Basal Ganglia in Boys with ADHD Deviate from Norm

candace — Fri, 20 Feb 2009 16:08:09 +0000

Research recently published in the January 2009 American Journal of Psychiatry, reinforces what many families managing ADHD already know. In a research study by Anqi Qiu, Ph.D. et al., significant anatomical brain differences were found in the basal ganglia during brain image studies of 66 typically developing children, 35 of which were boys, and 47 children with ADHD, 27 of which were boys. The volume and shape of the basal ganglia of the boys with ADHD were significantly smaller and remarkably different when compared with typically developing boys. Volume compression was seen on both sides of the front of caudate and anterior putamen as well as in the left anterior globus pallidus and right ventral putamen. Volume expansion was most pronounced in the rear of the putamen. It is important to note that no volume or shape differences were noted between girls with ADHD and girls who were normally developing.

When one understands what the basal ganglia of the brain does, these findings add to a growing volume of research that confirms what families living with boys and ADHD anecdotally experience and understand. The basal ganglia is basically composed of the caudate, putamen, and globus pallidus. The caudate nucleus is a a part of the basal ganglia, located deep inside the brain. It is highly involved in learning and memory, and plays a role in processing feedback. The main function of the putamen is to regulate movements and influence various types of learning, specifically reinforcement and implicit types. It uses the neurotransmitter, dopamine to perform its functions and plays a role in this neurotransmitter’s regulation. The globus pallidus plays an active part in pre-filtering external stimuli and may help reduce the amount of irrelevant information the brain needs to store. Given that kids and adults with ADHD by definition, can struggle with learning implicit rules, filtering stimuli, remembering rote facts, and accurately processing feedback, none of these findings are shocking. It is a welcome addition to the growing body of evidence that ADHD is medical condition that has concrete anatomical findings.

Sources:

Anqi Qiu, Ph.D., et al. Basal Ganglia Volume and Shape in Children With Attention Deficit Hyperactivity Disorder. Am J Psychiatry; 166:74-82, January 2009.

Ell SW, Marchant NL, Ivry RB. 2006. Focal putamen lesions impair learning in rule-based, but not information-integration categorization tasks. Neuropsychologia 44:1737-51

Graybiel AM (2005) The basal ganglia: learning new tricks and loving it. Curr Opin Neurobiol 15:638-644.

Griffiths P. D.; Perry R. H.; Crossman A. R. A detailed anatomical analysis of neurotransmitter receptors in the putamen and caudate in Parkinson’s disease and Alzheimer’s disease. Neuroscience Letters [0304-3940] GRIFFITHS yr:1994 vol:169 iss:1-2 pg:68

Mark G. Packard and ¬ Barbara J. Knowlton. Learning and Memory Functions of the Basal Ganglia. Annual Review of Neuroscience. Vol. 25: 563-593, March 2002.

Packard MG, Knowlton BJ (2002) Learning and memory functions of the Basal Ganglia. Annu Rev Neurosci 25:563-593.

Yelnik, J., Percheron, G., and François, C. (1984) A Golgi analysis of the primate globus pallidus. II- Quantitative morphology and spatial orientation of dendritic arborisations. J. Comp. Neurol. 227:200-213

NIMH Research Supports Assertion that Kids with ADHD Catch-up

candace — Fri, 16 Jan 2009 13:37:46 +0000

In a November 2007 press release from the National Institute of Mental Health (NIHM), brain image studies confirmed that the brains of children with attention deficit hyperactivity disorder (ADHD), on average, followed a normal pattern of development but was delayed by 3 years in some regions of the brain when compare to their peers without the disorder. The delay occurred primarily in the front of the brain’s outer cortex, critical to the control of thinking, attention, and planning. It is important to note however, according to Dr. Jay Giedd, MD, a researcher on the project and a keynote speaker at the 2008 Children and Adults with ADD (CHADD) Conference, researchers were surprised to discover that the brain maturation process continued until 25 years of age in the average young adult; thus, youths with ADHD, on average could have brains still maturing until 28 years.

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Basal Ganglia in Boys with ADHD Deviate from Norm

NIMH Research Supports Assertion that Kids with ADHD Catch-up