Therapeutic Effect of Direct Current Stimulation on Cognitive Function of Mild to Moderate Alzheimer Patients

Study Overview
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Brief Summary
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The current study is planed to compare the efficacy of real (anodal and cathodal) vs sham transcranial direct current stimulation (tDCS) applied over the left dorsolateral prefrontal cortex (DLPFC) on cognitive functions and cortical excitability of patients with Alzheimer disease (AD). Thirty three with mild to moderate Alzheimer's disease (AD) patients (diagnosis of probable AD according to the criteria of the National Institute of Neurological and Communicative Disorders and Stroke Alzheimer Disease and Related Disorders Association [NINCDS-ADRDA] were included in this study) were randomly classified into one of three groups (eleven for each group). The first group received anodal tDCS over left DLPFC and 2rd group received cathodal tDCS on the left DLPFC and the 3rd group received sham tDCS stimulation, daily for 10 consecutive days (5 days/week for 2 weeks). Minimental State Examination (MMSE), psychometric assessment for cognitive functions (MMSE, Wechsler memory scale, Wechsler adult Intelligent scale) were assessed before, after 10th sessions, and then after 1 and 2 month. Cortical excitability was assessed in both hemispheres before and after the end of sessions. Neurophysiological evaluations included resting and active motor threshold (rMT and aMT), and cortical silent period (CSP). At the time of recruitment, none of the patients taking antidepressants, or neuroleptic, sedative-hypnotic drugs for at least two weeks before the assessment. All participants or their caregivers will give informed consent before participation in the test and after full explanation of the study protocol. Outcome: The real group received (anodal and cathodal) tDCS are expected to have more improvement on cognitive functions compared to sham tDCS group. tDCS is considered new adjuvant non pharmacological therapeutic tool for management of AD patients with mild to moderate degree dementia.

Conditions
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Alzheimer Disease

Intervention / Treatment
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* Procedure: Direct current stimulation using Anodal electrode
* Procedure: direct current stimulation using cathodal electrode
* Procedure: Sham direct current stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Thirty patients with a diagnosis of probable AD according to the criteria of the National Institute of Neurological and Communicative Disorders Association (NINCDS-ADRDA) (McKhann G et al.,1994) will be included in this study. Exclusion Criteria: previous history of stroke Metabolic disturbances Other major medical illness or epilepsy Patients metallic objects in the body Patients subjected to a craniotomy in the past.

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 79 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Group 1<br>11 patients We Applied real anodal tDCS on the left dorsolateral prefrontal cortex (DLPFC)20 minutes every day for 10 consecutive days. | Procedure: Direct current stimulation using Anodal electrode<br>* 11 patients who received real anodal tDCS on the left DLPFC, 2 mA for 20 minute every day for 10 consecutive days<br>|
| Active Comparator: Group 2<br>11 patients we applied cathodal tDCS on left DLPFC for 20 minutes every day for 10 consecutive days. | Procedure: direct current stimulation using cathodal electrode<br>* 11 patients who received real cathodal tDCS on the left DLPFC, 2 mA for 20 minute every day for 10 consecutive days<br>|
| Sham Comparator: Group 3<br>11 patients We applied sham stimulations(anodal tDCS) on the left DLPFC for few seconds the stop stimulations 2 mA every day for 10 days. | Procedure: Sham direct current stimulation<br>* 11 patients who received sham anodal tDCS on the left DLPFC just for few seconds, 2 ma, every day for 10 consecutive days<br>* Other names: Germany).;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Minimental state Examination | To measure the cognitive function in alzheimer patients through measuring orientation, Registration, Attention and calculation, Recall,language, and copying with a total score 30. | base line and after 2 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| changes in cortical excitability |  | Base line and after 10 days | 
| Wechsler memory scale |  | Basal and 2 months | 
| Intelligent questant ( IQ) |  | basal and 2 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Alzheimer disease, Direct current stimulation, cognitive function, memory