Jade-Jocelyn Zouki
PhD Candidate | Functional brain connectivity & TS | Deakin University
Many thanks for chatting with us Jade. How did you get into researching Tourette syndrome?
I got involved in Tourette syndrome research in the third year of my Psychology degree while undertaking an internship at the Royal Children’s Hospital here in Melbourne. I was fortunate to have the opportunity to continue researching Tourette syndrome for my PhD.
Could you give us more insight into your PhD?
Our team’s research aims to understand brain function in individuals with Tourette syndrome and the personal experience of the urge to tic.
We mainly use a neuroimaging technique called functional magnetic resonance imaging (fMRI), which allows us to examine brain activity and function by way of changes in blood flow in the brain. We use fMRI to try and understand which brain regions are involved in tics and the urge to tic, which is commonly called ‘premonitory urge’. Our team is a mix of neuroscience and philosophy researchers, so we also use an interview method called ‘micro-phenomenological’ interview to learn more about the individual experience of Tourette syndrome, that is, what people think and feel before and during a tic (1).
In my first PhD study just published (2), we used neuroimaging methods to identify a brain network (i.e. a set of interconnected brain structures) associated with tics in Tourette syndrome – we used insights from brain structure in individuals with Tourette syndrome and case reports of damage to the brain causing tics, for example, after a traumatic brain injury.
These findings are exciting because they may help locate targets for effective therapeutic brain stimulation. For example, one of the regions in this network we identified is the precuneus – because this structure is on the surface of the brain, this offers a testable target for therapeutic non-invasive brain stimulation (3).
You stated previously that your research is focused on understanding the neurobiological aspects of Tourette syndrome. Does neurobiology differ from studying the neurology or neuroscience of Tourette?
Neurobiology is a field dedicated to examining the nervous system.
So, the neurobiology of a disorder, broadly speaking, describes how brain function and structure relates to the symptoms within a disorder, for example, tics and premonitory urge.
Neuroscience encompasses the field of neurology, which involves the diagnosis and treatment of various conditions of the nervous system (the brain, spinal cord, and peripheral nerves).
With your research focused on understanding which brain regions (or networks) are associated with TS, is there a good understanding of which regions are associated with tics and the premonitory urge?
I guess it’s important to first discuss what premonitory urge is. Research suggests that for ~90% of individuals with Tourette syndrome, their tics are preceded by an urge or sensation, often described as inner tension (4).
This unseen symptom has been described by some individuals as the ‘core’ symptom of Tourette syndrome (5). Over the past two decades, clinicians and neuroscientists alike have been interested in trying to understand which brain regions may be linked to tics and the preceding urge (6).
fMRI has been increasingly used to try and answer this question (6). For example, Neuner and colleagues (7) conducted an interesting study specifically focused on disentangling the brain activity underlying tics and the preceding urge.
They found that before a tic, several areas of the brain were active (e.g. supplementary motor area, parietal operculum, cingulate cortex, and insula), while regions deep within the brain, such as the thalamus, were active once a tic started.
This preceding activity may be relevant specifically to premonitory urges (6).
This is interesting. So, the areas of the brain that cause or control tics may differ from the areas of the brain that creates the urge to tic? As someone with the condition but with no expertise in the neurobiology, could tics and the urge to tic be more different than they seem to be?
Research does suggest that there are some brain regions that may be more involved in the preceding urge and selecting the behavioural response to this urge, such as the insula and cingulate cortex (8).
Interestingly, these regions have also been linked to common everyday bodily urges (8), such as blinking, which further suggests their involvement in premonitory urge.
However, when talking to children and adolescents with Tourette syndrome through our research, they often describe that it is not always easy to disentangle the experience of tics and the premonitory urge. The tic might just ‘pop out’ without any feeling in their bodies beforehand. Some research suggests that ‘simple’ tics, such as those involving the face (e.g. mouth movements) are less likely to be preceded by an urge, which might help explain this (6,9).
It is important for neuroimaging research to try and link brain activity with the personal experience of premonitory urge as described by individuals with Tourette syndrome and understand how these change with treatment, which is what our research aims to do.
Jade-Jocelyne Zouki is a PhD candidate researching Functional brain connectivity & Tourette Syndrome at Deakin University in Melbourne, Australia.
Twitter: @JadeJZouki
References
- Curtis-Wendlandt L, Reynolds J. Why Tourette syndrome research needs philosophical phenomenology. Phenomenol Cogn Sci. 2021 Sep;20(4):573–600. https://doi.org/10.1007/s11097-020-09688-w
- Zouki JJ, Ellis EG, Morrison-Ham J, Thomson P, Jesuthasan A, Al-Fatly B, et al. Mapping a network for tics in Tourette syndrome using causal lesions and structural alterations. Brain Commun. 2023 Apr 4;fcad105. https://doi.org/10.1093/braincomms/fcad105
- Dyke K, Jackson G, Jackson S. Non-invasive brain stimulation as therapy: systematic review and recommendations with a focus on the treatment of Tourette syndrome. Exp Brain Res. 2022 Feb;240(2):341–63. https://doi.org/10.1007/s00221-021-06229-y
- Kwak C, Dat Vuong K, Jankovic J. Premonitory sensory phenomenon in Tourette’s syndrome. Mov Disord. 2003 Dec;18(12):1530–3. https://doi.org/10.1002/mds.10618
- Hollenbeck PJ. Insight and hindsight into Tourette syndrome. Adv Neurol. 2001;85:363–7.
- Cavanna AE, Black KJ, Hallett M, Voon V. Neurobiology of the Premonitory Urge in Tourette’s Syndrome: Pathophysiology and Treatment Implications. J Neuropsychiatry Clin Neurosci. 2017 Apr;29(2):95–104. https://doi.org/10.1176/appi.neuropsych.16070141
- Neuner I, Werner CJ, Arrubla J, Stöcker T, Ehlen C, Wegener HP, et al. Imaging the where and when of tic generation and resting state networks in adult Tourette patients. Front Hum Neurosci [Internet]. 2014 May 28 [cited 2022 May 31];8. https://doi.org/10.3389/fnhum.2014.00362
- Jackson SR, Parkinson A, Kim SY, Schüermann M, Eickhoff SB. On the functional anatomy of the urge-for-action. Cogn Neurosci. 2011 Sep;2(3–4):227–43. https://doi.org/10.1080/17588928.2011.604717
- Leckman JF. Premonitory urges in Tourette’s syndrome. Am J Psychiatry. 1993 Jan;150(1):98–102. https://doi.org/10.1176/ajp.150.1.98