Editorial Review (Thematic Issue: An Update on Central Sensitivity Syndromes and the Issues of Nosology and Psychobiology)

Abstract

Central sensitization (CS), simply defined as an amplified response of the central nervous system to peripheral input, is a concept of great importance in clinical medicine. It has helped to explain aspects of the pathophysiology of common diseases, e.g. fibromyalgia syndrome (FMS), irritable bowel syndrome, vulvodynia, headaches, chronic pelvic pain and other overlapping conditions (collectively called central sensitivity syndromes, or CSS). It also applies to pain of complex regional pain syndrome, osteoarthritis (OA), rheumatoid arthritis (RA) and post-operative pain. The pathology-pain gap in CSS is readily explained by CS. Many FMS and other CSS patients have peripheral pathology, e.g. nociceptive areas in the muscles, arthritis, small fiber neuropathy and inflammation. Pro-inflammatory cytokines are elevated in some patients. Identification of CS in patients with structural pathology, e.g. OA and RA, has helped to explain why not all patients benefit from nonsteroidal anti-inflammatory drugs or joint replacement surgery, and require therapy directed at CS. Glial cells are important in pain processing. Remarkable advances have been achieved in neuroimaging, including visualization of grey matter and white matter, not only during provoked pain but also pain at rest. Based on CS mechanisms, targeted individual therapy may now be possible. Appropriate nosology is important particularly for effective patient care. Dichotomy of neurochemical-structural ("functional") and structural ("organic") pathology should be abandoned; many patients have both. Psychobiology is also biology. Patient-blaming terms like somatization, somatizer and catastrophizing should be avoided. For therapy, both pharmacological and non- pharmacological approaches are important, including recognition of subgroups and person/patient-centered care.

Somatisation and function of HPA in fibromyalgia: an investigation using sham and true pain stimuli

“…Fibromyalgia (FM) often accompanies multiple chronic functional symptoms like pain, fatigue, sleep disorders, and irritable bowel syndrome [1]. This spectrum of illness might best be characterized as a condition of generalized sensory amplification of bodily experiences, generally, but not limited to, painful complaints.…”

Potential drug therapies for the treatment of fibromyalgia

“…Fibromyalgia (FM) is characterised by the core symptoms of generalized chronic pain, fatigue, stiffness, and sleep disturbance of variable intensity and thus considered to be a phenotype of a large spectrum of disorders that have substantial overlap [1][2][3][4][5]. In addition, the cognitive performance (working memory, verbal fluency, episodic memory) of FM patients is poor with the distraction of chronic pain and fatigue contributes to increased impairment of cognition [6,7].…”

“…In addition, the cognitive performance (working memory, verbal fluency, episodic memory) of FM patients is poor with the distraction of chronic pain and fatigue contributes to increased impairment of cognition [6,7]. The condition affects 2-4% of populations worldwide, is 7 times more prevalent in females than males and is complicated by the occurrence of co-morbidities which often belong to the family of CSS exhibiting similar symptoms [1][2][3][4][5].…”

Decrease of Serum IGF-1 Level is Not Associated With Obstructive Sleep Apnea in Fibromyalgia Patients

“…[2][3][4] In several studies which researched the etiopathogenesis of FMS, it is argued that it is a neuroendocrine disorder. 5 It is suggested that abnormalities in hormone levels or the deficiencies in hormonal responses to various stimuli might be effective in occurrence of FMS. 6,7 The major neuroendocrine disorder defined in patients with FMS is the decline in the release of growth hormone (GH) and insulin-like growth factor 1 (IGF-1).…”