Patient (sex, age) | Nerve | Motor NCS | Sensory NCS | ||||||
---|---|---|---|---|---|---|---|---|---|
Distal CMAP amplitude (mV) | Distal latency (m/s) | NCV (m/s) | SNAP amplitude (μV) | NCV (m/s) | |||||
II–2 (F, 46 y) | Median | 13 | 5.21-150 | 49 | 2.61-150 | 381-150 | |||
Tibial | 6.3 | 4.2 | 391-150 | ||||||
Sural | 6.51-150 | 361-150 | |||||||
III–1 (F, 25 y) | Median | 19.5 | 4.31-150 | 54 | 5.81-150 | 421-150 | |||
Tibial | 20.2 | 3.4 | 50 | ||||||
Sural | 25.3 | 51 | |||||||
III–2 (M, 21 y) | Median | 8.5 | 5.11-150 | 351-150 | 0.51-150 | 241-150 | |||
Tibial | 3.01-150 | 5.1 | 321-150 | ||||||
Sural | 4.81-150 | 321-150 | |||||||
III–3 (M, 19 y) | Median | 2.21-150 | 7.91-150 | 281-150 | 0.91-150 | 311-150 | |||
Tibial | 2.61-150 | 5.31-150 | 311-150 | ||||||
Sural | 0.71-150 | 341-150 | |||||||
III–4 (M, 13 y) | Median | ND | ND | ND | ND | ND | |||
Tibial | 8.6 | 4.5 | 301-150 | ||||||
Sural | NR | NR |
↵1-150 Pathological values; ND=not done; NR=no response upon stimulation; CMAP=compound muscle action potential; SNAP=sensory nerve action potential; NCV=nerve conduction velocity.
Although not clinically affected, the transmitting mother (II-2) showed slight abnormalities in sensory and motor NCVs. The unaffected daugther (III-1) has subtle signs of a (clinically asymptomatic) carpal tunnel syndrome, which is not related to the CMTX mutation. The carriers of the mutation show pathological motor and sensory NCVs .