Association between olfactory loss and cognitive deficits in Parkinson's disease

OBJECTIVE

The aim of this study was to compare the cognitive deficits and olfaction in PD patients.

PATIENTS AND METHODS

In all, 42 PD patients and 38 controls were selected. All the individuals in both groups underwent cognitive assessment with the SCOPA-Cog neuropsychological battery and Mini-Mental State Examination (MMSE) and olfactory assessment with the Sniffin' Sticks Screening 12 Test. Parkinson's disease dementia (PDD) was diagnosed using the International Parkinson and Movement Disorder Society (MDS) criteria.

RESULTS

The prevalence of olfactory dysfunction in PD patients was 95.24% (40/42). There was no statistically significant difference in olfaction when compared to patients with PDD and PD without cognitive deficits (5.12 ± 3.25 vs. 6.71 ± 2.63, p = 0.115). Attention [r = 0.35, 95% CI = (0.05-0.59), p =  0.01] was the only cognitive domain correlated with olfactory loss in PD patients. There was a higher correlation among the scores of cognitive and olfactory assessments in controls, r=0.40 (95% CI = [0.09-0.64], p = 0.007), with MMSE.

CONCLUSION

The olfactory deficits prevalence in PD patients was significantly high. There may be a correlation between frontal lobe dysfunction and olfactory deficit.

Differentiating Between Apathy and Depression in Patients With Parkinson Disease Dementia

In Parkinson disease (PD), apathy and depression often overlap, making it difficult to differentiate between them. This study sought to analyze apathy and depression in patients with PD dementia (PDD). Forty patients were diagnosed with PDD using the Movement Disorder Society criteria. A statistically significant correlation was identified between worsening dementia and an improvement in depression ( r = .3695; r2 = .1365, 95% confidence interval [CI]: 0.0985 to 05.894, P = .0044) and between worsening dementia and worsening apathy ( r = -.2578, r2 = .0664, 95% CI: -0.5025 to .0251, P = .036). Depression had a greater correlation with advanced motor symptoms ( r = .4988, r2 = .2438, 95% CI: 0.2218-0.7013, P = .0005]. In conclusion, depression was associated with less advanced PDD and more intense motor features, while apathy was associated with more advanced cognitive impairment.

The perception of apathy by caregivers of patients with dementia in Parkinson's disease

Background

Apathy is one of the main neuropsychiatric symptoms in patients with Parkinson's disease (PD) and is associated with Parkinson's disease dementia (PDD).

Objective

To identify the characteristics of apathy in individuals with PDD according to caregiver perception.

Methods

Thirty-nine patients with PD according to MDS criteria for PDD were included. The following scales were used: the Hoehn and Yahr, the Unified Parkinson's Disease Rating Scale III, Scales for Outcomes in Parkinson's Disease-Cognition (SCOPA Cog), the Montgomery-Åsberg Depression Rating Scale (MADRS) and the Apathy Evaluation Scale (AES).

Results

A total of 97.4% of the patients showed results consistent with apathy. Analysis of question 14 of the AES revealed no correlation with the total result of all the questions [r=-1293, r²=0.0167, 95%CI (-0.4274 to 0.1940), P=0.2162], however, there was a correlation of responses to the same question with depression data on the MADRS scale [r=-0.5213, r²=0.2718, 95%CI (-0.7186 to -0.2464), P=0.00033].

Conclusion

Apathy is a disorder associated with PDD. However, the scoring scheme of the AES questions can lead to different interpretations of caregiver responses, highlighting limitations of the tool for use in studies of PDD.