Evaluation of Olfactory and Gustatory Functions in Patients With Fibromyalgia Syndrome: Its Relationship With Anxiety, Depression, and Alexithymia

Fibromyalgia is linked to increased subjective sensory sensitivity across multiple senses

Changes in subjective sensory sensitivity - reporting sensory stimuli as being atypically intense or weak - are a transdiagnostic symptom of several disorders. The present study documents for the first time the sensory sensitivity profile of fibromyalgia, taking a questionnaire measure that asks about different sensory modalities and both hyper- and hyposensitivity (the Glasgow Sensory Questionnaire, GSQ). The fibromyalgia group had higher overall scores on this measure. This was linked more strongly to sensory hypersensitivity and was pervasive across all senses that were surveyed. Although differences in hyposensitivity were found, these were sporadic (perhaps linked to the symptoms of fibromyalgia itself) and did not resemble the pattern documented for autism (e.g., self-stimulating and repetitive behaviours were not a feature of fibromyalgia). We suggest that individual differences in subjective sensory hypersensitivity may be a multisensory dispositional trait linked to fibromyalgia which ultimately becomes most pronounced for pain.

Motor Dysfunctions in Fibromyalgia Patients: The Importance of Breathing

The classification of fibromyalgia (FM) is not always immediate and simple, with the time from the first diagnosis, compared to the onset of symptoms, of a few years. Currently, we do not have instrumental or biochemical tests considered as gold standards; the clinician will make a diagnosis of FM based on the patient's medical history and subjective assessment. The symptoms can involve physical, cognitive and psychological disorders, with the presence of pain of different origins and classifications: nociplastic, nociceptive and neuropathic pain. Among the symptoms highlighted, postural disorders and neuromotor uncoordination emerge, whose functional dysfunctions can increase the mortality and morbidity rate. An alteration of the diaphragm muscle could generate such functional motor problems. Considering that the current literature underestimates the importance of breathing in FM, the article aims to highlight the relationship between motor and diaphragmatic difficulties in the patient, soliciting new points of view for the clinical and therapeutic framework.

Alexithymia modulates the attitudes towards odors but not the olfactory abilities or the affective reactions to odors

Although emotion and olfaction are closely linked, only a few studies have investigated olfactory processing in alexithymia, a condition characterized by altered emotional processing. These results do not allow comprehensive conclusions on whether individuals with alexithymia present lower olfactory abilities or only altered affective reactions and awareness of odors. Three pre-registered experiments were conducted to clarify this relation. We assessed olfactory functions, the affective qualities of odors, the awareness of odors, the attitudes towards them, and the ability to form olfactory images in the mind. Bayesian statistics were used to assess differences between low, medium and high alexithymia groups, and Linear Mixed Models (LMMs) were applied to investigate the modulation of the affective and cognitive components of alexithymia. We observed that individuals with a high level of alexithymia presented the same olfactory abilities, and did not show differences in their rating of odors compared to individuals with low alexithymia levels, while they reported lower levels of social and common odor awareness and a more indifferent attitude towards odors. Olfactory imagery was not affected by alexithymia level, and the affective and cognitive components of alexithymia, when considered separately, modulated olfactory perception differently. Learning more about olfactory perception in individuals with alexithymia leads to a better understanding of how alexithymia impacts the perception of hedonic stimuli coming from different sensory modalities. Our results imply that treatment goals for alexithymia should be the enhancement of the conscious perception of odors, supporting the use of mindfulness-based protocols in the alexithymia treatment.

The relationship of alexithymia to pain and other symptoms in fibromyalgia: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

People with fibromyalgia (FM) often report having difficulty with emotional identification and expression, and this "alexithymia" may contribute to their pain and other symptoms. Multiple studies have assessed alexithymia in FM, and we systematically reviewed and meta-analyzed this literature to: (a) describe the prevalence of alexithymia in people with FM; (b) compare the level of alexithymia in FM to both healthy controls and controls with other pain conditions; and (c) determine the association of alexithymia to pain intensity, depression, and anxiety in people with FM.

DATABASES AND DATA TREATMENT

Following PRISMA guidelines, we searched multiple databases (Scopus, PubMed/MEDLINE, Embase, Web of Science, PsycINFO and Google Scholar) from inception to May 31, 2022. Study quality was assessed with The Joanna Briggs Institute (JBI) tools for cross-sectional studies, and STATA:17 was used for meta-analysis. A total of 32 studies met eligibility criteria and were included in meta-analyses.

RESULTS

The prevalence of alexithymia in FM averaged 48%. People with FM had substantially higher alexithymia than healthy controls (SMD = 1.00; 95% CI: 0.79 to 1.22), as well people with other pain-related conditions (SMD = 0.35, 95% CI = 0.04 to 0.65), particularly rheumatoid arthritis (SMD = 0.49; 95% CI: 0.08-0.91). Alexithymia was positively associated with pain intensity (r = 0.24), anxiety (r = 0.50), and depression (r = 0.41) among people with FM.

CONCLUSIONS

Due to the high level of alexithymia in people with FM and the positive relationship of alexithymia with pain and psychological distress, interventions to improve emotional awareness, expression, and processing in FM are recommended.

Beyond Face and Voice: A Review of Alexithymia and Emotion Perception in Music, Odor, Taste, and Touch

Alexithymia is a clinically relevant personality trait characterized by deficits in recognizing and verbalizing one's emotions. It has been shown that alexithymia is related to an impaired perception of external emotional stimuli, but previous research focused on emotion perception from faces and voices. Since sensory modalities represent rather distinct input channels it is important to know whether alexithymia also affects emotion perception in other modalities and expressive domains. The objective of our review was to summarize and systematically assess the literature on the impact of alexithymia on the perception of emotional (or hedonic) stimuli in music, odor, taste, and touch. Eleven relevant studies were identified. On the basis of the reviewed research, it can be preliminary concluded that alexithymia might be associated with deficits in the perception of primarily negative but also positive emotions in music and a reduced perception of aversive taste. The data available on olfaction and touch are inconsistent or ambiguous and do not allow to draw conclusions. Future investigations would benefit from a multimethod assessment of alexithymia and control of negative affect. Multimodal research seems necessary to advance our understanding of emotion perception deficits in alexithymia and clarify the contribution of modality-specific and supramodal processing impairments.