Reversible striatal hypermetabolism in chorea associated with moyamoya disease: a report of two cases.

BACKGROUND: The pathophysiological mechanism of chorea as a presentation of pediatric moyamoya disease remains unknown, although ischemia is suspected as a likely cause. The authors describe two cases of pediatric moyamoya disease, both of which presented with hemichorea in the stable phase after successful bypass surgery. CLINICAL PRESENTATION: Cerebral blood flow was almost normal in one case and decreased in the basal ganglia and watershed area in the other case due to infarcts occurring before surgery. In both cases, 18F-fluorodeoxyglucose positron emission tomography revealed elevated glucose metabolism in the corresponding side of the striatum, which reverted to normal after recovery from chorea. Magnetic resonance angiography revealed a dilated and extended lenticulostriate artery at the exact site of the hypermetabolic lesion.

Inhibition of VEGF receptors induces pituitary apoplexy: An experimental study in mice.

Anti-vascular endothelial growth factor (VEGF) therapy has been developed for the treatment of a variety of cancers. Although this therapy may be a promising alternative treatment for refractory pituitary adenomas and pituitary carcinomas, the effects of anti-VEGF agents on the pituitary gland are not yet well understood. Here, we found that mice administered with OSI-930, an inhibitor of receptor tyrosine kinases including VEGF receptor 1 and 2, frequently exhibited hemorrhage in the pituitary gland. This is the first report that anti-VEGF therapy can cause pituitary apoplexy. C57BL/6 mice were daily injected intraperitoneally with 100 mg/kg body weight of OSI-930 for one to six days. Pituitary glands were immunohistochemically examined. Four of six mice treated for three days and all of five mice treated for six days exhibited hemorrhage in the pituitary gland. In all cases, the hemorrhage occurred just around Rathke's cleft. In OSI-930-administered mice, the vascular coverage and branching were reduced in the anterior lobe, and capillary networks were also decreased in the intermediate lobe in a treatment-day dependent manner. Few blood vessels around Rathke's cleft of the intermediate lobe express VE-cadherin and are covered with platelet-derived growth factor receptor-ß (PDGFR-ß)-positive cells, which suggests that capillaries around Rathke's cleft of the intermediate lobe were VE-cadherin-negative and not covered with pericytes. The reduction of capillary plexus around Rathke's cleft was observed at the site where hemorrhage occurred, suggesting a causal relationship with the pathogenesis of pituitary hemorrhage. Our study demonstrates that anti-VEGF agents have a risk of pituitary apoplexy. Pituitary apoplexy should be kept in mind as an adverse effect of anti-VEGF therapy.

Severe Hypoglycemia-induced Right Hemiparesis with Reversible Diffusion Restriction in the Left Internal Capsule Due to Combination Therapy Using Disopyramide and Clarithromycin.

Severe hypoglycemia is known to cause acute focal neurological symptoms. In cases with a medical history of diabetes mellitus (DM), the diagnosis and treatment of hypoglycemia-induced neurological symptoms are simple. However, severe hypoglycemia can occur in patients who are not taking hypoglycemic agents such as insulin or long-acting sulfonylurea drugs. We describe a 95-year-old man with sudden onset of right hemiparesis who showed high signal intensity on diffusion-weighted imaging involving the left internal capsule with corresponding reduced apparent diffusion coefficient hypointensity. Laboratory findings revealed severe hypoglycemia (27 mg/dl). However, he was not taking insulin or long-acting sulfonylurea drugs but disopyramide and clarithromycin had been administered. In addition, he had kidney dysfunction with an estimated glomerular filtration rate (GFR) of 42.9 ml/min/1.73 m2. After the blood glucose level was normalized, the left hemiparesis completely recovered and abnormal findings of magnetic resonance imaging (MRI) study also became normal. A combination of disopyramide and clarithromycin may cause severe hypoglycemia-induced neurological symptoms particularly in patients with kidney dysfunction. Even in a patient with sudden-onset hemiparesis and no history of DM, the possibility of hypoglycemia-induced neurological deficit should be considered.

Discrepancy between radiological and histological findings in ganglioglioma of the optic chasm: Case report.

BACKGROUND: Gangliogliomas involving the optic nerve or chiasm are extremely rare tumors, which can be confused radiologically with other neoplasms. α-[N-methyl-11C]-methylaminoisobutyric acid (11C-MeAIB) is a new artificial amino acid positron emission tomography (PET) tracer, which is metabolically more stable in vivo and may be more specific for tumors than 11C-methionine. However, the utility of 11C-MeAIB PET in the diagnosis of brain tumors has not yet been reported. CASE DESCRIPTION: A 26-year-old man presented with visual field defects and headache, and magnetic resonance imaging demonstrated a suprasellar mass involving the optic chiasm. A biopsy and partial tumor resection were performed via an interhemispheric approach. We diagnosed the tumor as ganglioglioma (WHO grade I) involving the optic chiasm. Although this lesion was histologically benign, 11C-MeAIB PET, 2-deoxy-2-[18F] fluoro-D-glucose (18F-FDG) PET and proton magnetic resonance spectroscopy indicated malignant features. CONCLUSION: The discrepancy between radiological and histological findings implies that this new amino acid tracer PET may have a limitation in the diagnosis of gangliogliomas. Although further study is necessary, gangliogliomas should be included in the differential diagnosis of suprasellar tumors, even if PET findings show malignant features.