Ola A. Shawky

Effect of daily repetitive transcranial magnetic stimulation on motor performance in Parkinson's disease

Previous studies in patients with Parkinsons disease have reported that a single session of repetitive transcranial magnetic stimulation (rTMS) can improve some or all of the motor symptoms for 30 to 60 minutes. A recent study suggested that repeated sessions of rTMS lead to effects that can last for at least 1 month. Here we report data that both confirm and extend this work. Fifty‐five unmedicated PD patients were classified into four groups: two groups (early and late PD) received 25 Hz rTMS bilaterally on the motor arm and leg areas; other groups acted as control for frequency (10 Hz) and for site of stimulation (occipital stimulation). All patients received six consecutive daily sessions (3,000 pulses for each session). The first two groups then received a further three booster sessions (3 consecutive days of rTMS) after 1, 2, and 3 months, while the third group had only one additional session after the first month. Unified Parkinsons Disease Rating Scale (UPDRS), walking time, key‐tapping speed, and self‐assessment scale were measured for each patient before and after each rTMS session and before and after the monthly sessions. Compared to occipital stimulation, 25 Hz rTMS over motor areas improved all measures in both early and late groups; the group that received 10 Hz rTMS improved more than the occipital group but less than the 25 Hz groups. The effect built up gradually during the sessions and was maintained for 1 month after, with a slight reduction in efficacy. Interestingly, the effect was restored and maintained for the next month by the booster sessions. We conclude that 25 Hz rTMS can lead to cumulative and long‐lasting effects on motor performance.

Effect of Anodal Versus Cathodal Transcranial Direct Current Stimulation on Stroke Rehabilitation A Pilot Randomized Controlled Trial

Objective. We compared the long-term effect of anodal versus cathodal transcranial direct current stimulation (tDCS) on motor recovery in patients after subacute stroke. Methods. Forty patients with ischemic stroke undergoing rehabilitation were randomly assigned to 1 of 3 groups: Anodal, Cathodal (over-affected and unaffected hemisphere, respectively), and Sham. Each group received tDCS at an intensity of 2 mA for 25 minutes daily for 6 consecutive days over of the motor cortex hand area. Patients were assessed with the National Institutes of Health Stroke Scale (NIHSS), Orgogozo’s MCA scale (OMCASS), the Barthel index (BI), and the Medical Research Council (MRC) muscle strength scale at baseline, after the sixth tDCS session and then 1, 2, and 3 months later. Motor cortical excitability was measured with transcranial magnetic stimulation (TMS) at baseline and after the sixth session. Results. By the 3-month follow-up, all groups had improved on all scales with P values ranging from .01 to .0001. Improvement was equal in the Anodal and Cathodal groups. When these treated groups were combined and compared with Sham, significant interactions were seen for the OMCASS and BI scales of functional ability (P = .002 for each). There was increased cortical excitability of the affected hemisphere in all groups with the changes being greater in the real versus sham groups. There were borderline significant improvements in muscle strength. Conclusion. A brief course of 2 types of tDCS stimulation is superior to sham stimulation in enhancing the effect of rehabilitation training to improve motor recovery after stroke.

Epidemiological study of chronic tinnitus in Assiut, Egypt.

Background and Aim: Few comprehensive epidemiological studies of the prevalence of tinnitus have been undertaken, and none has been carried out in Egypt. A community-based survey was conducted in the Assiut Governorate to estimate the prevalence of tinnitus, its associations with psychiatric disorders and its effect on the quality of life. Material and Methods: The study involved 8,484 subjects, 5,783 (68.2%) from the rural community and 2,701 (31.8%) from the urban community. Patients were identified from a door-to-door survey and evaluated using a semistructured questionnaire, the Tinnitus Handicap Inventory and the Hamilton Anxiety and Depression Scales. Results: Four hundred and thirty-nine patients with tinnitus were found, giving a prevalence of 5.17 tinnitus cases/100 inhabitants. Males and females were equally affected. The highest age-specific prevalence rate was recorded among subjects above 60 years (17.66%) and was significantly higher among urban than rural inhabitants (6.3 vs. 4.6%) and among illiterate than among educated persons (10.15 vs. 3.07%). A majority of patients (53.3%) had some hearing loss; otitis media was common. Only 15.2% of cases were classified as having severe to catastrophic tinnitus. Nearly two thirds had a degree of depression. There were significant correlations between the severity of tinnitus and the degree of hearing loss, temporomandibular joint pain and the Hamilton depression score. Sleep disturbance was reported by 39.4% of subjects. Life enjoyment was severely affected in 15% of tinnitus patients. Conclusion: Tinnitus is a common problem in our locality, especially in older adults, and is associated with some modifiable risk factors.

