Cognitive performance, SPECT, and blood viscosity in elderly non-demented people using Ginkgo biloba

The aging process is associated with several cognitive alterations. This study looks at the effects of taking dried extract of Ginkgo biloba, which has been used in several countries in an attempt to minimize these effects. The subjects were 48 men aged 60 - 70 matched between control and experimental groups for educational level. Evaluation was based on a number of neuropsychological tests in an attempt to cover the largest possible number of functions including Single Photon Emission Computer Tomography (SPECT) and measures of blood viscosity. The study was run on a double-blind basis with placebo and Ginkgo biloba groups evaluated over a period of 8 months. After treatment, the experimental group showed a reduction in blood viscosity, improved cerebral perfusion in specific areas and improved global cognitive functioning. The control group showed the opposite - higher blood viscosity, a reduction in cerebral perfusion (in specific areas), and cognitive deterioration in different functions. Although the mechanisms by which Ginkgo biloba may contribute to overall enhancement of the parameters evaluated have not been specified, this plant extract certainly appears to be effective in the treatment of cognitive deficits in older people. Further research into its use is called for on the basis of the results obtained here.

Effect of sequential intermittent pneumatic compression on both leg lymphedema volume and on lymph transport as semi-quantitatively evaluated by lymphoscintigraphy

Sequential Intermittent Pneumatic Compression (SIPC) is an accepted method for treatment of peripheral lymphedema. This prospective study evaluated the effect in 11 patients of a single session of SIPC on both lymphedema volume of the leg and isotope lymphography (99Tc dextran) before SIPC (control) and 48 hours later after a 3 hour session of SIPC. Qualitative analysis of the 2 lymphoscintigrams (LS) was done by image interpretation by 3 physicians on a blind study protocol. The LS protocol attributed an index score based on the following variables: appearance, density and number of lymphatics, dermal backflow and collateral lymphatics in leg and thigh, visualization and intensity of popliteal and inguinal lymph nodes. Volume of the leg edema was evaluated by measuring limb circumference before and after SIPC at 6 designated sites. Whereas there was a significant reduction of circumference in the leg after SIPC (p<0.05), there was no significant difference in the index scores of the LS before and after treatment. This acute or single session SIPC suggests that compression increased transport of lymph fluid (i.e., water) without comparable transport of macromolecules (i.e., protein). Alternatively, SIPC reduced lymphedema by decreasing blood capillary filtration (lymph formation) rather than by accelerating lymph return thereby restoring the balance in lymph kinetics responsible for edema in the first place.

[Lymphedemas of the lower limbs: a lymphoscintigraphic study]

Patients with lymphoedema of the lower limbs (LLL) are usually affected by recurrent erysipelas. This bacterial infection is usually admitted as an aetiological factor, but it can be a consequence of some previous lymphatic abnormality. Classically, the commonest causative factors of LLL are bacterial infection, venous ulcers, trauma (leading to secondary lymphoedema) and congenital disorders of the lymphatic system (primary lymphoedema--praecox or tarda).

PURPOSE

To identify previous lymphatics abnormalities in patients with LLL, admitted as having secondary lymphatic lymphoedema--as consequences of infection, trauma or other factors--, by using lymphoscintigraphic method. To observe advantages of this approach in practical assistance and evaluation of LLL cases.

METHODS

Twelve patients with LLL, supposed to have primary (congenital) or secondary disorder affecting one or both lower extremities were submitted to lymphoscintigraphy at the Escola Paulista de Medicina of Sao Paulo, Brazil. Each patient received an intradermal injection of labelled Dextran (Dx-99mTc) at the first interdigital space of each foot and, after one to three hours, images of lower extremities, pelvic and abdominal areas were obtained with Gammatome CGR.

RESULTS

Examination of all 24 lower extremities disclosed clinical diagnosis of lymphoedema in 17 (70.8%), being five (41.6%) with clinical signs of lymphoedema of both lower limbs and seven (58.3%) of a single one. The lymphoscintigraphic images revealed lymphatic disorders in 22 of the 24 extremities (91.7%). Lymphoscintigraphic abnormalities in clinically normal lower extremities were observed in five cases (41.3%).

