Prediction of Parkinson's disease subsequent to severe depression: a ten-year follow-up study

Systematic review-based guideline "Parkinson's disease" of the German Society of Neurology: diagnostic use of transcranial sonography

BACKGROUND AND OBJECTIVE

Transcranial brain parenchyma sonography (TCS) has been recommended as a tool for the early and differential diagnosis of Parkinson's disease (PD) in German and European clinical guidelines. Still, the brain structures to be examined for the diagnostic questions and the requirements for being a qualified investigator were not specified in detail. These issues have now been addressed in the 2023 update of the clinical guideline on PD by the German Society of Neurology (DGN).

METHODS

The recommendations were based on a systematic literature review following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.

RESULTS

Three diagnostic questions were defined: (1) What is the accuracy of TCS in the differential diagnosis of PD versus atypical and secondary Parkinsonian syndromes? (2) What is the accuracy of TCS in the differential diagnosis of PD versus essential tremor? (3) What is the accuracy of TCS in the diagnosis of PD in persons with typical early symptoms, compared with the diagnosis established by clinical follow-up? The brain structures to be assessed and the level of recommendation were formulated for these questions. The training requirements for being regarded as qualified TCS investigator were stipulated by the responsible medical societies (German Society of Ultrasound in Medicine, DEGUM; German Society for Clinical Neurophysiology and Functional Imaging, DGKN). Finally, the recommendations for these diagnostic questions reached strong consensus (each ≥ 97%) of the guideline committee. Here, the details of review and recommendations are presented.

CONCLUSION

The updated guideline clarifies the diagnostic uses and limitations of TCS in PD.

Motor dysfunction in Parkinson's patients: depression differences in a latent growth model

Objective

This study aims to utilize latent growth model (LGM) to explore the developmental trajectory of motor dysfunction in Parkinson's disease (PD) patients and investigate the relationship between depression and motor dysfunction.

Methods

Four-year follow-up data from 389 PD patients were collected through the Parkinson's Progression Marker Initiative (PPMI). Firstly, a univariate LGM was employed to examine the developmental trajectory of motor dysfunction in PD patients. Subsequently, depression levels were introduced as covariates into the model, and depression was further treated as a parallel growth latent variable to study the longitudinal relationship between motor dysfunction and depression.

Results

In the trajectory analysis of motor dysfunction, the fit indices for the quadratic growth LGM model were χ2 = 7.419, df = 6, CFI = 0.998, TLI = 0.997, SRMR = 0.019, and RMSEA = 0.025, indicating that the growth trend of motor dysfunction follows a quadratic curve rather than a simple linear pattern. Introducing depression symptoms as time-varying covariates to explore their effect on motor dysfunction revealed significant positive correlations (β = 0.383, p = 0.026; β = 0.675, p < 0.001; β = 0.385, p = 0.019; β = 0.415, p = 0.014; β = 0.614, p = 0.003), suggesting that as depression levels increase, motor dysfunction scores also increase. Treating depression as a parallel developmental process in the LGM, the regression coefficients for depression intercept on motor dysfunction intercept, depression slope on motor dysfunction slope, and depression quadratic factor on motor dysfunction quadratic factor were 0.448 (p = 0.046), 1.316 (p = 0.003), and 1.496 (p = 0.038), respectively. These significant regression coefficients indicate a complex relationship between depression and motor dysfunction, involving not only initial level associations but also growth trends over time and possible quadratic effects.

Conclusion

This study indicates a quadratic growth trajectory for motor dysfunction in PD, suggesting a continuous increase in severity with a gradual deceleration in growth rate. The relationship between depression and motor dysfunction is complex, involving initial associations, evolving trends over time, and potential quadratic effects. Exacerbation of depressive symptoms may coincide with motor function deterioration.

Depression in Patients with Parkinson's Disease: Current Understanding of its Neurobiology and Implications for Treatment

