Progression of prodromal motor and non-motor symptoms in the premotor phase study - 2-year follow-up data.

BACKGROUND AND PURPOSE: The neuropathological process starts years before the diagnosis of Parkinson's disease (PD). Assessment of prodromal features in healthy individuals may help to define those with high risk for future PD. Our aim was to evaluate the presence and progression of prodromal markers in individuals with low risk [healthy controls (HC), n = 14] and high risk for PD (HR-PD, n = 34) and early PD (n = 14) patients. METHODS: Several risk or prodromal markers were combined to define HR-PD. Other prodromal markers were followed in 6-month intervals for 2 years. As recommended by the Movement Disorder Society Task Force, likelihood ratios (LRs) of markers, motor scores and PD probability scores were calculated and compared. RESULTS: The baseline LR for non-motor prodromal markers was significantly higher in PD and HR-PD compared to HC. Within 2 years, changes in these LRs did not significantly differ between the groups. Motor worsening was significant only in the PD group (50% of the patients) against HR-PD (15%) and HC (7%). Change in the non-motor prodromal LR did not significantly correlate with motor worsening, but higher baseline non-motor LRs were associated with Unified Parkinson's Disease Rating Scale III values at 2 years of follow-up. CONCLUSIONS: Our study shows that the frequency of non-motor prodromal markers is higher in the HR-PD group but does not increase within 2 years. The progression of motor and non-motor markers seems to be independent, but higher baseline non-motor burden is associated with the motor status after 2 years. Moreover, our data argue for a high impact of motor markers in the risk estimation for future PD.

[Helpful instrumental examinations in idiopathic Parkinson's disease]. / Hilfreiche Zusatzuntersuchungen beim idiopathischen Parkinson-Syndrom.

BACKGROUND: The clinical diagnosis of idiopathic Parkinson's disease (iPD) can be challenging. In these cases, additional diagnostic methods are available that can help to improve diagnostic accuracy. OBJECTIVES, MATERIAL AND METHODS: This article provides an overview of currently available and promising novel ancillary methods for the early and differential diagnosis of iPD. RESULTS: Imaging tools, such as 1.5 Tesla magnetic resonance imaging (MRI) and computed tomography (CT) are mainly used for the differentiation between iPD and symptomatic parkinsonian syndromes (PS). High-resolution diffusion tensor imaging and iron and neuromelanin-sensitive high-field MRI sequences can become important in the future, particularly for earlier diagnosis. Transcranial B­mode sonography of the substantia nigra and basal ganglia is established for early and differential diagnostics, especially in the combination of diagnostic markers but necessitates an adequately trained investigator and the use of validated digital image analysis instruments. DATScan can discriminate iPD from essential tremor, medication-induced parkinsonism and psychogenic movement disorder but not iPD from atypical PS. For the latter differential diagnosis, fluorodeoxyglucose positron emission tomography and myocardial metaiodobenzylguanidine scintigraphy can be helpful. Olfactory testing should preferably be used in combination with other diagnostic tests. Genetic, biochemical and histopathological tests are currently not recommended for routine use. Novel sensor-based techniques have a high potential to support clinical diagnosis of iPD but have not yet reached a developmental stage that is sufficient for clinical use. Novel sensor-based techniques have high potential to support clinical diagnosis of iPD, but have not yet reached a development stage that is sufficient for clinical use. CONCLUSION: Ancillary diagnostic methods can support the early and differential diagnosis of iPD.

[Diagnostics of clinical and prodromal idiopathic Parkinson's disease : New criteria]. / Diagnostik des klinischen und prodromalen idiopathischen Parkinson-Syndroms : Neue Kriterien.

BACKGROUND: Recently, the Movement Disorder Society (MDS) published an adaptation of the previous United Kingdom Brain Bank Society (UKBBS) criteria for the diagnosis of idiopathic Parkinson's disease (iPD). OBJECTIVES: This article presents the changes in the current clinical diagnostic criteria for IPD. Furthermore, the new MDS criteria for prodromal iPD are discussed. RESULTS: The recently introduced MDS criteria for the clinical diagnosis of iPD include useful novel features (e.g. postural instability is no longer listed as a cardinal symptom, familiar history of iPD and intake of neuroleptics at the first visit no longer lead to exclusion of the diagnosis) and red flags do not lead to exclusion of the diagnosis; however, they must be counterbalanced by the presence of supportive criteria for iPD. The criteria for identification of persons in the prodromal stage are currently established only for scientific investigations. CONCLUSION: The new MDS criteria for the diagnostics of iPD should help to improve the sensitivity and specificity.

Substantia nigra hyperechogenicity is related to decline in verbal memory in healthy elderly adults.

