Changes in Hippocampal Metabolites After Effective Fibromyalgia Treatment

The Clinical Journal of Pain just published a case study that evaluates the impact of fibromyalgia on hippocampal brain metabolite ratios. Researchers at the Department of Family Medicine, Anesthesiology and Psychiatry at Louisiana State University's Biomedical Research Institute based this case study on the results of previous studies that used single voxel magnetic resonance spectroscopy (1H-MRS) to reveal an association between fibromyalgia and disruptions in hippocampal brain metabolite ratios in fibromyalgia patients with no psychiatric conditions. The hippocampus is an area of the brain located in the temporal lobes and near the amygdala. It is part of the limbic system and is involved in long-term memory (it's the first area to be affected by Alzheimer's Disease) as well as spatial navigation. It is extremely vulnerable to stress.

Exposure to stress is considered a risk factor for the development and exacerbation of fibromyalgia symptoms. Basic science has demonstrated the hippocampus to be exquisitely sensitive to the effects of stressful experience, which results in changes including alterations in metabolite content and frank atrophy.

The case study detailed in the report is of a 47-year old female fibromyalgia patient who, when evaluated, was shown to have a "profound depression of the ratio of N-acetylaspartate to creatine in her right hippocampus" when she participated in another study assessing brain metabolite disturbances in fibromyalgia. This irregularity had been diagnosed using single voxel proton magnetic resonance spectroscopy. The research team came up with an individualized treatment strategy based on the "physiological abnormalities associated with the disorder and symptoms that characterized the patient's unique clinical profile." What they discovered upon evaluating her after nine months of treatment was an "improvement in her clinical profile and normalization of the NAA/Cr ratio within her right hippocampus." The researchers concluded that:

Therapeutic strategies aimed at demonstrable lesions associated with fibromyalgia appear to represent rational targets for pharmacological intervention. The rationale for development of novel pharmacotherapies for this unusual disorder is discussed.

Study Details: Clin J Pain. 2009 Nov-Dec;25(9):810-4. PMID: 19851163.

Elavil (Amitryptiline) vs. Physical Therapy - What Works Better for Fibromyalgia?

In a recently published study entitled Effect of amitriptyline vs. physiotherapy in management of fibromyalgia syndrome: What predicts a clinical benefit?, researchers in Maharashtra, India, compared the efficacy of treating fibromyalgia with amitriptyline (Elavil) versus physiotherapy. The research subjects were 175 fibromyalgia patients at a rural hostpial in Central India. After six months of treatment with physical therapy or amitryptiline, they conducted a follow-up in which they assessed the benefits of the two different approaches. They used the fibromyalgia impact questionnaire (FIQ) score as their primary measure. They found a "significant but similar (P=0.82) improvement in disability in both groups." They found that a "high FIQ score at baseline and low socioeconomic status scores were significant predictors of benefit," and concluded that amitryptiline and physical therapy are of equal efficacy in improving fibromyalgia symptoms over a 6-month period.

Study details: PMID: 19884743. J Postgrad Med. 2009 Jul-Sep;55(3):159-60.

Yet Another Study Showing Decreased Gray Matter in the Brains of Fibromyalgia Patients

In their study findings, titled Decreased Gray Matter Volumes in the Cingulo-Frontal Cortex and the Amygdala in Patients With Fibromyalgia, researchers at the University Hospital Münster (Germany) present the results of their investigation into the gray matter of fibromyalgia patients. Because previous studies supported the assertion that fibromyalgia involves central pain augmentation, they aimed to find out "whether structural changes in areas of the pain system are additional preconditions for the central sensitization in fibromyalgia." To do so, they performed MRI's and a neuroimaging technique called voxel based morphometry on 14 fibromyalgia patients and 14 healthy controls. They scanned and analyzed the brains of their subjects, finding that there were "[r]egional differences of the segmented and normalized gray matter volumes in brain areas of the pain system between both groups." They analyzed the "correlation of disease-related factors with gray matter volumes." The researchers found that there was a decrease in gray matter volume in the prefrontal cortex, the amygdala, and the anterior cingulate cortex (ACC) of fibromyalgia patients.

Our results suggest that structural changes in the pain system are associated with fibromyalgia. As disease factors do not correlate with reduced gray matter volume in areas of the cingulo-frontal cortex and the amygdala in patients, one possible interpretation is that volume reductions might be a precondition for central sensitization in fibromyalgia.

Biochemical Basis of Myofascial Pain Syndrome

Uncovering the biochemical milieu of myofascial trigger points using in vivo microdialysis: an application of muscle pain concepts to myofascial pain syndrome is the title of an article published by members of the Rehabilitation Medicine Department of the National Institutes of Health (Bethesda, MD). The article "discusses muscle pain concepts in the context of myofascial pain syndrome (MPS) and summarizes microdialysis studies that have surveyed the biochemical basis of this musculoskeletal pain condition." Myofascial pain condition is extremely common in fibromyalgia patients, though it is unclear whether MPS can cause fibromyalgia or vice versa.

The pathophysiology of MPS is "only beginning to be understood due to its enormous complexity." It is considered to be characterized by the presence of myofascial trigger points (MTrPs), which should not be confused with fibromyalgia tender points. Myofascial trigger points are hyperirritable nodules located within a taut band of skeletal muscle. These bumps or bands can usually be felt through the skin. The authors of this article write that "MTrPs may be active (spontaneously painful and symptomatic) or latent (non-spontaneously painful)." Active trigger points can refer pain to other parts of the body as well as being painful to direct touch.

Painful MTrPs activate muscle nociceptors that, upon sustained noxious stimulation, initiate motor and sensory changes in the peripheral and central nervous systems. This process is called sensitization.

The researchers sought to discover what influences this sensitization process using a microdialysis technique that was created in order to "quantitatively measure the biochemical milieu of skeletal muscle."

They found significant biochemical differences between active and latent myofascial trigger points (MTrPs) as well as biochemical differences between healthy muscle tissue and muscle tissue afflicted with trigger points.

40% of Patients with Cervical (Neck) Myofascial Pain Syndrome Also Have Fibromyalgia

A study from Selcuk University in Turkey (PMID: 19085177) recently analyzed the demographic features, clinical findings and functional status of a group of cervical (neck) myofascial pain syndrome patients. They evaluated the patients using the short form health survey (SF-36), pain and depression levels, patient demographics and physical examinations. They used the visual analog scale, Beck Depression Inventory, and medical history to evaluate the patients. A total of 82 patients had a diagnosis of cervical myofascial syndrome. Almost 88% of these patients were female, and they were around 37 years of age on average.

53.1% had trigger points in the trapezius muscle with high percentage of autonomic phenomena like skin reddening, lacrimation, tinnitus and vertigo. 58.5% of the series had suffered from former cervical trauma and 40.2% also had fibromyalgia syndrome and 18.5% had benign Joint hypermobility syndrome.

They concluded that younger female patients who present with autonomic system dysfunctions and early onset cervical spine injury should be "examined for cervical myofascial pain syndrome and also for fibromyalgia syndrome since this study demonstrated a high percentage of fibromyalgia syndrome in these patients."