Depression is one of the most frequent and burdensome non-motor symptoms in Parkinson’s disease (PD), across all stages. Even when its severity is mild, PD depression has a great impact on quality of life for these patients and their caregivers. Accordingly, accurate diagnosis, supported by validated scales, identification of risk factors, and recognition of motor and non-motor symptoms comorbid to depression are critical to understanding the neurobiology of depression, which in turn determines the effectiveness of dopaminergic drugs, antidepressants and non-pharmacological interventions. Recent advances using in vivo functional and structural imaging demonstrate that PD depression is underpinned by dysfunction of limbic networks and monoaminergic systems, depending on the stage of PD and its associated symptoms, including apathy, anxiety, rapid eye movement sleep behavior disorder (RBD), cognitive impairment and dementia. In particular, the evolution of serotonergic, noradrenergic, and dopaminergic dysfunction and abnormalities of limbic circuits across time, involving the anterior cingulate and orbitofrontal cortices, amygdala, thalamus and ventral striatum, help to delineate the variable expression of depression in patients with prodromal, early and advanced PD. Evidence is accumulating to support the use of dual serotonin and noradrenaline reuptake inhibitors (desipramine, nortriptyline, venlafaxine) in patients with PD and moderate to severe depression, while selective serotonin reuptake inhibitors, repetitive transcranial magnetic stimulation and cognitive behavioral therapy may also be considered. In all patients, recent findings advocate that optimization of dopamine replacement therapy and evaluation of deep brain stimulation of the subthalamic nucleus to improve motor symptoms represents an important first step, in addition to physical activity. Overall, this review indicates that increasing understanding of neurobiological changes help to implement a roadmap of tailored interventions for patients with PD and depression, depending on the stage and comorbid symptoms underlying PD subtypes and their prognosis.

Cognition, motor symptoms, and glycolipid metabolism in Parkinson's disease with depressive symptoms

Depressive symptoms and abnormal glycolipid metabolisms are common in patients with Parkinson's disease (PD), but their relationship has not been fully reported. It is not clear whether glycolipid impairments lead to poor cognitive and motor function, and aggravate depressive symptoms. Therefore, we aimed to explore the relationships between glycolipid variables, cognition, motor and depressive symptoms in PD patients cross-sectionally. Two hundred ten PD patients were recruited. Glycolipid parameters and Uric acid (UA) were measured. Depressive symptoms, cognitive function and motor symptoms were assessed using the Hamilton Depression Rating Scale-17 (HAMD-17), the Montreal Cognitive Assessment (MOCA) and the Movement Disorder Society Unified Parkinson's Disease Rating Scale Part-III (UPDRS-III). Depressive PD patients had significantly worse motor symptoms and higher levels of fasting plasma glucose (FPG) than those in non-depressive patients (F = 24.145, P < 0.001). Further, logistic regression analysis indicated that UPDRS-III (OR = 1.039, 95% CI 1.019-1.057, P = 0.044), FPG (OR = 1.447, 95% CI 1.050-1.994, P = 0.024) were independently associated with depression. In PD patients without depression, UA (β = - 0.068, t = - 2.913, P = 0.005) and cholesterol (CHOL) (β = - 3.941, t = - 2.518, P = 0.014) were independent predictors of the UPDRS-III score; in addition, UPDRS-III score was negatively associated with MOCA score (β = - 0.092, t = - 2.791, P = 0.007). FPG levels and motor symptoms were related to depressive symptoms in PD patients. Further, in non-depressive PD patients, UA and CHOL showed putative biomarkers of motor symptoms.

How specific are non-motor symptoms in the prodrome of Parkinson's disease compared to other movement disorders?

The clinical diagnosis of Parkinson's disease (PD) based on motor signs is often preceded by several non-motor symptoms that can indicate early prodromal neurodegenerative processes. Such prodromal symptoms can aid the early detection of PD, but their specificity for prodromal PD in comparison to prodromes of other movement disorders is still largely unclear. We here aim to give a first insight into the published evidence of prodromal non-motor symptoms in PD, dementia with Lewy bodies (DLB), multiple system atrophy (MSA), Huntington's disease (HD), progressive supranuclear palsy (PSP) and spinocerebellar ataxia (SCA). REM-sleep behavior disorder (RBD) and autonomic dysfunction have been observed in the prodromes of PD, MSA, DLB and SCA. Depression and cognitive decline have been reported for prodromal PD, DLB, HD, SCA, and PSP. Olfactory loss has only been described in prodromal PD/DLB. However, estimating the specificity of prodromal non-motor symptoms in PD is so far complicated by scarce prospective evidence and study limitations. Information on marker specificity is a prerequisite for an accurate early (differential) diagnosis of prodromal diseases, as well as specific recruitment for targeted neuroprotective interventions. We here would like to raise awareness of these issues and encourage further prospective research of prodromal non-motor symptoms in neurodegenerative movement disorders and other diseases.

Ages at Onset of Anxiety and Depressive Disorders in Parkinson's Disease

OBJECTIVE

Parkinson's disease (PD) is a quintessential neuropsychiatric condition in which anxiety and depressive symptoms are common and may precede motor manifestations. The authors explored the ages at onset of anxiety and depressive disorders among patients with PD evaluated by psychiatrists at a deep brain stimulation center.

