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Biomedical subjects

K A Nolan

Publications and source records attributed to K A Nolan.

9 recordsLinked to original sources

Pentoxifylline in cerebrovascular dementia.

OBJECTIVE: To test the effect of pentoxifylline, a hemorheologic agent used to treat intermittent claudication, on the course of vascular dementia. DESIGN: Randomized, double-blind, placebo-controlled, parallel group trial. SETTING: Outpatient tertiary care center. PATIENTS: 64 patients meeting DSM-III criteria for multi-infarct dementia with modified Hachinski ischemic scores greater than or equal to 6, 38 of whom completed the trial. INTERVENTION: Pentoxifylline (Trental) 400 milligram tablets three times daily vs placebo for 36 weeks. MAIN OUTCOME MEASURE: Alzheimer's Disease Assessment Scale (ADAS). RESULTS: Baseline demographic values and psychometric variables were similar in the placebo and control groups; endpoint statistical analysis was used to allow the use of data from all patients in this clinically high-risk group. For the total group, the slowing of deterioration did not reach statistical significance (by 2-tailed t test), as measured by scores on the total ADAS (P = 0.058) or on the cognitive (ADAS items 1-11; P = 0.064) or non-cognitive subscales (ADAS items 12-21; P = 0.234), although it was significant on the cognitive subscales excluding memory (ADAS items 2-6, 8-10; P = 0.036). For the subgroup of 40 patients who had CT and/or MRI evidence of stroke as well as meeting the other inclusion criteria, treatment with pentoxifylline was associated with significantly slower deterioration, as measured by the total ADAS (P = 0.023) and cognitive subscores (P = 0.020) but not non-cognitive subscores (P = 0.118). For the subgroup of 37 patients who had at least one discrete clinical stroke, treatment with pentoxifylline was associated with significantly less deterioration on the total ADAS (P = 0.002) and both the cognitive (P = 0.001) and non-cognitive (P = 0.017) subscores. CONCLUSION: Treatment with pentoxifylline may slow the progression of dementia in patients who meet DSM-III criteria for "multi-infarct dementia" and who also have clinical and neuroradiological evidence of cerebrovascular disease.

Academic Medical Centers

Preventing cognitive decline.

Many studies of age-related cognitive decline have failed to distinguish between usual and successful aging. Although some degree of cognitive impairment is associated with aging, when one looks at average performance, there is great variability among individuals, with many showing little or no deleterious effects of aging on intellectual abilities. Many of the risk factors for dementia and for conditions associated with cognitive impairments can be treated or controlled. Among the preventable causes of cognitive decline are the following: AIDS, Alcohol and drug abuse, Cerebrovascular disease, Exposure to organic solvents or lead, Head trauma, Overmedication, Syphilis. Other conditions that may cause cognitive decline can be controlled or treated: Atherosclerosis, Depression, Diabetes, Emphysema, High blood pressure, Obesity, Sleep disorders, Thyroid dysfunction. In addition, it may be possible to enhance the cognitive performance of even healthy elderly people through changes in diet and lifestyle. Recent data raise the possibility that improved prenatal and perinatal care and greater access to educational opportunities may result in a decreased incidence of dementia in future generations of older adults. Although they are rapidly becoming more numerous, the efficacy of cognitive training programs in preventing or slowing cognitive decline has not yet been demonstrated. Nevertheless, such programs may ameliorate cognitive impairment by reducing the psychiatric disabilities associated with anxiety and depression. The general principle underlying these strategies for limiting cognitive impairment with age is to maximize brain reserve and minimize brain damage.

Aging

A trial of thiamine in Alzheimer's disease.

Because a previous short-term study demonstrated a statistically significant, but not clinically important, improvement in cognitive test scores during thiamine treatment in patients with dementia of the Alzheimer's type, a 12-month, double-blind, parallel-group study was conducted to examine whether long-term administration of thiamine at 3 g/d might slow the progression of dementia of the Alzheimer's type. Fifteen subjects were enrolled and 10 completed the 1-year study. Data are available for two additional subjects through the first 9 months of study. No significant differences were found between the placebo and thiamine groups at any point during the study. In both groups, overall means for the Mini-Mental State Examination, verbal learning, and naming scores decreased significantly over the 12-month study period. These results do not support the hypothesis that long-term administration of thiamine at 3 g/d might slow the progression of dementia of the Alzheimer's type.

Aged

Delirium: phenomenology and diagnosis--a neurobiologic view.

"Delirium" is a reversible confusional state. It results from widespread but reversible interference with the function of cortical neurons, as documented by diffuse slowing on EEG and decreases in cerebral metabolic rate. Delirium can be due to impairments in neuronal metabolism, in neurotransmission (notably cholinergic), or in input from subcortical structures. Engel and Romano (1959) formulated delirium and dementia as the two poles of a spectrum of "cerebral insufficiency," with delirium resulting from reversible functional impairment and dementia from irreversible anatomic damage. So many disorders can precipitate delirium that the differential diagnosis tests every facet of one's knowledge of medicine. With aging, both normative changes in the brain and the increasing incidence of brain diseases predispose to the development of delirium. The brain damage responsible for a dementia can sensitize to the development of a superimposed delirium.

Aged

An analysis of writing in a case of deep dyslexia.

In tests of her ability to produce written and spoken language, this deep dyslexic patient produced semantic, visual, and derivational errors, including functor substitutions, and exhibited part-of-speech and abstractness effects in oral reading, oral and written naming, and writing to dictation, but not in repetition of single words and copying from memory. This patient therefore provides confirmation of the hypothesis presented in Nolan and Caramazza (1982) that the defining symptoms of deep dyslexia will be observed in responses to any task which requires lexical mediation. The patient's written responses in all tasks but direct copying were characterized by spelling errors which included transpositions, omissions, substitutions, and additions of letters. A model of writing is proposed which explains these errors in terms of a disruption of a phoneme-grapheme conversion process which normally functions to prevent decay of information from a Graphemic Buffer.

Agraphia