Neural Correlates (EEG and fMRI) of Gait in Small Vessel Disease

Cerebral small vessel disease (SVD) is a common cause of walking and balance problems in older adults. These problems are often not explained by muscle weakness alone. They are believed to result from changes in how different parts of the brain communicate and coordinate movement.

This study will explore how brain network function is affected in people with SVD who experience gait difficulties. To do this, two safe and non-invasive techniques will be used:

Functional MRI (fMRI): to identify which brain areas become active when participants watch videos that simulate walking and turning.

Electroencephalography (EEG): to measure brain waves and the timing of brain activity while watching the same gait-related videos.

Participants will include 20 patients diagnosed with cerebral small vessel disease and gait problems, and 20 healthy adults of similar age without such problems.

All participants will undergo:

• Clinical evaluation including walking, balance, and cognitive tests (Timed Up and Go, Berg Balance Scale, and Montreal Cognitive Assessment).
• Brain MRI to confirm the diagnosis and exclude other causes.
• Resting and task-based EEG recordings to assess brain connectivity.
• Functional MRI for a subset of participants to study brain activity patterns related to gait imagery.

Researchers will compare the brain activation and connectivity between patients and healthy participants. They will also look for relationships between imaging findings and clinical test results.

By combining fMRI and EEG findings, this research aims to identify brain networks that are disrupted in people with SVD-related gait problems. Understanding these patterns may lead to better tools for early detection and more targeted rehabilitation approaches to improve walking and prevent falls.

All study procedures will be conducted at the Neurology Department, Ain Shams University Hospitals, Cairo, Egypt.

Inclusion criteria

• Age 50 years or older.
• Clinical and radiological diagnosis of cerebral small vessel disease (SVD), confirmed by MRI findings such as white matter hyperintensities, lacunes, or microbleeds.
• Fazekas score 2 or 3 on MRI.
• Presence of slowly progressive gait disturbance (e.g., slowness, imbalance, freezing) rather than acute stroke presentation.

• Ability to give informed consent and cooperate with testing procedures.

Exclusion criteria

• Presence of other neurodegenerative disorders (e.g., Parkinson's disease, Alzheimer's disease).
• History of large vessel stroke or intracerebral hemorrhage.
• Contraindications to MRI (e.g., pacemaker, metallic implants, severe claustrophobia).
• Severe cognitive impairment that prevents participation (MoCA <10).
• Musculoskeletal or orthopedic causes of gait disturbance not related to neurological dysfunction.