CONCLUSION

Lymphoscintigraphy is a non-invasive useful method to study LLL, with involvement of one or both limbs. It does not differentiate between primary and secondary lymphoedema, but makes possible to detect cases of normal appearance of the limbs with previous lymphatic defect(s), changing aetiological diagnosis. Some cases that appear to be secondary lymphoedema could be, in fact, associated with congenital abnormality(ies) of lymphatics, triggered by factors like trauma or venous ulcers.

[Radioisotopic mapping of the arrhythmogenic focus in patients with chronic chagasic cardiomyopathy and sustained ventricular tachycardia]

PURPOSE

To localize the site of the origin of sustained ventricular tachycardia in chronic chagasic cardiomyopathy patients refractory to antiarrhythmic therapy by radionuclide angiography techniques.

METHODS

Five patients underwent radionuclide angiography by intravenous administration of 25mCi 99mTc. The images were obtained in sinus rhythm and during sustained ventricular tachycardia induced in the electrophysiologic laboratory for endocardial mapping. Amplitude and phase images were obtained resulting in a contraction wave synchronic to ventricular dispolarization.

RESULTS

All patients had haemodynamic stability during the arrhythmia. One patient had incessant ventricular tachycardia. Mean ejection fraction was 0.38. In 4 patients the site of the origin of ventricular tachycardia was posterior and in one it was localized in the interventricular septum. There was identity in the site of the origin of ventricular tachycardia obtained by endocardial mapping or radionuclide angiography in all patients. The therapy was chemical ablation in 3 patients, surgical aneurysmectomy in one and pharmacologic therapy in the last patient.

CONCLUSION

The site of the origin of ventricular tachycardia can be estimated by analyzing the contraction wave obtained by radionuclide angiography techniques in patients with hemodynamic stable sustained ventricular tachycardia.

Lung and myocardial thallium-201 kinetics in resting patients with congestive heart failure: correlation with pulmonary capillary wedge pressure

Increased lung thallium-201 activity occurs with exercise in patients with severe coronary artery disease as a result of increased pulmonary capillary wedge pressure. No study has shown resting lung kinetics in chronic congestive heart failure. To better understand the relationship between lung and myocardial thallium uptake and pulmonary capillary wedge pressure, this study was performed. Resting lung and myocardial thallium uptake, expressed as a ratio, were compared with simultaneous pulmonary capillary wedge pressure in 16 patients with congestive heart failure and cardiomyopathy, all New York Heart Association class IV. There were no variations in pulmonary capillary wedge pressure throughout the study protocol. There was a significant reduction in the lung/myocardium thallium ratio from 10 to 60 minutes (0.83 +/- 0.30 to 0.59 +/- 0.17; p less than 0.001). At 60 minutes after thallium injection there was a linear correlation between the lung/myocardium ratio and capillary wedge pressure with an r value of 0.62 (p less than 0.01). Thus thallium-201 washout is rapid despite persistence of pulmonary capillary wedge pressure elevation, indicating that clearance does not imply resolution of congestive heart failure. In addition, a significant but imprecise correlation was found between capillary pressure and the lung/myocardium ratio. Rapid changes in lung activity during the early postinjection period may limit the clinical use of the lung/myocardium ratio.

Dipyridamole-thallium tests are predictive of severe cardiac arrhythmias in patients with left ventricular hypertrophy

In a population of patients with chronic renal failure (CRF) and a high prevalence of left ventricular hypertrophy (LVH) undergoing chronic hemodialysis, we investigated the association between the results of dipyridamole-thallium tests (DTTs) and the occurrence of ventricular arrhythmias. We observed a positive significant association between positive DTTs and the occurrence of severe forms of ventricular arrhythmias. A significant association was also observed between the presence of severe LVH and the occurrence of severe ventricular arrhythmias. However, no association was found between the presence of LVH and the positivity of the DTT. As most of our patients with positive DTTs had unimpaired coronary circulations, we conclude that positive DTTs, although falsely indicative of impaired myocardial blood supply, does have an important clinical relevance, indicating increased risk of morbidity (and, possibly, mortality) due to ventricular arrhythmias in a population of CRF patients submitted to chronic renal function replacement program.