Mental object rotation in Parkinson's disease.

Deficits in visual-spatial ability can be associated with Parkinson's disease (PD), and there are several possible reasons for these deficits. Dysfunction in frontal-striatal and/or frontal-parietal systems, associated with dopamine deficiency, might disrupt cognitive processes either supporting (e.g., working memory) or subserving visual-spatial computations. The goal of this study was to assess visual-spatial orientation ability in individuals with PD using the Mental Rotations Test (MRT), along with other measures of cognitive function. Non-demented men with PD were significantly less accurate on this test than matched control men. In contrast, women with PD performed similarly to matched control women, but both groups of women did not perform much better than chance. Further, mental rotation accuracy in men correlated with their executive skills involving mental processing and psychomotor speed. In women with PD, however, mental rotation accuracy correlated negatively with verbal memory, indicating that higher mental rotation performance was associated with lower ability in verbal memory. These results indicate that PD is associated with visual-spatial orientation deficits in men. Women with PD and control women both performed poorly on the MRT, possibly reflecting a floor effect. Although men and women with PD appear to engage different cognitive processes in this task, the reason for the sex difference remains to be elucidated.     

Testosterone not associated with violent dreams or REM sleep behavior disorder in men with Parkinson's.

We examined the relationship between testosterone levels, violent dreams, and REM sleep behavior disorder (RBD) in 31 men with Parkinson's disease (PD): 12 with clinical RBD and 19 without. All PD patients with clinical RBD experienced violent dreams, but none of the 19 non-RBD patients reported violent dreams. While dream content appears to be more aggressive in PD patients with clinical RBD, the presence of violent dreams or clinical RBD is not associated with testosterone levels in men with PD.     

Transient ischemic attacks resulting from carotid duplex imaging

Duplex imaging has been widely embraced as a safe and an accurate means of interrogating the extracranial carotid vessels. One reason for this is its appearance as a risk-free diagnostic tool. We report the cases of two patients in whom transient ischemic attacks developed during duplex imaging--attacks that began soon after application of the ultrasound transducer to the cervical region, were identical to prior attacks, and ceased within seconds of removal of the transducer from the neck. The underlying cause of this complication is discussed as is its proper management.     

Atrial fibrillation after stroke in the elderly

To examine the relationship between atrial fibrillation and mortality after stroke, we studied 186 men and 167 women from the Waikato Stroke Registry whose mean age was 75.2 +/- 7.5 years. Twenty-three percent (82 of 353) had atrial fibrillation or flutter on their admission electrocardiogram. This group differed significantly from that with sinus rhythm in three respects: 1) They were older (p less than 0.01); 2) they had more severe current stroke deficit as evidenced by lower limb power (p less than 0.05) and Mini-Mental State Score (p less than 0.001), higher incidence of homonomous hemianopia (p less than 0.05), and lower incidence of lacunar syndrome stroke (p less than 0.001); and 3) they had a significantly higher incidence of cardiomegaly and congestive heart failure (p less than 0.01). Functional outcome was insignificantly better in the group with sinus rhythm. During a mean follow-up period of 18 months, mortality was significantly higher in the group with atrial fibrillation (p = 0.001). Proportional hazards modeling, however, showed that the apparently poorer survival in those patients with atrial fibrillation could be explained by factors other than cardiac rhythm, such as age, Mini-Mental State Score, level of consciousness, and interstitial edema on admission chest radiograph. Thus, atrial fibrillation was not an independent predictor of survival after stroke.     

A not-so-basic case of metabolic alkalosis: an analysis featuring Leendert Paul and emphasizing Occam’s razor

A patient had the onset of a severe degree of metabolic alkalosis associated with a very large daily loss of diarrheal fluid. Because the expected acid-base disorder in this setting is metabolic acidosis, factors that could result in the markedly increased concentration of bicarbonate (HCO₃⁻) in plasma (P ₃) were sought. In our approach, there is an emphasis on electroneutrality, mass balance, a quantitative analysis, and the application of basic concepts in physiology at the bedside. We suggest that there were 3 major factors that could explain why the P ₃ was so high. First, a severe degree of extracellular fluid volume contraction was probably the most important factor that raised her P ₃. Second, there may have been an unusual way to have an electroneutral addition of HCO₃⁻ and removal of chloride ions from her extracellular fluid compartment. Third, the diarrheal fluid could have contained little HCO₃⁻ because of a down-regulated intestinal secretion of HCO₃⁻. This analysis challenges the traditional pathophysiology of metabolic alkalosis.     

The role of psychiatry in the public mental health delivery system: An introduction

The papers which follow are revised and expanded versions of presentations made at the Conference on Improving Florida's Services for the Mentally Ill: The Role of Psychiatry, held in Tallahassee, Florida on October 7–8, 1986, and organized by the Florida Mental Health Institute, University of South Florida. The conference was sponsored by the Florida Department of Health and Rehabilitative Services through the Committee on Public Psychiatry. The authors and their organizational affiliations are listed below