Table 2. Diagnostic Evaluations of Mitochondrial Disease and MRI Findings at the Last Visit.
| Evaluation | Findings | Prevalence (n=40) |
|---|---|---|
| Serum lactate level | Normal | 23 (57.5) |
| Mildly increased (1–2-fold) | 9 (22.5) | |
| Moderately increased (2–3-fold) | 2 (5.0) | |
| Severely increased (≥3-fold) | 2 (5.0) | |
| Syndromic diagnosis | Nonspecific mitochondrial disease | 34 (85) |
| Leigh syndrome | 5 (7.5) | |
| MELAS | 1 (2.5) | |
| Biochemical enzyme assay | Normal | 2 (5.0) |
| MRC complex I defect | 36 (90) | |
| MRC complex IV defect | 2 (5.0) | |
| Muscle pathology | Light microscopy | |
| Normal | 4 (10.0) | |
| Mitochondrial specific finding | 28 (70) | |
| Mitochondrial nonspecific finding | 8 (20) | |
| Electron microscopy | ||
| Normal | 23 (57.5) | |
| Pleoconia | 14 (35) | |
| Megaconia | 11 (27.5) | |
| MRI at last visit | Normal | 7 (17.5) |
| Basal ganglia signal abnormality | 6 (15.0) | |
| Thalamus signal abnormality | 3 (7.5) | |
| Brainstem signal abnormality | ||
| Midbrain | 1 (2.5) | |
| Pons | 2 (5.0) | |
| Medulla | 2 (5.0) | |
| Cortex signal abnormality | 11 (27.5) | |
| Cerebellar atrophy | 11 (27.5) | |
| White matter signal abnormality | 17 (42.5) | |
| Diffuse atrophy | 28 (70.0) |
MELAS, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes; MRC, mitochondrial respiratory chain; MRI, magnetic resonance imaging.
Data are given as number (percentage).