients with a residual memory deterioration after ECT, but a significant mean increase of the signal from Cho-containing compounds bilaterally, possibly due to an alteration of membrane turnover in the hippocampal region. The third paper showed that placebo-day Cho/Cr metabolite ratios were decreased in subjects with discontinuation syndrome, a finding that possibly reflects the dynamics of rostral anterior cingulate function. In spite of the limits deriving from the small number of papers published, our review demonstrated that H-MRS could be a useful instrument not only in evaluating therapy efficacy, but also for offering new insights into mechanisms underlying MDD treatments.