Chronic pain is a significant public health issue with serious medical and economic impacts; mechanisms underlying its generation and maintenance have long been a topic of study. Previous human and animal investigations have noted the presence of CNS low-threshold Ca++ spikes in pain states, but have not explained the global significance of this finding. Recently, it has been suggested that such spike bursts form the basis for abnormal thalamocortical dynamics which lead to a set of neurological and neuropsychiatric disorders (including neurogenic pain), characterized by positive symptoms. We propose to use magnetoencephalographic recordings of spontaneous neuromagnetic activity in awake, alert subjects suffering from various types of chronic pain to test the hypothesis that some central pain is maintained by thalamocortical dysrhythmia. We intend to examine the frequencies, correlation among frequencies, and localization of abnormal activity in these subjects. We hypothesize that chronic pain patients will display thalamocortical oscillations in the theta (4-8 Hz) band, coupled with a widespread increase in coherence between oscillations in the theta and gamma (30-60 Hz) ranges. Furthermore, we hypothesize that structurally distinct areas of the brain which respond to painful stimuli will be activated in this condition.
| Jeanmonod, D; Schulman, J; Ramirez, R et al. (2003) Neuropsychiatric thalamocortical dysrhythmia: surgical implications. Neurosurg Clin N Am 14:251-65 |
