0
Editorial |

Increased Neuron Number and Head Size in Autism

Janet E. Lainhart, MD; Nicholas Lange, ScD
JAMA. 2011;306(18):2031-2032. doi:10.1001/jama.2011.1633.
Text Size: A A A
Published online

Extract

In this issue of JAMA, the report by Courchesne and colleagues1 documents an increase in neuron number in the prefrontal cortex (PFC) in male children and adolescents with autism. Those findings build on Leo Kanner's original observations2 in 1943 and 2 decades of recent research investigating macrocephaly in autism. Macrocephaly occurs in 20% of individuals with autism on average and is usually due to megalencephaly—abnormal enlargement of the brain during childhood.3 The enlargement is rarely present at birth; it develops during early childhood when head growth accelerates during the first 18 months of life.4 Mean total brain, lobar, white matter, and gray matter volumes, including volume of the cortex, are significantly increased by 2 to 3 years of age in children with autism when compared with typically developing and also nonautistic developmentally delayed individuals.57 The excessive head growth and brain growth occur prior to most clinical manifestations of the disorder, raising the possibility that the mechanisms that cause excessive growth also play a role in the primary developmental neuropathology of autism.

Sign In to Access Full Content

Don't have Access?

Register and get free email Table of Contents alerts, saved searches, PowerPoint downloads, CME quizzes, and more

Subscribe for full-text access to content from 1998 forward and a host of useful features

Activate your current subscription (AMA members and current subscribers)

Purchase Online Access to this article for 24 hours

First Page Preview

View Large
/>
First page PDF preview

Figures

Tables

References

CME
Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.
NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Multimedia

Some tools below are only available to our subscribers or users with an online account.

Web of Science® Times Cited: 6

Sign In to Access Full Content

Related Content

Customize your page view by dragging & repositioning the boxes below.

See Also...
Articles Related By Topic
Related Topics
PubMed Articles
Jobs
brightcove.createExperiences();