Table 1: Nerve Conduction Studies (summarised)

Transcription

1 Table 1: Nerve Conduction Studies (summarised) Sensory nerve conduction 1 week* 3 months Superficial radial sensory Normal, symmetric SNAP and CV No change Median to digit II Normal, symmetric SNAP and CV No change Ulnar to digit V Normal, symmetric SNAP and CV No change Left Sural Normal SNAP and CV, (left only) ~ Motor nerve conduction Right median to APB Normal CMAP and CV up to the elbow No change Left median to APB Normal CMAP and CV up to Erb's point No change Right ulnar to ADM Normal CMAP and CV up to the elbow No change Left ulnar to ADM Normal CMAP and CV up to Erb's point No change Left tibial to AH Normal CMAP and CV up to the popliteal fossa ~ F-waves Right median to APB Normal Normal Left median to APB Very infrequent, low amplitude Normal Right ulnar to ADM Normal Normal Right ulnar to ADM Very infrequent, low amplitude Normal Left tibial to AH Normal Normal SNAP - sensory nerve action potential, CMAP - compound muscle action potential, CV - conduction velocity APB - Abductor policis brevis, ADM - Abductor digiti minimi, AH - abductor hallucis * time after onset of first weakness, ~ not tested

2 Table 2: Nerve Conduction Studies (with numbers) Amplitude (μv) 1 week after onset of weakness 3 months later Distal Latency Conductio n Velocity (m/s) Minimal F-wave latency Amplitude (μv) Distal Latency Conductio n Velocity (m/s) Sensory nerve conduction R Median digit II R Median digit III R Ulnar digit V R Radial L Median digit II L Median digit III L Ulnar digit V L Radial L Sural Minimal F-wave latency Motor nerve conduction R Median: APB Wrist Elbow L Median: APB Wrist * Elbow Axilla Erb's point

3 R Ulnar: ADM Wrist Below elbow Erb's point L Ulnar: ADM Wrist * Below elbow Above elbow Axilla Erb's point L Tibial: AH ankle knee * very infrequent, low amplitude F waves APB - Abductor pollicis brevis, ADM - Abductor digiti minimi, AH - abductor hallucis For sensory nerve conduction median and ulnar responses are recorded in an antidromic manner whereas radial and sural are orthodromic. The study at 1 week was curtailed due to commencement of non-invasive ventilation. Upper limbs were very cool bilaterally at the 3 month visit, this is reflected in the mild reduction motor and sensory conduction velocity seen distally in both upper limbs.

4 Right Left Table 3: Electromyography Muscle Upper cervical paraspinal Spontaneous activity 1 week after onset of weakness 3 months Motor units Motor units Morphology Recruitment Spontaneous Morphology activity Fibs, PSW High amplitude, broad Recruitment Reduced with incomplete interference Sternocleidomastoid Normal Normal Upper trapezius No voluntary activity Fibs, PSW No voluntary activity Infraspinatus Fibs, PSW broad recruitment Pectoralis major broad recruitment Deltoid Normal Single unit Fibs, PSW broad recruitment Biceps Normal Mildly Reduced Essentially normal Essentially normal Reduced with High amplitude, incomplete Triceps Normal Reduced Fibs, PSW broad interference First dorsal interosseous Normal Reduced Reduced but with a full interference Tibialis anterior Normal Normal Infraspinatus Triceps Normal Reduced but with a full interference

5 Deltoid Fibs - Fibrillation potentials, PSW - positive sharp waves. Commencement of ventilatory support curtailed the initial study. Normal