Summary of clinical diagnosis and MR spectroscopy results

Patient No.SexAge (yr)Clinical SyndromeSupportive DataMR Spectroscopy Findings
LactateSite Interrogated
Group 1: well-established diagnosis
1M29Kearns-SayreLarge mtDNA deletion on muscle biopsyN/ALeft mesial frontal lobe (STEAM)
5M31MELASPoint mutation mitochondrial tRNA (Leu)N/A+Small right parietal lesion, more Lac in control left side (STEAM)
++Second MR spectroscopy 3 yr later: gray > white matter stroke-like lesions (MRSI)
7M37MERRFAbundant RRF on muscle biopsyN/ALeft front and occipital, 3 cm single voxel (STEAM)
10M7MELASMuscle biopsy: RRF, mitochondrial tRNA point mutation, serum Lac 2.9N/A+Left frontal white matter, single voxel (STEAM)
N/A+Second MR spectroscopy 3 mo later: left frontal, smaller after vitamin treatment in 2 days (STEAM)
12M1Elevated LacSerum Pyr 1.4–2.4*, Lac 1.0–3.2*N/A+Left basal ganglia, single voxel (STEAM)
18M3MELAS/MERRF overlapping syndromeMitochondrial DNA point mutation(MRSI)
1995 normal Lac, Pyr, 1998 Pyr 1.1*, Lac 3.4*++2nd MR imaging 11 months later: (MRSI), periventricular white matter
26F8Complex I mitochondrial diseaseDiagnosed at age 3 yr++Frontal white matter, corpus callosum lesions (MRSI)
32M13Leigh diseaseElevated CSF Lac and PyrN/APost parietal gray and white matter, thalami, single voxel (PRESS)
Group 2: possible diagnosis
3F27GI disturbances, “leukodystrophy” pattern white matter abnormalityAbnormal ultrastructure of mitochondria on intestinal muscle biopsyN/AWhite matter abnormality (STEAM)
4F6Multiple stroke-like episodesMuscle biopsy normalN/ADeep white matter lesions (STEAM)
8M8Suspected Leigh diseaseBasal ganglia abnormality, negative CSF LacN/ALeft high cortical region (STEAM)
9F0.5Developmental delay, poor vision, global cerebral Lac acidosisDiffuse cortical atrophy, decreased white matter volume and hypomyelinationN/A+Left frontal cortex, single voxel (STEAM)
11M37“Occipital stroke,” suspected MELASN/ALeft and right occipital lobes, single voxel (PRESS)
13F2Progressive ataxia, encephalitis-like symptoms++Basal ganglia (MRSI)
15M2Suspected MELAS, peri-varicella encephalocerebellitis, progressive myoclonusSerum Lac and Pyr, elevated CSF Lac normal, muscle biopsy normal(MRSI)
17M13ADEM, 2 episodesSerum Lac normal(MRSI)
19M1Lennox-Gastaut with myoclonic epilepsy, cerebral palsy+(MRSI)
21M1Probable neurodegenerative disease, seizure, mental retardation, failure to thriveSerum Lac 2.6–3.1*, abnormal fatty acid oxidation(MRSI)
22M3Developmental delay, seizure, progressive spasticity(MRSI)
24F17Progressive spastic paraparesis, ataxiaSerum Lac 1.2, Pyr 0.3(MRSI)
28F21Relapsing subacute encephalopathy, suspect Leigh diseaseHistory of elevated serum Lac and Pyr(MRSI)
29M7Suspected MELAS(MRSI)
30M12Movement disorder with seizures++Left anterior medial temporal lobe T2-hyperintense lesions (MRSI)
31M32Suspected MELAS, mental retardation, mitochondrial encephalopathy(MRSI)
Group 3: diagnosis excluded by other data
20M8Cerebral palsy w/choreoform movements, probable guanidinoacetate N-methyltransferase deficiencySkin biopsy EM normal(MRSI)
23M7Cerebral palsy with spastic diplegia(MRSI)
25F30Developmental delay, bipolar syndromeLaboratory results normal(MRSI)
27F39Carbohydrate metabolic disease, stroke, endocrine abnormalities, hyperreflexia, poor coordination(MRSI)
33F20Acquired lipid myopathy and sensory axonal neuropathyBiochemical ETF-QO deficiency with defined mutation(MRSI)
  • Note.—Age indicates patient age in years at time of presentation; Clinical Syndrome, diagnoses made clinically in conjunction with biochemical, genetic, and/or histologic tests (if no final diagnosis available, presenting clinical symptoms listed); M, male; F, female; mtDNA, mitochondrial DNA; N/A, not available; +, presence of lactate; −, absence of lactate; STEAM, stimulated-echo acquisition mode; MELAS, mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes; tRNA (Leu), transfer RNA leucine; Lac, lactate; MRSI, MR spectroscopic imaging; MERRF, myoclonus, epilepsy, and ragged red fibers; RRF, ⧫; tRNA, transfer RNA; Pyr, pyruvate;

  • * , abnormal laboratory value; MELAS/MERRF, overlap of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes with myoclonus, epilepsy, and ragged red fibers; PRESS, point-resolved spectroscopy; GI, gastrointestinal; ADEM, acute disseminated encephalomyelitis; ETF-QO, electron transfer flavoprotein ubiquinone oxidoreductase.

  • ⧫. In general, CSF data were obtained from the MRSI records only.