There have been no reports of studies on nocturnal sleep or quantitative studies of sleep spindle density in Huntington's disease, whereas sleep in Parkinson's disease has been extensively reported. We therefore examined nocturnal sleep changes in patients with Parkinson's and Huntington's disease and compared them with a control group. The previously reported decrease in sleep spindle density was observed in patients with Parkinson's disease. The patients with Huntington's disease, however, had a significant increase in sleep spindle density, the nocturnal sleep pattern being normal in other respects when compared with the control group. This observation may provide a further diagnostic criterion in Huntington's disease.

Because of the ultrashort tracer half-life and high positron energy of 82 Rb, PET images acquired with this tracer are noisier and of lower resolution than those obtained with other PET tracers. The validity of electrocardiographic gating using 82 Rb for assessment of left ventricular (LV) function is not well established. To support feasibility, we compared functional parameters from gated 82 Rb PET with simultaneous high-resolution contrastenhanced CT ventriculography, obtained as a byproduct a CT coronary angiography during hybrid cardiac PET/CT. Methods: A total of 24 patients underwent PET/CT, consisting of rest and dipyridamole 82 Rb perfusion studies and contrast-enhanced CT angiography, using a 64-slice scanner, for the workup of coronary artery disease. From gated PET images, LV ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV) were calculated using 2 commercial products. For functional CT analysis, commercial software using endocardial contour detection was applied. Results: Inter-and intraobserver agreement was good for all methods. On CT, EF was 66% 6 13%, ESV was 41 6 29 mL, and EDV was 115 6 36 mL. On PET, EF during dipyridamole was 56% 6 15% and 52% 6 15% using the 2 commercial products (P , 0.05 vs. CT), ESV was 36 6 28 and 47 6 35 mL (P 5 not significant vs. CT), and EDV was 75 6 30 and 91 6 33 mL (P , 0.05 vs. CT). Correlations with CT were 0.85 and 0.87 for EF using commercial software, 0.76 and 0.88 for ESV, and 0.60 and 0.68 for EDV (P , 0.01 for all). Bland-Altman analysis confirmed systematic underestimation of EF and EDV by PET versus CT but did not show a significant deviation from linearity. Conclusion: Global LV function can be measured reproducibly from gated 82 Rb PET, using different available software products. However, underestimation of EF by 82 Rb PET, compared with CT ventriculography, is present, which is a result of underestimation of EDV from countpoor ED frames. This underestimation needs to be considered for clinical interpretation of 82 Rb PET.

(99m)Tc-DMSA renal cortical imaging using dual-head SPECT offers no statistically significant diagnostic advantage over planar imaging for detection of cortical defects.

Intravenous administration of amantadine has been shown to be a quick-acting and highly effective method of treating patients with Parkinson's disease. The duration of this therapeutic effect during long-term oral treatment has, however, remained controversial. Therefore, the effect of intravenous treatment was compared with long-term oral treatment over a period of 6 months. Clinical scores and psychometrically determined dexterity improved significantly during 10-day infusion therapy (200 mg amantadine sulphate/day). This improvement was successfully maintained by oral treatment (600 mg/day). A decrease in effectiveness was not observed. Reaction times were within the normal range for the age group involved and did not change significantly during the course of the study. Amantadine serum concentration during the infusion period ranged between 500 and 1000 micrograms/l and produced values nearly half as high as those obtained during oral treatment (600 mg/day). There was a constant relationship (quotient: 1.3) between serum and cerebrospinal fluid concentration. Considerable inter-individual variations were noted. A significant inter-individual correlation between serum concentration and clinical and psychological improvement was not discernible.

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