Thermal pain in complex regional pain syndrome type I.

BACKGROUND: Quantitative sensory testing (QST), with thermal threshold determinations, is a routine part of the comprehensive clinical workup of patients suffering from chronic pain, especially those with Complex Regional Pain Syndrome seen at our outpatient pain clinic. This is done to quantitatively assess each patient's small fiber and sensory function in a controlled manner. Most patients have normal sensory detection thresholds, but there are large differences in thermal pain thresholds. Some patients display no thermal hyperalgesia, while other patients display severe thermal hyperalgesia when tested in all 4 limbs. OBJECTIVES: To ascertain the prevalence of thermal hyperalgesia in patients with complex regional pain syndrome type 1 (CRPS-I). STUDY DESIGN: This was a retrospective review of the results of QST performed on 105 patients as part of their clinical workup. SETTING: The outpatient clinic of the Department of Neurology at Drexel University College of Medicine. METHODS: All patients had a diagnosis of CRPS-I. Thermal quantitative sensory testing, including cool detection, warm detection, cold pain, and heat pain, was performed on 8 distal sites on each patient as part of a comprehensive clinical examination. RESULTS: With regards to thermal hyperalgesia, patients with CPRS-I appear to fall into distinct groups. One subgroup displays evidence of generalized cold and heat hyperalgesia, one subgroup displays evidence of generalized cold hyperalgesia only, one displays evidence of heat hyperalgesia only, and one subgroup does not display evidence of cold or heat hyperalgesia. LIMITATIONS: This study is based on retrospective information on a relatively small (105 patient records) number of patients. Since only patients with CRPS-I were included, the results are only applicable to this group. CONCLUSIONS: Thermal QST provides useful information about the sensory phenotype of individual patients. Subgrouping based on thermal hyperalgesia may be useful for future studies regarding prognosis, treatment selection, and efficacy.

Objective sensory evaluation of the spread of complex regional pain syndrome.

BACKGROUND: The spread of complex regional pain syndrome (CRPS) has been well documented. Many severe refractory long-standing patients have total body pain (TBP) that evolved from a single extremity injury. OBJECTIVE: The purpose of this study was to document by objective sensory threshold testing the extent of body area involvement in 20 long-standing patients with CRPS who have TBP. STUDY DESIGN: A comparison of sensory threshold testing parameters between 20 long-standing refractory patients with CRPS who have TBP versus 10 healthy participants. METHODS: Twenty patients with CRPS who stated that they suffered from total body pain were chosen from the Drexel University College of Medicine CRPS database. They were compared to 10 healthy participants that were age and gender matched to the patients with CRPS. The sensory parameters tested were: skin temperature; static and mechanical allodynia; thermal allodynia; mechanical hyperalgesia; after sensations following all sensory tests. The sites chosen for testing in the patients with CRPS were the most painful area in each of 8 body regions that comprised the total body area. RESULTS: Five patients with CRPS had signs of CRPS over 100% of their body (20%). One patient had pain over 87% and another had pain over 90% of their body area. The average percentage of body involvement was 62% (range 37% - 100%). All patients with CRPS had at least one sensory parameter abnormality in all body regions. All patients with CRPS had lower pain thresholds for static allodynia in all body areas, while 50% demonstrated a lower threshold for dynamic allodynia in all body regions compared to the healthy participants. Cold allodynia had a higher median pain rating on the Likert pain scale in all body areas versus healthy participants except for the chest, abdomen, and back. Eighty-five percent of the patients with CRPS had a significantly lower pain threshold for mechanical hyperalgesia in all body areas compared to the healthy participants. After sensations occurred after all sensory parameters in the extremities in patients with CRPS. LIMITATIONS: The primary limitations of this study would be the variability of self-reported data (each subject's assessment of pain/ discomfort to a tested parameter) and the challenge to uniformly administer each parameter's assessment since simple tools and not precision instruments were used (with the exception of skin temperature). CONCLUSIONS: TBP and objective sensory loss occur in 20% of patients with refractory long-standing CRPS.

The natural history of complex regional pain syndrome.

