No abstract

The corticostriate projections of temporal areas TA, TE, TF, TG, 35, and 28 were studied in the rhesus monkey with the use of autoradiography. Widespread projections were observed to rostral as well as caudal parts of the striatum for all areas except area 28. For example, areas TA and TG have sizable projections to the medial or periventricular part of the head of the caudate nucleus, as well as to the medial part of the tail of this structure and the dorsally adjacent putamen. Areas TE and TF also were observed to send strong projections to the head of the caudate nucleus. In addition, they project to the rostral putamen. Both have projections to the tail of the caudate nucleus and caudal putamen. The widespread distribution of temporostriate axons to the rostral striatum suggests strongly that previous silver impregnation studied have not only underestimated the strength of the temporal cortical contribution to the corticostriate system, but also failed to identify the major projection zone of temporostriate axon terminals. For example, while all temporal cortical areas contribute projections to an organized topography in the tail of the caudate nucleus and the ventrocaudal putamen, they were observed consistently to have larger projections to the head of the caudate nucleus and rostral putamen. These results add to a growing body of evidence which demonstrates the existence of widespread nonmotor cortical input to the basal ganglia, and an organization of this input far greater in complexity than that demonstrated by earlier suppressive silver impregnation methods.

Dehydration is the most common fluid and electrolyte disorder among the elderly, yet risk factors are not known. This study identifies risk factors for dehydration in acutely ill nursing home residents. All 339 elderly resident of two nursing homes who developed an acute illness requiring hospitalization during 1984 were included in the study. The 173 patients having a serum Na less than 150 mg/dL and blood urea nitrogen to creatinine ratio (BUN:Cre) less than 20 were designated controls; 91 patients having a serum Na greater than 150 mg/dL or a serum BUN:Cre greater than 25 were designated cases. Odds ratios (OR) and confidence intervals were calculated for age, sex, chronic conditions, acute illnesses, medications, functional status measures, and season. Acutely ill dehydrated patients were female (OR, 3.3); over 85 years old (OR, 2.2); had more than four chronic conditions (OR, 4.0); took more than four medications (OR, 2.8); and were bedridden (OR, 2.9). Among the most severely dehydrated (serum Na greater than 150 mg/dL and BUN:Cre greater than 25), the odds ratios for the above factors were strengthened and other factors, such as inability to feed oneself and type of acute diagnosis, emerged as risk factors. Among the variables unrelated to functional status, laxatives (OR, 3.2) and chronic infections (OR, 1.8) were risk factors. We conclude that a group at high risk for dehydration can be defined and that they are better characterized by the number of chronic diseases and debilitated functional status than by acute disease processes.

It appears that although the web-based technology is gaining popularity and leads to lower cost per response, the conventional postal method of surveying continues to deliver a better response rate among the geriatric medicine division chiefs. The web-based approach holds promise given its lower costs and acceptable response rate combined with the shorter response time.

Living wills and other advance directives currently play a limited role in medical decision making. A new federal law, the Patient Self-Determination Act, will require health care providers in hospitals, nursing homes, and other facilities to inquire about the presence of advance directives, to record patient preferences in the medical record, and to develop institutional policies regarding the implementation of these directives. Unfortunately, the law does little to promote discussion or preparation of advance directives before hospitalization. Additional efforts to promote the use of advance directives can take place in the outpatient medical care system, in attorneys' offices, or through health insurers. Because most people have not yet prepared an advance directive, we suggest that institutions develop treatment policies for situations in which the wishes of patients who lack decisional capacity are not known. These policies should be designed to promote the patients' best interests, as defined by the consensus of the institutions' staff and members of the surrounding community.