| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
From the Comprehensive Pain Program (Drs. Mailis-Gagnon and Nicholson), Division of Neurosurgery (Dr. Davis), Department of Medical Imaging (Drs. Mikulis and Crawley), and Toronto Western Research Institute (Drs. Mailis, Mikulis, and Davis, and I. Giannoylis, J. Downar, C.L. Kwan, and D.J. Mikulis), Toronto Western Hospital; and Department of Surgery (Dr. Davis) and Institute of Medical Sciences (J. Downar and C.L. Kwan, and Dr. Davis), University of Toronto, Ontario, Canada.
Address correspondence and reprint requests to Dr. Karen D. Davis, Toronto Western Hospital, Division of Neurosurgery, MP14-306, 399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8; e-mail: kdavis{at}uhnres.utoronto.ca
Objective: The authors hypothesized that central factors may underlie sensory deficits in patients with nondermatomal somatosensory deficits (NDSD) and that functional brain imaging would reveal altered responses in supraspinal nuclei.
Background: Patients with chronic pain frequently present with NDSD, ranging from hypoesthesia to complete anesthesia in the absence of substantial pathology and often in association with motor weakness and occasional paralysis. Patients with pain and such pseudoneurologic symptoms can be classified as having both a pain disorder and a conversion disorder (Diagnostic and Statistical Manual of Mental Disorders–IV classification).
Methods: The authors tested their hypothesis with functional MRI (fMRI) of brush and noxious stimulation-evoked brain responses in four patients with chronic pain and NDSD.
Results: The fMRI findings revealed altered somatosensory-evoked responses in specific forebrain areas. Unperceived stimuli failed to activate areas that were activated with perceived touch and pain: notably, the thalamus, posterior region of the anterior cingulate cortex (ACC), and Brodmann area 44/45. Furthermore, unperceived stimuli were associated with deactivations in primary and secondary somatosensory cortex (S1, S2), posterior parietal cortex, and prefrontal cortex. Finally, unperceived (but not perceived) stimuli activated the rostral ACC.
Conclusions: Diminished perception of innocuous and noxious stimuli is associated with altered activity in many parts of the somatosensory pathway or other supraspinal areas. The cortical findings indicate a neurobiological component for at least part of the symptoms in patients presenting with nondermatomal somatosensory deficits.
This article has been cited by other articles:
|
|
 |
|
  J. Stone, A. Zeman, E. Simonotto, M. Meyer, R. Azuma, S. Flett, and M. Sharpe fMRI in Patients With Motor Conversion Symptoms and Controls With Simulated Weakness Psychosom Med, November 1, 2007; 69(9): 961 - 969. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Maihofner, R. Baron, R. DeCol, A. Binder, F. Birklein, G. Deuschl, H. O. Handwerker, and J. Schattschneider The motor system shows adaptive changes in complex regional pain syndrome Brain, October 1, 2007; 130(10): 2671 - 2687. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. A. Hurwitz and J. W. Prichard Conversion disorder and fMRI Neurology, December 12, 2006; 67(11): 1914 - 1915. [Full Text] [PDF]
|
|
|
|
|
|
O. Ghaffar, W. R. Staines, and A. Feinstein Unexplained neurologic symptoms: An fMRI study of sensory conversion disorder Neurology, December 12, 2006; 67(11): 2036 - 2038. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. M. Stonnington, J. J. Barry, and R. S. Fisher Conversion Disorder Am J Psychiatry, September 1, 2006; 163(9): 1510 - 1517. [Full Text] [PDF]
|
|
|
|
 |
|
 S. A. Spence All in the mind? The neural correlates of unexplained physical symptoms Advan. Psychiatr. Treat., September 1, 2006; 12(5): 349 - 358. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Maihofner, H. O. Handwerker, and F. Birklein Functional imaging of allodynia in complex regional pain syndrome Neurology, March 14, 2006; 66(5): 711 - 717. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. L. Kwan, N. E. Diamant, G. Pope, K. Mikula, D. J. Mikulis, and K. D. Davis Abnormal forebrain activity in functional bowel disorder patients with chronic pain Neurology, October 25, 2005; 65(8): 1268 - 1277. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. H. Gracely Is seeing believing? Functional imaging of hysterical anesthesia Neurology, May 13, 2003; 60(9): 1410 - 1411. [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
