Chronic Pain Patients, CRPS 1 & 2

A debate is currently raging as to whether diagnoses, such as fibromyalgia and complex regional pain syndrome 1, can be classified as neuropathic. Our NPS cut-off score results suggest that these diagnoses may have a neuropathic pain component. The reliability and validity of our NPS method will need to be tested further in other neuropathic pain models, such as diabetic peripheral neuropathic pain.

Study Suggests Fibromyalgia Pain is Neuropathic

In the March issue of the journal Pain Medicine, researchers at three institutions in Florida conducted a study to determine whether the neuropathic pain scale (NPS) can be used to classify chronic pain patients (CPPs) as having primarily neuropathic vs non-neuropathic pain, as well as to determine whether there is a cut-off score that can be used reliably to make this distinction between types of pain. This study evaluated 305 chronic pain patients (CPPs) admitted to The Rosomoff Pain Center (Miami, FL). All were administered the NPS, a diagnostic tool designed to assess the distinct pain qualities associated with neuropathic pain, and were given a diagnosis on the basis of a physical examination and all available test results.

Using patients known to have neuropathic or non-neuropathic pain conditions as a reference, esearchers were able to derive "an NPS cut-off score above which CPPs would be classified as having neuropathic pain." Patients who had diagnoses of myofascial pain syndromes, spinal stenosis, epidural fibrosis, fibromyalgia, complex regional pain syndromes, and failed back surgery syndrome, a predicted NPS score was calculated and compared with the cut-off score.

The NPS appeared to be able to separate CPPs into neuropathic pain vs non-neuropathic pain subtypes. The cut-off score the researchers derived was 5.53 on the NPS. Myofascial pain syndrome and spinal stenosis had scores lower than this cut-off score at 3.81 and 4.26, respectively - Therefore they did not meet the criteria for neuropathic pain. Epidural fibrosis, fibromyalgia, complex regional pain syndromes, and failed back surgery syndrome had predictive scores higher than the cut-off score at 6.15, 6.35, 6.87, 9.34, and 7.19, respectively. Thus, these syndromes did meet the qualifications for neuropathic pain according to this study's criteria. The researchers conclude that the NPS does appear to be able to discriminate between patients experiencing neuropathic and non-neuropathic pain.

Pain Medicine, Vol. 9, No. 2. (March 2008), pp. 149-160.

David A. Fishbain MDFAPA, John E. Lewis PhD, Robert Cutler PhD, Brandly Cole PsyD, Hubert L. Rosomoff MDDMedScFAAPM, Rennée S. Rosomoff BSNMBA (2008)
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1526-4637.2007.00302.x

Insomnia, Depression, Anxiety, Mood disorders

Insomnia Patients Often Denied Sleep Treatment When They Have Mental Health Conditions

ScienceDaily (2008-02-07) -- Patients with insomnia who are diagnosed with accompanying mental health ailments often are not prescribed medication that will help them sleep -- which could then make related anxiety or depression worse, new research suggests. Scientists examining treatment patterns for insomniacs say that their findings suggest that many doctors appear to be reluctant to prescribe sleep aids, even those that pose no risk of dependence, if patients also have depression, anxiety or mood disorders. ... > read full article

Alphabet Soup - CRPS (RSD) FMS & WBC's

Immunological Changes in Fibromyalgia & Other Chronic Pain Conditions?

The newest issue of the medical journal Neuroimmunomodulation [2008 Feb 1;14(5):272-280] includes the results of a study conducted by Department of Anesthesiology of Ludwig Maximilians University, Munich, Germany.

The study address immunological changes in chronic pain patients, specifically complex regional pain syndrome (CRPS) and fibromyalgia (FMS), both of which the researchers describe as "chronic pain syndromes occurring in highly stressed individuals.

"Despite the known connection between the nervous system and immune cells, information on distribution of lymphocyte subsets under stress and pain conditions is limited. Lymphocytes are white blood cells that play a critical role in the body's defenses. They include T cells, B cells, and natural killer cells. They also modulate the activities of other cells.

The researchers performed a comparative study of 15 patients with CRPS, 22 patients with FMS and 37 age- and sex-matched healthy controls. Their aim was to investigate the influence of pain and stress on lymphocyte number, subpopulations and the Th1/Th2 cytokine ratio in T lymphocytes.

Lymphocyte numbers did not differ between the groups studied. However, when the subtypes of lymphocytes were studied using quantitative analyses, it became evident that there was "a significant reduction of cytotoxic CD8+ lymphocytes in both CRPS... and [fibromyalgia]... patients as compared with healthy controls. Additionally, CRPS patients were characterized by a lower percentage of IL-2-producing T cell subpopulations reflecting a diminished Th1 response in contrast to no changes in the Th2 cytokine profile."

The article concludes that future studies are necessary in order to answer "whether such immunological changes play a pathogenetic role in CRPS and [FMS] or merely reflect the consequences of a pain-induced neurohumoral stress response, and whether they contribute to immunosuppression in stressed chronic pain patients."

Monday, February 04, 2008