Cerebellar Stimulation for Aphasia Rehabilitation

Overview

The optimal site of neuromodulation for post-stroke aphasia has yet to be established. This study will investigate whether multiple sessions of cerebellar transcranial direct current stimulation (tDCS) boosts language therapy in helping people recover from aphasia as well as predict who is likely to respond to cerebellar tDCS.

Detailed description

Aphasia is a devastating complication of stroke. Speech and language treatment (SLT) can be helpful in restoring language function, but not all individuals show improvement. Recent studies indicate that Transcranial Direct Current Stimulation (tDCS) is a promising adjuvant approach to enhance the effectiveness of SLT. tDCS is a noninvasive, non-painful, electrical stimulation of the brain. It is believed that tDCS boosts neural plasticity that underlies recovery with SLT. A majority of the tDCS studies of aphasia have stimulated the left hemisphere regions. However, left hemisphere lesions common in post-stroke aphasia affect the electrical field in unpredictable ways, potentially preventing stimulation from reaching perilesional tissue associated with optimal recovery. The investigators' prior work addressed this problem by stimulating a novel region, the right cerebellum. The right cerebellum is connected to the left hemisphere and involved in a variety of cognitive and language functions, including naming, which is often impaired in people with aphasia. The investigators' work has shown that cerebellar tDCS is safe, easily tolerated, and improved language skills in a number of stroke participants with aphasia. The proposed project will build on these findings by conducting a randomized, double-blind, sham-controlled, trial to determine the effectiveness of cathodal tDCS to the right cerebellum for the treatment of post-stroke aphasia. The investigators will test the hypothesis that 15 sessions of cerebellar tDCS combined with an evidenced-based anomia treatment (semantic feature analysis, SFA) is associated with greater gains in accuracy in naming pictures, compared to 15 sessions of sham combined with semantic feature analysis

Interventions

• Device Cathodal Cerebellar tDCS
  2 mA of cathodal tDCS is induced between two 5cm X 5cm saline soaked sponges where the cathode sponge is placed on the right cerebellum. Ramping up of the current to 2 mA occurs over 15-30 seconds to allow participants to habituate to the tingling sensation. The stimulation will be delivered at an intensity of 2 mA for a maximum of 25 minutes.
• Behavioral Semantic Feature Analysis (SFA)
  Semantic Feature Analysis (SFA) is a treatment technique designed to improve lexical retrieval by increasing the level of activation within a semantic network. The treatment will proceed according to a series of steps including naming aloud the target picture, generating semantic features, naming aloud the target picture again, and generating a sentence using the target word.
• Device Sham
  2 mA of cathodal tDCS is induced between two 5cm X 5cm saline soaked sponges where the cathode sponge is placed on the right cerebellum. Ramping up of the current to 2 mA occurs over 15-30 seconds to allow participants to habituate to the tingling sensation. Then, the current will be ramped back down to 0 mA in the sham condition. Termination of the stimulation after the ramping up process is generally undetectable, and the brief duration of stimulation yields no functional effects.

Primary outcome measures

• Change in accuracy of naming untrained pictures (Philadelphia Naming Test) [Time frame: Pre-treatment to one week after the end of SFA treatment]

Secondary outcome measures (8)

• Change in accuracy of naming untrained pictures (Philadelphia Naming Test) [Time frame: Pre-treatment and at 1, 3 and 6 months post treatment]
• Change in accuracy of naming trained pictures [Time frame: Pre-treatment to one week after the end of SFA treatment]
• Change in accuracy of naming trained pictures [Time frame: Pre-treatment and at 1, 3 and 6 months post treatment]
• Change in the total content units produced during picture description. [Time frame: Pre-treatment, 1 week, 1, 3, and 6 months post treatment]
• Change in the syllable per content units produced during picture description. [Time frame: Pre-treatment, 1 week, 1, 3, and 6 months post treatment]
• Change in functional communication skills [Time frame: Pre-treatment, 1 week, 1, 3, and 6 months post treatment]
• Change in Stroke and Aphasia Quality of Life (SAQOL) scale [Time frame: Pre-treatment, 1 week, 1, 3, and 6 months post treatment]
• Change in General Health Questionnaire-12 item (GHQ-12) [Time frame: Pre-treatment, 1 week, 1, 3, and 6 months post treatment]

Eligibility criteria

Inclusion criteria

• Chronic ischemic or hemorrhagic left hemisphere stroke
• Fluent speaker of English by self-report
• Age 18 or older
• 6 months post onset of stroke
• Diagnosis of aphasia and naming impairment using the Western Aphasia Battery-Revised

Exclusion criteria

• Lesion in the right cerebellum
• Previous neurological disorder (other than stroke) affecting the brain, or any other neurodegenerative disorder or psychiatric disorder
• Seizures during the previous 6 months
• Uncorrected visual loss or hearing loss by self-report
• Use of medications that lower the seizure threshold (e.g., methylphenidate)
• Use of N-methyl-D-aspartate (NMDA) antagonists (e.g., memantine)
• History of brain surgery or any metal in the head
• Severely impaired auditory comprehension (lower than 2 on the Comprehension subscore on the Western Aphasia Battery-Revised)
• Severely limited verbal output (lower than 2 on the Spontaneous Speech rating scale on the Western Aphasia Battery-Revised)
• Individuals with severe claustrophobia, cardiac pacemakers or ferromagnetic implants, and pregnant women will be excluded from the MRI portion of the study.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Quadruple blind

Primary purpose

Treatment

Study locations

United States · 1 center

• Johns Hopkins Hospital — Baltimore

Publications

• Sebastian R, Saxena S, Tsapkini K, Faria AV, Long C, Wright A, Davis C, Tippett DC, Mourdoukoutas AP, Bikson M, Celnik P, Hillis AE. Cerebellar tDCS: A Novel Approach to Augment Language Treatment Post-stroke. Front Hum Neurosci. 2017 Jan 12;10:695. doi: 10.3389/fnhum.2016.00695. eCollection 2016. PMID 28127284
• Sebastian R, Kim JH, Brenowitz R, Tippett DC, Desmond JE, Celnik PA, Hillis AE. Cerebellar neuromodulation improves naming in post-stroke aphasia. Brain Commun. 2020 Nov 9;2(2):fcaa179. doi: 10.1093/braincomms/fcaa179. eCollection 2020. PMID 33241212
• Lammers B, Sydnor MJ, Cust S, Kim JH, Yenokyan G, Hillis AE, Sebastian R. Protocol for Cerebellar Stimulation for Aphasia Rehabilitation (CeSAR): A randomized, double-blind, sham-controlled trial. PLoS One. 2024 Aug 26;19(8):e0298991. doi: 10.1371/journal.pone.0298991. eCollection 2024. PMID 39186573
• Lammers B, Sydnor MJ, Cust S, Kim JH, Yenokyan G, Hillis AE, Sebastian R. Protocol for Cerebellar Stimulation for Aphasia Rehabilitation (CeSAR): A randomized, double-blind, sham-controlled trial. medRxiv [Preprint]. 2024 Feb 6:2024.02.05.24302365. doi: 10.1101/2024.02.05.24302365. PMID 38370630

Identifiers

NCT: NCT05093673 · IRB00300301 · R56DC019639 · R01DC019639

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