OBJECTIVE: Complex regional pain syndrome (CRPS) is a severe chronic pain condition characterized by sensory, autonomic, motor, and dystrophic signs and symptoms. This study was undertaken to expand our current knowledge of the evolution of CRPS signs and symptoms with duration of disease. METHOD: This was a retrospective, cross-sectional analysis using data extracted from a patient questionnaire to evaluate the clinical characteristics of CRPS at different time points of disease progression. Data from the questionnaire included pain characteristics and associated symptoms. It also included autonomic, motor, and dystrophic symptoms and also initiating events, ameliorating and aggravating factors, quality of life, work status, comorbid conditions, pattern of pain spread, family history, and demographics. Comparisons were made of different parameters as they varied with disease duration. RESULTS: A total of 656 patients with CRPS of at least 1-year duration were evaluated. The average age of all participants was 37.5 years, with disease duration varying from 1 to 46 years. The majority of participants were white (96%). A total of 80.3% were females. None of the patients in this study demonstrated spontaneous remission of their symptoms. The pain in these patients was refractory showing only modest improvement with most current therapies. DISCUSSION: This study shows that although CRPS is a progressive disease, after 1 year, the majority of the signs and symptoms were well developed and although many variables worsen over the course of the illness, the majority demonstrated only moderate increases with disease duration.

Self-reported vs measured body mass indices in migraineurs.

OBJECTIVE: To compare and contrast body mass indices calculated based on self-reported height and weight as compared with measured height and weight in migraine patients. BACKGROUND: Obesity is a risk factor for multiple neurological disorders including stroke, dementia, and migraine chronification. In addition, several cytokines and adipocytokines associated with migraine are modulated by body mass. The body mass index (BMI) is a commonly used anthropometric measure to estimate total body fat and is often calculated based on patient's self-reported height and weight. METHODS: This was a retrospective study evaluating consecutive migraine patients presenting to a headache clinic.Demographic characteristics and self-reported height and weight were obtained from a standardized questionnaire that each new patient completes upon presentation to the clinic. In addition, as depression has been shown to be associated with both migraine and obesity, information in regards to major depression utilizing the Patient Healthcare Questionnaire-9 was extracted as well. Following completion of the questionnaire, body mass indices are routinely measured, with height measured to the nearest 0.5 inch utilizing a mounted stadiometer, and weight measured with a standard scale to the nearest 0.5 lb. After this information was extracted from the charts, BMI was then calculated for both self-reported and measured body mass indices.Using the measured body mass indices as a standard, this was then compared and contrasted to the patient's self-reported body mass indices. RESULTS: A total of 110 patients were included in the study. Patients were predominantly female (91%) with a mean age of 38.6 +/- 11.6 years. Of the total patients included, no significant difference in self-reported height (mean 64.7 +/- 3.1 inches) as compared with measured height (mean 64.5 +/- 3.4 inches) was seen, P = .463. However, self-reported weight (169 +/- 41.3) was underestimated as compared with the measured weight (173.5 +/- 43.2), P = .001. And, the self-reported BMI (28.4 +/- 6.8) was significantly less than the measured BMI (29.4 +/- 7.5), P < .001. CONCLUSIONS: In our study, the self-reported mean weight and BMI for migraineurs was significantly less than the measured mean weight and BMI, and was of greater magnitude in the obese migraineurs. This suggests that conclusions drawn from studies evaluating obesity utilizing self-reported BMI in migraineurs may undercall the effect of total body obesity.

Effect of transgene copy number on survival in the G93A SOD1 transgenic mouse model of ALS.

Transgenic mice expressing multiple copies of the G93A mutant form of SOD1 develop motor neuron pathology and clinical symptoms similar to those seen in patients with amyotrophic lateral sclerosis (ALS). The phenotype of these mice is dependent on the number of transgene copies in their genome. Changes in transgene copy number, although rare, can sometimes occur while mating due to intra locus recombination events during meiosis. The objective of this study was to develop a real time quantitative PCR method to determine changes in transgene copy number in these mice and to evaluate the effect of transgene copy number on the phenotype of the G93A SOD1 mouse model of ALS.