Overview
This study will assess the effects of transcranial alternating current stimulation (tACS) on language recovery after stroke.
Description
Aphasia is a debilitating disorder, typically resulting from damage to the left hemisphere, that can impair a range of communication abilities, including language production and comprehension, reading, and writing. Approximately 180,000 new cases of aphasia are identified per year, and approximately 1 million or 1 in 250 are living with aphasia in the United States. Treatments are limited and provide modest benefits at best. The current emphasis in aphasia rehabilitation is to formulate intensive speech and language therapies and augment therapeutic benefits, potentially with brain stimulation concurrent with therapies.
The current study will investigate the efficacy of high-definition tACS (HD-tACS) to help restore neural oscillatory activity in stroke survivors with aphasia. TACS differs from trancranial direct current stimulation (tDCS), a widely used brain stimulation paradigm, in that sinusoidal or alternating currents are delivered rather than direct currents. TACS is shown to manipulate ongoing oscillatory brain activity and also to modulate synchronization (or connectivity) between targeted brain areas. This feature of tACS is quite attractive, given the new body of evidence suggesting that language impairments stem from diminished brain connectivity and ensuing disruptions in the language network due to stroke.
The study will employ high-definition tACS (HD-tACS) in a parallel, double-blinded, sham-controlled design combined with language therapy targeting phonological short-term memory (STM) function in stroke survivors with aphasia. Magnetoencephalography (MEG) and fMRI BOLD data collection will occur to determine tACS parameters and to evaluate stimulation-induced neural changes, respectively. The investigators plan to recruit 120 stroke survivors with aphasia in a 2-group tACS study design.
Eligibility
Inclusion Criteria:
- Men aged 18 to 45 years
- Andrological profile including altered semen parameters such as oligozoospermia, asthenozoospermia and/or teratozoospermia (O±A±T)
- No clinical indication for sperm DNA fragmentation testing or advanced sperm selection techniques
- Willingness and ability to comply with the study protocol, including adherence to a standardized Mediterranean diet
- Signed and dated written informed consent form
Exclusion Criteria:
- Use of antioxidant supplements during the three months prior to study start.
- Active smokers or men who have stopped smoking within the last three months.
- Diagnosis of azoospermia, leucocytospermia or necrozoospermia.
- Presence of severe systemic diseases or chronic conditions that could interfere with semen quality or adherence to the study.
- Known allergy or intolerance to any ingredient of the gazpacho used in the study.
- Any medical, psychological or social condition that, in the investigator's judgement, could compromise the subject's ability to participate fully or comply with the protocol requirements.
- Simultaneous participation in another clinical study.
