Among Early Appearing Non-Motor Signs of Parkinson's Disease, Alteration of Olfaction but Not Electroencephalographic Spectrum Correlates with Motor Function

Hyposmia correlates with axial signs and gait disorder in Parkinson's disease: an Italian Olfactory Identification Test study

BACKGROUND

Olfactory dysfunction is a non-motor symptom and an important biomarker of Parkinson's disease (PD) because of its high prevalence (> 90%). Whether hyposmia correlates with motor symptoms is unclear. In the present study, we aim to investigate the relationship between olfactory impairment with both motor and non-motor features and disease variables (disease duration, stage, and severity).

METHODS

One-hundred fifty-four PD patients were evaluated. Odor identification ability was tested using Italian Olfactory Identification Test (IOIT). A comprehensive spectrum of motor and non-motor features was assessed. Cognitive function was investigated through MMSE. Patients were divided into 3 different clinical phenotypes using UPDRS-III: tremor-dominant type (TDT), akinetic-rigid type (ART), and mixed type (MXT).

RESULTS

Three of the 33 IOIT items were most frequently misidentified: basil (74.3%), coffee (66.9%), and mushroom (59.6%). Hyposmia was found in 93%. Hyposmic patients were older than controls (p = 0.01). Hoehn & Yahr (H&Y) score of 2 or greater was associated with higher probability of being hyposmic (OR = 5.2, p = 0.01). IOIT score did not significantly differ between TDT, ART, and MXT of analyzed PD patients. Performance to IOIT inversely correlated with age (p < 0.01), disease duration (p = 0.01), and H&Y score of 2 or higher (p < 0.01). Clinical features that associated with higher IOIT score were freezing of gait (FOG) (p < 0.001) and camptocormia (p < 0.05).

CONCLUSIONS

In our cohort, IOIT scores showed a positive correlation with axial motor signs, but not with non-motor symptoms. IOIT may be a useful tool not only for supporting PD diagnosis but also for providing prognostic information about motor function.

High-frequency multimodal training with a focus on Tai Chi in people with Parkinson's disease: a pilot study

Background and objectives

Cognitive decline is an important and common complication in patients with Parkinson's disease (PD) since it significantly reduces the quality of life. A breakthrough in treating and preventing cognitive decline in PD remains to be achieved. This study aimed to evaluate the effectiveness of high-frequency and intensive multimodal training in improving motor and cognitive function.

Methods

Twenty-eight patients diagnosed with idiopathic PD completed a comprehensive neuropsychological test battery and were neurologically examined. The patients of the intervention group (n = 15) underwent 2 weekly sessions of Tai Chi therapy over 4 weeks and participated in an individually tailored training program consisting of two modules (smartphone-based speech training and cognitive training). A matched control group consisted of n = 13 patients with PD who received computer-assisted cognitive training. The data were analyzed with repeated-measures ANOVA.

Results

Four weeks of high-frequency training showed significant effects on verbal and figural episodic memory and visuospatial function in the intervention group. Compared to the control group, the cognitive performance of the intervention group improved significantly in visuospatial function and figural episodic memory. A significant improvement was also shown in the intervention group in the Tinetti Mobility Test and the Epworth Sleepiness Scale. The significant effects in the Tinetti mobility test remained after the 6 months follow-up. After the intervention, the patients reported high motivation and satisfaction with the multimodal training.

Conclusion

In patients with PD, a multimodal training program not only improves gait and stability but may also contribute to improving cognition.

Clinical trial registration

ClinicalTrials.gov Identifier: NCT04103255; https://register.clinicaltrials.gov/prs/app/action/LoginUser?ts=1&cx=-jg9qo4.

Short- and long term hyposmia, hypogeusia, dysphagia and dysphonia after facial burn injury - A prospective matched cohort study

BACKGROUND

Facial burns frequently occur in occupational or household accidents. While dysphagia and dysphonia are known sequelae, little is known about impaired smell and taste after facial burns.

METHODS

In a prospective observational controlled study, we evaluated hyposmia via the Sniffin' Stick Test (SnS), hypogeusia via a taste strip test, and dysphonia and dysphagia via validated questionnaires acutely and one-year after burn, respectively. A matched control group consisting of a convenience sample of healthy volunteers underwent the same assessments.

RESULTS

Fifty-five facial burn patients (FB) and 55 healthy controls (CTR) were enrolled. Mean burn size was 11 (IQR: 29) % total body surface area (TBSA); CTR and FB were comparable regarding age, sex and smoking status. Acutely, hyposmia was present in 29% of the FB group (CTR: 9%, p = 0.014) and burn patients scored worse on the SnS than CTR (FB: 10; CTR: 11; IQR: 2; p = 0.013). Hyposmia per SnS correlated with subjective self-assessment. Hyposmia and SnS scores improved over time (FB acute: 10.5 IQR: 2; FB one year: 11; IQR: 2; p = 0.042) and returned to normal at one-year post burn in most patients who completed the study (lost to follow-up: 21 patients). Taste strip scores were comparable between FB and CTR, as was the acute prevalence of dysphagia and dysphonia.

