A Network-Informed Perspective on Targeting the Urge to Tic With Deep Brain Stimulation of the Centromedian-Parafascicular

Premonitory urges precede tics in Tourette Syndrome (TS) and are usually transiently relieved after tic execution. Despite the proposal that premonitory urges arise through aberrant interoceptive signaling, relatively little is known about their underlying mechanisms or how they respond to treatment. The centromedian-parafascicular complex (CM-Pf) is a proposed target for deep brain stimulation (DBS) in medically refractory TS on the basis of the convergence of limbic and sensorimotor corticostriatal pathways. The CM-Pf also contributes to processing the affective and motivational dimensions of pain.

In this narrative review, we explore how the intersection between CM-Pf connectivity, pain-processing, and interoceptive function supports investigation of DBS at the CM-Pf complex as a potential modulator of both premonitory urges and tics in TS.

Neural structures associated with premonitory urges overlap with interoceptive and pain-processing pathways and may be part of a broader "urge-for-action" network. On the basis of its structural and functional connectivity, the CM-Pf appears to link paralimbic and motor circuits, helping to facilitate the transition from internal bodily sensations (ie, urges) to action (ie, tics). Existing but limited evidence shows that CM-Pf DBS in TS can improve both urges and tics and that modulation of urge-related structures may be important to its mechanism of action.

Premonitory urge-related circuitry is a relevant therapeutic substrate in TS. Further dedicated exploration of CM-Pf DBS in TS is warranted to better understand its capacity to address urge and tic symptoms and the mechanisms underlying its therapeutic effects.