CMAJ • September 9, 2008; 179 (6). doi:10.1503/cmaj.070672.
© 2008 Canadian Medical Association or its licensors
All editorial matter in CMAJ represents the opinions of the authors and not necessarily those of the Canadian Medical Association.
This Article
Right arrow Figures Only
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow View responses
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Rebick, G.
Right arrow Articles by Morin, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Rebick, G., MD
Right arrow Articles by Morin, S., MD MSc
Related Collections
Right arrow Other respiratory medicine
Right arrow Heart failure
Right arrow Clinical Images
Right arrowRelated Articles

The thinker's sign

Gabriel Rebick, MD* and Suzanne Morin, MD MSc{dagger}

*Department of Medicine, Weill Cornell Medical Center, New York, NY; {dagger}Department of Medicine, McGill University, Montréal, Que.

This patient presented with tachypnea and use of the inspiratory accessory muscles. Chest auscultation revealed diffusely decreased air entry bilaterally and early inspiratory rales. A chest radiograph showed hyperinflation and increased radiolucency of the lungs. The results of pulmonary function tests were consistent with severe airflow obstruction that did not respond to bronchodilators (forced expiratory volume in the first second of expiration [FEV1] 29% predicted). On physical examination, we noticed circular, bilateral, hyperkeratotic skin patches above both knees (Figure 1).


Figure 128
View larger version (75K):
[in this window]
[in a new window]

  		Figure 1: A 73-year-old woman with circular, bilateral, hyperkeratotic skin patches above both knees (left). These patches may develop when patients spend long periods of time in the "thinker's position" (right).

 

These lesions, also known as the "thinker's sign,"1 arise from irritation of the skin caused by pressure from the elbows in patients who spend long periods of time in the tripod position (Figure 1). The braced body position, a nonspecific finding in respiratory distress, maximizes effectiveness of the accessory muscles of inspiration. Leaning forward also increases intra-abdominal pressure, allowing the flattened diaphragm to regain its natural shape and its ability to function as a piston.2 Although it is most often observed in severe obstructive lung disease (FEV1 < 30% predicted), this sign can be seen in other conditions where respiratory distress occurs, including congestive heart failure.

Footnotes

Clinical images are chosen because they are particularly intriguing, classic or dramatic. Submissions of clear, appropriately labelled high-resolution images must be accompanied by a figure caption and the patient's written consent for publication. A brief explanation (300 words maximum) of the educational significance of the images with minimal references is required.


REFERENCES

  1. Rothenberg HJ. The thinker's sign. JAMA 1963;184:902-3.[Abstract/Free Full Text]
  2. Sapira JD. The art and science of bedside diagnosis. Baltimore (MD): Urban and Schwarzerberg; 1990.

Related Articles

Highlights
Can. Med. Assoc. J. 2008 179: 497. [Full Text] [PDF]

Dans ce numéro
Can. Med. Assoc. J. 2008 179: 499. [Full Text] [PDF]



eLetters:

Read all eLetters

Namaz sign
Vishal Sharma
CMAJ, 23 Sep 2008 [Full text]
This Article
Right arrow Figures Only
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow View responses
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Rebick, G.
Right arrow Articles by Morin, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Rebick, G., MD
Right arrow Articles by Morin, S., MD MSc
Related Collections
Right arrow Other respiratory medicine
Right arrow Heart failure
Right arrow Clinical Images
Right arrowRelated Articles