Older-onset levodopa-responsive parkinsonism with normal DAT-SPECT and pterin hypometabolism.

Pterin species participate in dopamine biosynthesis, and abnormal pteridine metabolism contributes to reduced dopamine. GTP cyclohydrolase 1 (GCH-1) deficiency, which triggers pteridine hypometabolism and normally develops in childhood, can mediate an adult-onset decrease in levodopa production and dopa-responsive dystonia (DRD), with normal dopamine transporter single-photon emission computed tomography (DAT-SPECT). A recent study described normal DAT-SPECT in adult-onset cases with GCH-1 mutations, clinically diagnosed with Parkinson's disease, which raises the possibility that the abnormal metabolism of pteridine may be a differential diagnosis for adult-onset parkinsonism. We report an older patient with levodopa-responsive parkinsonism with normal DAT-SPECT, or scans without evidence of dopamine deficit (SWEDD), whose biochemical analysis showed pterin hypometabolism, which occurs in GCH-1-deficient DRD. Surprisingly, this patient presented no dystonia or GCH-1 gene mutation or deletion. This case suggests that low pterin metabolism should be considered in older-onset levodopa-responsive parkinsonism with normal DAT-SPECT, even without GCH-1 mutations or deletions.

Significance of Nonfocal Symptoms in Patients With Transient Ischemic Attack.

Background and Purpose- Patients with transient ischemic attack (TIA) occasionally show nonfocal symptoms, such as unconsciousness, amnesia, and unsteadiness. The purpose of this study was to clarify the characteristics and prognosis of patients with TIA with nonfocal symptoms, using data from the PROMISE-TIA (Prospective Multicenter Registry to Identify Subsequent Cardiovascular Events After Transient Ischemic Attack). Methods- Patients with TIA within 7 days of onset were consecutively enrolled in the Japanese nationwide registry. Factors associated with nonfocal symptoms and 1-year risks of ischemic stroke and coronary artery diseases were assessed in multivariate-adjusted models. Results- We studied 1362 patients with TIA (879 men; mean age, 69±12 years), including 219 (16%) with nonfocal symptoms. Patients with TIA with nonfocal symptoms were more likely to show acute ischemic lesions in the posterior circulation on diffusion-weighted imaging (multivariate-adjusted odds ratio, 3.07; 95% confidence interval, 1.57-5.82) and arterial stenosis or occlusion in the posterior circulation on vascular examination (odds ratio, 1.94; 95% confidence interval, 1.19-3.09) than those without nonfocal symptoms. Although 1-year risk of ischemic stroke did not differ significantly between groups (adjusted hazard ratio, 0.79; 95% confidence interval, 0.42-1.37), risk of coronary artery disease was higher in patients with TIA with nonfocal symptoms (hazard ratio, 3.37; 95% confidence interval, 1.14-9.03). Conclusions- Both acute ischemic lesions and arterial stenosis and occlusion in the posterior circulation were more frequently observed in patients with TIA with nonfocal symptoms.

Embolic Stroke due to Carotidynia Potentially Associated with Moving Carotid Artery Caused by Swallowing.

A 63-year-old woman with end-stage renal disease on maintenance hemodialysis discontinued her medication for rheumatoid arthritis with prednisolone and azathioprine. One month later, she was admitted because of consciousness disturbance and right hemiparesis. Diffusion-weighted brain magnetic resonance imaging (MRI) revealed multiple hyperintensities in her left frontal and parietal lobes. She also developed high fever and left neck pain. Carotid ultrasonography showed calcified plaque with vessel wall swelling at the bifurcation of the left common carotid artery (LCCA) and surrounding hypoechoic soft tissue. The tissue was identified as an isodense lesion on noncontrast computed tomography (CT) and as a high-intensity lesion on fat-saturated T2-weighted MRI. From her symptoms and radiological findings, she was diagnosed with carotidynia. Cervical MRI also showed that the LCCA was transposed to a retropharyngeal location, suggesting a moving carotid artery. Carotid ultrasonography revealed that the LCCA moved to and from the retropharyngeal position with swallowing and was thus being compressed by the hyoid bone. After corticosteroid therapy was initiated with 30 mg of prednisolone, her symptoms and radiological findings improved. To our knowledge, this is the first report of a case of cerebral embolism due to carotidynia. The repetitive compressions by the hyoid bone during swallowing were presumed to have provoked shear stress and inflammation of the carotid vessel wall, which was aggravated by discontinuation of steroid therapy in our case. These mechanical and inflammatory stresses might cause dysfunction of endothelial cells, hypercoagulation, platelet hyperaggregation, and vulnerability and rupture of carotid plaques, and may subsequently result in embolic strokes.

Methodological development of a clonogenic assay to determine endothelial progenitor cell potential.

The precise and conceptual insight of circulating endothelial progenitor cell (EPC) kinetics is hampered by the absence of an assay system capable of evaluating the EPC differentiation cascade. An assay system for EPC colony formation was developed to delineate circulating EPC differentiation. EPC colony-forming assay using semisolid medium and single or bulk CD133(+) cells from umbilical cord blood exhibited the formation of two types of attaching cell colonies made of small or large cells featuring endothelial lineage potential and properties, termed small EPC colony-forming units and large EPC colony-forming units, respectively. In vitro and in vivo assays of each EPC colony-forming unit cell revealed a differentiation hierarchy from small EPC to large EPC colonies, indicating a primitive EPC stage with highly proliferative activity and a definitive EPC stage with vasculogenic properties, respectively. Experimental comparison with a conventional EPC culture assay system disclosed EPC colony-forming unit cells differentiate into noncolony-forming early EPC. The fate analysis of single CD133(+) cells into the endothelial and hematopoietic lineage was achieved by combining this assay system with a hematopoietic progenitor assay and demonstrated the development of colony-forming EPC and hematopoietic progenitor cells from a single hematopoietic stem cell. EPC colony-forming assay permits the determination of circulating EPC kinetics from single or bulk cells, based on the evaluation of hierarchical EPC colony formation. This assay further enables a proper exploration of possible links between the origin of EPC and hematopoietic stem cells, representing a novel and powerful tool to investigate the molecular signaling pathways involved in EPC biology.