Cerebellar Brain Stimulation Plus Language Therapy for People at Risk of Poor Aphasia Recovery After Stroke (PART-CN)

Predicting Aphasia Recovery and Testing Cerebellar Neuromodulation (PART-CN): A Pilot Wait-List Randomized Trial of Cathodal Cerebellar Transcranial Direct Current Stimulation Plus Computerized Language Therapy in Stroke Survivors Predicted to Have Poor Language Recovery

This pilot study tests whether a mild form of brain stimulation to the cerebellum, combined with computer-based language therapy, helps people recover language after a stroke when a poor natural recovery is predicted.

People already taking part in a Johns Hopkins study of stroke and language recovery, whose early data suggest the aphasia is unlikely to resolve without treatment, are invited about 3 months after the stroke. Half begin 15 treatment sessions right away and half begin about 3 months later. Each session pairs 25 minutes of transcranial direct current stimulation (tDCS) over the right cerebellum with 45 to 60 minutes of language exercises, with a speech-language pathologist present.

The main question is whether language ability, measured with the Western Aphasia Battery-Revised Aphasia Quotient, improves more by 6 months after stroke in the group treated first than in the group still waiting. The study also checks how accurately a machine learning model, built from data collected in the first days after stroke, predicted each person's language ability 12 months after stroke.

Study Overview

• Status: Not yet recruiting
• Conditions: Stroke; Aphasia; Anomia
• Intervention / Treatment: Device: Cathodal cerebellar transcranial direct current stimulation; Behavioral: Computerized language therapy

Detailed Description

About one third of people with aphasia after stroke respond poorly to language therapy, and current clinical tools cannot identify these individuals early, when recovery is steepest. This study pairs a recovery prediction model with a targeted treatment.

Aim 1: A machine learning model trained on acute-phase data from the parent longitudinal study (Johns Hopkins IRB NA_00042097; neuroimaging, cognitive-linguistic testing, demographics) predicts each participant's 12-month Western Aphasia Battery-Revised Aphasia Quotient (WAB-R AQ). Participants predicted to remain below 93.8 (aphasia not expected to resolve) are eligible. Prediction accuracy is evaluated prospectively against observed 12-month scores (mean absolute error, correlation, and sensitivity, specificity, positive predictive value and F1 for the below-93.8 classification).

Aim 2: Eligible participants are randomized 1:1 to early intervention (treatment beginning about 3 months post-stroke) or wait-list control (usual care until about 6 months post-stroke, then the same treatment). Treatment is 15 sessions, up to 5 per week over about 3 to 5 weeks. In each session, cathodal tDCS (2 mA, 25 minutes; cathode over the right cerebellum, 1 cm below the inion and 4 cm lateral; anode over the right deltoid; Soterix Medical 1×1 device) is delivered during the first 25 minutes of 45 to 60 minutes of computer-delivered language therapy targeting picture naming, auditory comprehension, reading and spelling, with a speech-language pathologist present throughout. Sessions may take place at a Johns Hopkins site or at home with a study team member present.

The primary comparison is change in WAB-R AQ from baseline (about 3 months post-stroke) to 6 months post-stroke between the treated early group and the untreated wait-list group. Secondary measures include naming of trained items, discourse (content units and syllables per content unit in picture description), functional communication (Communication Activities of Daily Living, Third Edition), emotional well-being (General Health Questionnaire), quality of life (Stroke and Aphasia Quality of Life Scale), and resting-state functional connectivity measured with functional near-infrared spectroscopy (fNIRS). Participants are followed to 12 months post-stroke.

As a pilot, the study is designed to show feasibility of the predict-then-intervene approach and to estimate effect sizes for a future fully powered, sham-controlled trial.

