Cerebellar Transcranial Direct Current Stimulation for Dysphagia After Supratentorial Stroke

Efficacy and Mechanisms of Cerebellar Transcranial Direct Current Stimulation for Treating Dysphagia After Supratentorial Stroke

It is estimated that 400,000 to 800,000 people worldwide develop neurogenic dysphagia annually. Stroke represents the most common etiology, with approximately 65% of acute stroke patients experiencing pharyngeal swallowing difficulties. Clinical manifestations of dysphagia vary widely in severity and may include residue, reflux, delayed swallowing initiation, aspiration, and cricopharyngeal muscle dysfunction. Due to its detrimental effects on nutrition, respiration, and psychosocial well-being, dysphagia significantly impairs patients' quality of life. Furthermore, the inability to swallow safely and efficiently can lead to serious complications such as aspiration pneumonia, malnutrition, and depression. The traditional swallowing rehabilitation treatment has limited effect in clinical practice, which makes it necessary to search for new effective swallowing methods.

Conventional swallowing rehabilitation often yields limited clinical benefits, highlighting the urgent need for more effective therapeutic strategies. Transcranial direct current stimulation (tDCS) is a non-invasive and safe neuromodulation technique that has shown promise in the field of neurorehabilitation. Its mechanisms extend beyond immediate cortical modulation and cerebral blood flow changes to include the regulation of synaptic plasticity, neurotransmitters such as glutamate and GABA, and excitability in remote subcortical regions. In recent years, tDCS has been increasingly applied to various neurological disorders, including post-stroke motor impairment, dysphagia, aphasia, depression, addiction, and spinal cord injury-related movement disorders. Currently, tDCS is being explored to elucidate its regulatory effects on cerebellar swallowing control, positioning it as a potential innovative treatment for neurogenic dysphagia.

This multicentre randomized controlled trial will enroll 76 patients with dysphagia after stroke from Zhejiang Provincial People' s Hospital. All patients will be centrally randomized to either tDCS combined with traditional swallowing rehabilitation or traditional rehabilitation alone. The tDCS group will be further divided into three subgroups based on stimulation parameters. Observation indicators will be Standardized Swallowing Assessment (SSA), videofluroscopic swallowing study (VFSS) and neuroimaging examinations including fMRI, MRS And quantitative electroencephalography (QEEG).

Inclusion Criteria:

1. Patients with supratentorial stroke, confirmed by cranial MRI or CT as having cerebral infarction or hemorrhage;
2. Stable vital signs after conventional treatment, with disease duration between 1 and 6 months;
3. 30 ≤ age ≤75 years, male or female;
4. Presence of dysphagia, drinking-induced coughing, and a Kubota Water Drinking Test grade of 3-5;
5. Signed informed consent form.

Exclusion Criteria:

1. MRI-confirmed lesion involving the cerebellum;
2. Unstable vital signs;
3. Significant cognitive impairment (MMSE score ≤ 24);
4. Presence of swallowing apraxia;
5. Unwilling or unable to cooperate with treatment, or taking any medication that may affect swallowing function or nervous system activity.