Central motor conduction times using transcranial stimulation and F Wave latencies

Robinson, Lawrence R.; Jantra, P; MacLean, Ian C.

doi:10.1002/mus.880110214

Cited by 58 publications

(12 citation statements)

References 21 publications

(6 reference statements)

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“…Our results showed that functional recovery in the corticospinal tract following cervical laminoplasty in patients with CCM can be quantitatively assessed and that the corticospinal conduction block improvements due to the increase in the number of axons that propagate the evoked potentials were one of the causes of improved JOA scores. The CMCT values did not completely improve to the normal range, which has been reported previously, 10,28 and the mean CMCT recovery rate and (JOA score) RR in our series were 0.91 and 0.43, respectively. The data should be important information on the pathophysiology of recovery following surgery.…”

Section: Discussionsupporting

confidence: 78%

Electrophysiological evidence of functional improvement in the corticospinal tract after laminoplasty in patients with cervical compressive myelopathy

Nakanishi¹,

Tanaka²,

Kamei³

et al. 2014

SPI

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Object Cervical laminoplasty is a surgical procedure for cervical compressive myelopathy (CCM), and satisfactory outcomes have been reported. However, few reports have examined the pathophysiology of improvements in spinal cord function. The aim of this study was to investigate the variation in central motor conduction time (CMCT) before and after cervical laminoplasty in patients with CCM. Methods Motor evoked potentials (MEPs) following transcranial magnetic stimulation and compound muscle action potentials (CMAPs) and F-waves following electrical stimulation of the ulnar and tibial nerves at the wrist and ankle were measured from the abductor digiti minimi muscle (ADM) and abductor hallucis muscle (AH) in 42 patients with CCM before and 1 year after cervical laminoplasty. The peripheral conduction time (PCT) was calculated as follows: (latency of CMAPs + latency of F-waves − 1)/2. The CMCT was calculated by subtracting the PCT from the onset latency of the MEPs. The CMCT recovery ratio was defined and calculated as the ratio of CMCT values 1 year after surgery to those before surgery. The CMCT data were analyzed as longer or shorter CMCT between the patients' right and left ADMs and AHs. The Japanese Orthopaedic Association (JOA) score for cervical myelopathy was obtained as a clinical outcome before and 1 year after surgery. The recovery rate (RR) 1 year after surgery was calculated using the following formula: (postoperative JOA score 1 year after surgery – preoperative JOA score)/(17 – preoperative JOA score) × 100. Correlations among CMCT parameters, patient age, JOA score, and RR were determined. Results The longer and shorter CMCTs from the ADM (longer, p = 0.000; shorter, p = 0.008) and the longer CMCT from the AH (longer, p = 0.000) before surgery decreased significantly 1 year after surgery; the shorter CMCT from the AH did not significantly differ (shorter, p = 0.078). The mean JOA score before surgery was 10.1 ± 3.0 and improved significantly to 12.9 ± 2.7 at 1 year after surgery (p = 0.000). The mean CMCT recovery ratio and RR were 0.91 ± 0.18 and 0.43 ± 0.27, respectively. The longer/shorter CMCT parameters in the ADM and AH before or 1 year after surgery correlated significantly with the JOA score both before and 1 year after surgery. The CMCT recovery ratio from the longer CMCT in the ADM correlated significantly with the RR (r = − 3090, p = 0.011). There were no significant correlations between age and any CMCT parameters or CMCT recovery ratios. Conclusions These results suggest that cervical laminoplasty improves corticospinal tract function 1 year after surgery, which may be one of the reasons for the JOA score improvements in patients with CCM. The degree of improvement in corticospinal tract function did not correlate with patient age in this case series. The results demonstrated quantitative evidence of the pathophysiology of functional recovery in the corticospinal tract following cervical laminoplasty in patients with CCM.

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Section: Discussionsupporting

confidence: 78%

Electrophysiological evidence of functional improvement in the corticospinal tract after laminoplasty in patients with cervical compressive myelopathy

Nakanishi¹,

Tanaka²,

Kamei³

et al. 2014

SPI

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“…In 40 of the 138 patients (18 with IDDM including 10 with neuropathy and 8 without neuropathy, and 22 with NIDDM including 9 with neuropathy and 13 without neuropathy), a calculated CMCT (CMCT-F) was determined using the following formula [12]:…”

Section: Methodsmentioning

confidence: 99%

Central motor conduction after magnetic stimulation in diabetes

et al. 1998

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Central motor conduction times (CMCTs), obtained by means of magnetic stimulation of the motor cortex and spinal roots, were studied in 138 patients affected by diabetes mellitus but with no signs or symptoms of central nervous system (CNS) involvement. CMCTs were significantly increased in diabetic patients (p < 0.001, t-test) with respect to normal controls, with values exceeding upper confidence limits (mean +/- 2.5 SD of controls) in about 30% of patients. There was no correlation between CMCT delay and type of diabetes (insulin-dependent or non-insulin-dependent), patient age, disease duration, degree of metabolic control compensation, presence or absence of retinopathy or nephropathy, and presence or absence of peripheral or autonomic neuropathy. CNS involvement in diabetes mellitus is discussed. Particular emphasis is given to the sensitivity and reliability of CMCTs obtained by means of magnetic stimulation as a tool in the early diagnosis of CNS functional alterations in diabetes mellitus.

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“…All of them use the difference between the latency of the motor-evoked potential (MEP) elicited by TMS or transcranial electrical stimulation, and the peripheral motor conduction time. 17,18,20,21 Peripheral motor conduction time is measured by four different methods: F-wave latency; 20 needle stimulation of the cervical roots; 10 transcutaneous magnetic stimulation of the cervical roots; 9 and high-voltage, low-impedance percutaneous electrical stimulation of the cervical roots. 25 Studies of reproducibility in measuring various electrodiagnostic parameters 1,2,12 are helpful in identifying the optimal method of making such measurements.…”

Section: Transcranial Magnetic Stimulation (Tms) Is a Safementioning

confidence: 99%

Central motor conduction time: Reproducibility and discomfort of different methods

1998

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Central motor conduction times using transcranial stimulation and F Wave latencies

Cited by 58 publications

References 21 publications

Electrophysiological evidence of functional improvement in the corticospinal tract after laminoplasty in patients with cervical compressive myelopathy

Electrophysiological evidence of functional improvement in the corticospinal tract after laminoplasty in patients with cervical compressive myelopathy

Central motor conduction after magnetic stimulation in diabetes

Central motor conduction time: Reproducibility and discomfort of different methods

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