Stimulation in Supplementary Motor Area Versus Motor Cortex for Freezing of Gait in Parkinson's Disease

BACKGROUND AND PURPOSE: Freezing of gait (FOG) is a frustrating problem in Parkinson's disease (PD) for which there is no effective treatment. Our aim was to find brain stimulation areas showing greater responses for reducing FOG. METHODS: Twelve PD patients with FOG were selected for inclusion. We explored the therapeutic effect of repetitive transcranial magnetic stimulation (rTMS) in the supplementary motor area (SMA) and the motor cortex (MC). We measured the number of steps, completion time, and freezing episodes during the stand-walk-sit test before and after rTMS treatment. We also tested freezing episodes in two FOG-provoking tasks. RESULTS: There was a trend for a greater reduction in freezing episodes with SMA stimulation than MC stimulation (p=0.071). FOG was significantly improved after SMA stimulation (p < 0.05) but not after MC stimulation. CONCLUSIONS: Our study suggests that the SMA is a more-appropriate target for brain stimulation when treating PD patients with FOG. This study provides evidence that stimulating the SMA using rTMS is beneficial to FOG, which might be useful for future developments of therapeutic strategies.

Clinical and electrophysiological value of sensory tricks in cervical dystonia / 中华神经科杂志

Objective To investigate demography of sensory tricks in cervical dystonia (CD),and to discuss the relationship between sensory tricks and the function of sensorimotor integration of cerebral cortex,meanwhile to explore potential worthiness using sensory tricks in the management of CD.Methods We recruited 75 patients (23 male,52 female,male female ratio:1:2.26;aged 19-72 years,mean (42.45 ± 13.09) years) admitted to the Dystonia Clinic Center of the First Affiliated Hospital of Dalian Medical University from March 2016 to April 2013.Standardized questionnaire on sensory tricks was used to investigate the sensory tricks first recognized in 75 patients retrospectively.Median nerve somatosensory evoked potential via multipoint recording was measured in 43 CD patients who manifested as simple rotation of neck.Bilateral amplitudes of P22/N30 derived from F (3,4) were compared.Results Frequency of sensory tricks in CD was 85.53％ (64/75) in our research.As disease progressed,the type of sensory tricks used by patients may transform from one to another or even disappear.No statistically significant differences were found in ages among patients using classic sensory tricks,forcible tricks and patients without sensory tricks,whereas the complexity of the disease showed increased tendency among the three groups.Bilateral P22/N30 amplitudes of patients with classic sensory tricks showed no significant differences.P22/N30 amplitudes contralateral to the head turn were significantly higher than ipsilateral in patients using forcible tricks ((3.16 ± 1.71) μV vs (2.47 ± 1.28) μV,t =2.243,P=0.038) and patients without sensory tricks ((3.62 ±1.58) μV vs (2.73 ±1.14) μV,t=2.893,P=0.023).Tsui scores among patients using classic sensory tricks (9.36 ± 3.52) and forcible tricks (12.67 ± 5.00) or patients without sensory tricks (15.18 ± 4.07) had statistically significant differences (classic sensory tricks vs forcible tricks,t =-3.020,P =0.004;classic sensory tricks vs patients without sensory tricks,t =-4.452,P =0.000).Conclusions Types of sensory tricks used by patients are associated with severity of the disease.Different types of sensory tricks may reflect status of adaptive compensatory mechanism of the cerebral cortex.

Magnetic resonance imaging of active, passive and imaginary movement / 中华物理医学与康复杂志

Objective To assess any differences in brain activation during active,passive and imaginary movement of the hands using blood oxygen level-dependent functional magnetic resonance imaging (fMRI),and to provide references for the cortical reorganization in patients with brain injuries.Methods Twenty healthy,righthanded,adult volunteers were studied,fMRI was performed during active,passive and imaginary fist clutching.Whole brain analysis and group analysis were applied to get the voxels,the volume of activation,the peak t-score and its coordinates.Results Active and passive movement both produced significant activation in the contralateral sensorimotor cortex,the contralateral supplementary motor area and the ipsilateral cerebellum.The sensorimotor cortex was the most frequently and most strongly activated brain area.Imaginary movement produced significant bilateral activation in the supplementary motor area.Conclusions Active and passive movement induce similar brain activation patterns.This indicates that passive might replace active movement when observing activation of the brain's cortex during the rehabilitation of patients with hemiplegia.

