Table 2.
Brain metabolites and memory performance across clinical groups.
| MELAS | Carriers | Controls | Between group comparisons | |
|---|---|---|---|---|
| n = 18 | n = 58 | n = 20 | ||
| Verbal memory: N (%)* | ||||
| Within normal limits (>16th %ile) | 8 (44.4) | 44 (75.8) | 13 (65.0) | p = 0.02 |
| Mildly impaired (16th–2nd %ile) | 5 (27.8) | 12 (20.7) | 6 (30.0) | |
| Severely impaired (<2nd %ile) | 5 (27.8) | 2 (3.5) | 1 (5.0) | |
| Visual memory: N (%) § | ||||
| Within normal limits (>16th %ile) | 3 (16.7) | 31 (53.5) | 16 (80.0) | p < 0.0001 |
| Mildly impaired (16th–2nd %ile) | 1 (5.6) | 16 (27.6) | 2 (10.0) | |
| Severely impaired (<2nd %ile) | 14 (77.8) | 11 (18.9) | 2 (10.0) | |
| Occipital NAA levels: N (%)° | ||||
| Low (≤14.0 i.u.) | 11 (61.1) | 9 (15.5) | 5 (25.0) | p = 0.0007 |
| Within normal limits (14.0–17.6 i.u.) | 4 (22.2) | 22 (37.9) | 12 (60.0) | |
| High (≥17.6 i.u.) | 3 (16.7) | 27 (46.6) | 3 (15.0) | |
| Occipital lactate levels: N (%) § | ||||
| Within normal limits (≤4.5 i.u.) | 4 (22.2) | 45 (77.6) | 17 (85.0) | p < 0.0001 |
| High (4.5–5.4 i.u.) | 5 (27.8) | 8 (13.8) | 3 (15.0) | |
| Very high (≥5.4 i.u.) | 9 (50.0) | 5 (8.6) | 0 (0.0) | |
| Ventricular lactate levels: N (%)° | ||||
| Within normal limits (≤4.8 i.u.) | 3 (16.7) | 28 (48.2) | 16 (80.0) | p < 0.0001 |
| High (4.8–5.7 i.u.) | 1 (5.5) | 15 (25.9) | 4 (20.0) | |
| Very high (≥ 5.7 i.u.) | 14 (77.8) | 15 (25.9) | 0 (0.0) | |
Note: Differed between MELAS and carriers, MELAS and controls, and carriers and controls (all p < 0.05). Bold indicated Alpha was set at 0.05.
*
Differed between MELAS and carriers only (p = 0.0008).
§
Differed between MELAS and carriers (p < 0.0001) and MELAS and controls (p = 0.000) only.
°
Differed between MELAS and carriers, MELAS and controls, and carriers and controls (all p = 0.05).