VASCULAR RISKS AND COMPLICATIONS IN DIABETES MELLITUS: THE ROLE OF HELICOBACTER PYLORI INFECTION

Patients with diabetes mellitus (DM) are at risk for Helicobacter pylori infection. This infection has been linked to atherosclerosis and its vascular complications. The aim of this study was to evaluate the: (1) prevalence of H pylori infection in patients with DM; (2) association between diabetic vascular complications and H pylori infection; and (3) influence of H pylori infection on atherosclerosis and inflammatory biomarkers. In this study, we evaluated 80 patients with DM for atherosclerosis; cardiac, cerebral, and peripheral vascular diseases; retinopathy; neuropathy; and nephropathy. We estimated the blood levels of glucose, glycosylated hemoglobin, complete blood cell count, erythrocytic sedimentation rate, lipid profile, tumor necrosis factor-alpha, interleukin (IL)-6, and anti-H pylori IgG antibodies. H pylori infection was detected in 85% of patients versus 76.7% for control subjects. Carotid artery intima-media thickness was significant in H pylori-infected patients. IL-6 and tumor necrosis factor-alpha were significantly associated with H pylori infection. In multivariate analysis, blood glucose, triglycerides, erythrocytic sedimentation rate, IL-6, and tumor necrosis factor-alpha increased the odds for atherothrombotic cause of cerebral ischemia in H pylori infection. We concluded that H pylori infection is common in DM and seems to be linked to the presence of atherosclerosis and ischemic cerebrovascular stroke. This effect could be mediated by increasing cytokine levels.

Dopamine Levels After Repetitive Transcranial Magnetic Stimulation of Motor Cortex in Patients with Parkinson's Disease: Preliminary Results

Background: Repeated sessions of repetitive transcranial magnetic stimulation (rTMS) over motor cortex have been reported to produce significant improvement of motor performance in patients with Parkinsons disease (PD). In addition, it is known that a single session of rTMS over motor cortex transiently increases DA in striatum. Here, we test whether repeated sessions of rTMS increase serum dopamine in PD patients and whether this correlates with changes in clinical rating scales. Material and Methods: Twenty untreated PD patients with moderate to severe symptoms (Hoehn & Yahr stage III–V 1967) were assessed on the Unified Parkinsons Disease Rating Scale (UPDRS), and with an enzyme immunoassay for quantitative determination of plasma dopamine before and after six daily sessions of 25 Hz rTMS with 3,000 stimuli over the right and left hand and leg motor cortex. Results: There was significant improvement in UPDRS compared with the baseline. Serum dopamine level also was significantly elevated ever the same interval. There was a significant correlation between UPDRS and serum dopamine level before and after treatment. Conclusion: Improved motor performance in PD after repeated sessions of rTMS may be related to an elevation of serum dopamine concentration.

Modulation of motor cortical excitability following rapid-rate transcranial magnetic stimulation

OBJECTIVE To investigate the effect of high frequency rTMS (25 Hz at 90-100% of resting motor threshold) on the excitability of the motor cortex of healthy human subjects. METHODS Resting and active motor threshold, MEP recruitment curve (I/O curve), short interval intracortical inhibition (SICI) and facilitation (ICF), and the duration of the silent period (SP) were tested in the right first dorsal interosseous muscle (FDI) before and twice after the end of 1500 pulses in 16 normal young adult male volunteers. RESULTS Twenty-five Hertz rTMS decreased motor thresholds, reduced the duration of the silent period and had a tendency to increase the slope of the I/O curve. Most of these effects lasted for the duration of the two post-testing sessions (at least 30 min) and had returned to normal by 2h. There were no significant effects on SICI/ICF. CONCLUSION Twenty-five Hertz rTMS can produce a long lasting increase in cortical excitability in healthy subjects. SIGNIFICANCE This method may prove useful for the study of normal human physiology and for therapeutic manipulation of brain plasticity.

Cognitive impairment after cerebrovascular stroke: Relationship to vascular risk factors.

Background: Cognitive decline after cerebrovascular stroke has adverse outcome consequences. Since some vascular causes can be prevented and treated, the identification of stroke-related cognitive impairment is a challenge. Patients with cognitive impairment and vascular diseases exhibit higher homocysteine (Hcy) concentrations. Whether Hcy is an independent risk factor for cognitive impairment after stoke is still in question. The objectives of this study were to determine: 1) the relative frequency of first-ever post-stroke dementia (PSD) (three months after onset) in a consecutive sample of our population, 2) the risk factors associated with PSD, and 3) the relationship between Hcy levels and PSD. Methods: Eighty-one inpatients with first-ever stroke were prospectively evaluated with a neuropsychological battery and event-related evoked potentials (P300) at onset and then after three months. A wide range of demographic, clinical, radiological and laboratory variables were examined. PSD was diagnosed if the clinical presentation fulfilled DSM-IV criteria of vascular dementia, the patient scored ≤21 on Mini Mental State Examination (MMSE) and ≤67 points on Cognitive Abilities Screening Instruments (CASI). Results: PSD was diagnosed in 21%. PSD was significantly associated with increasing age, low levels of education, large sized and lacunar infarctions, severity of stroke, prolonged P300 latency, smoking, hypertension, and elevated Hcy levels. High Hcy levels increased the odds ratio of PSD after adjustment of significantly relevant variables including age, smoking, size of infarction, and carotid stenosis. Conclusions: Cognitive decline is common after stroke. The results of this study indicate that PSD may result from stroke and its related risk factors including possible direct association with high Hcy levels. Better knowledge of the risk factors for PSD should increase the effectiveness of preventive strategies in patients with this condition.

