Advanced techniques in magnetic resonance imaging of the brain in children with ADHD

Abstract

Attention deficit hyperactivity disorder (ADHD) affects about 5% of school-aged child. Previous published works using different techniques of magnetic resonance imaging (MRI) have demonstrated that there may be some differences between the brain of people with and without this condition. This review aims at providing neurologists, pediatricians and psychia trists an update on the differences between the brain of children with and without ADHD using advanced techniques of magnetic resonance imaging such as diffusion tensor imaging, brain volumetry and cortical thickness, spectroscopy and functional MRI. Data was obtained by a comprehensive, non-systematic review of medical literature. The regions with a greater number of abnormalities are splenium of the corpus callosum, cingulated girus, caudate nucleus, cerebellum, striatum, frontal and temporal cortices. The brain regions where abnormalities are observed in studies of diffusion tensor, volumetry, spectroscopy and cortical thickness are the same involved in neurobiological theories of ADHD coming from studies with functional magnetic resonance imaging. Key words: attention deficit disorder with hyperactivity, magnetic resonance imaging, diffusion tensor imaging, cerebral cortex, magnetic resonance spectroscopy, functional MRI.Técnicas avançadas de ressonância magnética do crânio em crianças portadoras de TDAH RESUMO O transtorno do déficit de atenção e hiperatividade (TDAH) afeta cerca de 5% das crianças em idade escolar. Diversos trabalhos publicados utilizando diferentes técnicas de ressonância magnética mostram que pode haver diferenças entre o cérebro de portadores e não-portadores deste transtorno. Esta revisão visa fornecer aos neurologistas, pediatras e psiquiatras uma atualização sobre diferenças entre o cérebro de portadores e não-portadores deste transtorno, utilizando técnicas avançadas de ressonância magnética, como imagem pelo tensor da difusão, volumetria e espessura cortical, espectroscopia e ressonância magnética funcional. Os dados foram obtidos pela revisão abrangente não-sistemática da literatura médica. As regiões com maior número de anormalidades são: esplênio do corpo caloso, giro do cíngulo, núcleo caudado, cerebelo, estriado, córtex frontal e temporal. As regiões do cérebro onde as anormalidades são observadas em estudos de tensor de difusão, volumetria, espectroscopia e espessura cortical são as mesmas envolvidas nas teorias neurobiológicas do TDAH provenientes de estudos com

Have we been ignoring the elephant in the room? Seven arguments for considering the cerebellum as part of addiction circuitry

“…This specific increase has also been found in heavy marijuana users (Medina et al, 2010;Cousijn et al, 2012;Battistella et al, 2014). The interesting thing is that this gray matter increase was not related to the age of first use or the extent of cannabis consumption 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 Growing evidence links abnormalities in the cerebellum with those neuropsychiatric disorders that show comorbidity with addiction, including schizophrenia (Leiner et al, 1986;Andreasen et al, 1998;Konarski et al, 2005;Yeganeh-Doost et al, 2011) and attention-deficit hyperactivity disorder (ADHD) (Pastura et al, 2011) (see Villanueva, 2012 for a recent review).…”

The impact of ADHD persistence, recent cannabis use, and age of regular cannabis use onset on subcortical volume and cortical thickness in young adults

“…ADHD in childhood and early adolescence appears to affect several neuronal regions, with abnormalities seen in the prefrontal cortex (PFC), anterior (ACC) and posterior cingulate cortex, basal ganglia, insula, cerebellum and parietal, temporal and occipital cortices (Castellanos and Proal, 2012; Castellanos et al, 2003; Cherkasova and Hechtman, 2009; Frodl and Skokauskas, 2012; Pastura et al, 2011; Peng et al, 2013). Adolescence is marked by ongoing neurodevelopment, including pruning of the cortical gray matter and increases in white matter (Barnea-Goraly et al, 2005; Bava et al, 2010; Giedd et al, 1999; Giorgio et al, 2010; Gogtay and Thompson, 2010; Jernigan et al, 1991; Simmonds et al, 2014; Sowell et al, 2002; Toga et al, 2006).…”

“…Subcortical regions that are abnormal in adults with ADHD include the caudate (Almeida et al, 2010; Almeida Montes et al, 2010; Onnink et al, 2014; Proal et al, 2011; Seidman et al, 2011), amygdala (Frodl et al, 2010), hippocampus in medicated individuals (Onnink et al, 2014), nucleus accumbens (Seidman et al, 2006), and cerebellum (Biederman et al, 2008). Therefore, studies in adults with persistent ADHD have found brain structural abnormalities that are also seen in childhood (Castellanos et al, 2003; Castellanos and Proal, 2012; Cherkasova and Hechtman, 2009; Frodl and Skokaukas, 2012; Pastura et al, 2011; Peng et al, 2013). However, it is notable that most of these studies included samples that were, on average, older than twenty-five years of age (Ahrendts et al, 2011; Almeida et al, 2010; Almeida Montes et al, 2010; Amico et al, 2011; Biederman et al, 2008; Clerkin et al, 2013; Frodl et al, 2010; Hesslinger et al, 2002; Makris et al, 2007; Mattfeld et al, 2014; Onnink et al, 2014; Perlov et al, 2008; Seidman et al, 2011, 2006; Almeida Montes et al, 2013) when most gray matter neuromaturation is complete (e.g., Giedd et al, 1999) and in older samples, gray matter may be reducing due to aging.…”

Sex differences in white matter integrity in youths with attention-deficit/hyperactivity disorder: a pilot study

“…Numerous structural and functional neuroimaging studies have identified widespread differences in youths with ADHD when compared to typically developing youths (Weyandt et al, 2013 ). For instance, brain regions such as the anterior cingulate cortex, prefrontal, temporal and parietal regions, insula, caudate, basal ganglia, corpus callosum, splenium, and cerebellum have been associated with the pathophysiology of ADHD (Silk et al, 2008 ; Qiu et al, 2009 ; Cao et al, 2010 ; Pastura et al, 2011 ; Lopez-Larson et al, 2012 ; Bledsoe et al, 2013 ). From a brain network perspective, fronto-striatal-cerebellar, default-mode, and attentional networks have been consistently reported as being atypical in ADHD (Konrad et al, 2006 ; Uddin et al, 2008 ; Cubillo et al, 2010 ).…”