Discriminative Properties of Hippocampal Hypoperfusion in Marijuana Users
posted 24/11/2016
publication Journal of Alzheimer's Disease
Compared to Healthy Controls: Implications for Marijuana Administration in Alzheimer’s Dementia
Article type: Research Article
Authors: Amen, Daniel G.a | Darmal, Borhana | Raji, Cyrus A.b; * | Bao, Weiningc | Jorandby, Lantiea | Meysami, Somayeha | Raghavendra, Cauligi S.c
Affiliations: [a] Amen Clinics Inc. Costa Mesa, CA, USA | University of California San Francisco, San Francisco, CA, USA | [c] Department of Electrical Engineering, University of Southern California, Los Angeles, CA, USA
Correspondence: [*] Correspondence to: Cyrus A. Raji, MD, PhD, University of California San Francisco, San Francisco, CA, USA. E-mail: cyrusraji@gmail.com.
Abstract: Background: Few studies have evaluated the impact of marijuana use on regional cerebral blood flow. Objective: To determine whether perfusion in specific brain regions on functional neuroimaging, including those affected by Alzheimer’s disease pathology, are abnormal in marijuana users compared to controls. Method: Persons with a diagnosis of cannabis use disorder by DSM-IV and DSM-V criteria (n = 982) were compared to controls (n = 92) with perfusion neuroimaging with SPECT at rest and at a concentration task. Perfusion estimates were quantified using a standard atlas. Cerebral perfusion differences were calculated using one-way ANOVA. Diagnostic separation was determined with discriminant analysis of all subjects. Feature selection with a minimum redundancy maximum relevancy (mRMR) identified predictive regions in a subset of marijuana users (n = 436) with reduced psychiatric co-morbidities. Results: Marijuana users showed lower cerebral perfusion on average (p < 0.05). Discriminant analysis distinguished marijuana users from controls with correct classification of 96% and leave one out cross-validation of 92%. With concentration SPECT regions, there was correct classification of 95% with a leave-one-out cross validation of 90%. AUC analysis for concentration SPECT regions showed 95% accuracy, 90% sensitivity, and 83% specificity. The mRMR analysis showed right hippocampal hypoperfusion on concentration SPECT imaging was the most predictive in separating marijuana subjects from controls. Conclusion: Multiple brain regions show low perfusion on SPECT in marijuana users. The most predictive region distinguishing marijuana users from healthy controls, the hippocampus, is a key target of Alzheimer’s disease pathology. This study raises the possibility of deleterious brain effects of marijuana use.
Keywords: Hippocampus, imaging, marijuana, SPECT
DOI: 10.3233/JAD-160833
Journal: Journal of Alzheimer's Disease, vol. Preprint, no. Preprint, pp. 1-13, 2016
Accepted 19 October 2016
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Published: 24 November 2016
