Smell as a clinical-marker for functional limitations in multiple sclerosis: A pilot study

Exploring the Efficacy of a Remote Strategy-Based Intervention for People With Multiple Sclerosis With Everyday Memory Impairments: A Pilot Study

IMPORTANCE

This pilot study evaluates a remote strategy-based intervention for individuals with multiple sclerosis who experience everyday memory impairments. The intervention can potentially inform cognitive rehabilitation for this population.

OBJECTIVE

To investigate the feasibility and efficacy of an intervention (TELE-Self-GEN) to determine whether it can alleviate everyday memory impairments of individuals with multiple sclerosis.

DESIGN

Pretest-posttest.

SETTING

Community.

PARTICIPANTS

Ten adults with multiple sclerosis.

INTERVENTION

Six synchronous treatment sessions were delivered online via Zoom. The treatment protocol embedded a memory strategy (self-generated learning) within a metacognitive framework, including self-awareness and self-management strategies. The treatment emphasizes when and how self-generation should be used.

OUTCOME

Measurements assessed feasibility and participants' satisfaction with the intervention and its delivery method, as well as memory, everyday memory, and functional performance.

RESULTS

Participants expressed high satisfaction with the virtual treatment, highlighting its convenience as a key factor. Treatment resulted in improvements in memory performance, perceived memory ability in daily life, and functional performance.

CONCLUSIONS AND RELEVANCE

Results provide initial proof of concept in the utilization of a remotely delivered, strategy-based treatment approach to improve memory performance and functional abilities. The pilot data support a larger randomized clinical trial of the TELE-self-GEN. Plain-Language Summary: The results of this pilot study highlight the promising potential of TELE-self-GEN for people with multiple sclerosis (MS), who face memory challenges every day. This remotely delivered, strategy-based occupational therapy treatment approach, TELE-self-GEN, has the potential to significantly improve functional memory. The study participants reported improvements in their memory performance, perceived memory ability in daily life, and functional performance. These encouraging results serve as a foundation for more extensive clinical trials using TELE-self-GEN for people with MS.

Vitamin D levels and olfactory dysfunction in multiple sclerosis patients

OBJECTIVE

The objective was to explore the possible relationship between the serum vitamin D level and olfactory impairment in a population of multiple sclerosis (MS) patients in Guizhou, China.

METHODS

We included 25 patients with MS and 18 healthy controls (HCs) who were recruited from the Affiliated Hospital of Guizhou Medical University from February 2021 to September 2021. The University of Pennsylvania Smell Identification Test (UPSIT) was used to test the patients' sense of smell, and the level of serum 25-hydroxyethylene polyprotein D was measured.

RESULTS

Serum vitamin D levels and UPSIT scores were significantly different between the MS group and the control group (both p < 0.001). Moreover, a significant positive correlation emerged between vitamin D levels and UPSIT scores in MS patients (r = 0.537, p = 0.021).

CONCLUSIONS

The serum vitamin D level may be involved in the regulation of olfactory dysfunction in MS patients in Guizhou, China.

Olfactory function in Susac syndrome

OBJECTIVES

Susac syndrome is a rare autoimmune endotheliopathy involving the brain, retina, and inner ear. Olfactory dysfunction is a common early manifestation of several central nervous system diseases, including neurodegenerative diseases and autoimmune-mediated diseases such as Multiple Sclerosis. While the literature is abundant about the Susac syndrome classic triad of encephalopathy, branch retinal artery occlusion, and low-frequency sensorineural hearing loss, little is known about the extent of olfactory sense involvement.

METHODS

Using the Sniffin' Sticks test, this study evaluated olfactory function (identification and threshold) in ten recovering Susac syndrome patients under our clinic surveillance with a median of 3.1 (SD=1.53) years post-disease onset.

RESULTS

olfactory assessment by threshold and odor identification were within the normal range. No differences between recovering Susac syndrome patients to standard norms of odor identification and threshold were found.

CONCLUSIONS

Our findings do not support olfactory dysfunction in Susac syndrome and thereby, do not support olfactory assessment as a reliable biomarker for this condition.

