Quantitative and Qualitative Responses to Topical Cold in Healthy Caucasians Show Variance between Individuals but High Test-Retest Reliability.

Increased sensitivity to cold may be a predictor of persistent pain, but cold pain threshold is often viewed as unreliable. This study aimed to determine the within-subject reliability and between-subject variance of cold response, measured comprehensively as cold pain threshold plus pain intensity and sensation quality at threshold. A test-retest design was used over three sessions, one day apart. Response to cold was assessed at four sites (thenar eminence, volar forearm, tibialis anterior, plantar foot). Cold pain threshold was measured using a Medoc thermode and standard method of limits. Intensity of pain at threshold was rated using a 10cm visual analogue scale. Quality of sensation at threshold was quantified with indices calculated from subjects' selection of descriptors from a standard McGill Pain Questionnaire. Within-subject reliability for each measure was calculated with intra-class correlation coefficients and between-subject variance was evaluated as group coefficient of variation percentage (CV%). Gender and site comparisons were also made. Forty-five healthy adults participated: 20 male, 25 female; mean age 29 (range 18-56) years. All measures at all four test sites showed high within-subject reliability: cold pain thresholds r = 0.92-0.95; pain rating r = 0.93-0.97; McGill pain quality indices r = 0.87-0.85. In contrast, all measures showed wide between-subject variance (CV% between 51.4% and 92.5%). Upper limb sites were consistently more sensitive than lower limb sites, but equally reliable. Females showed elevated cold pain thresholds, although similar pain intensity and quality to males. Females were also more reliable and showed lower variance for all measures. Thus, although there was clear population variation, response to cold for healthy individuals was found to be highly reliable, whether measured as pain threshold, pain intensity or sensation quality. A comprehensive approach to cold response testing therefore may add validity and improve acceptance of this potentially important pain measure.Thus, although there was clear population variation, response to cold for healthy individuals was found to be highly reliable, whether measured as pain threshold, pain intensity or sensation quality. A comprehensive approach to cold response testing therefore may add validity and improve acceptance of this potentially important pain measure

Autonomic neuropathy in Fabry disease: a prospective study using the Autonomic Symptom Profile and cardiovascular autonomic function tests

<p>Abstract</p> <p>Background</p> <p>Fabry patients have symptoms and signs compatible with autonomic dysfunction. These symptoms and signs are considered to be due to impairment of the peripheral nervous system, but findings indicative of autonomic neuropathy in other diseases, such as orthostatic intolerance and male sexual dysfunction, are infrequently reported in Fabry disease. The aim of our study was to investigate autonomic symptoms and cardiovascular autonomic function in a large cohort of male and female Fabry patients.</p> <p>Methods</p> <p>Forty-eight Fabry patients (15 male, 30 treated with enzyme replacement therapy) and 48 sex- and age-matched controls completed a questionnaire on autonomic symptoms (the Autonomic Symptom Profile). Thirty-six Fabry patients underwent cardiovascular function tests.</p> <p>Results</p> <p>The Autonomic Symptom Profile revealed a significantly higher sum score in Fabry patients than in healthy control subjects (22 versus 12), but a relatively low score compared to patients with proven autonomic neuropathy. Fabry patients scored worse than healthy controls in the orthostatic intolerance domain. Scores in the male sexual dysfunction domain were comparable between healthy controls and male Fabry patients. The cardiovascular autonomic function tests revealed only mild abnormalities in seven patients. None of these seven patients showed more than one abnormal test result. Enzyme replacement therapy was not associated with less severe disease, lower ASP scores or less frequent abnormal cardiovascular function test results.</p> <p>Conclusions</p> <p>Male sexual function and autonomic control of the cardiovascular system are nearly normal in Fabry patients, which cast doubt on the general accepted assumption that autonomic neuropathy is the main cause of symptoms and signs compatible with autonomic dysfunction in Fabry disease. Possibly, end-organ damage plays a key role in the development of symptoms and signs in Fabry patients. An exceptional kind of autonomic neuropathy is another but less likely explanation.</p

Altered thermal sensitivity in facial skin in chronic whiplash-associated disorders

There is a close functional relationship between the jaw and neck regions and it has been suggested that trigeminal sensory impairment can follow whiplash injury. Inclusion of manageable routines for valid assessment of the facial sensory capacity is thus needed for comprehensive evaluations of patients exposed to such trauma. The present study investigated facial thermal thresholds in patients with chronic whiplash-associated disorders (WADs) with both a qualitative method and quantitative sensory testing (QST). Ten women with pain and dysfunction following a whiplash injury were compared to 10 healthy age-matched women. Thermal detection thresholds were assessed by qualitative chair-side testing and by QST according to the method-of-limits. Seven test sites in the facial skin (overlying each trigeminal branch bilaterally, and the midpoint of the chin) were examined. The detection warm and cold thresholds were defined as the mean values of 10 individual thresholds. For the WAD patients, the qualitative assessment demonstrated both reduced and increased sensitivity compared to the healthy, whereas QST systematically showed significantly higher detection thresholds (i.e., decreased sensitivity) for both cold and warm stimuli. For the individuals who were assessed as having increased sensitivity in the qualitative assessment, the QST displayed either normal or higher thresholds, i.e., decreased sensitivity. The results suggest that QST is more sensitive for detecting thermal sensory disturbances in the face than a qualitative method. The impaired thermal sensitivity among the patients corroborates the notion of altered thermal detection capacity induced by WAD-related pain