Search PubMed⌕ Search

Biomedical subjects

T Sunderland

Publications and source records attributed to T Sunderland.

At least 127 records · Page 7Linked to original sources
PubMed1990

Reflections of the self: atypical misidentification and delusional syndromes in two patients with Alzheimer's disease.

Two patients with moderately severe AD, when asked directly, could identify their own images in a mirror, but also consistently misidentified their own reflections as that of another person. Both patients were paranoid and mildly depressed at times, but had no evidence of other concurrent psychotic symptoms. It appeared that mood substantially modified the nature of the symptom and the patients' reaction to it over time. These cases illustrate the ability of an organic symptom to be modified by a concurrent affective state, indicating the importance of the interaction between biological and psychological factors in the expression of such symptoms.

Alzheimer Disease↗
PubMed1989

A preliminary study of the effects of intravenous m-chlorophenylpiperazine, a serotonin agonist, in elderly subjects.

m-Chlorophenylpiperazine (m-CPP), a serotonin receptor agonist, is currently being investigated as a probe of serotonergic responsivity in various neuropsychiatric disorders. The safety of m-CPP in elderly populations and its potential usefulness in exploring possible serotonergic dysfunction in Alzheimer's disease and normal aging were assessed by examining the behavioral, neuroendocrine, and physiological effects of this agent in 15 elderly subjects (mean age 69 +/- 2 years): 9 Alzheimer patients and 6 healthy normal volunteers. Intravenous m-CPP (0.08 mg/kg) was well tolerated in all subjects and produced no serious adverse effects. The behavioral effects were modest; in particular, minimal anxiety was observed, a finding that contrasted to results from an earlier study reporting that intravenous m-CPP at a slightly higher dose induced marked anxiety and panic attacks in younger subjects. m-CPP produced significant increases in plasma cortisol and prolactin, and significant changes in blood pressure and temperature in these elderly subjects. The results of this preliminary study suggest that intravenous m-CPP is safe and well-tolerated in elderly subjects. Future studies at higher doses can now proceed to study more definitively the question of possible age- and disorder-related reductions in central nervous system (CNS) serotonergic responsivity.

Aged↗
PubMed1989

Divided attention, as measured by dichotic speech performance, in dementia of the Alzheimer type.

To determine if impaired dichotic performance in patients with dementia of the Alzheimer type is due to the inability to divide attention or the inability to perceive degraded auditory stimuli, we measured performance on tasks of both dichotic and degraded monotic speech materials. We also examined whether perception of degraded speech stimuli presented monaurally is related to abnormalities of temporal lobe anatomy and physiology, as we have shown for dichotic performance. Although the patients were impaired on both dichotic and monotic tests, significantly greater impairment was seen on the dichotic test. Our earlier finding of a significant relation between dichotic performance and measures of anterior temporal lobe atrophy and reduced glucose metabolism was replicated, but no significant relation was found between monotic tests and measures to temporal lobe integrity. We conclude that the inability to divide attention, rather than abnormal processing of degraded stimuli per se, is reflected in poor dichotic performance in patients with dementia of the Alzheimer type, and that dichotic performance, unlike degraded monotic perception, depends directly on the integrity of temporal cortex in these patients.

Aged↗
PubMed1989

Hyperresponsivity to the serotonin agonist m-chlorophenylpiperazine in Alzheimer's disease. A controlled study.

The serotonin agonist m-chlorophenylpiperazine (mCPP) was administered intravenously to 12 patients with Alzheimer's disease and ten age-matched controls. It produced distinct behavioral effects in both treatment groups; however, significantly greater responsivity to mCPP was found in patients with Alzheimer's disease than in controls in measures of psychomotor activation, restlessness, and perceptual abnormalities. Significant and similar increases in plasma prolactin and cortisol levels were found in both patients with Alzheimer's disease and controls following the administration of mCPP vs placebo. Furthermore, blood pressure and pulse changes following mCPP were not significantly different between the groups. Elderly controls, however, did show a significantly greater temperature response following mCPP than did patients with Alzheimer's disease. The overall cognitive effects of mCPP were minimal; however, mCPP produced significantly greater worsening in recent memory and knowledge memory in patients with Alzheimer's disease than in controls. These findings could not be explained by pharmacokinetic differences across populations, because plasma concentrations of mCPP were similar in patients with Alzheimer's disease and controls. The increased behavioral responsivity but unchanged neuroendocrine or other physiologic responsivity to mCPP may be related to damaged brain serotonin neurons or other neuronal systems that interact with serotonin neurons that have been found in postmortem and biopsy studies of patients with Alzheimer's disease.

