There is an increasing interest in understanding the biological mechanism underpinning fibromyalgia (FM) and chronic fatigue syndrome (CFS). Despite the presence of mixed findings in this area, a few biological systems have been consistently involved, and the increasing number of studies in the field is encouraging. This chapter will focus on inflammatory and oxidative stress pathways and on the neuroendocrine system, which have been more commonly examined. Chronic inflammation, together with raised levels of oxidative stress and mitochondrial dysfunction, has been increasingly associated with the manifestation of symptoms such as pain, fatigue, impaired memory, and depression, which largely characterise at least some patients suffering from CFS and FM. Furthermore, the presence of blunted hypothalamic-pituitary-adrenal axis activity, with reduced cortisol secretion both at baseline and in response to stimulation tests, suggests a role for the hypothalamic-pituitary-adrenal axis and cortisol in the pathogenesis of these syndromes. However, to what extent these systems' abnormalities could be considered as primary or secondary factors causing FM and CFS has yet to be clarified.

BackgroundThe connection between psychopathology and tinnitus is complex and not adequately studied. The aim of this study is to investigate the relationship between tinnitus and psychiatric comorbidities from different points of view: categorical, dimensional, temperamental, and perceived stress level.MethodsTwo hundred and thirty-nine patients affected by tinnitus were recruited between January and October 2012. Patients underwent a preliminary battery of tests including the Tinnitus Handicap Inventory (THI), Symptom Check List (SCL90-R), Temperament and Character Inventory (TCI), and Stress-Related Vulnerability Scale (VRS), and eventually a full psychiatric evaluation.ResultsOne hundred and fourteen patients (48% of the total sample) presented psychiatric comorbidity. Among these, a higher prevalence of depression, somatization, obsession, and anxiety was found. More than 41% of patients affected by decompensated tinnitus reported a family history of psychiatric disorders. Significant positive correlations between the psychopathological screening tools (SCL90-R and VRS) and THI were found. Patients affected by comorbid psychiatric disorder showed specific temperamental and characterial predispositions.ConclusionPsychiatric comorbidity in subjects affected by tinnitus is frequent. Stress can be considered as a factor leading to damage and dysfunction of the auditory apparatus. The vulnerability to neurotic disorders and the lack of coping capabilities can play a critical role in the clinical history of patients affected by severe tinnitus.

A sodium lactate test was performed during the premenstrual phase in 35 women suffering from prospectively confirmed premenstrual syndrome (PMS) and in 16 controls in order to assess whether these patients were sensitive to this test and whether this sensitivity was accounted for primarily by the presence of concomitant panic disorder. Patients with PMS also underwent the Structured Clinical Interview for the DSM-III-R (SCID) to determine the presence of co-morbid anxiety and/or mood disorders. Only 31% of the PMS patients were free from a depressive/anxiety disorder, while nine patients met criteria for panic disorder, and the remaining 15 subjects were diagnosed as having anxiety and/or mood disorders. Lactate infusion induced panic attacks in 22 subjects (62.9%) and two controls (12.5%). Panickers were equally distributed among PMS patients with or without a concurrent anxiety/mood disorder. Although cardiovascular responses to lactate were similar among PMS patients regardless of the presence of concomitant anxiety/mood disorders, both plasma cortisol levels and panic and mood scores were higher during the test in those patients with concomitant panic disorder. These results suggest that PMS patients display an increased sensitivity to lactate, which is not primarily accounted for by the presence of co-morbid panic disorder.

In the last few decades there has been a growing interest in the role of psychoneuroimmunological dysfunction in neuropsychiatric disorders. This article presents recent advances in the literature, from preclinical and clinical studies, suggesting that mood and anxiety disorders are, at least in part, conditions in which the inflammatory system is activated. The evidence-base comprises alterations in the peripheral immune systems of patients with mood or anxiety disorders, together with the development of depressionand anxiety-like symptoms induced by inflammatory agents. The reported anti-inflammatory effects of current psychotropic medications as well as the efficacy of anti-inflammatory medications in treating symptoms of depression and anxiety are also reviewed. Finally, potential mechanisms mediating the link between inflammation and symptomatology presented in these neuropsychiatric illnesses are discussed as well.

Introduction. Comorbid psychiatric disorders are frequent among patients affected by tinnitus. There are mutual clinical influences between tinnitus and psychiatric disorders, as well as neurobiological relations based on partially overlapping hodological and neuroplastic phenomena. The aim of the present paper is to review the evidence of alterations in brain networks underlying tinnitus physiopathology and to discuss them in light of the current knowledge of the neurobiology of psychiatric disorders. Methods. Relevant literature was identified through a search on Medline and PubMed; search terms included tinnitus, brain, plasticity, cortex, network, and pathways. Results. Tinnitus phenomenon results from systemic-neurootological triggers followed by neuronal remapping within several auditory and nonauditory pathways. Plastic reorganization and white matter alterations within limbic system, arcuate fasciculus, insula, salience network, dorsolateral prefrontal cortex, auditory pathways, ffrontocortical, and thalamocortical networks are discussed. Discussion. Several overlapping brain network alterations do exist between tinnitus and psychiatric disorders. Tinnitus, initially related to a clinicoanatomical approach based on a cortical localizationism, could be better explained by an holistic or associationist approach considering psychic functions and tinnitus as emergent properties of partially overlapping large-scale neural networks.