A community based epidemiological study of epilepsy in Assiut Governorate/Egypt.

BACKGROUND The aim of the study was to estimate the prevalence of different types of epilepsy and their possible risk factors in the region of the Assiut Governorate/Egypt. MATERIAL AND METHODS A community based study with random sampling of 7 districts, involving 6498 inhabitants. Out of this sample, 578 dropped out leaving 3066 males (51.8%) and 2854 females (48.2%). There were 3660 (61.8%) urban residents and 2260 (38.2%) from the rural community. Patients were evaluated using a screening questionnaire for epilepsy, and then referred to the hospital to be re-evaluated by a qualified neurologist and with electroencephalography (EEG) and computed tomography of the brain (CT). RESULTS Seventy-five cases were diagnosed with epilepsy giving an overall the crude lifetime prevalence rate (CPR) for epilepsy of 12.67/1000 (95% CI: 9.8-15.54). The active prevalence rate was 9.3/1000 and the incidence rate was 1.5/1000 (95% confidence interval: 0.53-2.51). Fifty-six cases (75%) had idiopathic epilepsy (CPR 9.5/1000). Symptomatic epilepsy was recorded in 19 (25%) cases (CPR 3.2/1000). Generalized seizures were more common (CPR 6.75/1000) than partial seizures (CPR 2.5/1000). The prevalence rate of partial seizures evolving to secondary generalization was 0.84/1000 while simple partial and complex partial seizures had CPR 1.4/1000 and 0.34/1000, respectively. The CPR of mixed seizures was 0.17/1000. Epilepsy was slightly but not significantly more common among males than females (CPR of 14.4 and 10.9 per 1000 population, respectively). The CPR was higher in rural than urban populations (17.7/1000, with 95% CI 12.2-23.18 and 9.56/1000, with 95% CI: 6.39-12.7, respectively) and in the illiterate group than the literate population (12.02/1000 and 9.94/1000, respectively). The highest prevalence rate was recorded in the early and late childhood period (69.78/100,000 and 43.78/100,000, respectively). Prenatal insults and infection represented major causes of symptomatic epilepsy. CONCLUSIONS We found a high prevalence rate of epilepsy (comparable with that in other Arabic and European countries) in our community particularly among children and teenagers. Overall the prevalence was higher in the rural than in the urban population. A family history of epilepsy, prenatal insults, and infection represented major risk factors of symptomatic epilepsy.

Cortical excitability of amyotrophic lateral sclerosis: Transcranial magnetic stimulation study

OBJECTIVE The primary purpose of this study was to provide insight into the central changes that occur in amyotrophic lateral sclerosis (ALS) with a view to understanding how these could contribute to symptoms. MATERIAL AND METHODS Seventeen patients with definite ALS and 17 control healthy volunteers were included in the study. Clinical examination, amyotrophic lateral sclerosis severity score (ALSSS) and TMS investigations including measurement of resting and active motor threshold (RMT and AMT), motor evoked potential (MEP), input-output curve, contralateral silent period, and transcallosal inhibition (CSP and TI, postulated markers of GABAb function) were measured for each participant. RESULTS There were no significant differences in RMT or AMT in either hemisphere between patients and the control group. Despite this there was a significant negative correlation between ALSSS and RMT and AMT meaning that increased severity was associated with higher thresholds. MEPs were significantly smaller in ALS patients in comparison to the control group (P = 0.03). There was a significant decrease in the slope of the I/O relationship of MEP amplitude to TMS intensity in patients group in comparison to controls. ALS patients had a significant prolongation of CSP and TI for both hemispheres. There was a tendency for a significant negative correlation between left TI and ALSSS (P = 0.051). CONCLUSION Measurements of cortical motor excitatory changes in ALS confirm the presence of corticospinal hypoexcitability. Additionally we found increased excitability of presumed intracortical GABAb circuits that correlated with the severity of ALS. We postulate that the disease results in an imbalance between excitation and inhibition in the cortex that can contribute to clinical symptoms.