• Study Type: Interventional
• Enrollment (Estimated): 8
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Manuel J Marte, PhD, CCC-SLP; Phone Number: 845-598-6911; Email: mmarte1@jh.edu
• Study Contact Backup: Name: Melissa D Stockbridge, PhD, CCC-SLP; Phone Number: 301-906-2401; Email: md.stockbridge@jhmi.edu

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21287
      • The Johns Hopkins Hospital, Phipps Building
      • Contact: Manuel J Marte, PhD, CCC-SLP; Phone Number: 845-598-6911; Email: mmarte1@jh.edu

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Enrolled in the Johns Hopkins longitudinal stroke and aphasia study (IRB NA_00042097)
• Consented to future contact for research studies
• Predicted to have poor language recovery from acute-phase data, defined as a predicted Western Aphasia Battery-Revised Aphasia Quotient below 93.8 at 12 months post-stroke
• Ischemic left hemisphere stroke
• Aphasia with naming impairment on the Western Aphasia Battery-Revised
• Approaching 3 months post-stroke at enrollment
• Fluent speaker of English by self-report
• Age 18 or older

Exclusion Criteria:

• Lesion in the right cerebellum
• Previous neurological disorder other than stroke affecting the brain, or any neurodegenerative or psychiatric disorder
• Seizures during the previous 6 months
• Uncorrected visual or hearing loss by self-report
• Use of medications that lower the seizure threshold (e.g., methylphenidate)
• Use of N-methyl-D-aspartate (NMDA) receptor antagonists (e.g., memantine)
• History of brain surgery or any metal in the head
• Severely impaired auditory comprehension (below 2 on the Western Aphasia Battery-Revised Auditory Verbal Comprehension sub-score)
• Severely limited verbal output (below 2 on the Western Aphasia Battery-Revised Spontaneous Speech rating)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Early intervention; 15 sessions of cathodal right cerebellar transcranial direct current stimulation (tDCS; 2 mA, 25 minutes) during computerized language therapy (45 to 60 minutes per session, with a speech-language pathologist present), up to 5 sessions per week over about 3 to 5 weeks, beginning about 3 months post-stroke.	Device: Cathodal cerebellar transcranial direct current stimulation; Cathode (saline-soaked sponge electrode) over the right cerebellum, 1 cm below the inion and 4 cm lateral; anode over the right deltoid. Constant current of 2 mA for 25 minutes, ramped up over the first 15 seconds, from a battery-powered Soterix Medical 1x1 stimulator with pre-programmed parameters. Delivered during the first 25 minutes of each language therapy session.; Other Names: tDCS; Soterix Medical 1x1 tDCS; Behavioral: Computerized language therapy; Computer-delivered language exercises on a tablet, targeting spoken and written picture naming, auditory comprehension, reading and spelling, 45 to 60 minutes per session, with difficulty adjusted to performance and a speech-language pathologist present. Each participant uses the same delivery platform for all sessions.; Other Names: Computer-delivered naming treatment
Other: Wait-list control (delayed intervention); Usual care, which may include outpatient speech-language therapy, from about 3 to 6 months post-stroke; then the same 15-session protocol of cathodal right cerebellar tDCS plus computerized language therapy, beginning about 6 months post-stroke.	Device: Cathodal cerebellar transcranial direct current stimulation; Cathode (saline-soaked sponge electrode) over the right cerebellum, 1 cm below the inion and 4 cm lateral; anode over the right deltoid. Constant current of 2 mA for 25 minutes, ramped up over the first 15 seconds, from a battery-powered Soterix Medical 1x1 stimulator with pre-programmed parameters. Delivered during the first 25 minutes of each language therapy session.; Other Names: tDCS; Soterix Medical 1x1 tDCS; Behavioral: Computerized language therapy; Computer-delivered language exercises on a tablet, targeting spoken and written picture naming, auditory comprehension, reading and spelling, 45 to 60 minutes per session, with difficulty adjusted to performance and a speech-language pathologist present. Each participant uses the same delivery platform for all sessions.; Other Names: Computer-delivered naming treatment

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Western Aphasia Battery-Revised Aphasia Quotient (WAB-R AQ)	The WAB-R AQ is a composite measure of overall language impairment, with scores ranging from 0 to 100; higher scores indicate milder aphasia (better outcome). Change from baseline to 6 months post-stroke is compared between the early intervention group (after treatment) and the wait-list group (before treatment).	Baseline (approximately 3 months post-stroke) and 6 months post-stroke
Mean Absolute Error Between Predicted and Observed 12-Month Western Aphasia Battery-Revised Aphasia Quotient	Mean absolute difference, in WAB-R AQ points (scale 0 to 100), between the machine learning model's predicted 12-month Western Aphasia Battery-Revised Aphasia Quotient (generated from acute-phase data) and the observed 12-month score. Lower values indicate more accurate prediction.	12 months post-stroke

