Medical decision-making in neurodegenerative disease: mild AD and PD with cognitive impairment.

The authors compared medical decision-making capacity in patients with mild Alzheimer disease (AD), Parkinson disease (PD) with cognitive impairment, and older controls. Relative to controls and patients with PD, patients with AD were impaired on the consent ability of understanding the medical treatment situation and choices. Patients with PD were impaired on the consent ability of electing a treatment choice.

Quality of life and psychosocial adjustment in patients after Roux-en-Y gastric bypass: a brief report.

BACKGROUND: While Roux-en-Y gastric bypass (RYGBP) appears to be the most effective procedure for weight loss in morbidly obese patients, objective outcome data regarding quality of life (QoL) and psychosocial status following surgery are lacking. METHODS: The present study examined the effects of RYGBP in 32 morbidly obese subjects on a variety of outcome measures including QoL and psychosocial functioning. Assessments were conducted before surgery, 1 to 3 weeks post-surgery, and at 6-month follow-up. RESULTS: In addition to weight loss, results show significant improvements in health-related QoL, depression, and self-esteem, as well as a significant reduction in eating pathology following surgery. Results also show that neither the presence of binge-eating disorder nor clinical depression predicted poorer outcome post-surgery. CONCLUSION: RYGBP results in a dramatic reduction in weight, and marked improvements in health-related QoL, depression, self-esteem, and eating pathology, including binge-eating in the short term. These findings need to be replicated in a larger cohort of patients and followed for a longer time before we can reach more definitive conclusions regarding the psychosocial outcome in RYGBP.

Competency to consent to medical treatment in cognitively impaired patients with Parkinson's disease.

OBJECTIVES: To investigate capacity to consent to medical treatment (competency) in cognitively impaired patients with PD. BACKGROUND: Although competency has been studied empirically in patients with cortical dementia (AD), no empirical studies have examined competency in patients with PD or other subcortical neurodegenerative disorders. METHODS: Patients with PD with cognitive impairment (n = 20) and older controls (n = 20) were compared using a standardized competency measure (Capacity to Consent to Treatment Instrument [CCTI]) and neuropsychological test measures. The CCTI tests competency performance and assigns outcomes (capable, marginally capable, incapable) under four different legal standards (LS). RESULTS: Patients with PD performed below controls on the four LS: capacity to evidence a treatment choice (LS1) (p < 0.03), capacity to appreciate consequences of a treatment choice (LS3) (p < 0.03), capacity to provide rational reasons for a treatment choice (LS4) (p < 0.0001), and capacity to understand the treatment situation and choices (LS5) (p < 0.0001). With respect to competency outcomes, patients with PD demonstrated increasing compromise (marginally capable or incapable outcomes) across the four standards: LS1 (25%), LS3 (45%), LS4 (55%), and LS5 (80%). In the PD group, simple measures of executive function (the Executive Interview) and to a lesser extent memory/orientation (Dementia Rating Scale, Memory subscale) were key predictors of competency performance and outcome on the LS. CONCLUSIONS: Cognitively impaired patients with PD are likely to have impaired consent capacity, and are at risk of losing competency over the course of their neurodegenerative illness. Patients with PD have particular difficulty meeting more stringent, clinically relevant competency standards that tap reasoning skills and comprehension of treatment information. Executive dysfunction appears to be a primary neurocognitive mechanism for competency loss in PD.

Informed consent, competency, and the neurologist.

BACKGROUND: Obtaining informed consent to treatment is an important medical-legal and clinical aspect of neurological practice. REVIEW SUMMARY: This review discusses the doctrine of informed consent and its role in neurological practice. We first provide an overview of the informed consent doctrine and discuss its historical origins and current modern form. The three component elements of informed consent--being informed, voluntary, and competent--are presented, with a focus placed on the competency element. The increasingly important role of informed consent in everyday neurological practice is profiled, with particular emphasis on patients with dementia. Recent empirical research is presented on loss of consent capacity (competency) in patients with Alzheimer's disease and Parkinson's disease. Finally, a conceptually based approach to clinical assessment of competency is presented to assist neurologists dealing with these issues. CONCLUSIONS: The increasing prevalence of patients with neurodegenerative disorders in neurological practice heightens the importance of obtaining valid informed consent to treatment.