Longitudinal Olfactory Patterns in Multiple Sclerosis: A Scoping Review and Implication for Use in Management of Disease

BACKGROUND

Although studies regarding multiple sclerosis (MS) and olfactory dysfunction (OD) have been previously described and summarized, there is not a sole review of longitudinal studies regarding the matter. This review examines the existing literature investigating MS and its effect on olfaction. In addition, the role of OD in the diagnosis and prognosis of MS is explored.

METHODS

A scoping review of the literature was performed covering longitudinal studies investigating MS and OD. Systematic searches of PubMed, Google Scholar, Web of Science, Embase, PsycInfo, Cumulative Index to Nursing and Allied Health Literature, AgeLine, and MEDLINE were performed using terms that encompassed MS and olfaction. The aim of this review was to build on the existing literature by summarizing only findings that were demonstrated longitudinally.

RESULTS

Of 6938 articles identified from the search, 9 met the inclusion criteria: longitudinal observation of relapsing-remitting or progressive MS. Olfaction was measured and scored using various testing arrays, and these scores were then correlated with a multitude of clinical markers. Across all studies, patients with MS demonstrated increased OD. Longitudinally, 2 contrasting patterns were identified: (1) clinical markers of acute inflammation correlated with an increased odor threshold and (2) clinical markers of neurodegeneration, or progression of disease, correlated with a decreased ability to discriminate and identify odors.

CONCLUSIONS

These studies suggest that olfaction is a dynamic, dependent variable of neurodegeneration, correlating with inflammation and clinical markers. This opens the door for future exploration of olfaction's relationship with MS diagnosis, characterization, and therapeutic response.

The effects of cognition, quality of life, and fatigue on olfactory function in patients with multiple sclerosis

AIM

The frequency of olfactory dysfunction in patients with Multiple Sclerosis (MS) has revealed very different results in studies. Some studies have shown that olfactory dysfunction may be associated with cognitive impairment and poor quality of life. In these studies, different odor tests and cognitive tests were used and different results were obtained.

MATERIALS AND METHODS

Forty literate patients over the age of 18 and 24 healthy volunteers of similar age and education were included in the study. Sniffin' Sticks Odor Test, California Verbal Learning Test II, Symbol Digit Modalities Test, Revised Brief Visuospatial Memory Test, Trail-Making Test, Quality of Life Short Form-36, Fatigue Impact Scale, Beck Depression Inventory, and Beck Anxiety Inventory were applied to the individuals.

RESULTS

Olfactory dysfunction was detected in 50 % of the patients. High disability rate, low cognitive functions, low quality of life, and fatigue were identified as the factors affecting olfactory function negatively. Odor discrimination and identification abilities were associated with disability level and cognitive functions, whereas quality of life was linked to odor threshold scores. The olfactory function and cognitive abilities of patients with progressive MS (n = 5) were worse than those of patients with relapsing remitting MS (n = 35).

CONCLUSION

Olfactory dysfunction is common in patients with MS and is associated with disability and quality of life. Olfactory function can be used in the follow-up of patients and olfactory dysfunction deserves further study as a metric that might emerge as a biomarker.

Olfactory Dysfunction Reflects Disease Progression in Japanese Patients with Multiple Sclerosis

Objective Olfactory dysfunction is an important clinical feature in patients with multiple sclerosis (MS). The incidence and extent of olfactory dysfunction are reportedly higher in secondary progressive (SP) MS than in relapsing and remitting (RR) MS. We investigated the use of olfactory dysfunction for evaluating the disease status of Japanese patients with MS. Methods Olfactory identification was evaluated using the Odor Stick Identification Test for the Japanese (OSIT-J) in patients with RRMS (n=40) and SPMS (n=11) and compared the findings with those of healthy controls (n=40). Patients with RRMS for more than 10 years (L-RRMS, n=10) were included in the RRMS group. The cognitive function was evaluated using the Japanese version of the Wechsler Adult Intelligence Scale, 3rd edition. The third ventricle width (3rd VW) was measured as a marker of central brain atrophy using magnetic resonance imaging. Results SPMS patients had significantly lower OSIT-J scores than RRMS and L-RRMS patients. More SPMS patients had OSIT-J scores below the lower limit of the normal score (LLN) than RRMS patients. The LLN effectively discriminated between RRMS and SPMS (sensitivity 70%, specificity 91.5%, area under the curve 0.933, 95% confidence interval 0.874-1.000). Patients with SPMS had a significantly lower processing speed and larger 3rd VW than those with RRMS or L-RRMS. Conclusion The olfactory dysfunction was worse, along with cognitive impairment and brain atrophy, in SPMS patients than in RRMS patients, independent of disease duration, in our Japanese population. This directly reflected the disease progression and may have been able to distinguish SPMS from RRMS, independent of ethnic and cultural background.

