Neural mechanism of central post-apoplectic pain: experimental study of P2X7 receptor and BDNF

Abstract

Central post-stroke pain (CPSP) refers to pain resulting from a primary lesion or dysfunction of the central nervous system after a stroke. Stroke in the thalamus is one of the most common causes of neuropathic central pain. The lesions anywhere in the spinothalamocortical pathway lead to prominent over-activity of the lateral thalamus. These patients suffer from allodynia and hyperalgesia after stroke, which are among the most troublesome post-stroke sequelae (consequences). The distribution of pain ranges from small to large areas and is often described as long-lasting, severe and persisting. It can also be spontaneous or evoked. The intensity of spontaneous pain often fluctuates and can be increased by internal or external stimuli, such as stress or cold. Symptoms therefore interfere with sleep and reduce quality of life.Pain caused by CPSP results from a primary lesion or dysfunction of the central nervous system after stroke. More specifically, strokes located in the thalamus are one of the most common causes of neuropathic pain. A stroke causes local tissue damage and inflammation at its site. This leads to the onset of nociceptive pain, which is pain resulting from the stimulation of nerve cell. This stimulation and subsequent hyperactivity of the brain region is the root cause of the pain, but it is poorly understood which molecular pathways are involved in firing of the stimulated cells. Recent evidence, however, has suggested the involvement of ion channels and adenosine triphosphate (ATP) gated cation channel P2X receptors. The involvement of these channels and receptors means the molecules that activate and pass through them, various cytokines and proteins, have the potential to be used to indicate that the nociceptive pain pathway is being activated. One researcher attempting to unravel the mysteries surrounding CPSP is Dr. Bai Chuang Shyu, along with his team at the Institute of Biomedical Sciences, Academia Sinica in Taiwan. His work has focused on the neuronal mechanisms underlying this condition. ‘The purpose of our study is to draw attention to the importance of this ‘hidden’ disorder and place it within the context of central neuropathic pain,’ he explains. In order to do so, Shyu is searching for biomarkers for early diagnosis of CPSP, as well as working on the development of a therapeutic strategy.