Concurrent tDCS for Chronic Pain in Adults With Cerebral Palsy

Feasibility of the protocol

Feasibility of study procedures will be determined based on ≥60% retention through the follow-up participant surveys, and (2) ≥60% adherence to scheduled intervention sessions.

Acceptability of the protocol.

Aim will be evaluated using the following methods: Acceptability will be measured using the Theoretical Framework of Acceptability (TFA) which is an 8-item measure used to assess intervention acceptability. Each item measures a different component of acceptability ranging from a 1-5 Likert scale.

Intervention tolerability

Tolerability will be assessed by monitoring side effects/adverse events, through structured assessments and clinical interactions. At all intervention session visits, the tDCS operator will conduct a general inquiry regarding how the participant is feeling, go through a structured assessment of potential side effects/symptoms, and visually inspect the skin at the site of stimulation for redness or irritation before and after each tDCS session. Adverse events will be coded on a standardized Adverse Events tracking form. The PI or delegated investigator will assess all adverse effects for their severity, their unexpectedness, their relation to study procedures, and whether they represent increased risk to other participants or the greater community.

Participant burden associated with the intervention

Participant burden will be quantified by asking participants to report their travel time, recording the duration of participant visits, and providing an open text box for participant feedback on study burden. These will be combined to determine the feasibility of concurrent tDCS and motor tasks for the treatment of chronic pain in adults with CP.

fMRI BOLD activation map volume in M1

Task functional magnetic resonance imaging (fMRI) activation intensity during the two motor tasks. Intensity is represented as the Blood oxygen level dependent (BOLD) map volume (integration of z-score within activated regions in M1. This will be assesed through M1 activation during the task fMRI will be assessed. If M1 can be activated according to the first-level neuroimaging analysis, it is considered as feasible to have tDCS concurrent with the corresponding motor taskfor adult CP with chronic pain. These measures will be combined to gain preliminary understanding whether the motor tasks, motor imagery and action observation, are suitable to be paired concurrently with tDCS over M1 for chronic pain treatment in adults with CP.

Brief Pain Inventory (BPI)

This survey utilizes Pain Interference Items that assess the degree to which pain interferes with activities of daily living (e.g., sleep, relationships, and mobility). Items are scored on a 10-point scale (0 = does not interfere, 10 = completely interferes).

Dallhousie Pain Interview

The Dalhousie Pain Interview (DPI) uses a 10-item survey to quantify pain intensity (scored 0-10), duration (minutes/seconds in pain), pain frequency (number of pain episodes), cause, description, and methods of treatment for pain reported in the last week. DPI also asks about chronic pain (pain that has lasted longer than 3 months).

Quality of Life Likert scale

Participants will be asked to rate their overall quality of life in the past week (5-point Likert scale ranging from Very Poor to Very Good).