Tourette syndrome (TS) is a common neurological disorder of childhood onset that is characterised by the occurrence of vocal and motor tics, and has been associated with alterations in the balance of excitatory and inhibitory signalling within cortical-striatal-thalamic-cortical brain circuits that are implicated in movement selection and habit learning. Specifically, TS has been linked with the impaired operation of GABA (inhibitory) signalling within the striatum and cortical motor areas, and with hyper-excitability of limbic and motor regions of the brain that may contribute to the occurrence of tics.
There is also mounting evidence that TS may be associated with the altered processing of somatosensory information, including altered interoception. First, the majority (~90%) of individuals with TS report that their tics are often preceded by ‘premonitory sensory phenomena’ that are described as uncomfortable bodily sensations that occur prior to the execution of a tic and are experienced as a strong urge for motor discharge (hereafter referred to as premonitory urges [PU]). Second, it has been suggested that PU may arise in part from heightened sensitivity to somatic stimulation. Consistent with this proposal, individuals with TS also often report heightened sensitivity to external sensory stimuli, such as irritation due to clothing fabrics, that causes great distress.
Physiological inhibition associated with GABAergic signalling may play a key role in determining the precise neurophysiological response to somatic stimulation and can be studied using converging brain imaging/spectroscopy, brain stimulation, and psychophysical methods. This project will aim to investigate alterations in physiological inhibition in individuals with TS using one or more of the following techniques: ultra-high-field (7 Tesla) functional MRI [fMRI]; GABA-edited MR spectroscopy [MRS]; transcranial magnetic stimulation [TMS]; and psychophysical investigation of human somatomotor function.
Funding: This 3-year studentship is partly funded by the NIHR Nottingham Biomedical Research Centre and partly funded by the University of Nottingham. The studentship will provide and stipend to the student and will cover University bench fees. It is important that the student be in a position to commence their doctoral study in February 2020. Applicants with previous experience using brain imaging/spectroscopy/stimulation techniques and expertise in programming in Matlab/Python will be particularly encouraged to apply.