METHODS

Psychiatric diagnoses and ages at onset were collected via clinical interviews. The ages at PD diagnosis were ascertained by chart review. Onset ages for anxiety and depressive disorders (overall and for specific disorders) were compared with patients' ages at PD diagnosis by using t tests. Onset ages for major depressive disorder (MDD), generalized anxiety disorder (GAD), and panic disorder were compared with typical onset ages in the general population by using the sign test. A total of 108 patients (66.7% men; age 63.7 years [SD=8.9]) were included in the analysis.

RESULTS

Anxiety and depressive disorders occurred significantly earlier than PD diagnoses. Among patients whose anxiety and depression predated motor symptoms, the mean age at onset of anxiety disorders was 25.6 years earlier, and the mean age at onset of depressive disorders was 17.6 years earlier compared with the mean age at PD diagnosis (both p values <0.0001). Median onset ages for MDD (p<0.0001), GAD (p=0.0002), and panic disorder (p=0.0005) were significantly higher than typical median onset ages in the general population.

CONCLUSIONS

These results may indicate that neurodegenerative changes are present in parts of the brainstem reticular core and limbic system before motor circuits are affected to a degree that causes motor symptoms. Psychiatrists should be mindful that onset of MDD, GAD, and panic disorder after age 45 might signal a neurodegenerative movement disorder such as PD.

Transcranial brain sonography for Parkinsonian syndromes

Substantia nigra (SN) hyperechogenicity has been proved to be a characteristic finding for idiopathic Parkinson's disease (PD), occurring in more than 90% of the patients. This echofeature is owed to increased amounts of iron in the SN region and reflects a functional impairment of the nigrostriatal dopaminergic system. In a prospective blinded study in which a group of patients with early mild signs and symptoms of unclear Parkinsonism were followed until a definite clinical diagnosis of PD, the hyperechogenicity of the SN was demonstrated to be highly predictive of a final diagnosis of PD. For the diagnosis of PD in individuals with early motor symptoms, both the sensitivity and positive predictive value of SN hyperechogenicity were higher than 90% and both the specificity and negative predictive value were higher than 80%. For early differential diagnosis between PD and atypical Parkinsonian syndromes, the sensitivity and positive predictive value of SN hyperechogenicity were higher than 90%, and both the specificity and negative predictive value were higher than 80%. The diagnostic specificity is increased if combining the TCS findings of SN, lenticular nucleus and third ventricle. In asymptomatic adult subjects, SN hyperechogenicity, at least unilaterally, indicates a subclinical functional insufficiency of the nigrostriatal dopaminergic system. Recent papers revealed that SN hyperechogenicity might suggest preclinical PD. Reduced echogenicity of midbrain raphe indicates increased risk of depression in PD patients. Caudate nucleus hyperechogenicity has been associated with drug-induced psychosis, and frontal horn dilatation >20 mm with dementia. Transcranial brain sonography can be a valuable tool for managing patients with Parkinsonian signs and symptoms.

Inflammation Effects on Motivation and Motor Activity: Role of Dopamine

Motivational and motor deficits are common in patients with depression and other psychiatric disorders, and are related to symptoms of anhedonia and motor retardation. These deficits in motivation and motor function are associated with alterations in corticostriatal neurocircuitry, which may reflect abnormalities in mesolimbic and mesostriatal dopamine (DA). One pathophysiologic pathway that may drive changes in DAergic corticostriatal circuitry is inflammation. Biomarkers of inflammation such as inflammatory cytokines and acute-phase proteins are reliably elevated in a significant proportion of psychiatric patients. A variety of inflammatory stimuli have been found to preferentially target basal ganglia function to lead to impaired motivation and motor activity. Findings have included inflammation-associated reductions in ventral striatal neural responses to reward anticipation, decreased DA and DA metabolites in cerebrospinal fluid, and decreased availability, and release of striatal DA, all of which correlated with symptoms of reduced motivation and/or motor retardation. Importantly, inflammation-associated symptoms are often difficult to treat, and evidence suggests that inflammation may decrease DA synthesis and availability, thus circumventing the efficacy of standard pharmacotherapies. This review will highlight the impact of administration of inflammatory stimuli on the brain in relation to motivation and motor function. Recent data demonstrating similar relationships between increased inflammation and altered DAergic corticostriatal circuitry and behavior in patients with major depressive disorder will also be presented. Finally, we will discuss the mechanisms by which inflammation affects DA neurotransmission and relevance to novel therapeutic strategies to treat reduced motivation and motor symptoms in patients with high inflammation.

