Читать книгу Neurology - Charles H. Clarke - Страница 151

Five measurements are of value in neuropathies and peripheral nerve entrapment:

 Motor conduction velocity (MCV) – normal values 41–49 m/s or greater

 Sensory conduction velocity – normal 40–50 m/s

 Distal motor latency (DML) – less than 4.4 m/s in median nerve, less than 3.3 m/s in ulnar

 Sensory (nerve) action potentials (SAPs or SNAPs) – 2–15 mV, depending on nerve

 Compound muscle action potentials (MAPs or CMAPs).

Nerve conduction studies use supramaximal stimulation, that measures conduction in fastest fibres – a blunt instrument compared with the finesse of EMG interpretation. Technique: see Figure 4.8.