alpha-synuclein and Dystonia

Dystonia and Parkinson's disease are closely linked disorders sharing many pathophysiological overlaps. Dystonia can be seen in 30% or more of the patients suffering with PD and sometimes can precede the overt parkinsonism. The response of early dystonia to the introduction of dopamine replacement therapy (levodopa, dopamine agonists) is variable; dystonia commonly occurs in PD patients following levodopa initiation. Similarly, parkinsonism is commonly seen in patients with mutations in various DYT genes including those involved in the dopamine synthesis pathway. Pharmacological blockade of dopamine receptors can cause both tardive dystonia and parkinsonism and these movement disorders syndromes can occur in many other neurodegenerative, genetic, toxic and metabolic diseases. Pallidotomy in the past and currently deep brain stimulation largely involving the GPi are effective treatment options for both dystonia and parkinsonism. However, the physiological mechanisms underlying the response of these two different movement disorder syndromes are poorly understood. Interestingly, DBS for PD can cause dystonia such as blepharospasm and bilateral pallidal DBS for dystonia can result in features of parkinsonism. Advances in our understanding of these responses may provide better explanations for the relationship between dystonia and Parkinson's disease.

Topics: alpha-Synuclein; Deep Brain Stimulation; Dystonia; GTP Cyclohydrolase; Humans; Levodopa; Parkinson Disease

Parkinson disease (PD) and dystonia are two major part of neurodegenerative disorders. The underlying cause of PD development has been considered to be a combination of genetic factors and environmental substrates. In case of dystonia, which includes primary sporadic dystonia, such as task specific dystonia, cervical dystonia and so on, are also considered to associate with unknown vulnerable genetic factors. In this paper, the clinical features and causative genes for PD and dystonia were described; especially in particular, the description of those genes associated with the PARK and DYT series were provided. Most of the identified causative genes for PD are associated with the protein degradation and cell death process via convergent mechanisms such as ubiquitin-proteasome system, mitochondrial dysfunction, oxidative stress, and lysosomal system (autophagia). On the other hand, the pathogenic mechanism for dystonia is gradually discovered to be divergent suggested by identified genes, such as torsinA, GCH1, etc, which is compatible and well understood with the divergent expression of dystonia phenotype. Another breakthroughs are required to investigate the treatment of both PD and dystonia based on the pathogenic mechanisms.

Topics: alpha-Synuclein; Dystonia; Histone Acetyltransferases; Intracellular Signaling Peptides and Proteins; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; Molecular Chaperones; Oncogene Proteins; Parkinson Disease; Protein Deglycase DJ-1; Protein Kinases; Protein Serine-Threonine Kinases; Proton-Translocating ATPases; TATA-Binding Protein Associated Factors; Transcription Factor TFIID; Ubiquitin Thiolesterase; Ubiquitin-Protein Ligases

Topics: alpha-Synuclein; Attention Deficit Disorder with Hyperactivity; Biogenic Amines; Diagnosis, Differential; Dystonia; Homozygote; Humans; Intellectual Disability; Molecular Chaperones; Parkinsonian Disorders; Phenylketonurias; Protein Aggregation, Pathological; Proteostasis; Repressor Proteins

The α-synuclein gene (SNCA) multiplication causes autosomal dominant Parkinson's disease (PD). Particularly triplication, but also duplication, of the SNCA is associated with early-onset rapidly progressing parkinsonism with increased risk of cognitive impairment. There is no report about the effect and safety of Deep Brain Stimulation (DBS) in carriers of this mutation and, in general, data in patients with genetic parkinsonism are scarce. We report a one-year prospective follow-up of subthalamic nucleus (STN) DBS in a 46-year old female carrier of SNCA duplication who developed PD at the age of 41 years, and rapidly showed disabling motor fluctuations and dyskinesias refractory to pharmacological strategies. One year after surgery there was a clinically relevant improvement in motor features with a reduction of 64% in UPDRS III in "off medication" and a complete abolition of peak dose dyskinesias. Patient did not report procedure-related adverse events following STN-DBS except for stimulation-induced right foot dystonia relieved by modulating stimulation parameters. Postoperative cognitive testing showed a decline in executive functions, mostly verbal fluency and attention shifting, compared with presurgical assessment. STN-DBS is safe and effective in patients with SNCA duplication showing a clinical pattern similar to idiopathic PD. Our case suggests that clinical phenotype rather genotype is the main predictor for DBS outcome.

