tDCS Associated to Blindsight Rehabilitation for the Treatment of Homonymous Hemianopsia (TABRTHH)

Homonymous hemianopia is one of the most common symptoms following a neurologic damage and has many negative effects on functional abilities and daily activities.

There are two main kind of restorative rehabilitation of hemianopia: "border training", which involves exercising vision at the edge of the damaged visual field, and "blindsight training", which is based on exercising the unconscious perceptual functions in the mild of the blind hemifield.

In literature only border training effects were shown to be facilitated by transcranial direct current stimulation (tDCS).

The investigators treat two patients with blindsight rehabilitation associated to tDCS over parieto-occipital cortex. The two patients undergo a cycle of blindsight treatment associated to tDCS and a cycle of blindsight training alone in inverted order.

Aim of the study is to investigate if the anodic stimulation of perilesional areas enhance the improvement induced by blindsight rehabilitation treatment.

Study Overview

• Status: Withdrawn
• Conditions: Hemianopsia
• Intervention / Treatment: Other: Blindsight Training associated to tDCS; Other: Blindsight Training alone

Detailed Description

The study design is a crossover AB BA. Treatment A consist in a cycle of blindsight training associated to tDCS, Treatment B consist in a a cycle of blindsight training alone.

During the blindsight training, the patient is asked to maintain central fixation and is exposed to visual stimuli in his blind hemifield. The patient task is detection and/or discrimination of stimuli.

During each session the patient is subjected to around 700 different stimuli variously associated in space and/or time.

One out of two blindsight training cycles is associated to tDCS treatment. Anodal tDCS is applied using a battery-driven constant current stimulator, and a pair of surface saline-soaked sponge electrodes (5 x 5 cm). Current intensity is of 2 mA (Fade-in/-out= 10 sec), for a total duration of 30 min. The stimulation start at the beginning of the rehabilitation session, and continue for 30 min, during treatment.

Anode is placed over the parieto-occipital cortex. The cathode is placed in the contralateral supraorbital position.

To assess the actual improvement patients performed:

1. Clinical-instrumental assessment: Threshold visual field Humphrey SITA-standard 30-2 program is used to measure the visual perception within the central 30 degrees.
2. Peripheral visual field test Schofield Vienna PP-R test is used to measure the visual perception up to 180 degrees. A double task in central vision was performed in order to verify test reliability.
3. Functional visual field assessment: Test for Attention Performance (TAP - v. 2.3) visual field 92 stimuli subtest (26) is performed.
4. Ecological assessment: during initial and final interview an ICF profile of the subject is edited. The profile includes mainly the Activity and Participation categories of ICF.

All these investigations is performed before the treatment and after each cycle

• Study Type: Interventional
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Italy
  • CB
    • Carate Brianza, CB, Italy, 20841
      • Polo universitario presso I.C. Zucchi

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• The subject is able to give his informed consent
• Stroke
• Hemianopsia brain damage documented by means of TAC or RMN
• Hemianopsia diagnosed by means automated visual field and Neurological Evaluation
• Time from lesion at least six months
• normal or corrected-to-normal visual acuity

Exclusion Criteria:

• Presence of Ophthalmologic neuropsychologic or psychiatric pathology
• Global cognitive deficit,
• Presence of other neurological pathology
• Presence of cardiac peacemaker
• Presence metallic or electronic items in the head or in the body
• Story/familiarity of epilepsy, taking medications that can induce epileptic crisis
• Severe heart disease
• History of high alcohol consumption
• Pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Blindsight training associated to tDCS; During the blindsight training (one-hour time), the patient is asked to maintain central fixation and is exposed to visual stimuli in his blind hemifield. The patient task is detection and/or discrimination of stimuli. During each session the patient is subjected to around 700 different stimuli variously associated in space and/or time. tDCS stimulation start at the beginning of the rehabilitation session, and continue for 30 min, during treatment. Anode is placed over the parieto-occipital cortex. The cathode is placed in the contralateral supraorbital position.	Other: Blindsight Training associated to tDCS; The patient undergo visual rehabilitation while his brain is electrically stimulated with tDCS.
Active Comparator: Blindsight training alone; During the blindsight training (one-hour time), the patient is asked to maintain central fixation and is exposed to visual stimuli in his blind hemifield. The patient task is detection and/or discrimination of stimuli. During each session the patient is subjected to around 700 different stimuli variously associated in space and/or time.	Other: Blindsight Training alone; The patient undergo visual rehabilitation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in Humphrey visual field 30.2 SITA standard test	10 weeks and 20 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
Change in Battery for Attentional Performance (TAP) subtest: Visual Field	10 weeks and 20 weeks
International Classification of Functioning (ICF)	20 weeks
Change in Schuhfried Vienna Test Peripheral Perception (PP-R)	10 weeks and 20 weeks

Collaborators and Investigators

• Sponsor: University of Milano Bicocca
• Investigators: Principal Investigator: Barbara M Matteo, Università degli studi di Milano - Bicocca

Study record dates

Study Major Dates

• Study Start: September 1, 2016
• Primary Completion (Anticipated): December 1, 2017
• Study Completion (Anticipated): December 1, 2017

Study Registration Dates

• First Submitted: October 27, 2016
• First Submitted That Met QC Criteria: November 3, 2016
• First Posted (Estimate): November 6, 2016

Study Record Updates

• Last Update Posted (Estimate): January 23, 2017
• Last Update Submitted That Met QC Criteria: January 20, 2017
• Last Verified: January 1, 2017

More Information

Terms related to this study

• Keywords: tDCS; Stroke; Visual field
• Additional Relevant MeSH Terms: Nervous System Diseases; Eye Diseases; Neurologic Manifestations; Sensation Disorders; Vision Disorders; Blindness; Hemianopsia
• Other Study ID Numbers: 264-BSTDCS

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided