The goal of this clinical trial is to learn if a non-invasive brain stimulation method called continuous theta burst stimulation (cTBS) can improve attention in adults who have hemispatial neglect after stroke. Hemispatial neglect is a common consequence of stroke where a person fails to notice things on one side of their environment and body after brain damage despite having intact sensory organs. Current treatments include physiotherapy, occupational therapy, and visual scanning training.

The main questions it aims to answer are:

• Does cTBS applied to the cerebellum shift spatial attention toward the neglected side, as measured by eye movements during a visual exploration task?
• Does cTBS change brain activity patterns linked to attention networks, as measured by EEG?

Researchers will compare different conditions, cerebellar cTBS, cerebral cTBS and sham cTBS to see which approach best improves visuospatial attention. Sham cTBS looks and feels identical to real stimulation but does not deliver effective magnetic pulses.

Participants, who are already admitted to the neurology and neurorehabilitation ward, will attend four study visits over approximately two weeks, each lasting about one hour. They receive active or sham cTBS at three stimulation sessions, each separated by at least 48 hours. They also have their eye movements recorded using a camera-based eye-tracking system before and after each session and have their brain activity recorded using EEG, a method that measures electrical activity through small electrodes on the scalp. Participation is voluntary. Participants may withdraw at any time without any impact on their regular medical care. The study is conducted at the Neurocenter of Luzerner Kantonsspital, Switzerland, and is funded by the Swiss National Science Foundation (SNF).

Inclusion Criteria:

• First-ever, subacute right hemispheric stroke
• Left-sided visual neglect defined by MGP > 1.333°
• Age ≥18 years
• Normal or corrected-to-normal visual acuity
• MRI compatibility (MRI-based neuronavigation for cTBS)
• Capacity to consent and ability to follow study procedures

Exclusion Criteria:

• Cerebellar lesion
• History of epilepsy
• Metallic implants in the head region
• Scalp or skin conditions that interfere with EEG electrode placement (e.g. open wounds, infections, severe psoriasis)
• Co-morbidities including: neurological, degenerative or major psychiatric disorder (other than index stroke), alcohol or drug abuse, severe liver or kidney disease, and active malignant tumor disease
• Pregnancy
• Enrolment in an ongoing clinical trial