1.MR neurography of median nerve using diffusion tensor imaging (DTI) and its efficacy to diagnose carpal tunnel syndrome in Malaysian population
Vikneswary PANIANDI ; John George FRCR ; Khean Jin GOH ; Li Kuo TAN
Neurology Asia 2018;23(1):17-25
Objective: This study evaluates the feasibility of diffusion tensor imaging(DTI) in assessing median nerve by measuring diffusion parameters such as fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) at different sites of median nerve and evaluating their differences in patients with and without carpal tunnel syndrome (CTS) in local setting. Methods: A prospective cross sectional study was performed with 9 female patients diagnosed with CTS by clinical evaluation and nerve conduction study and 8 age and sex matched normal patients. Magnetic resonance imaging (MRI) wrist was performed with pre-set axial PD and DTI protocol on a 3T MRI, images post-processed using 3D SLICER software to generate median nerve tract and measure diffusion parameters FA, MD, AD and RD in segments and focal points. Results: The FA values were significantly lower in CTS patients, 0.454 (± 0.065), p< 0.002 and demonstrates negative correlation with disease severity, r = - 0.510, p = 0.002.The mean MD, 1.090 (± 0.178) and mean RD, 0.834 (± 0.128) is higher in CTS patients, p = 0.041 and p = 0.014 respectively. They show an increasing trend with increasing disease severity. Negative correlation was noted between the FA values and age groups. FA cut of value of ≤ 0.487 with sensitivity 70.6 % and specificity 76.5%, is suggested for diagnosing CTS.Conclusion: MR neurography using DTI can be utilised to detect CTS. Patients with CTS demonstrate lower FA and higher MD and RD values.
2.Functional electrical stimulation increases neural stem/progenitor cell proliferation and neurogenesis in the subventricular zone of rats with stroke.
Hui-Hua LIU ; Yun XIANG ; Tie-Bin YAN ; Zhi-Mei TAN ; Sheng-Huo LI ; Xiao-Kuo HE
Chinese Medical Journal 2013;126(12):2361-2367
BACKGROUNDFunctional electrical stimulation (FES) is known to promote the recovery of motor function in rats with ischemia and to upregulate the expression of growth factors which support brain neurogenesis. In this study, we investigated whether postischemic FES could improve functional outcomes and modulate neurogenesis in the subventricular zone (SVZ) after focal cerebral ischemia.
METHODSAdult male Sprague-Dawley rats with permanent middle cerebral artery occlusion (MCAO) were randomly assigned to the control group, the placebo stimulation group, and the FES group. The rats in each group were further assigned to one of four therapeutic periods (1, 3, 7, or 14 days). FES was delivered 48 hours after the MCAO procedure and divided into two 10-minute sessions on each day of treatment with a 10-minute rest between them. Two intraperitoneal injections of bromodeoxyuridine (BrdU) were given 4 hours apart every day beginning 48 hours after the MCAO. Neurogenesis was evaluated by immunofuorescence staining. Wnt-3 which is strongly implicated in the proliferation and differentiation of neural stem cells (NSCs) was investigated by Western blotting analysis. The data were subjected to one- way analysis of variance (ANOVA), followed by a Tukey/Kramer or Dunnett post hoc test.
RESULTSFES significantly increased the number of BrdU-positive cells and BrdU/glial fibrillary acidic protein double- positive neural progenitor cells in the SVZ on days 7 and 14 of the treatment (P < 0.05). The number of BrdU/doublecortin (DCX) double-positive migrating neuroblast cells in the ipsilateral SVZ on day 14 of the FES treatment group ((522.77 ± 33.32) cells/mm(2)) was significantly increased compared with the control group ((262.58 ± 35.11) cells/mm(2), P < 0.05) and the placebo group ((266.17 ± 47.98) cells/mm(2), P < 0.05). However, only a few BrdU/neuron-specific nuclear protein-positive cells were observed by day 14 of the treatment. At day 7, Wnt-3 was upregulated in the ipsilateral SVZs of the rats receiving FES ((0.44 ± 0.05)%) compared with those of the control group rats ((0.31 ± 0.02)%, P < 0.05) or the placebo group rats ((0.31 ± 0.04)%, P < 0.05). At day 14, the corresponding values were (0.56 ± 0.05)% in the FES group compared with those of the control group rats ((0.50 ± 0.06)%, P < 0.05) or the placebo group rats ((0.48 ± 0.06)%, P < 0.05).
CONCLUSIONFES augments the proliferation, differentiation, and migration of NSCs and thus promotes neurogenesis, which may be related to the improvement of neurological outcomes.
