Not all drug-induced parkinsonism are the same: the effect of drug class on motor phenotype

The clinical diagnosis of Parkinson's disease

After more than 200 years since its initial description, the clinical diagnosis of Parkinson's disease (PD) remains an often-challenging endeavor, with broad implications that are fundamental for clinical management. Despite major developments in understanding it's pathogenesis, pathological landmarks, non-motor features and potential paraclinical clues, the most accepted diagnostic criteria remain solidly based on a combination of clinical signs. Here, we review this process, discussing its history, clinical criteria, differential diagnoses, ancillary diagnostic testing, and the role of non-motor and pre-motor signs and symptoms.

Updated Perspectives on the Management of Drug-Induced Parkinsonism (DIP): Insights from the Clinic

Parkinsonism refers to the clinical combination of bradykinesia, rigidity, tremor, and postural instability. Parkinsonism is often neurodegenerative, but it can be secondary or iatrogenic, as in drug-induced parkinsonism (DIP), which is the topic of this review. We review the pathophysiology of DIP, differentiate DIP and idiopathic Parkinson's disease (PD), list culprit medications in the development of DIP, discuss the diagnosis of DIP as well as the motor and nonmotor signs and symptoms that can help with differentiation of DIP and PD, and detail the management of DIP.

Treatable Hyperkinetic Movement Disorders Not to Be Missed

Hyperkinetic movement disorders are characterized by the presence of abnormal involuntary movements, comprising most notably dystonia, chorea, myoclonus, and tremor. Possible causes are numerous, including autoimmune disorders, infections of the central nervous system, metabolic disturbances, genetic diseases, drug-related causes and functional disorders, making the diagnostic process difficult for clinicians. Some diagnoses may be delayed without serious consequences, but diagnosis delays may prove detrimental in treatable disorders, ranging from functional disabilities, as in dopa-responsive dystonia, to death, as in Whipple's disease. In this review, we focus on treatable disorders that may present with prominent hyperkinetic movement disorders.

Differences in cause and 12-month follow-up outcome of parkinsonian symptoms in depressed older adults treated with antipsychotics: a case series

BACKGROUND

Parkinsonian symptoms are common adverse effects of antipsychotics. Older adults are particularly vulnerable to drug-induced parkinsonism. Nonetheless, parkinsonian symptoms in seniors treated with antipsychotics cannot be straightforwardly attributed to antipsychotic medication. A comprehensive diagnostic workup is necessary in many cases in order to shed light on the cause of such symptoms in this patient population.

CASE SERIES

Eight cases of hospitalized depressed older adults with parkinsonian symptoms, who were treated for at least one year with antipsychotics, are reported. Based on neurological consultation, structural brain imaging and Ioflupane (I-123) dopamine transporter (DAT) single photon emission computerized tomography (SPECT), Parkinson's disease was diagnosed in one case, idiopathic tremor in another, vascular parkinsonism in another one, while in another individual parkinsonian symptoms persisted at 12-month post-discharge follow-up even though his/her symptoms were classified as drug-induced on discharge. In four patients, parkinsonian symptoms were definitely drug-induced and no movement disturbances were reported at follow-up.

CONCLUSIONS

Differences in the cause and outcome of parkinsonian symptoms in seniors treated with antipsychotics merit systematic and in-depth study considering the therapeutic and prognostic implications of an accurate detection of the cause of such symptoms. Familiarizing clinical psychiatrists with these differences could pave the way towards approaching seniors with severe, atypical and/or persistent parkinsonian symptoms in a more individualized diagnostic and therapeutic manner, and towards more cautious prescribing of antipsychotics in this age group.

Recognition and Management of Antipsychotic-Induced Parkinsonism in Older Adults: A Narrative Review

Background: Parkinsonism is a common side-effect of antipsychotic drugs especially in older adults, who also present with a higher frequency of neurodegenerative disorders like Idiopathic Parkinson’s disease (IPD). Distinguishing between antipsychotic-induced parkinsonism (AIP) and IPD is challenging due to clinical similarities. Up to 20% of older adults may suffer from persisting parkinsonism months after discontinuation of antipsychotics, suggesting underlying neurodegeneration. A review of the literature on AIP in older adults is presented, focusing on epidemiology, clinical aspects, and management. Methods: A literature search was undertaken on EMBASE, MEDLINE and PsycINFO, for articles on parkinsonism induced by antipsychotic drugs or other dopamine 2 receptor antagonists in subjects aged 65 or older. Results: AIP in older adults is the second most common cause of parkinsonism after IPD. Older age, female gender, exposure to high-potency first generation antipsychotics, and antipsychotic dosage are the main risk factors. The clinical presentation of AIP resembles that of IPD, but is more symmetrical, affects upper limbs more, and tends to have associated motor phenomena such as orofacial dyskinesias and akathisia. Presence of olfactory dysfunction in AIP suggests neurodegeneration. Imaging of striatal dopamine transporters is widely used in IPD diagnosis and could help to distinguish it from AIP. There is little evidence base for recommending pharmacological interventions for AIP, the best options being dose-reduction/withdrawal, or switching to a second-generation drug. Conclusions: AIP is a common occurrence in older adults and it is possible to differentiate it from IPD. Further research is needed into its pathophysiology and on its treatment.

