Cortical Thickness in Parkinsonians With Impulse Control Disorders: A Comment We read with great interest the study by Biundo et al. investigating the neural correlates of impulse control disor- ders (ICDs) in patients with Parkinson’s disease (PD) by means of structural 1.5T MRI. 1 The investigators observed significant cortical thinning in frontostriatal circuitry, specifi- cally in the right superior orbitofrontal, left rostral middle frontal, bilateral caudal middle frontal region, and corpus callosum, as well as volume reduction in the right accum- bens and increase in the left amygdala. They suggested that “the mesolimbic and cortical-cortical pathways are involved in ICDs occurrence in PD, and that their severity is associ- ated with gray matter alterations in regions linked to the reward and control networks.” 1 Several neuropsychological studies investigated cognitive dysfunctions associated with ICDs in PD and provided dif- ferent results. Siri et al. found that the occurrence of patho- logical gambling (PG) was associated with preserved executive functions. 2 In contrast, we have demonstrated that PG in PD was associated with severe derangements of some frontal lobe functions, such as set-shifting and cognitive flex- ibility (assessed by means of part B of the Trail Making Test and by a phonological fluency task, respectively). 3 Such find- ings were confirmed in a further neuropsychological study in which we systematically explored and compared cognitive profiles of PD patients affected by PG, hypersexuality (HS), or compulsive eating (CE) alone or in combination. 4 With respect to patients with PG, patients affected by HS showed more severe impairments of inhibitory control and verbal learning, whereas patients with CE evidenced a somewhat intermediate pattern. On this basis, we suggested that PG and other ICDs are behavioral symptoms that might arise from difficulty in monitoring one’s own behavior and in shifting from negative to positive conduct; differences among subtypes of ICDs may reflect differential involvement of the neural substrates devoted to process intrinsic (e.g., sex and feeding) or learned rewards (e.g., money). 4 Bentivoglio et al. 5 further supported our findings and suggested that onset of ICDs in PD might be the result of a selective impairment in top-down regulation of behavior, likely related to dysfunction of an anatomical and functional loop, including several prefrontal areas and subcortical structures in combination with dopamine replacement therapy. Taking into account the above-mentioned evidences, we wonder that the investigators did not find any significant dif- ference in neuropsychological profile between patients with and without ICDs. Nevertheless, their finding of altered cort- ical thickness support our observations of a cognitive impair- ment of both frontal/executive and memory dysfunctions in PD patients with ICDs. It is possible that discrepancies between cognitive results in our and their studies might be owing to the fact that they considered the ICD as a whole without differentiating among the different types. It would be interesting to explore also cortical thickness in the differ- ent ICD types. Gabriella Santangelo, PhD, 1,2 Luigi Trojano, MD, 1 Paolo Barone, MD, PhD, 4, * and Carmine Vitale, MD, PhD 2,3 1 Neuropsychology Laboratory, AQ1 Department of Psychology, Second University of Naples, Caserta, Italy 2 IDC Hermitage-Capodimonte, Naples, Italy 3 University Parthenope, Naples, Italy 4 Center for Neurodegenerative Diseases (CEMAND), University of Salerno, Salerno, Italy References 1. Biundo R, Weis L, Facchini S, et al. Patterns of cortical thickness associated with impulse control disorders in Parkinson’s disease. Mov Disord 2015 Feb 4. doi: 10.1002/mds.26154. [Epub ahead of print] 2. Siri C, Cilia R, De Gaspari D, et al. Cognitive status of patients with Parkinson’s disease and pathological gambling. J Neurol 2010;257:247-252. 3. Santangelo G, Vitale C, Trojano L, Verde F, Grossi D, Barone P. Cognitive dysfunctions and pathological gambling in patients with Parkinson’s disease. Mov Disord 2009;24:899-905. 4. Vitale C, Santangelo G, Trojano L, et al. Comparative neuropsy- chological profile of pathological gambling, hypersexuality, and compulsive eating in Parkinson’s disease. Mov Disord 2011;26: 830-836. 5. Bentivoglio AR, Baldonero E, Ricciardi L, De Nigris F, Daniele A. Neuropsychological features of patients with Parkinson’s disease and impulse control disorders. Neurol Sci 2013;34:1207-1213. ------------------------------------------------------------ *Correspondence to: Prof. Paolo Barone, Center for Neurodegenerative Diseases (CEMAND), University of Salerno, Salerno 84131, Italy. E-mail: pbarone@unisa.it AQ2 Relevant conflicts of interest/financial disclosures: Nothing to report. AQ3 Full financial disclosures and author roles may be found in the online ver- sion of this article. Received: 10 March 2015; Accepted: 20 March 2015 Published online 00 Month 2015 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/mds.26262 LETTERS: NEW OBSERVATIONS Movement Disorders, Vol. 00, No. 00, 2015 1 J_ID: MDS Customer A_ID: MDS26262 Cadmus Art: MDS26262 Ed. Ref. No.: 15-0281 Date: 11-May-15 Stage: Page: 1 ID: pachiyappanm Time: 11:55 I Path: N:/3b2/MDS#/Vol00000/150107/APPFile/JW-MDS#150107