Ignite Creation Date:
2024-05-06 @ 1:26 PM
Last Modification Date:
2024-10-26 @ 1:14 PM
Study NCT ID:
NCT04021160
Status:
COMPLETED
Last Update Posted:
2021-07-21
First Post:
2019-04-06
Brief Title:
Repetitive Transcranial Magnetic Stimulation for Post-Stroke Visual Field Defects
Sponsor:
Ain Shams University
Organization:
Ain Shams University
Study Overview
Official Title:
The Efficacy of Navigated Perilesional Repetitive Transcranial Magnetic Stimulation on Post-Stroke Visual Field Defects
Status:
COMPLETED
Status Verified Date:
2021-07
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Visual field defects VFD usually do not show improvement beyond 12 weeks from onset Plasticity occurs in areas of residual vision ARV at the visual field which are the functional counterpart of partially damaged brain regions at the areas around brain lesion Few treatment options are currently available for post-stroke VFD In this pilot study the effect of repetitive transcranial magnetic stimulation rTMS applied to these areas on VFD in patients with cortical infarction will be studied Patients will be divided into two groups an active group which will receive active stimulation and a sham group which will receive placebo stimulation through a sham coil
Detailed Description:
Visual functions are widely distributed over large areas within the cerebrum Secondary to such wide distribution visual field defects VFD are a common outcome of brain insults especially cerebrovascular stroke whether hemorrhagic or ischemic Among these homonymous hemianopia is the most frequently encountered VFD in clinical practice VFD ranges from 83 to 16 in the chronic stage of stroke while it reaches 25 in acute and subacute stages of stroke In other studies it was reported to be even higher In a database of 11900 stoke patients VFD was found in 605 with homonymous hemianopia accounting for 35
These VFDs usually show some degree of improvement within few months from onset secondary to resolution of edema and diaschisis yet by 3 to 6 months the condition tends to become stationary with no further improvement and only 5 of patients will show full recovery of their visual field In some studies recovery was mostly along the first 10 days of insult followed by decrease in recovery rate that nearly stops 10-12 weeks after insult Beyond this time point very few cases develop spontaneous recovery
Plasticity occurs in areas of residual vision ARV at the visual field borders rather than areas of absolute blindness These ARVs are the functional counterpart of partially damaged brain regions at the perilesional areas Recovery of function - both early in life and in adults - is stimulation dependent This stimulation can be either through visual experience behavioral training or brain stimulation To the investigators knowledge direct current stimulation DCS is the only brain stimulation modality that has been studied in cases of VFDs Results showed that DCS can expand visual field in stroke patients with the effects being stable over time
In the current study it is hypothesized that stimulation of the perilesional seemingly healthy brain tissue close to the visual cortex would result in clinical improvement based on the concept of ARVs To achieve this precise targeting navigated rTMS would be the most suitable technique
The investigators aim to study the effect of navigated repetitive transcranial magnetic stimulation rTMS applied to perilesional areas on patients with cortical visual field defects cVFD due to stroke
This is a randomized sham-controlled clinical trial that will be conducted in the neuromodulation research lab neurology department Ain Shams University The study is approved by Ain Shams University faculty of medicine local research ethics committee REC
Procedures
3D MRI An MRI Brain T1WI with 200 cuts of 09 mm sections will be obtained Segmentation of the head model will be done to separate scalp skull and brain layers A three-dimensional virtual head model will then be created for each patient
Target Selection The target for stimulation will be determined and marked for each patient using a neuronavigation system on his virtual head model Targets will be selected along the perilesional area in the nearest seemingly healthy tissue to the visual cortex based on the following steps
1 ARV grey zone will be identified in the perimetry of the patient
2 Corresponding area in the 3D head model will then be determined based on visuotopy of the primary visual cortex
These VFDs usually show some degree of improvement within few months from onset secondary to resolution of edema and diaschisis yet by 3 to 6 months the condition tends to become stationary with no further improvement and only 5 of patients will show full recovery of their visual field In some studies recovery was mostly along the first 10 days of insult followed by decrease in recovery rate that nearly stops 10-12 weeks after insult Beyond this time point very few cases develop spontaneous recovery
Plasticity occurs in areas of residual vision ARV at the visual field borders rather than areas of absolute blindness These ARVs are the functional counterpart of partially damaged brain regions at the perilesional areas Recovery of function - both early in life and in adults - is stimulation dependent This stimulation can be either through visual experience behavioral training or brain stimulation To the investigators knowledge direct current stimulation DCS is the only brain stimulation modality that has been studied in cases of VFDs Results showed that DCS can expand visual field in stroke patients with the effects being stable over time
In the current study it is hypothesized that stimulation of the perilesional seemingly healthy brain tissue close to the visual cortex would result in clinical improvement based on the concept of ARVs To achieve this precise targeting navigated rTMS would be the most suitable technique
The investigators aim to study the effect of navigated repetitive transcranial magnetic stimulation rTMS applied to perilesional areas on patients with cortical visual field defects cVFD due to stroke
This is a randomized sham-controlled clinical trial that will be conducted in the neuromodulation research lab neurology department Ain Shams University The study is approved by Ain Shams University faculty of medicine local research ethics committee REC
Procedures
3D MRI An MRI Brain T1WI with 200 cuts of 09 mm sections will be obtained Segmentation of the head model will be done to separate scalp skull and brain layers A three-dimensional virtual head model will then be created for each patient
Target Selection The target for stimulation will be determined and marked for each patient using a neuronavigation system on his virtual head model Targets will be selected along the perilesional area in the nearest seemingly healthy tissue to the visual cortex based on the following steps
1 ARV grey zone will be identified in the perimetry of the patient
2 Corresponding area in the 3D head model will then be determined based on visuotopy of the primary visual cortex
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None