CONCLUSION

Hyposmia acutely after facial thermal trauma appeared frequently in this study, especially when complicated by inhalation trauma or large TBSA involvement. Of all complete assessments, a fraction of burn patients retained hyposmia after one year while most improved over time to normal. Prevalence of dysphonia, dysphagia and hypogeusia was comparable to healthy controls in this study, perhaps due to overall minor burn severity.

Olfaction and declarative memory in aging: a meta-analysis

Olfactory and declarative memory performances are associated, as both functions are processed by overlapping medial-temporal and prefrontal structures and decline in older adults. While a decline in olfactory identification may be related to a decline in declarative memory, the relationship between olfactory detection threshold and declarative memory remains unclear. In this meta-analysis, we assessed (i) the relationship between olfactory identification/detection threshold and verbal declarative memory in cognitively normal older adults, and (ii) the effect of age on these relationships. We included articles from PsychNet, PubMed, and Academic Search Complete according to the following criteria: (i) inclusion of cognitively normal older adults; (ii) assessment of episodic or semantic memory; and (iii) assessment of olfactory identification or detection threshold. Seventeen studies and 22 effect sizes were eligible and included in this meta-analysis. Olfactory identification was associated with episodic (small effect size: r = 0.19; k = 22) and semantic memory (small effect size: r = 0.16; k = 23). Similarly, the olfactory detection threshold was associated with both episodic (small to medium effect size: r = 0.25; k = 5) and semantic memory (small effect size: r = 0.17; k = 7). Age was found to moderate the relationship between olfactory detection threshold and memory performance. Both olfactory identification and detection threshold performances are associated with declarative memory in older adults, and age only moderates the relationship between olfactory detection threshold and declarative memory performances.

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.

Systematic review and meta-analysis of Sniffin Sticks Test performance in Parkinson's disease patients in different countries

INTRODUCTION

Olfaction impairment occurs in about 90% of patients with Parkinson's disease. The Sniffin Sticks Test is a widely used instrument to measure olfactory performance and is divided into three subtests that assess olfactory threshold, discrimination and identification. However, cultural and socioeconomic differences can influence test performance.

OBJECTIVES

We performed a systematic review and meta-analysis of the existent data about Sniffin Sticks Test performance of Parkinson's disease patients and healthy controls in different countries and investigated if there are other cofactors which could influence the olfactory test results. A subgroup analysis by country was performed as well as a meta-regression using age, gender and air pollution as covariates.

RESULTS

Four hundred and thirty studies were found and 66 articles were included in the meta-analysis. Parkinson's disease patients showed significantly lower scores on the Sniffin Sticks Test and all its subtests than healthy controls. Overall, the heterogeneity among studies was moderate to high as well as the intra-country heterogeneity. The subgroup analysis, stratifying by country, maintained a high residual heterogeneity.

CONCLUSION

The meta-regression showed a significant correlation with age and air pollution in a few subtests. A high heterogeneity was found among studies which was not significantly decreased after subgroup analysis by country. This fact signalizes that maybe cultural influence has a small impact on the Sniffin Sticks Test results. Age and air pollution have influence in a few olfactory subtests.

Clinical correlates of quantitative EEG in Parkinson disease: A systematic review

OBJECTIVE

To assess the relevance of quantitative EEG (qEEG) measures as outcomes of disease severity and progression in Parkinson disease (PD).

METHODS

Main databases were systematically searched (January 2018) for studies of sufficient methodologic quality that examined correlations between clinical symptoms of idiopathic PD and cortical (surface) qEEG metrics.

RESULTS

Thirty-six out of 605 identified studied were included. Results were classified into 4 domains: cognition (23 studies), motor function (13 studies), responsiveness to interventions (7 studies), and other (10 studies). In cross-sectional studies, EEG slowing correlated with global cognitive impairment and with diffuse deterioration in other domains. In longitudinal studies, decreased dominant frequency and increased θ power, reflecting EEG slowing, were biomarkers of cognitive deterioration at an individual level. Results on motor dysfunction and treatment yielded contrasting findings. Studies on functional connectivity at an individual level and longitudinal studies on other domains or on connectivity measures were lacking.

CONCLUSION

qEEG measures reflecting EEG slowing, particularly decreased dominant frequency and increased θ power, correlate with cognitive impairment and predict future cognitive deterioration. qEEG could provide reliable and widely available biomarkers for nonmotor disease severity and progression in PD, potentially promoting early diagnosis of nonmotor symptoms and an objective monitoring of progression. More studies are needed to clarify the role of functional connectivity and network analyses.