White matter alterations in drug-naïve children with Tourette syndrome and obsessive-compulsive disorder

Komal Bharti; Giulia Conte; Silvia Tommasin; Costanza Giannì; Antonio Suppa; Giovanni Mirabella; Francesco Cardona; Patrizia Pantano

doi:10.3389/fneur.2022.960979

White matter alterations in drug-naïve children with Tourette syndrome and obsessive-compulsive disorder

Front Neurol. 2022 Oct 3:13:960979. doi: 10.3389/fneur.2022.960979. eCollection 2022.

Authors

Komal Bharti¹, Giulia Conte¹, Silvia Tommasin¹, Costanza Giannì^{1

2}, Antonio Suppa^{1

2}, Giovanni Mirabella³, Francesco Cardona¹, Patrizia Pantano^{1

2}

Affiliations

¹ Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy.
² Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Isernia, Italy.
³ Department of Clinical and Experimental Sciences Section, Brescia University, Brescia, Italy.

Abstract

Tourette syndrome (TS) and early-onset obsessive-compulsive disorder (OCD) are frequently associated and conceptualized as distinct phenotypes of a common disease spectrum. However, the nature of their relationship is still largely unknown on a pathophysiological level. In this study, early structural white matter (WM) changes investigated through diffusion tensor imaging (DTI) were compared across four groups of drug-naïve children: TS-pure (n = 16), TS+OCD (n = 14), OCD (n = 10), and 11 age-matched controls. We analyzed five WM tracts of interest, i.e., cortico-spinal tract (CST), anterior thalamic radiations (ATR), inferior longitudinal fasciculus (ILF), corpus callosum (CC), and cingulum and evaluated correlations of DTI changes to symptom severity. Compared to controls, TS-pure and TS+OCD showed a comparable pattern of increased fractional anisotropy (FA) in CST, ATR, ILF and CC, with FA changes displaying negative correlation to tic severity. Conversely, in OCD, FA decreased in all WM tracts (except for the cingulum) compared to controls and negatively correlated to symptoms. We demonstrate different early WM microstructural alterations in children with TS-pure/TS+OCD as opposed to OCD. Our findings support the conceptualization of TS+OCD as a subtype of TS while suggesting that OCD is characterized by independent pathophysiological mechanisms affecting WM development.

Keywords: Tourette syndrome; diffusion tensor imaging (DTI); drug-naïve; fractional anisotropy (FA); obsessive-compulsive disorder (OCD); white matter (WM) microstructural organization.