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Treatment Items Produced Correctly	Percentage of items trained during treatment that are produced correctly, scored 0 to 100%; higher values indicate better performance.	During treatment, up to one week post final treatment session (about 4 to 6 weeks after treatment starts)
Change in Number of Content Units in Picture Description	Total number of content units (accurate, relevant pieces of information) produced when describing the Modern Cookie Theft picture and the Precarious Painter picture. Higher values indicate more informative discourse.	Baseline (approximately 3 months post-stroke) and 6 months post-stroke
Change in Syllables per Content Unit in Picture Description	Number of syllables produced per content unit in the same picture descriptions	Baseline (approximately 3 months post-stroke) and 6 months post-stroke
Change in Communication Activities of Daily Living, Third Edition (CADL-3) Total Score	The Communication Activities of Daily Living, Third Edition measures everyday functional communication in people with aphasia. Total raw score ranges from 0 to 100; higher scores indicate better functional communication.	Baseline (approximately 3 months post-stroke) and 6 months post-stroke
Change in General Health Questionnaire (GHQ) Total Score	The General Health Questionnaire (Goldberg and Hillier) measures psychological distress and emotional well-being. Items are rated using 0 to 3 Likert scale, giving a total score from 0 to 84; higher scores indicate greater psychological distress (worse outcome).	Baseline (approximately 3 months post-stroke) and 6 months post-stroke
Change in Stroke and Aphasia Quality of Life Scale (SAQOL-39) Mean Score	The Stroke and Aphasia Quality of Life Scale-39 measures health-related quality of life after stroke and aphasia. Mean score ranges from 1 to 5; higher scores indicate better quality of life.	Baseline (approximately 3 months post-stroke) and 6 months post-stroke
Change in Resting-State Functional Connectivity Between Cortical Language Regions and the Right Cerebellum	Resting-state functional connectivity (correlation coefficient of oxygenated hemoglobin signals) between cortical language regions and the right cerebellum, measured with functional near-infrared spectroscopy (fNIRS). Higher values indicate stronger connectivity.	Baseline (approximately 3 months post-stroke), 6 months, and 9 months post-stroke

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Western Aphasia Battery-Revised Aphasia Quotient (WAB-R AQ) at 9 Months Post-Stroke	The WAB-R AQ is a composite measure of overall language impairment (range 0 to 100; higher scores indicate milder aphasia). Compared between groups to explore the effect of treatment timing (treatment starting about 3 versus 6 months post-stroke).	9 months post-stroke
Western Aphasia Battery-Revised Aphasia Quotient (WAB-R AQ) at 12 Months Post-Stroke	The WAB-R AQ is a composite measure of overall language impairment (range 0 to 100; higher scores indicate milder aphasia). Used to assess durability of treatment effects in all participants.	12 months post-stroke

Collaborators and Investigators

• Sponsor: Johns Hopkins University
• Collaborators: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
• Investigators: Principal Investigator: Melissa D Stockbridge, PhD, CCC-SLP, Johns Hopkins University

Study record dates

Study Major Dates

• Study Start (Estimated): November 1, 2026
• Primary Completion (Estimated): June 1, 2028
• Study Completion (Estimated): June 1, 2028

Study Registration Dates

• First Submitted: October 27, 2026
• First Submitted That Met QC Criteria: October 27, 2026
• First Posted (Actual): November 3, 2026

Study Record Updates

• Last Update Posted (Actual): November 3, 2026
• Last Update Submitted That Met QC Criteria: October 27, 2026
• Last Verified: October 1, 2026

More Information

Terms related to this study

• Keywords: tDCS; transcranial direct current stimulation; cerebellar stimulation; aphasia rehabilitation; precision rehabilitation
• Additional Relevant MeSH Terms: Neurologic Manifestations; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Neurobehavioral Manifestations; Communication Disorders; Language Disorders; Speech Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Stroke; Aphasia; Anomia; Therapeutics; Behavioral Disciplines and Activities; Electric Stimulation Therapy; Convulsive Therapy; Psychiatric Somatic Therapies; Electroshock; Psychological Techniques; Transcranial Direct Current Stimulation
• Other Study ID Numbers: IRB00562650; 2T32HD007414-31 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

IPD Plan Description

Individual participant data will not be shared outside Johns Hopkins. Data collected in this study are coded protected health information under the approved protocol and consent. Aggregate results will be published.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No