Expanding the Spectrum of Dopa-Responsive Dystonia (DRD) and Proposal for New Definition: DRD, DRD-plus, and DRD Look-alike

Previously, we defined DRD as a syndrome of selective nigrostriatal dopamine deficiency caused by genetic defects in the dopamine synthetic pathway without nigral cell loss. DRD-plus also has the same etiologic background with DRD, but DRD-plus patients have more severe features that are not seen in DRD because of the severity of the genetic defect. However, there have been many reports of dystonia responsive to dopaminergic drugs that do not fit into DRD or DRD-plus (genetic defects in the dopamine synthetic pathway without nigral cell loss). We reframed the concept of DRD/DRD-plus and proposed the concept of DRD look-alike to include the additional cases described above. Examples of dystonia that is responsive to dopaminergic drugs include the following: transportopathies (dopamine transporter deficiency; vesicular monoamine transporter 2 deficiency); SOX6 mutation resulting in a developmentally decreased number of nigral cells; degenerative disorders with progressive loss of nigral cells (juvenile Parkinson's disease; pallidopyramidal syndrome; spinocerebellar ataxia type 3), and disorders that are not known to affect the nigrostriatal dopaminergic system (DYT1; GLUT1 deficiency; myoclonus-dystonia; ataxia telangiectasia). This classification will help with an etiologic diagnosis as well as planning the work up and guiding the therapy.

Berberine alleviates symptoms of anxiety by enhancing dopamine expression in rats with post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a trauma-induced psychiatric disorder characterized by impaired fear extermination, hyperarousal, anxiety, depression, and amnesic symptoms that may involve the release of monoamines in the fear circuit. The present study measured several anxiety-related behavioral responses to examine the effects of berberine (BER) on symptoms of anxiety in rats after single prolonged stress (SPS) exposure, and to determine if BER reversed the dopamine (DA) dysfunction. Rats received BER (10, 20, or 30 mg/kg, intraperitoneally, once daily) for 14 days after SPS exposure. BER administration significantly increased the time spent in the open arms and reduced grooming behavior during the elevated plus maze test, and increased the time spent in the central zone and the number of central zone crossings in the open field test. BER restored neurochemical abnormalities and the SPS-induced decrease in DA tissue levels in the hippocampus and striatum. The increased DA concentration during BER treatment may partly be attributed to mRNA expression of tyrosine hydroxylase and the DA transporter in the hippocampus, while BER exerted no significant effects on vesicular monoamine transporter mRNA expression in the hippocampus of rats with PTSD. These results suggest that BER had anxiolytic-like effects on behavioral and biochemical measures associated with anxiety. These findings support a role for reduced anxiety altered DAergic transmission and reduced anxiety in rats with PTSD. Thus, BER may be a useful agent to treat or alleviate psychiatric disorders like those observed in patients with PTSD.

Genetic analysis of P387L mutation in SLC18A2 gene in sporadic Parkinson's disease in Chinese Han population / 中南大学学报(医学版)

OBJECTIVE@#To investigate whether the mutation of P387L in SLC18A2 gene is a cause for sporadic Parkinson's disease (PD) in Chinese Han population.
@*METHODS@#A total of 931 subjects (455 sporadic PD patients and 476 healthy controls) were enrolled in our study. SLC18A2 P387L was genotyped by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and the results were verified by Sanger sequencing. Furthermore, a case-control study was used to investigate the relationship between the mutation and sporadic PD.
@*RESULTS@#There was no mutation in any of the 931 individuals.
@*CONCLUSION@#The P387L mutation in SLC18A2 gene is rare in Chinese Han population, and P387L might not be a cause for Chinese sporadic PD. However, the role of this mutation in PD needs to be further verified through replication studies with large number of subjects and different population.

Molecular Imaging in Neurodegenerative Diseases

Neurodegenerative diseases are highly morbid and widespread in the nation with aged population. Since these are progressive and irreversible diseases, early detection and differentiation of the disease are important for possible therapeutic intervention. Alzheimer's disease and Parkinson's disease are the most frequent and costly devastating neurodegenerative diseases. Recent advances of molecular imaging, especially positron emission tomography (PET) technique, allows non-invasive evaluation of not only regional cerebral metabolism or perfusion, but also the change of neurotransmission and presence of abnormal protein such as beta amyloid. In Parkinsonism, dopamine transporter and vesicular monoamine transporter imaging are useful in the diagnosis and evaluation of the disease progression since these provide information about the integrity of presynaptic striatal dopaminergic neurons. In Alzheimer s disease, beta-amyloid imaging can assess the amyloid deposition. It improves early diagnosis and possibility of a presymptomatic diagnostic biomarker; improves understanding of the natural history of amyloid deposition; and has the capability to directly measure the effects of newly developed anti-amyloid therapies. Cholinergic and microglial imaging can be also useful in the early diagnosis of dementia and improves understanding of insights into pathophysiology of neurodegenerative diseases. Therefore, the ability of molecular imaging to identify and quantify cerebral pathology has significant implications for early detection, differential diagnosis, and therapeutic monitoring in neurodegenerative diseases.

Molecular Imaging in Neurodegenerative Diseases

Neurodegenerative diseases are highly morbid and widespread in the nation with aged population. Since these are progressive and irreversible diseases, early detection and differentiation of the disease are important for possible therapeutic intervention. Alzheimer's disease and Parkinson's disease are the most frequent and costly devastating neurodegenerative diseases. Recent advances of molecular imaging, especially positron emission tomography (PET) technique, allows non-invasive evaluation of not only regional cerebral metabolism or perfusion, but also the change of neurotransmission and presence of abnormal protein such as beta amyloid. In Parkinsonism, dopamine transporter and vesicular monoamine transporter imaging are useful in the diagnosis and evaluation of the disease progression since these provide information about the integrity of presynaptic striatal dopaminergic neurons. In Alzheimer s disease, beta-amyloid imaging can assess the amyloid deposition. It improves early diagnosis and possibility of a presymptomatic diagnostic biomarker; improves understanding of the natural history of amyloid deposition; and has the capability to directly measure the effects of newly developed anti-amyloid therapies. Cholinergic and microglial imaging can be also useful in the early diagnosis of dementia and improves understanding of insights into pathophysiology of neurodegenerative diseases. Therefore, the ability of molecular imaging to identify and quantify cerebral pathology has significant implications for early detection, differential diagnosis, and therapeutic monitoring in neurodegenerative diseases.