Effects of cortical intermittent theta burst stimulation combined with precise root stimulation on motor function after spinal cord injury: a case series study

Activation and reconstruction of the spinal cord circuitry is important for improving motor function following spinal cord injury.We conducted a case series study to investigate motor function improvement in 14 patients with chronic spinal cord injury treated with 4 weeks of unilateral(right only)cortical intermittent theta burst stimulation combined with bilateral magnetic stimulation of L3-L4 nerve roots,five times a week.Bilateral resting motor evoked potential amplitude was increased,central motor conduction time on the side receiving cortical stimulation was significantly decreased,and lower extremity motor score,Berg balance score,spinal cord independence measure-III score,and 10 m-walking speed were all increased after treatment.Right resting motor evoked potential amplitude was positively correlated with lower extremity motor score after 4 weeks of treatment.These findings suggest that cortical intermittent theta burst stimulation combined with precise root stimulation can improve nerve conduction of the corticospinal tract and lower limb motor function recovery in patients with chronic spinal cord injury.

Combined monitoring of evoked potentials during microsurgery for lesions adjacent to the brainstem and intracranial aneurysms

Background Neurophysiologic monitoring during surgery is to prevent permanent neurological injury resulting from surgical manipulation. To improve the accuracy and sensitivity of intraoperative neuromonitoring, combined monitoring of transcranial electrical stimulation motor evoked potentials （TES-MEPs）, somatosensory evoked potentials （SSEPs） and brainstem auditory evoked potentials （BAEPs） was attempted in microsurgery for lesions adjacent to the brainstem and intracranial aneurysms. Methods Monitoring of combined TES-MEPs with SSEPs was attempted in 68 consecutive patients with lesions adjacent to the brainstem as well as intracranial aneurysms. Among them, 31 patients （31 operations, 28 of posterior cranial fossa tumors, 3 of posterior circulation aneurysms） were also subjected to monitoring of BAEPs. The correlation of monitoring results and clinical outcome was studied prospectively. Results Combined monitoring of evoked potentials （EPs） was done in 64 （94.1%） of the 68 patients. MEPs monitoring was impossible for 4 patients （5.9%）. No complication was observed during the combined monitoring in all the patients. In 45 （66.2%） of the 68 patients, EPs were stable, and they were neurologically intact. Motor dysfunction was detected by MEPs in 8 patients, SSEPs in 5, and BAEPs in 4, respectively. Conclusions A close relationship exists between postoperative motor function and the results of TES-MEPs monitoring TES-MEPs are superior to SSEPs and BAEPs in detecting motor dysfunction, but combined EPs serve as a safe, effective and invasive method for intraoperative monitoring of the function of the motor nervous system. Monitoring of combined EPs during microsurgery for lesions adjacent to the brainstem and intracranial aneurysms may detect potentially hazardous maneuvers and improve the safety of subsequent procedures.

Role of transient receptor potential vanilloid subetype 1 in the increase of thermal pain threshold by moxibustion

OBTECTIVE:To explore the role of transient receptor potential vaniiloid subetype 1(TRPV1) in the increase of the thermal pain threshold by moxibustion.METHODS:Forty Kunming mice(20 ± 2) g were randomized into control group,capsaicin group,capsazepine group,moxibustion group and moxibustion + capsazepine(MC) group with 8 mice in each,and 16 C57BL/6 wild-type mice(18 ± 2) g were randomized into wild-type(WT) control group and WT moxibustion group with 8 mice in each,and 14 TRPV1 knockout mice(18 ± 2) g were randomized into knockout(KO) control group and KO moxibustion group with 7 in each.Each mouse in the capsaicin group was subcutaneously injected with the amount of 0.1 mL/10 g into L5 and L6 spinal cords;each mouse in the capsazepine group was intraperitoneally injected with the amount of0.1 mL/10 g.Similarly,each mouse in the moxibustion group was given a suspended moxibustion with specially-made moxa-stick for 20 min on L5 and L6 spinal cords.Each mouse in MC group was intraperitoneally injected with the amount of 0.1 mL/10 g first,then after 15 min was given a suspended moxibustion for 20 min on L5 and L6 spinal cords.Each mouse in WT moxibustion group and KO moxibustion group was given a suspended moxibustion with specially-made moxa-stick for 20 min on L5 and L6 spinal cords.The control group,WT control group and KO control group were of no treatment in any way.After all treatments were completed,the digital-display measurement instrument for thermal pain was used to measure the threshold of thermal pain in each group respectively.RESULTS:Compared with the control group,the thresholds of thermal pain in the moxibustion group and MC group were significantly increased(P <0.01);no significant changes in the thresholds in the capsaicin group and the capsazepine group(P > 0.05);compared with moxibustion group,he threshold of thermal in MC group was obviously decreased(P < 0.01).Compared with WT control group,the threshold of thermal pain in WT moxibustion group was significantly increased(P <0.01);compared with KO control group,no changes in the threshold in KO moxibustion group(P > 0.05).CONCLUSION:TRPV1 participated in the process of increasing the threshold of thermal pain by stimulating L5 and L6 of mice spinal cord with burning mosa-stick.

Temporal sequential correlation analysis on compoundaction potentials of the auditory nerve versus the stimulating AM-sound envelope

Compound action potentials of the auditory nerve in response to amplitude modulating tones were recorded in guinea pigs with electrode implanted to the exit of the internal auditory meatus and temporal sequential correlation between the responses and the modulators was studied in a paradigm of systematically changing acoustic parameters. Three kinds of modulators were used. continuous or burst sinusoids of fixed frequency (in the range of 40 Hz-5 kHz), short bursts of sinusoids with changing frequency and short segments of speech signal. Ranges of parametric variation were 500 Hz-20 kHz for carrier frequency, 5%-95% for modulation depth and 20 dB-90 dB SPL for intensity. For continuous or burst sinusoidal modulators of fixed frequencies, the correlation coefficient (r) remained quite high in most parametric conditions, ranging from 0.80 to 0.95. It became smaller mainly in instances of decreased response amplitude on account of unfavourable parameters. For burst modulators of changing frequency, r varied around 0.66-0.86. When segments of speech signal served as the modulators, significant correlation (r around 0.50 ) also existed, indicating the validity of the timing mode of information encoding for speech sound at the cochlear nerve level. Some theoretical and technical points in studying the timing mechanism of audition is discussed.