Effects of Psychotropics on the Microbiome in Patients With Depression and Anxiety: Considerations in a Naturalistic Clinical Setting

BACKGROUND

The antibacterial effects of psychotropics may be part of their pharmacological effects when treating depression. However, limited studies have focused on gut microbiota in relation to prescribed medication.

METHOD

We longitudinally investigated the relationship between patients' prescribed medications and intestinal bacterial diversity in a naturalistic treatment course for patients with major depressive disorders and anxiety disorders. Patients were recruited and their stool was collected at 3 time points during their usual psychiatric treatments. Gut microbiota were analyzed using 16S rRNA gene sequencing. We examined the impact of psychotropics (i.e., antidepressants, anxiolytics, antipsychotics) on their gut microbial diversity and functions.

RESULTS

We collected 246 stool samples from 40 patients. Despite no differences in microbial diversity between medication groups at the baseline, over the course of treatment, phylogenic diversity whole-tree diversity decreased in patients on antipsychotics compared with patients without (P = .027), and beta diversity followed this trend. Based on a fixed-effect model, antipsychotics predicted microbial diversity; the higher doses correlated with less diversity based on the Shannon index and phylogenic diversity whole tree (estimate = -0.00254, SE = 0.000595, P < .0001; estimate = -0.02644, SE = 0.00833, P = .002, respectively).

CONCLUSION

Antipsychotics may play a role in decreasing the alpha diversity of the gut microbiome among patients with depression and anxiety, and our results indicate a relationship with medication dosage. Future studies are warranted and should consider patients' types and doses of antipsychotics in order to further elucidate the mechanisms of gut-brain interactions in psychiatric disorders.

Cinnarizine- and flunarizine-associated movement disorder: a literature review

Introduction

Cinnarizine (CNZ) and flunarizine (FNZ) belong to the calcium channel blockers class of medication.

Main text

The aim of this literature review is to evaluate the clinical epidemiological profile, pathological mechanisms, and management of CNZ/FNZ-associated movement disorder (MD). Relevant reports in six databases were identified and assessed by two reviewers without language restriction. One hundred and seventeen reports containing 1920 individuals who developed a CNZ/FNZ-associated MD were identified. The MD encountered were 1251 parkinsonism, 23 dyskinesias, 11 akathisia, 16 dystonia, and 5 myoclonus, and in the group not clearly defined, 592 extrapyramidal symptoms, 19 tremors, 2 bradykinesia, and 1 myokymia. The predominant sex was female with a percentage of 72.69% (466/641). The mean age was 74.49 (SD, 7.88) years. The mean CNZ dose was 148.19 mg (SD, 42.51) and for the FNZ dose, 11.22 mg (5.39). The mean MD onset and recovery were 1.83 years (SD, 1.35) and 3.71 months (SD, 1.26). In the subgroup of subjects that had improvement of the symptoms, the complete recovery was achieved within 6 months of the drug withdrawal in almost all subjects (99%). The most common management was drug withdrawal. A complete recovery was observed in 93.77% of the patients (437/466).

Conclusions

CNZ/FNZ-associated MD was extensively reported in the literature. Parkinsonism was the most well described. Myoclonus (MCL) was the poorest described MD with missing data about the neurological examination and electrodiagnostic studies. The knowledge of this disorder probably can contribute to the understanding of the other drug-induced MDs.

Follow-Up of Advanced Parkinson's Disease Patients after Clinical or Surgical Emergencies: A Practical Approach

Background

Patients with advanced stage Parkinson's disease (PD) typically present with a myriad of motor and nonmotor symptoms in addition to comorbidities and, as a consequence, polypharmacy.

Objective

To analyze a series of cases of advanced PD in which a clinical or surgical emergency played a trigger role in the irreversible progression of landmarks of the course of the disease.

