INTRODUCTIONComplex regional pain syndrome (CRPS) patients show impaired visuospatial perception in the dark, as compared to normal patients with acute nociceptive pain. The purpose of this study is 2-fold: (i) to ascertain whether this distorted visuospatial perception is related to the chronicity of pain, and (ii) to analyse visuospatial perception of CRPS in comparison with another neuropathic pain condition.

MATERIALS AND METHODSWe evaluated visual subjective body-midline (vSM) representation in 27 patients with post-herpetic neuralgia (PHN) and 22 with CRPS under light and dark conditions. A red laser dot was projected onto a screen and moved horizontally towards the sagittal plane of the objective body-midline (OM). Each participant was asked to direct the dot to a position where it crossed their vSM. The distance between the vSM and OM was analysed to determine how and in which direction the vSM deviated.

RESULTSUnder light condition, all vSM judgments approximately matched the OM. However, in the dark, CRPS patients, but not PHN patients, showed a shifted vSM towards the affected side.

CONCLUSIONWe demonstrated that chronic pain does not always impair visuospatial perception. The aetiology of PHN is limited to the peripheral nervous system, whereas the distorted visuospatial perception suggests a supraspinal aetiology of CRPS.

Adult ; Aged ; Complex Regional Pain Syndromes ; complications ; etiology ; Darkness ; Female ; Functional Laterality ; physiology ; Humans ; Male ; Middle Aged ; Neuralgia, Postherpetic ; complications ; Perceptual Disorders ; etiology ; physiopathology ; Peripheral Nervous System ; physiopathology ; Task Performance and Analysis

From the start, World Health Organization has proposed that palliative medicine is applicable early in the course of illness. However, regrettably, palliative care has been usually provided to patients in the advanced cancer stage, as a terminal care. Recently, palliative medicine begins at the time-point when patients are diagnosed with cancer. In response to change in clinical settings of palliative medicine, cancer pain management has also changed. Considering long-term cancer treatment periods and increasing numbers of cancer survivors, cancer pain management should be recommended based on not only non-opioid pharmacotherapy but also the exercise/rehabilitation medicine and the cognitive-behavioral therapy. Especially, the exercise/rehabilitation medicine can provide beneficial effects on both pain management and cancer treatment itself: Sarcopenia is closely associated with poor prognosis of cancer and debilitating complications of chemotherapy. Further, non-sarcopenia patients can maintain their quality of life higher and show less fatigue during cancer treatment periods. To accomplish such favorable effects for cancer patients and cancer survivors, cancer pain should be managed adequately.