Subscale validity of the Mattis Dementia Rating Scale.

The Mattis Dementia Rating Scale (DRS), a widely used dementia screening instrument, generates five subscale scores in the areas of Attention (ATT), Initiation-Perseveration (IP), Construction (CN), Conceptualization (CON), and Memory (MEM). The present study sought to determine the criterion validity of the DRS subscales in a sample of 50 patients with Alzheimer's disease (25 with mild and 25 with moderate dementia). Subject performance on the five DRS subscales was correlated with performance on five well-validated neuropsychological criterion measures using Pearson r and stepwise regression. On a univariate level, each DRS subscale correlated most strongly with its assigned neuropsychological criterion measure. On a multivariate level, each DRS subscale emerged as the Step 1 predictor of its assigned criterion measure, with the exception of DRS CN, which was the Step 2 predictor. The results suggested that overall the DRS subscales are valid measures of their respective constructs and have value for both clinical and research purposes in mild and moderate dementia.

Color image processing with CGH filters in a white light optical system.

Computer simulation and experimental results of computer-generated hologram (CGH) spatial filters applied to the deblurring of color images in a dispersed white light optical processor are presented. Significant performance can be achieved with moderate resolution images and 1-D processing operations. Color smear and multiband filter/signal spectrum size mismatch limit applications involving large space-bandwidth images and/or 2-D processing operations with the dispersed system configuration. The flexibility of the CGH spatial filter fabrication technique, combined with the added processing dimension of wavelength and the inherent ability to reduce coherent artifact noise, make this processing scheme attractive for many image processing applications.

Optical information parallel processing: a technique.

A coherent optical information parallel processing technique using a multidiffraction grating is presented. We have shown that this parallel processing technique is capable of performing multichannel spatial filtering in the spatial frequency plane. The number of parallel processing channels is about 2N times the number of processing channels of the conventional coherent optical processor. However, in practice, the number of processing channels is limited by the number of multiplex gratings that can be synthesized and the available power of the light source. Extension of the monochromatic parallel processing system to polychromatic parallel processing is also presented. It can be shown that the number of processing channels of the polychromatic parallel processor is higher than the monochromatic parallel processor. Extension of this parallel processing concept to multisignal parallel processing is also discussed. However, the multisignal processing technique is not a real-time method because it requires an initial encoding step. Nevertheless, this disadvantage may be alleviated with ingenious design of the encoding system. We also assert that this parallel processing technique may be applied to white light parallel processing.

Optimum correlation detection by prewhitening.

An optimization technique for the optical correlation detection process is proposed. The noise correlation output is suppressed by prewhitening its spectrum. Since the optimization operates on the noise instead of the signal spectrum, the system tolerance for size and orientation variation is not severely affected. Experimental illustrations are also presented.

Real-time white light spatial frequency and density pseudocolor encoder.

A real-time white light pseudocolor encoding technique for spatial frequency and density encodings is presented. In spatial frequency color coding, the encoding is accomplished by spatial filtering of the color signal spectra, while in density pseudocoloring, the encoding consists of contrast reversal of a color object image. The technique is simple, versatile, and economical to operate, which may offer some practical applications. Because the encoding colors are primarily derived from a white light source, the annoying coherent artifact noise can be substantially reduced. Since the encoding is obtained with a broad spatial band of the signal spectra, this technique offers no apparent resolution loss. We stress that this real-time white light pseudocolor encoding technique may offer several major advantages that previous techniques have offered. Experimental demonstrations of this pseudocolor encoding technique are also provided.