Low frequency transcranial magnetic stimulation for children with Tourette's syndrome / 中华物理医学与康复杂志

Objective To investigate the effects of low frequency repetitive transcranial magnetic stimulation (rTMS) applied to the supplementary motor area (SMA) of children with Tourette's syndrome (TS). Methods Thirty TS subjects less than 16 years old were treated with 1 Hz rTMS to the SMA at 110％ of the resting motor threshold (RMT) in 20 daily sessions,receiving 1200 pulses/day.Clinical assessment and physiological measures of the left and right RMT were conducted at different time points during the treatment. ResultsAfter 4 weeks of treatment,statistically significant reductions were observed in assessments with the Yale global tic severity scale (YGTSS) and in terms of clinical global impression (CGI).Symptomatic improvement was correlated with dramatic increases in both right and left RMTs. ConclusionApplication of 1 Hz rTMS to the SMA can improve the clinical symptoms of TS children.

Functional Specialisation and Effective Connectivity During Self-paced Unimanual and Bimanual Tapping of Hand Fingers: An Extended Analysis Using Dynamic Causal Modeling and Bayesian Model Selection for Group Studies

Introduction: This multiple-subject fMRI study continue to further investigate brain activation within and effective connectivity between the significantly (p<0.001) activated primary motor area (M1), supplementary motor area (SMA) with the inclusion of BA44 during unimanual (UNIright and UNIleft) and bimanual (BIM) self-paced tapping of hand fingers. Methods: The activation extent (spatial and height) and effective connectivity were analysed using statistical parametric mapping (SPM), dynamic causal modeling (DCM) and the novel method of Bayesian model selection (BMS) for group studies. Results: Group results for UNIright and UNIleft showed contra-lateral and ipsi-lateral involvement of M1 and SMA. The results for BIM showed bilateral activation in M1, SMA and BA44. A larger activation area but with lower percentage of signal change (PSC) are observed in the left M1 due to the control on UNIright as compared to the right M1 due to the control on UNIleft. This is discussed as due to the influence of the tapping rate effects that is greater than what would be produced by the average effects of the dominant and sub-dominant hand. However, the higher PSC observed in the right M1 is due to a higher control demand used by the brain in coordinating the tapping of the sub-dominant hand fingers. Connectivity analysis indicated M1 as the intrinsic input for UNIright and UNIleft while for BIM, the inputs were both M1s. During unilateral finger tapping, the contra-lateral M1 acts as the input center which in turn triggers the propagation of signal unidirectionally to other regions of interest. The results obtained for BIM (BIMleft and BIMright) however yield a model with less number of significant connection. M1-M1 connection is unidirectional for UNIleft and UNIright originating from contra-lateral M1, and is inhibited during BIM. Conclusion: By taking into consideration the presence of outliers that could have arisen in any subject under study, BMS for group study has successfully chosen a model that has the best balance between accuracy (fit) and complexity.

The effects of repetitive transcranial magnetic stimulation of the supplementary motor area on the excitability of motor cortex in patients with Parkinson's disease / 中华物理医学与康复杂志

Objective To study the effects of repetitive transcranial magnetic stimulation(rTMS) of the supplementary motor area(SMA)on the cortical excitability in patients with Parkinson's disease(PD).Methods Sixteen patients with PD were included in this study.The motor evoked potentials(MEP)and the N30 component of somatosensory evoked potentials(SEP) were assessed for each patient before and after 1200 pulses of rTMS of the SMA at 5 Hz and an intensity of 100% of relaxed motor threshold (RMT) for the abductor pollicis brevis.Results Ten minutes after the rTMS intervention,the peak-to-peak amplitude of the SEP component P20-N30 increased significantly(P<0.05),with the P/F index decreased simultaneously(P<0.05).The MEP amplitude increased significantly,and reached the highest value at 10min after the rTMS intervention. Conclusion 5 Hz rTMS of the SMA can improve the excitability of the SMA itself temporarily.Meanwhile,it can induce a short-lasting facilitation of the excitability of M1 connected with SMA.