Methods

Data were collected during a 13-month observational period of a cohort of 230 PD patients, in 751 medical appointments. We included a total of 13 (5.65% of the total number) patients with advanced PD defined by Hoehn & Yahr (H&Y) stage ≥3 who presented with various clinical and surgical complications which, with the contribution of drug interventions, led to significant worsening of patients' overall clinical condition.

Results

Hip fractures and infections were the most common complications identified. As part of this scenario, most patients presented with delirium, often requiring treatment with dopamine receptor blocking agents and/or had dopaminergic treatment withdrawn. Upon reassessment after 3 months, all patients remained bed or wheel chair bound (H&Y 5) and presented significant worsening of their UPDRS part III score of at least 10 points (mean 51.5 ± 3.3; paired t-test two-tailed p < 0.0001 compared to baseline). The mean dose of levodopa at baseline was 907.7 ± 149.8 mg (600–1200) and significantly higher (paired t-test two-tailed p < 0.0001) on follow-up, 1061.5 ± 175.8 mg (700–1300).

Conclusion

Clinical and surgical emergencies are major determinants for a progression of PD to more advanced stages.

Iatrogenesis and neurological manifestations in the elderly

Older people are often exposed to polypharmacy in a multimorbidity context. Inappropriate polypharmacy is often harmful, increasing the risk of inappropriate prescriptions and therefore adverse drug events (ADEs). Five to 20% of all hospital admissions are related to ADE in older people, among which 40 to 70% could be prevented. However, identifying ADEs and drug-related admissions in the elderly is challenging because ADEs often present as common geriatric problems such as falls, delirium, which might be due to the aging process, underlying diseases, and/or medications. In the pharmacovigilance database of the World Health Organization, drug-related neurological manifestations are the third reported cause of ADEs in the elderly, and neurological drugs are the third leading class of medications involved in ADEs. We must therefore be particularly vigilant, both in our prescriptions but also in our diagnoses to avoid prescribing inappropriate treatments and detect ADEs. Even though multiple pharmacologic changes occur in the elderly (absorption, distribution, drug metabolism and excretion), most of medications are still often prescribed at the same daily dosage as in young adults. When prescribing any drug for old patients, we should remember that daily intake should be adapted to these specificities, keeping in mind the old well-known aphorism "start low, go slow". In this review, we describe the main drug-related neurological manifestations (drug-induced movement disorders, falls, seizures, delirium, hypoglycemia, stroke, hyponatremia, peripheral neuropathy and myopathy, and serotonin syndrome) and the main drugs associated with neurological manifestations (dopamine receptor blocking agents, antithrombotics, anticholinergics, beta-lactams, antidepressants, benzodiazepines, mood stabilizers).

Secondary parkinsonism due to drugs, vascular lesions, tumors, trauma, and other insults

In addition to neurodegenerative disorders, there are many secondary forms of parkinsonism. The most common cause for secondary parkinsonism is the intake of distinct drugs. Neuroleptics and calcium channel blockers have been mainly described to induce parkinsonism, but also other drugs were suspected to cause or worsen parkinsonism. Another common cause for secondary parkinsonism are vascular lesions (i.e. vascular parkinsonism). Furthermore, also brain tumors have been described as rare causes for parkinsonism. Moreover, parkinsonism can be caused by chronic traumatic encephalopathy, which is a special case, since secondary insults to the brain leads to the occurrence of a neuropathologically defined disease. Other rare causes for secondary parkinsonism are lesions caused by infectious or immunological diseases as well as toxins or street drugs.

Recent developments in drug-induced movement disorders: a mixed picture

A large and ever-growing number of medications can induce various movement disorders. Drug-induced movement disorders are disabling but are often under-recognised and inappropriately managed. In particular, second generation antipsychotics, like first generation agents, are associated with potentially debilitating side-effects, most notably tardive syndromes and parkinsonism, as well as potentially fatal acute syndromes. Appropriate, evidence-based management is essential as these drugs are being prescribed to a growing population vulnerable to these side-effects, including children and elderly people. Prevention of the development of drug-induced movement disorders is an important consideration when prescribing medications that can induce movement disorders. Recent developments in diagnosis, such as the use of dopamine transporter imaging for drug-induced parkinsonism, and treatment, with the approval of valbenazine and deutetrabenazine, the first drugs indicated for tardive syndromes, have improved outcomes for many patients with drug-induced movement disorders. Future research should focus on development of safer antipsychotics and specific therapies for the different tardive syndromes and the treatment of drug-induced parkinsonism.

