Conventional MRI and MR spectroscopy in nonclassical mitochondrial disease: report of three patients with mitochondrial DNA deletion.

Objects: The objectives were to present magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) findings in three patients with deletion on mitochondrial DNA (mtDNA) and nonclassical mitochondrial disorders (NCMD), correlating these findings with the percentage of deleted mtDNA.
Results: Our study confirms the high prevalence of white matter (WM), basal ganglia, and posterior fossa lesions in NCMD, ranging from mild to severe involvement. The subcortical WM, caudate, thalamus, globus pallidus, and dorsal brain stem were more frequently affected. A lactate peak was the most frequent finding at the MRS. We found a correlation between the percentage of mtDNA deletion and degree of MRS abnormalities.
Conclusions: Our findings showed that MRS is a useful investigational tool in patients with NCMD. Supplementary studies are necessary to elucidate the correlation of quantitative mtDNA deletion and neuroimaging phenotype.