Prodromal Markers in Parkinson's Disease: Limitations in Longitudinal Studies and Lessons Learned

A growing body of evidence supports a prodromal neurodegenerative process preceding the clinical onset of Parkinson's disease (PD). Studies have identified several different prodromal markers that may have the potential to predict the conversion from healthy to clinical PD but use considerably different approaches. We systematically reviewed 35 longitudinal studies reporting prodromal PD features and evaluated the methodological quality across 10 different predefined domains. We found limitations in the following domains: PD diagnosis (57% of studies), prodromal marker assessments (51%), temporal information on prodromal markers or PD diagnosis (34%), generalizability of results (17%), statistical methods (accounting for at least age as confounder; 17%), study design (14%), and sample size (9%). However, no limitations regarding drop-out (or bias investigation), or report of inclusion/exclusion criteria or prodromal marker associations were revealed. Lessons learned from these limitations and additional aspects of current prodromal marker studies in PD are discussed to provide a basis for the evaluation of findings and the improvement of future research in prodromal PD. The observed heterogeneity of studies, limitations and analyses might be addressed in future longitudinal studies using a, yet to be established, modular minimal set of assessments improving comparability of findings and enabling data sharing and combined analyses across studies.

Transcranial Sonography Findings in Depression in Association With Psychiatric and Neurologic Diseases: A Review

The transcranial sonography (TCS) finding of reduced echogenicity of brainstem raphe (hypoechogenic BR) has been associated with depressive states. Here, we review the TCS studies in subjects with depressive disorders and with depression related to degenerative brain diseases, and compare the frequency and clinical correlates of hypoechogenic BR in these reports. Summarizing the data published so far, hypoechogenic BR is present in 67% (range, 37-95%) of depressed but only in 15% (5-36%) of nondepressed subjects without history of neurodegenerative disease. The finding of hypoechogenic BR in these subjects is associated with a relative risk of 3.03 (95% CI, 2.44-3.75; P < .001) of being diagnosed with depression. In patients with Parkinson's disease, hypoechogenic BR is present in 63% (35-92%) of depressed but only in 27% (10-62%) of nondepressed patients, resulting in a relative risk of 2.18 (95% CI, 1.80-2.66; P < .001) of being diagnosed with depression. Hypoechogenic BR is associated with depression in a number of neurological disorders such Huntington's disease, idiopathic Rapid Eye Movement (REM) sleep behavior disorder, myotonic dystrophies, and cerebral small vessel disease. Although some studies did not show any relationship between BR echogenicity and severity of depression, others suggest an association with higher severity of depression, or even with suicidal ideation. In one study BR hypoechogenicity was found to be associated with better responsivity to serotonin reuptake inhibitors. Further studies are warranted to compare the TCS findings of BR alteration with post-mortem histopathological findings, and with genetic variants related to cerebral serotonin metabolism.

Tremor and clinical fluctuation are related to sleep disorders in Chinese patients with Parkinson's disease

Objective

To study the relationship between sleep disturbances and symptoms in patients with Parkinson’s disease (PD).

Methods

The Parkinson’s Disease Sleep Scale-Chinese Version (PDSS-CV) was used to evaluate the sleep disturbances of PD patients in a cross sectional study. The Unified Parkinson’s Disease Rating Scale (UPDRS) parts II-IV, and the Hoehn & Yahr (H&Y) stage were used to determine the level of motor function in PD and the severity of PD. The Spearman correlation and a multiple regression analysis were used to identify the relationship between sleep disturbances and symptoms of PD. The quantities derived from the UPDRS and the H&Y stage and disease duration were compared between groups of patients either with or without sleep disturbances identified by the PDSS. This study was conducted from December 2011 to March 2012 at the First Affiliated Hospital of Sun Yat-sen University, in Guangzhou.

Results

A total of 136 PD patients were included in this study. The overall total PDSS score in PD patients was 107.58 ± 23.35 points (range: 30–146). There were significant differences in the disease duration, the H&Y stage, and the UPDRS section subscores between groups of patients either with or without sleep disturbances (Kruskal-Wallis Test, p <0.05). There were significant negative correlations between PDSS scores and the UPDRS subscores, the H&Y stage and the disease duration (Spearman correlation, p < 0.05). The multiple regression analysis indicated that sleep disturbances identified by the PDSS were only associated with daily life activity, tremor intensity and clinical fluctuation (R² = 0.22, F(3,132) = 12.4, p < 0.001). The correlations were also significant when the contribution of the other two factors was excluded using partial correlations.

Conclusions

The level of daily life activity and the occurrences of tremor and clinical fluctuation are likely to be important factors that lead to PD patients’ sleep disturbances. This study may elucidate an important clue for the relationship between sleep disturbances and PD symptoms.