Investigating the association of mood and fatigue with objective and subjective cognitive impairment in multiple sclerosis

Discrepancies between subjective cognitive difficulties and objective measures of cognitive function in people with MS have been identified and may be related to mood and fatigue. The aim of the present study was to examine associations of depression and fatigue with discrepancies between subjective and objective cognitive functioning in pwMS. 177 participants with MS attending a University Hospital Department of Neurology MS Outpatient clinic completed the Brief International Cognitive Assessment for MS (BICAMS), MS Neuropsychological Questionnaire (MSNQ), Hospital Anxiety and Depression Scale (HADS) and Modified Fatigue Impact Scale (MFIS). To quantify the discrepancy between objective (BICAMS) and subjective (MSNQ) cognitive functioning, discrepancy scores were calculated by subtracting MSNQ z-score from composite BICAMS z-score. Based on their discrepancy score, participants were grouped as 'Underestimated', 'Overestimated' and 'Non-discrepant'. 39% of the total sample demonstrated poorer subjective cognitive functioning than their objective cognitive performance suggested ('Underestimated'). 23% of the total sample indicated lower objective scores than their subjective report suggests ('Overestimated'). 38% participants indicated relatively no discrepancy between objective and subjective cognitive measures ('Non-discrepant'). Significant differences were observed between the discrepancy groups in terms of depression and fatigue, with the 'Underestimated' group demonstrating greater levels of depression and fatigue (ps < .01). Regression analysis indicated that cognitive fatigue and depression significantly contributed to variance in subjective cognitive functioning. Our findings suggest that subjective reports of cognitive function may be influenced by depression and fatigue, emphasising the importance of cognitive, mood and fatigue screening as part of routine clinical care.

Not Only COVID-19: Involvement of Multiple Chemosensory Systems in Human Diseases

Chemosensory systems are deemed marginal in human pathology. In appraising their role, we aim at suggesting a paradigm shift based on the available clinical and experimental data that will be discussed. Taste and olfaction are polymodal sensory systems, providing inputs to many brain structures that regulate crucial visceral functions, including metabolism but also endocrine, cardiovascular, respiratory, and immune systems. Moreover, other visceral chemosensory systems monitor different essential chemical parameters of “milieu intérieur,” transmitting their data to the brain areas receiving taste and olfactory inputs; hence, they participate in regulating the same vital functions. These chemosensory cells share many molecular features with olfactory or taste receptor cells, thus they may be affected by the same pathological events. In most COVID-19 patients, taste and olfaction are disturbed. This may represent only a small portion of a broadly diffuse chemosensory incapacitation. Indeed, many COVID-19 peculiar symptoms may be explained by the impairment of visceral chemosensory systems, for example, silent hypoxia, diarrhea, and the “cytokine storm”. Dysregulation of chemosensory systems may underlie the much higher mortality rate of COVID-19 Acute Respiratory Distress Syndrome (ARDS) compared to ARDSs of different origins. In chronic non-infectious diseases like hypertension, diabetes, or cancer, the impairment of taste and/or olfaction has been consistently reported. This may signal diffuse chemosensory failure, possibly worsening the prognosis of these patients. Incapacitation of one or few chemosensory systems has negligible effects on survival under ordinary life conditions but, under stress, like metabolic imbalance or COVID-19 pneumonia, the impairment of multiple chemosensory systems may lead to dire consequences during the course of the disease.

International consensus statement on allergy and rhinology: Olfaction

BACKGROUND

The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O).

METHODS

Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence-based review, or evidence-based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus.

RESULTS

The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies.

CONCLUSION

This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.