The Dopamine Receptor Antagonism of Opipramol: Relevance to Parkinsonism?

Drug-induced Parkinsonism (DIP) represents the second most-frequent etiology of Parkinson syndromes after neurodegenerative disorders. It has been described mainly for antipsychotics, Ca-channel blockers, antiemetics, and gastrointestinal prokinetics. In this article, we present a clinical case series of 10 patients, retrieved within our movement disorders hospital, with DIP under intake of opipramol. Symptoms completely resolved after drug withdrawal, and associated risk factors were old age, high doses, and presence of cortical atrophy. This frequently prescribed anxiolytic drug has so far not been associated with DIP. Our objective is to raise awareness of DIP as an adverse effect of opipramol.

Virus-like particles and enterovirus antigen found in the brainstem neurons of Parkinson's disease

Background: In a previous study on encephalitis lethargica, we identified a virus related to enterovirus in autopsy brain material. Transmission electron microscopy (TEM), immunohistochemistry (IHC) and molecular analysis were employed.  Our present objective was to investigate, using a similar approach, as to whether virus-like particles (VLP) and enterovirus antigen are present in Parkinson's disease (PD) brainstem neurons. Methods: Fixed tissue from autopsy specimens of late onset PD and control brainstem tissue were received for study. The brain tissue was processed for TEM and IHC according to previous published methods. Results:  We observed VLP in the brainstem neurons of all the cases of PD that were examined.  In the neurons' cytoplasm there were many virus factories consisting of VLP and endoplasmic reticulum membranes. In some neurons, the virus factories contained incomplete VLP. Complete VLP in some neurons' virus factories had an average diameter of 31 nm, larger than control brain ribosomes. In the nuclei, there were VLP with an average diameter of 40 nm. In cases of human poliomyelitis, there were cytoplasmic virus factories and intranuclear virus particles similar to those observed in PD. On preparing PD brain sections for IHC there was positive staining using anti-poliovirus antibody and anti-coxsackie antibody. This result was statistically significant. Conclusions: We present evidence for an enterovirus infection in PD.  For future studies, virus isolation and molecular analysis are suggested.

Virus-like particles and enterovirus antigen found in the brainstem neurons of Parkinson's disease

Background: In a previous study on encephalitis lethargica, we identified a virus related to enterovirus in autopsy brain material. Transmission electron microscopy (TEM), immunohistochemistry (IHC) and molecular analysis were employed.  Our present objective was to investigate, using a similar approach, as to whether virus-like particles (VLP) and enterovirus antigen are present in Parkinson’s disease (PD) brainstem neurons.

Methods: Fixed tissue from autopsy specimens of late onset PD and control brainstem tissue were received for study. The brain tissue was processed for TEM and IHC according to previous published methods.

Results:  We observed VLP in the brainstem neurons of all the cases of PD that were examined.  In the neurons’ cytoplasm there were many virus factories consisting of VLP and endoplasmic reticulum membranes. In some neurons, the virus factories contained incomplete VLP. Complete VLP in some neurons’ virus factories had an average diameter of 31 nm, larger than control brain ribosomes. In the nuclei, there were VLP with an average diameter of 40 nm. In cases of human poliomyelitis, there were cytoplasmic virus factories and intranuclear virus particles similar to those observed in PD. On preparing PD brain sections for IHC there was positive staining using anti-poliovirus antibody and anti-coxsackie antibody. This result was statistically significant.

Conclusions: We present evidence for an enterovirus infection in PD.  For future studies, virus isolation and molecular analysis are suggested.

Evidence for association between hepatitis C virus and Parkinson's disease

Parkinson's disease (PD) is a globally prevalent neurodegenerative disorder, characterized by progressive neuronal loss in the substantia nigra and formation of Lewy bodies. These pathological characteristics are clinically translated into motor symptoms, such as bradykinesia, rigidity, resting tremors, and postural instability. Emerging data from epidemiological studies suggest a possible association between PD and hepatitis C virus (HCV) infection, which affects up to 71 million individuals worldwide. Preclinical studies have shown that HCV can penetrate and replicate within the brain macrophages and microglial cells, increasing their production of pro-inflammatory cytokines that can directly cause neuronal toxicity. Other studies reported that interferon, previously used to treat HCV infection, can increase the risk of PD through inhibition of the nigrostriatal dopaminergic transmission or induction of neuroinflammation. In this article, we provide a comprehensive review on the possible association between HCV infection and PD and highlight recommendations for further research and practice in this regard.