Table 1

Electrophysiological findings at admission (M0) and 1.5 or 3 months later (M1.5, M3) in the four patients who had acute multifocal motor neuropathy with persistent conduction blocks

Case 1Case 2Case 3Case 4
Symptomatic M0Symptomatic M3Symptomatic M0Asymptomatic M1.5Symptomatic M0Asymptomatic M3Symptomatic M0Symptomatic M1.5
RightLeftRightLeftRightLeftRightLeftRightLeftRightLeftRightLeftRightLeft
ND, not determined; A, absent; R, reduced.
Median nerve motor nerve conduction
    amplitude, thenar (mV)121111101310172011911101317.51213
    distal latency (ms)2.62.73.13.32.82.93.23.52.92.92.92.83.63.543.8
    conduction velocity, forearm (m/s)6764626755, block: 60%56, block: 60%54, block: 60%53, block: 60%5654605652555150
    conduction velocity, arm (m/s)70687474676760, block: 65% ND, block: >90% 60, block: 65%58, block: 65%67656062
    conduction velocity, Erb/axillary (m/s) ND, block: >90% ND, block: >90% ND, block: >90% ND, block: >90% ND, block: >90% 55, block: 70% ND, block: >90% 50, block: 75%
    F wave latency (ms)33 37 31 41 29.729.6303031.5 33.7 32 34.7 32.231.63333
Median nerve sensory nerve conduction
    amplitude (µV)7468849229522029528013015510010580899598
    conduction velocity, wrist (m/s)56575653656470605054566247574549
Ulnar nerve motor nerve conduction
    amplitude, hypothenar (mV)7799128121211612912111011
    distal latency (ms)2.22.32.82.42.73.533.32.72.72.72.62.732.82.9
    conduction velocity, forearm (m/s)6767636357, block: 80%55, block: 60%56, block: 60%48, block: 50%5760666854485048
    conduction velocity, arm (m/s)656475716363 ND, block: 88% ND, block: >90% 54, block: 55%45, block: 80%58485048
    conduction velocity, Erb/axillary (m/s) ND, block: >90% ND, block: >90% ND, block: >90% ND, block: >90% ND, block: >90% 43, block: 70%40, block: 90%48, block: 70%
    F wave latency (ms)35 38 33 40 A A A A 33.7 36.5 34.5 35.7 3334 37 37
Ulnar nerve sensory nerve conduction
    amplitude (µV)23202020696557602420221525252528
    conduction velocity, wrist (m/s)56565048565760555050605851495452
Radial nerve motor nerve conduction
    amplitude, forearm (mV)3256
    distal latency (ms)3.553.23.2
    conduction velocity, arm (m/s)50, block: 50%5050, block: 90%50
First interosseous muscle electromyography
    spontaneous activityAAAAAAAAAAAAAAAA
    interference patternRRRRRRRRRRRRRRRR
Peroneal nerve motor nerve conduction
    amplitude – foot (mV)79784444.53.53.54.53 1.3 4 1.7 2
    distal latency (ms)3.84.243.654.65.45.55.554.344.645.54.9
    conduction velocity – leg (m/s)5048505347,block: 60%45,block: 50%44, block: 60%37, block: 60%46 n.d., block: 85% 4536, block: 75% n.d., block: 90% 4034, block: 90%40
    conduction velocity – popliteal fossa (m/s)5048605847454543
    conduction velocity – thigh (m/s) n.d.,block: 90%
    F wave latency (ms) 57 50 59 53 absent absent absent absent absent absent 59 absent absent 59 absent absent
Peroneal nerve sensory nerve conduction
    amplitude (µV)biopsy13biopsy152627211615141515biopsy 8 biopsy 6
    conduction velocity - ankle (m/s)424253494147404242474038
Tibial nerve motor nerve conduction
    amplitude – foot (mV)6866 1 2 4.5 3.5 5.5578 5 12 1 11
    distal latency (ms)4.44.25.95.15.24.56.55.6665.25.66.56.26.56
    conduction velocity – leg (m/s)4744, block : 88%4845, block : 82%49, block : 40%45, block : 40%44, block : 70%42, block : 50%42, block : 75%4640, block : 80%42 n.d., block : >90% 42 n.d., block : >90% 40
    conduction velocity – thigh (m/s) n.d., block : 90%
    F wave latency (ms) 66 54 65 56 absent absent 66 65 absent 61.5 64 60.5 absent 54 absent 55
Sural nerve sensory nerve conduction
    amplitude (µV)biopsy18biopsy2542404226322932302424biopsy15
    conduction velocity - ankle (m/s)62455255405040424445404248
Tibialis anterior muscle Electromyography
    spontaneous activityAAAAAAAAAAAAAAAA
    interference patternRRRRRRRRRRRRRRRR