A population-based study on combined markers for early Parkinson's disease.

The prerequisite for an earlier diagnosis of Parkinson's disease (PD) are markers that are both sensitive and specific for clinically definite PD and its prediagnosic phases. Promising candidates include enlarged hyperechogenicity of the substantia nigra (SN+) on transcranial sonography (TCS) and hyposmia. However, despite good sensitivity and specificity, both markers have yet failed to yield reliable predictions. We pursue the possibility of combined use in an ongoing population-based cohort. Subjects were recruited from 10,000 inhabitants of Luebeck/Germany aged 50 to 79 years and additional PD patients from our outpatient clinic. After neurological examination, 715 subjects were grouped into clinically definite PD (n = 106), possible prediagnostic PD (ppPD; n = 73), and a control group subdivided into healthy individuals (n = 283) and controls with diseases other than PD (n = 253). Subjects underwent TCS and smell testing. Sensitivity and specificity of SN+ and hyposmia were good for PD; however, positive predictive values (PPV) of both SN+ (5.2%) and olfaction (2.5%) were low. At least one positive/both positive markers were present in 33%/1% of healthy controls, 33%/2% of diseased controls, 62%/7% of ppPD, and 94%/51% of PD. When combining SN+ and hyposmia, PPV increased to 17.6%, with a sensitivity of 51% and a specificity of 98%. Both SN+ and hyposmia offer good enrichment towards PD and ppPD, are stable against other diseases, and the combination of markers highly increases specificity. However, if the combination of SN+ and hyposmia were used as criterion for PD diagnosis, almost half of clinically definite PD and more than 90% of ppPD would have been missed.

Qualitative Characteristics of Depression in Parkinson's Patients and Controls.

BACKGROUND: Depression is common in Parkinson's disease (PD); in light of typical PD pathology it may differ phenomenologically from depression in the general population. OBJECTIVE: To assess depressive symptoms in PD patients and control groups and compare symptom profiles. METHODS: After postal screening of 10,000 citizens of Lübeck, 642 participants were examined and the Beck Depression Inventory (BDI) was sufficiently answered by 477 subjects. Based on motor examinations, we distinguished PD patients, Healthy Controls (HC, no motor impairment), and Disease Controls (DC, motor impairment other than PD). RESULTS: The sample comprised 331 men and 311 women, aged 65 ± 8 years. Out of the overall sample, 198 (41.5%) had a BDI score ≥9. BDI results above 9 points occurred in 34.5% of HC, 50.3% of DC, and 42.4% of PD patients. Compared to the control groups (HC, DC) the PD patients endorsed more "dissatisfaction" and "loss of appetite" but less "feelings of guilt," "self-hate," and "loss of libido." CONCLUSION: Depressive symptoms are more frequent in PD patients compared to HC but not DC. Interestingly, the distribution of individual symptoms of the BDI differs between groups with an emphasis on loss of pleasure/enjoyment in the PD group, a symptom typically considered to be dopaminergically transmitted.

Cohort Profile: a population-based cohort to study non-motor symptoms in parkinsonism (EPIPARK).

Parkinson's disease is increasingly viewed as a complex disorder including a range of typical non-motor symptoms in addition to the cardinal motor signs. This cohort was set up in 2010 to investigate the specificity of non-motor symptoms for Parkinson's disease. For this, we included several control groups with decreasing contrast from Parkinson's disease patients. Group definitions ranged from healthy control subjects to those with suspected early motor signs of parkinsonism. Using a mailed questionnaire, we screened 5838 inhabitants of Lübeck, Germany, out of a target population of 10 000 citizens, enquiring about motor impairment, pain, quality of life, comorbidities, somatization and demographics. Based on this information, participants were assigned to screening groups, and selected participants were invited for in-person examination (n = 623). The examination included cognitive examinations, transcranial ultrasound, a brief psychiatric interview and a standardized motor examination that was used to assign examination groups. In addition, all participants answered questionnaires addressing depression, anxiety, sleep and quality of life. The first-year follow-up examination was performed either in person using the same protocol or via mailed questionnaires. This study is ongoing and publications are in preparation, but you may contact the first author (meike.kasten@neuro.uni-luebeck.de) with suggestions for collaboration or data requests.