Pakorn Wivatvongvana’s research while affiliated with Chiang Mai University and other places

Background Single-time non-invasive brain stimulation was carried out using the two-technique approach on a patient suffering from treatment-resistant depression. Five treatment sessions given at weekly intervals resulted in a significant improvement in the Patient Health Questionnaire-9 score for up to 6 weeks. The findings of this study could pave the way for a more efficient less resource-intensive time- and budget-saving technique of employing non-invasive brain stimulation for patients with treatment-resistant depression by minimizing the number of stimulation sessions. Case presentation A 67-year-old married non-Latino white American woman suffering from treatment-resistant depression received intermittent tetraburst stimulation in combination with transcranial direct current stimulation weekly for 5 consecutive weeks. Diagnostic transcranial magnetic stimulation showed an observable electrophysiological change. The patient reported a drastic improvement in Patient Health Questionnaire-9 score up until 6-week follow-up and expressed satisfaction with the treatment. Conclusions This case study suggests that a streamlined protocol for using non-invasive brain stimulation could prove more effective for patients and healthcare providers in terms of safety in comparison to the present guidelines.

Background TMS is being used to aid in the diagnosis of central nervous system (CNS) illnesses. It is useful in planning rehabilitation programs and setting appropriate goals for patients. We used a parabolic coil with biphasic pulse stimulation to find normal values for diagnostic TMS parameters. Objectives 1. To determine the normal motor threshold (MT), motor evoked potentials (MEP), central motor conduction time (CMCT), intracortical facilitation (ICF), short-interval intracortical inhibition (SICI), and silent period (SP) values. 2. To measure the MEP latencies of abductor pollicis brevis (APB) and extensor digitorum brevis (EDB) at various ages, heights, and arm and leg lengths. Study design Descriptive Study. Setting Department of Rehabilitation Medicine, Chiang Mai University, Thailand. Subjects Forty-eight healthy participants volunteered for the study. Methods All participants received a single diagnostic TMS using a parabolic coil with biphasic pulse stimulation on the left primary motor cortex (M1). All parameters: MT, MEP, CMCT, ICF, SICI, and SP were recorded through surface EMGs at the right APB and EDB. Outcome parameters were reported by the mean and standard deviation (SD) or median and interquartile range (IQR), according to data distribution. MEP latencies of APB and EDB were also measured at various ages, heights, and arm and leg lengths. Results APB-MEP latencies at 120% and 140% MT were 21.77 ± 1.47 and 21.17 ± 1.44 ms. APB-CMCT at 120% and 140% MT were 7.81 ± 1.32 and 7.19 ± 1.21 ms. APB-MEP amplitudes at 120% and 140% MT were 1.04 (0.80–1.68) and 2.24 (1.47–3.52) mV. EDB-MEP latencies at 120% and 140% MT were 37.14 ± 2.85 and 36.46 ± 2.53 ms. EDB-CMCT at 120% and 140% MT were 14.33 ± 2.50 and 13.63 ± 2.57 ms. EDB-MEP amplitudes at 120% and 140% MT were 0.60 (0.38–0.98) and 0.95 (0.69–1.55) mV. ICF amplitudes of APB and EDB were 2.26 (1.61–3.49) and 1.26 (0.88–1.98) mV. SICI amplitudes of APB and EDB were 0.21 (0.13–0.51) and 0.18 (0.09–0.29) mV. MEP latencies of APB at 120% and 140% MT were different between heights < 160 cm and ≥ 160 cm ( p < 0.001 and p < 0.001) and different between arm lengths < 65 and ≥ 65 cm ( p = 0.022 and p = 0.002). Conclusion We established diagnostic TMS measurements using a parabolic coil with a biphasic pulse configuration. EDB has a higher MT than APB. The 140/120 MEP ratio of APB and EDB is two-fold. The optimal MEP recording for APB is 120%, whereas EDB is 140% of MT. CMCT by the F-wave is more convenient and tolerable for patients. ICF provides a twofold increase in MEP amplitude. SICI provides a ¼-fold of MEP amplitude. SP from APB and EDB are 121.58 ± 21.50 and 181.01 ± 40.99 ms, respectively. Height and MEP latencies have a modest relationship, whereas height and arm length share a strong positive correlation.

