Table 2.
Results of nerve conduction studies in patients with Hereditary spastic paraplegia caused by a c.2155C > T, p.R719W mutation in DNM2
| Patients | III:3 | III:5 | IV:1 | Normal values |
|---|---|---|---|---|
| Symptom duration (years) at time of study | 17 | 32 | 7 | |
| Motor nerve conduction studies | ||||
| n.Medianus | ||||
| Distal motor latency (m/s) | 3.6 | ND | 3.5 | <4.2 |
| Compound muscle action potential (mV)a | 4.5 | ND | 8.7 | >5.0 |
| Motor nerve conduction velocity (m/s) | 48.2 | ND | 57.1 | >47.6 |
| n.Peroneus | ||||
| Distal motor latency (m/s) | 4.49 | NR | 5.1 | <6.5 |
| Compound muscle action potential (mV)a | NR | 0.04 | 0.21 | >3.0 |
| Motor nerve conduction velocity (m/s) | NR | NR | 40.6 | >40.5 |
| n.Tibialis posterior | ||||
| Distal motor latency (m/s) | NR | NR | 6.2 | <6.0 |
| Compound muscle action potential (mV)a | NR | 0.5 | 1.9 | >5.0 |
| Motor nerve conduction velocity (m/s) | NR | NR | 39.7 | >40.0 |
| Sensory nerve conduction studies | ||||
| n.Medianus | ||||
| Distal sensory nerve conduction velocity (m/s)b | 61.4 | ND | 64.5 | >47.2 |
| Sensory nerve action potential amplitude (μV) | 10 | ND | 16.6 | >5.0 |
| n.Suralis | ||||
| Distal sensory nerve conduction velocity (m/s) | NR | 38.5 | 42.8 | >33.2 |
| Sensory nerve action potential amplitude (μV) | 0.7 | 0.43 | 5.82 | >6.0 |
ND not done
Bold: outside normal range
aDistal motor response amplitude
bOrthodromic stimulation
NR no response