BACKGROUND AND PURPOSE: Deficits in cognition have been reported in Parkinson's disease (PD) already in the early and even in the pre-motor stages. Whilst substantia nigra hyperechogenicity measured by transcranial B-mode sonography (TCS) represents a strong PD marker and is associated with an increased risk for PD in still healthy individuals, its association with cognitive performance in prodromal PD stages is not well established. METHODS: Two different cohorts of healthy elderly individuals were assessed by TCS and two different neuropsychological test batteries covering executive functions, verbal memory, language, visuo-constructional function and attention. Cognitive performance was compared between individuals with hyperechogenicity (SN+) and without hyperechogenicity (SN-). RESULTS: In both cohorts, SN+ individuals performed significantly worse than the SN- group in tests assessing verbal memory (word list delayed recall P = 0.05, logical memory II P < 0.017). Significant differences in Mini-Mental State Examination score (cohort 1, P = 0.02) and executive function tests (cohort 2, Stroop Color-Word Reading, P = 0.004) could only be shown in one of the two cohorts. No between-group effects were found in other cognitive tests and domains. CONCLUSIONS: These results indicate that individuals with the PD risk marker SN+ perform worse in verbal memory compared to SN- independent of the assessment battery. Memory performance should be assessed in detail in individuals at risk for PD.

The PRIPS study: screening battery for subjects at risk for Parkinson's disease.

BACKGROUND AND PURPOSE: Screening batteries to narrow down a target-at-risk population are essential for trials testing neuroprotective compounds aiming to delay or prevent onset of Parkinson's disease (PD). METHODS: The PRIPS study focuses on early detection of incident PD in 1847 at baseline PD-free subjects, and assessed age, male gender, positive family history, hyposmia, subtle motor impairment and enlarged substantia nigra hyperechogenicity (SN+). RESULTS: After 3 years follow-up 11 subjects had developed PD. In this analysis of the secondary outcome parameters, sensitivity and specificity of baseline markers for incident PD were calculated in 1352 subjects with complete datasets (10 PD patients). The best approach for prediction of incident PD comprised three steps: (i) prescreening for age, (ii) primary screening for positive family history and/or hyposmia, and (iii) secondary screening for SN+. CONCLUSION: With this approach, one out of 16 positively screened participants developed PD compared to one out of 135 in the original cohort. This corresponds to a sensitivity of 80.0%, a specificity of 90.6% and a positive predictive value of 6.1%. These values are higher than for any single screening instrument but still too low for a feasible and cost-effective screening strategy which might require longer follow-up intervals and application of additional instruments.

Co-occurrence of parkinsonism and dementia in clinical practice: relevant differential diagnoses.

Co-occurrence of parkinsonism and dementia is commonly observed in the aging population. This narrative review gives an overview of disorders regularly presenting with these symptoms, e.g., idiopathic Parkinson disease with dementia, dementia with Lewy bodies, progressive supranuclear palsy, corticobasal degeneration syndrome, vascular cognitive impairment, drug-induced parkinsonism, and normal-pressure hydrocephalus. Both a thoroughly performed medical history and a comprehensive clinical examination can narrow down relevant differential diagnoses. Characteristic clinical and neuropsychological features are highlighted, including cognitive screening strategies. Neurophysiological and neuropathological aspects of the disorders are briefly discussed to give a better understanding of treatment options.

Relation of risk factors and putative premotor markers for Parkinson's disease.

As both risk and premotor markers are increasingly discussed to play a key role in the pre-diagnostic phase of Parkinson's disease (PD) the aim of this study was to determine the relation between the risk factors hyperechogenicity of the substantia nigra (SN+) and/or positive family history of PD (faPD+) and putative premotor markers for PD. In a cross-sectional analysis of data of the PRIPS cohort, 1,149 volunteers older than 50 years free of PD were included. In addition to the risk factors SN+ and faPD+, olfactory dysfunction was tested using the Sniffin' sticks test and motor examination was performed. History of depression and constipation was evaluated by a semi-structured interview. Of all 1,149 individuals, 880 had none of the risk markers (76.6%), 143 persons (12.4%) had SN+, 84 (7.3%) were classified as faPD+ and 42 (3.7%) persons had both risk factors. Volunteers with SN+ showed olfactory dysfunction and mild motor impairment (p ≤ 0.001) more often. Depression was more prominent in individuals having two risk factors (p = 0.05). An accumulation of premotor markers was seen in the SN+ group with or without concomitant faPD+, but not in persons with faPD+ only. The profile of premotor markers seems to differ in participants having SN+ and/or faPD+, with SN+ showing the overall highest association with most premotor markers, which implies that SN+ might be a strong indicator for a neurodegenerative process.