Topics: Adult; alpha-Synuclein; Antiparkinson Agents; Deep Brain Stimulation; Depressive Disorder; Dystonia; Executive Function; Female; Follow-Up Studies; Functional Laterality; Gene Duplication; Humans; Levodopa; Neuropsychological Tests; Neurosurgical Procedures; Parkinson Disease; Subthalamic Nucleus; Treatment Outcome

To determine whether variable thalamic degeneration in Parkinson's disease (PD) contributes to less drug responsive clinical features. Formalin-fixed thalami from longitudinally followed patients with PD and early dystonia (N = 6), early falls (N = 5) or no dystonia or falls (N = 6) and age-matched controls without neuropathology (N = 10) were serially sectioned, stained, and analyzed. Neurons in the centromedian parafascicular (CM-Pf) nucleus were quantified using the optical disector method and analysis of variance with post hoc testing used to determine variability in neurodegeneration between groups. Patients with PD were confirmed to have significant neurodegeneration in the CM-Pf complex, with no difference in the degree of neurodegeneration between patients with PD with early falls compared with patients with no history of falls or dystonia. In contrast, patients with PD with early dystonia had significantly less neurodegeneration of the CM but not the Pf than patients without this feature. Preservation of the CM in patients with PD with early dystonia would result in a relative increase in CM activity through the direct basal ganglia pathway and increased primary motor cortex activity. Overall this data provides evidence for pathway-specific neurodegeneration as an underlying feature of the clinical variability observed in patients with PD.

Topics: Aged; alpha-Synuclein; Antiparkinson Agents; Atrophy; Cell Count; Disease Progression; Dystonia; Female; Humans; Imaging, Three-Dimensional; Intralaminar Thalamic Nuclei; Lewy Bodies; Male; Middle Aged; Nerve Degeneration; Parkinson Disease

Reduced activity of the mitochondrial respiratory chain--particularly complex I--may be implicated in the etiology of both Parkinson's disease and progressive supranuclear palsy, although these neurodegenerative diseases differ substantially as to their distinctive pattern of neuronal cell loss and the predominance of cerebral alpha-synuclein or tau protein pathology. To determine experimentally whether chronic generalized complex I inhibition has an effect on the distribution of alpha-synuclein or tau, we infused rats systemically with the plant-derived isoflavonoid rotenone. Rotenone-treated rats with a pronounced metabolic impairment had reduced locomotor activity, dystonic limb posture and postural instability. They lost neurons in the substantia nigra and in the striatum. Spherical deposits of alpha-synuclein were observed in a few cells, but cells with abnormal cytoplasmic accumulations of tau immunoreactivity were significantly more numerous in the striatum of severely lesioned rats. Abnormally high levels of tau immunoreactivity were found in the cytoplasm of neurons, oligodendrocytes and astrocytes. Ultrastructurally, tau-immunoreactive material consisted of straight 15-nm filaments decorated by antibodies against phosphorylated tau. Many tau+ cell bodies also stained positive for thioflavin S, nitrotyrosine and ubiquitin. Some cells with abnormal tau immunoreactivity contained activated caspase 3. Our data suggest that chronic respiratory chain dysfunction might trigger a form of neurodegeneration in which accumulation of hyperphosphorylated tau protein predominates over deposits of alpha-synuclein.

Topics: alpha-Synuclein; Amyloid beta-Peptides; Analysis of Variance; Animals; Antineoplastic Combined Chemotherapy Protocols; Behavior, Animal; Benzothiazoles; Body Weight; Caspase 3; Caspases; Cell Death; Cerebral Cortex; Cytarabine; Diagnostic Imaging; Dopamine and cAMP-Regulated Phosphoprotein 32; Doxorubicin; Dystonia; Electron Transport Complex III; Enzyme Activation; Glial Fibrillary Acidic Protein; Immunohistochemistry; Locomotion; Male; Microscopy, Electron, Transmission; Mitochondria; Neurons; Phosphopyruvate Hydratase; Phosphorylation; Posture; Psychomotor Performance; Rats; Rats, Inbred Lew; Rotenone; tau Proteins; Tauopathies; Thiazoles; Time Factors; Tyrosine; Tyrosine 3-Monooxygenase; Ubiquitin; Uncoupling Agents

We examined the clinical features of familial (n = 26) and sporadic (n = 52) Parkinson's disease (PD) in patients presenting over the age of 40 years. Familial PD cases were tested for alpha-synuclein or parkin mutations as appropriate. No mutations were found in any of the families investigated. We found no between-group differences in the age at onset of PD, the pattern or severity of parkinsonian features, the dose of antiparkinsonian medications or treatment related complications. Cases of familial and sporadic PD in our cohort of patients display similar clinical features. This may suggest similar etiologies for both familial and sporadic PD.

Topics: alpha-Synuclein; Antiparkinson Agents; Autonomic Nervous System Diseases; Cerebellar Ataxia; Chorea; Cohort Studies; Databases, Factual; Dementia; Disease Progression; Dystonia; Female; Humans; Ligases; Male; Middle Aged; Nerve Tissue Proteins; Paralysis; Parkinson Disease; Synucleins; Tremor; Ubiquitin-Protein Ligases