Background Strokes have recently become a leading cause of disability among Thai people. Non-invasive brain stimulation (NIBS) seems to give promising results in stroke recovery when combined with standard rehabilitation programs. Objective To evaluate the combined effect of low-frequency repetitive transcranial magnetic stimulation (rTMS) and cathodal transcranial direct current stimulation (tDCS) over the non-lesional primary motor cortex on upper limb motor recovery in patients with subacute stroke. No reports of a combination of these two techniques of NIBS were found in the relevant literature. Methods This pilot study was a double-blinded, randomized controlled trial of ten patients with subacute stroke admitted to the Rehabilitation Medicine Inpatient Unit, Maharaj Nakorn Chiang Mai Hospital, Chiang Mai University. They were randomized into two groups: five in an active and five in a sham intervention group. Fugl-Meyer’s upper extremity motor score (FMA-UE) and Wolf Motor Function Test (WMFT) were used to assess motor recovery at baseline, immediately, and 1 week after stimulation. Results A two-way repeated ANOVA (mixed design) showed a significant improvement in FMA-UE scores in the active intervention group both immediately and 1 week after stimulation in comparison to the baseline, [time, F (2, 16) = 27.44, p < 0.001, time x group interaction, F (2, 16) = 13.29, p < 0.001]. Despite no statistical significance, a trend toward higher WMFT scores was shown in the active intervention group. Conclusions A single session of low-frequency rTMS and cathodal tDCS over the non-lesional primary motor cortex may enhance upper limb motor recovery in patients with subacute stroke.

Background Most stroke survivors spent their lifetime with disability which not only affects the clients themselves and the family but also brings economic cost to the country. Therefore, this retrospective cohort study aimed to identify independent prognostic determinants associated with functional recovery in ischemic stroke within 6 months after onset. Methods Data from all first-onset ischemic stroke patients admitted to the acute stroke unit of the tertiary, university hospital were reviewed for 5 years consecutively. The functional outcome of the patients was recorded during 6-month follow-up by using the modified Rankin Scale (mRS). Baseline characteristics, motor assessment and all stroke-related variables were assessed during first week after stroke and 6-month follow-up. In order to derive clinical predictors, the backward stepwise multivariable risk regression analyses were used with the generalized linear model. Results The result revealed that in the 358 patients recruited into this study, 255 (71.2%) were in the functional recovery group (mRS score of 1 - 3) within 6 months after onset. The final model of multivariable risk regression analysis, with generalized linear model, demonstrated that the independent variables of functional recovery were leg score with a risk ratio (RR = 1.92, 95% confidence interval (CI): 1.14 - 3.21, P = 0.013), arm score (RR = 1.75, 95% CI: 1.02 - 3.01, P = 0.042) and age older than 75 years (RR = 1.36, 95% CI: 1.04 - 1.77, P = 0.025). Conclusions Achieving functional recovery during 6 months post stroke was related to age and motor improvement. With limited resources, continuity of rehabilitation training in the community system or allocation of caregiver training should be a part of discharge planning to promote recovery.

Although lateralization of the brain affects some specialized cortical functions, there are still limited data to address its influence on clinically important outcomes. This study aimed to reveal the prognostic variables that relate to functional recovery in stroke patients with a left-sided hemispheric lesion during 6 months of follow-up. Data from 167 left-sided and 183 right-sided hemispheric strokes were reviewed retrospectively. Outcomes in this study included walking capacity and functional recovery, assessed by the modified Rankin Scale (mRS). In order to obtain independent predictive variables, this study used the step-backward method of multivariable regression analysis of parameters. The final model demonstrated that motor function of the hemiparetic leg was the strongest independent predictor for both walking ability and functional recovery (risk ratio (RR) of 2.41, 95% CI: 1.61–3.60, and p<0.001 and RR of 1.83, 95% CI: 1.03–3.26, and p=0.04 , resp.). Therefore, lateralization did not seem to be involved. Understanding predictable variables that are associated with recovery can guide the rehabilitation team in setting priority and appropriate treatment for stroke patients.

BACKGROUND: Walking difficulty is one of the important neurological consequences after stroke, early prediction of factors related to walking ability may benefit for rehabilitation team to set suitable goals and discharge planning. PURPOSE: This study was performed to identify independent prognostic determinants associated with mobility recovery from ischemic stroke during six months after onset. METHODS: Medical records from first-ever stroke patients who were admitted to the rehabilitation unit were retrospectively reviewed. Baseline characteristics including demographic data, stroke risk factors, motor assessment and stroke-related complications were collected. Outcome measure was ability to walk. To identify clinical predictors, multivariable risk regression analysis was used for analysis. RESULTS: Of a total 146 stroke survivors, 81 patients (55.5) could be independent in walking and 65 (45.5) were non-functional mobility at six months follow-up. Stepwise, multivariable risk regression analysis with generalized linear model demonstrated that follow-up leg score was the strongest independent predictor of walking with risk ratio [RR] of 2.23 (P < 0.01). The association of some stroke-related factors, aphasia and unilateral neglect were found in univariable analysis but revealed no significance from the final model. CONCLUSION: Identification of early predictors associate walking recovery provided meaningful information for stroke care team to consider the amount of care needed and to initiate optimal plan according to realistic goal.