The Effects of Cerebellar rTMS on Brain Activity

Swallowing function is controlled by two swallowing centres (one on each half of the brain). There is a dominant and non-dominant swallowing centre. Damage to any part of the brain can lead to swallowing problems, for example in strokes. Recovery of the ability to swallow is associated with increased activity (compensation) over the undamaged centre. The cerebellum is an area of the brain involved in the control and modulation of muscle movements. It is found at the back of the skull. Anatomical evidence exists, showing cerebellar outputs projecting to several cortical areas, including the primary motor cortex (M1). Moreover, brain imaging studies have shown activation of the cerebellum during swallowing using positron emission tomography (PET) and magnetic resonance imaging (MRI). Over the past few years studies have tried to improve swallowing function using techniques to stimulate regions of the brain and encourage compensation. Repetitive transcranial magnetic stimulation (rTMS) is a technique which can temporarily increase or suppress activity over regions of the brain. No imaging studies have been conducted which have looked at how the brain is affected by cerebellar rTMS. The investigators hypothesise that cerebellar rTMS will cause increased activity in swallowing associated areas in the brain, including the cortex and brainstem