Sensory nerve conduction studies

Right side / Left side
Ampl. [mV] / CV [m/s] / Ampl. [mV] / CV [m/s]
Superficial radial / 30 / 55 / 39 / 64
Median F2 / 22 / 55 / 18 / 63
Median F3 / 20 / 54 / 30 / 57
Ulnar F5 / 10 / 48 / 20 / 63
Ulnar (dorsal cutaneous) / 13 / 50 / 29 / 56
Superficial peroneal / 25 / 47 / 18 / 54
Sural / 18 / 50 / 10 / 52

Sensory nerve conductions studies showed absolutely normal values except for asymmetries of the amplitudes for the ulnar nerve to the disadvantage of the right.

Thermal thresholds

Right side / Left side
WDT [° C] / CDT [° C] / WDT [° C] / CDT [° C]
Thenar eminence / 39.1 / 26.4 / 35.2 / 28.9
Lateral border of foot / 39.8 / 18.8 / 38.4 / 21.6

Abnormal values highlighted in red.

Motor nerve conduction studies

Right side / Left side
Ampl. [mV] / CV [m/s] / Dml [ms] / F-latency [ms] / Ampl. [mV] / CV [m/s] / Dml [ms] / F-latency [ms]
Median / 11.5 / 52 / 3.5 / 31.0 / 8.8 / 56 / 3.4 / 24.5
Ulnar / 11.7 / 60 / 2.9 / 27.3 / 13.3 / 66 / 2.6 / 24.7
Peroneal / 8.2 / 44 / 3.8 / 45.2 / 4.4 / 44 / 4.6 / 44.5
Tibial / 17.9 / 48 / 4.7 / 52.8 / 20.3 / 42 / 4.4 / 52.2

Motor nerve conductions studies showed absolutely normal values except for asymmetries of the minimal F-wave latencies to the disadvantage of the right.

Needle EMG

Examined and normal were right first dorsal interosseus, abductor digiti minimi, abductor pollicis brevis, flexor pollicis longus, extensor indicis proprius and tibialis anterior.

MEP

Motor evoked potentials showed normal latencies (20.5 ms right, 19.0 ms left) and central motor conduction times (6.4 ms right, 6.7 ms left). The asymmetry of the latencies following magnetic stimulation of the cervical spine (14.1 ms right, 12.3 ms left) is consistent with a lesion distal to the intervertebral foramina.

SSEP

Peripheral, cervical and cortical somatosensory evoked potentials to stimulation of either arm were of normal amplitude, latency and morphology.

Cortical somatosensory evoked potentials to stimulation of the left leg were of normal amplitude, latency and morphology. Cortical somatosensory evoked potentials to stimulation of the right leg were of low amplitude, however the latencies and morphologies were essentially normal.No lumbar responses could be obtained from either side.

VEP

Visual evoked potentials to stimulation of either eye were well formed, of normal amplitude, latency and distribution.

Sympathetic skin response

Responses recorded from the right hand (latency 1405 ms, amplitude 220 mV) and right foot (latency 1935 ms, amplitude 170 mV) were normal.

Blink reflex study

Right side / Left side
Ipsilateral R1 / 9.8ms / 10.8ms
Ipsilateral R2 / 36.1ms / 34.6ms
Contralateral R2 / 35.9ms / 31.7ms

Bilateral recording of orbicularis oculi muscles and stimulation of the supraorbital nerve. Blink responses were within normal limits on either side

Methods

All nerve conduction studies, reflex studies and EMG were carried out using VikingSelects (Cardinal Health) with conventional settings. Sensory nerve action potentials were recorded with surface electrodes using antidromic montage except for fingers 2, 3, and 5 where the recording was orthodromic.

MEPs were recorded using a VikingSelect EMG and a 200 Magstim (Magstim Company).

Thermal thresholds were studied using a Medoc TSAII machine and a 30 x 30 thermode and methods of limits with a temperature change of 1 °C/s from an adaptation temperature of 32 °C.

SEPs from median and tibial nerves were recorded using a Bravo machine (Cardinal Health) whereas VEPs were recorded with custom-made equipment.