Somatotopic Mapping of the Supplementary Motor Area

PURPOSE: The purpose of this study was to assess supplementary motor area (SMA) activation during motor, sensory, word generation, listening comprehension, and working memory tasks using functional magnetic resonance imaging (fMRI). MATERIALS AND METHODS: Sixteen healthy right-handed subjects (9M, 7F) were imaged on a Siemens 1.5T scanner. Whole brain functional maps were acquired using BOLD EPI sequences in the axial plane. Each paradigm consisted of five epochs of activation vs. the control condition. The activation tasks consisted of left finger complex movement, hot sensory stimulation of the left hand, word generation, listening comprehension, and working memory. The reference function was a boxcar waveform. Activation maps were thresholded at an uncorrected p=0.0001. The thresholded activation maps were placed into MNI space and the anatomic localization of activation within the SMA was compared across tasks. RESULTS: SMA activation was observed in 16 volunteers for the motor task, 11 for the sensory task, 15 for the word generation task, 5 for the listening comprehension task, and 15 for the working memory task. The rostral aspects of the SMA showed activity during the word generation and working memory tasks, and the caudal aspects of the SMA showed activity during the motor and sensory tasks. Right (contralateral) SMA activation was observed during the motor and sensory tasks, and left SMA activation during the word generation and memory tasks. CONCLUSION: Our results suggest that SMA is involved in a variety of functional tasks including motor, sensory, word generation, and working memory. The results obtained also support the notion that functionally specific subregions exist within the region classically defined as the SMA.

Cortical Activation Related to Motor and Sensory Tasks in Congenital Mirror Movement using Functional MRI

BACKGROUND: Mirror movements are symmetric, identical, contralateral involuntary movements that accompany vol-untary movements on one side of the body. The aim of this study is to examine the patterns of brain activation during motor and sensory tasks using a functional magnetic resonance imaging (fMRI) and to compare them between normal subjects and a patient with congenital mirror movements. METHODS: A 19 year-old patient with congenital mirror movements and seven normal volunteers (mean age: 29 years old), performed finger-tapping and tactile stimulation tasks with the right, left, and both hands, while gradient echo EPI (echo planar imaging) images were acquired in a 1.5T scanner. RESULTS: During the motor and sensory tasks, the patient showed a bilateral activation of the primary motor and sensory cortices, whereas normal subjects showed only unilateral activations. Activations related to the motor task was observed in the primary sensory cortex, the supplementary motor area, and the cerebellum as well as the primary motor cortex in the case of the patient, while only the primary motor cortex was significantly activated in normal subjects. CONCLUSIONS: These findings suggest that the abnormality underlying congenital mirror movements involves not only the primary motor cortices and interhemispheric connections between them, but also the more extended motor-sensory circuitry including the primary sensory cortex, supplementary motor area, and cerebellum.

Cortical Activation Related to Motor and Sensory Tasks in Congenital Mirror Movement using Functional MRI

BACKGROUND: Mirror movements are symmetric, identical, contralateral involuntary movements that accompany vol-untary movements on one side of the body. The aim of this study is to examine the patterns of brain activation during motor and sensory tasks using a functional magnetic resonance imaging (fMRI) and to compare them between normal subjects and a patient with congenital mirror movements. METHODS: A 19 year-old patient with congenital mirror movements and seven normal volunteers (mean age: 29 years old), performed finger-tapping and tactile stimulation tasks with the right, left, and both hands, while gradient echo EPI (echo planar imaging) images were acquired in a 1.5T scanner. RESULTS: During the motor and sensory tasks, the patient showed a bilateral activation of the primary motor and sensory cortices, whereas normal subjects showed only unilateral activations. Activations related to the motor task was observed in the primary sensory cortex, the supplementary motor area, and the cerebellum as well as the primary motor cortex in the case of the patient, while only the primary motor cortex was significantly activated in normal subjects. CONCLUSIONS: These findings suggest that the abnormality underlying congenital mirror movements involves not only the primary motor cortices and interhemispheric connections between them, but also the more extended motor-sensory circuitry including the primary sensory cortex, supplementary motor area, and cerebellum.