Animals ; Bromodeoxyuridine ; metabolism ; Cell Proliferation ; Cerebral Ventricles ; physiopathology ; Electric Stimulation Therapy ; Glial Fibrillary Acidic Protein ; analysis ; Male ; Neural Stem Cells ; physiology ; Neurogenesis ; Rats ; Rats, Sprague-Dawley ; Stroke ; physiopathology ; therapy ; Wnt3A Protein ; analysis
3.Alternating Hemiplegia of Childhood in a Person of Malay Ethnicity with Diffusion Tensor Imaging Abnormalities
Ai Huey TAN ; Tien Lee ONG ; Norlisah RAMLI ; Li Kuo TAN ; Jia Lun LIM ; Mohamad Addin AZHAN ; Azlina AHMAD-ANNUAR ; Khairul Azmi IBRAHIM ; Zariah ABDUL-AZIZ ; Laurie J OZELIUS ; Allison BRASHEAR ; Shen Yang LIM
Journal of Movement Disorders 2019;12(2):132-134
No abstract available.
Diffusion Tensor Imaging
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Diffusion
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Hemiplegia
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Humans
4.Causal Relations between Exposome and Stroke: A Mendelian Randomization Study
Hong-Qi LI ; Yi-Wei FENG ; Yu-Xiang YANG ; Xin-Yi LENG ; Prof Can ZHANG ; Shi-Dong CHEN ; Kevin KUO ; Shu-Yi HUANG ; Xue-Qing ZHANG ; Yi DONG ; Xiang HAN ; Xin CHENG ; Mei CUI ; Lan TAN ; Qiang DONG ; Jin-Tai YU
Journal of Stroke 2022;24(2):236-244
Background:
and Purpose To explore the causal relationships of elements of the exposome with ischemic stroke and its subtypes at the omics level and to provide evidence for stroke prevention. Methods We conducted a Mendelian randomization study between exposure and any ischemic stroke (AIS) and its subtypes (large-artery atherosclerotic disease [LAD], cardioembolic stroke [CE], and small vessel disease [SVD]). The exposure dataset was the UK Biobank involving 361,194 subjects, and the outcome dataset was the MEGASTROKE consortium including 52,000 participants.
Results:
We found that higher blood pressure (BP) (systolic BP: odds ratio [OR], 1.02; 95% confidence interval [CI], 1.01 to 1.04; diastolic BP: OR, 1.03; 95% CI, 1.01 to 1.05; pulse pressure: OR, 1.03; 95% CI, 1.00 to 1.06), atrial fibrillation (OR, 1.18; 95% CI, 1.13 to 1.25), and diabetes (OR, 1.13; 95% CI, 1.07 to 1.18) were significantly associated with ischemic stroke. Importantly, higher education (OR, 0.69; 95% CI, 0.60 to 0.79) decreased the risk of ischemic stroke. Higher systolic BP (OR, 1.06; 95% CI, 1.02 to 1.10), pulse pressure (OR, 1.08; 95% CI, 1.02 to 1.14), diabetes (OR, 1.28; 95% CI, 1.13 to 1.45), and coronary artery disease (OR, 1.58; 95% CI, 1.25 to 2.00) could cause LAD. Atrial fibrillation could cause CE (OR, 1.90; 95% CI, 1.71 to 2.11). For SVD, higher systolic BP (OR, 1.04; 95% CI, 1.00 to 1.07), diastolic BP (OR, 1.06; 95% CI, 1.01 to 1.12), and diabetes (OR, 1.22; 95% CI, 1.10 to 1.36) were causal factors.
Conclusions
The study revealed elements of the exposome causally linked to ischemic stroke and its subtypes, including conventional causal risk factors and novel protective factors such as higher education.
5.Effect of mindfulness meditation on brain-computer interface: fMRI perspective
Norlisah Ramli ; Su Sim Kuok ; Li Kuo Tan ; Yin Qing Tan ; Lee Fan Tan ; Khean Jin Goh ; Khairul Azmi Abd Kadir ; Pohchoo Seow ; Sing Yau Goh
Neurology Asia 2019;24(4):343-353
This study observed the functional changes in brain activity while performing real and imagery
movement using functional MRI (fMRI); and to compare the fMRI changes of motor imagery before
and after mindfulness meditation (MM) training for correlation with actual brain computer interface
(BCI) performance. Thirty-eight participants completed a randomized control trial consisting of 2 groups
(MM and non-intervention control groups) to study the effect of MM on BCI performance. The MM
group participated in a 4-week MM intervention programme. Out of the 38 cohorts, five participants
from the MM group and five from the control group were fMRI scanned for real and imagery movement
of right hand, left hand and both feet, before and after intervention. Statistical parametric mapping was
used for post processing and analysis of fMRI data. The MM group showed a significant improvement
in BCI performance compared to the control group. The fMRI results showed activation of right hand,
left hand and both feet motor imagery at fronto-parietal regions before MM training (p <0.05, family
wise error). After MM training, the fMRI results revealed a focused activation in 3 out of 4 of the
trained subjects during right hand motor imagery, 2 out of 4 of the trained subjects during both feet
motor imagery and 1 out of 4 of the trained subjects during left hand motor imagery, compared to
the control group. This is also correlated with the improvement of BCI accuracy of the intervention
group after MM training. Mindfulness meditation improves BCI performance and is correlated with
focused activation of the fronto-parietal region in fMRI during motor imagery.