Aged↗
PubMed1989

Acute effects of high-dose thyrotropin releasing hormone infusions in Alzheimer's disease.

Thyrotropin releasing hormone (TRH) was administered intravenously to ten patients with Alzheimer's Disease (AD) in a high-dose paradigm, thought to maximize central nervous system effects and potentially produce facilitation of cholinergic function, a known property of the neuropeptide. Acute effects of TRH on behavioral, cognitive and physiologic measures were assessed after patients received 0.1 mg/kg TRH, 0.3 mg/kg TRH and placebo, the higher TRH dose and placebo being given in a randomized, double-blind fashion. Patients showed statistically significant increases in arousal and improvement in affect, as well as a modest improvement in semantic memory, all after receiving the higher TRH dose. Both TRH doses produced transient rises in systolic blood pressure, with no effect on diastolic blood pressure, heart rate or temperature. This study suggests that high-dose TRH can be safely administered to AD patients and is neurobehaviorally active; further studies are needed to determine the extent and mechanism of the cognitive and psychobiological properties of this peptide in AD and other neuropsychiatric disorders.

Aged↗
PubMed1989

Low-dose oral lorazepam administration in Alzheimer subjects and age-matched controls.

Ten patients with Alzheimer's disease and ten age-matched normal controls were studied in a double-blind, placebo-controlled acute trial of 1 mg PO lorazepam to test the effects of low-dose benzodiazepine on memory and behavior in a mostly older population. Cognitive effects differed somewhat between Alzheimer patients and normal controls, with Alzheimer patients revealing predominantly "attentional" impairments and age-matched controls showing possible "disinhibition." Specifically, Alzheimer patients made more omission errors on a continuous performance task, whereas controls made more commission and intrusion errors with lorazepam versus placebo. This low dose of lorazepam (1 mg), which was associated with mild but statistically significant sedation in both groups, also produced no significant decrease in recent memory or in access to semantic memory. These cognitive findings contrast markedly to the reported effects of scopolamine on recent memory; therefore, supporting the idea that cholinergic interruption has a more specific effect on human memory and on learning than that of low-dose benzodiazepines. Further studies with a wider dose range of benzodiazepines are necessary to evaluate the possibility of differential sensitivity between Alzheimer patients and normal elderly controls.

Administration, Oral↗
PubMed1989

Evidence for a decline with age in behavioral responsivity to the serotonin agonist, m-chlorophenylpiperazine, in healthy human subjects.

The functional significance of alterations in brain serotonin (5HT) associated with normal aging in both animals and humans is largely unknown. Using the effects of the 5HT agonist, m-chlorophenylpiperazine (m-CPP), as a measure of central serotonergic responsivity, we compared the behavioral and neuroendocrine responses of older normal volunteers (mean age +/- SD = 62.4 +/- 4.12) to those of younger normal volunteers (mean age +/- SD = 31.6 +/- 5.52). When m-CPP was administered intravenously, older subjects showed decreased behavioral responses but similar neuroendocrine responses, compared to younger subjects. The decreased behavioral responsivity was unrelated to pharmaco-kinetic differences between the groups, since m-CPP plasma levels were similar in both groups. This report is the first in vivo study in humans to demonstrate decreased behavioral responsivity with age following serotonergic stimulation, and may indicate a functionally less responsive 5HT subsystem in older subjects.

Adult↗
PubMed1989

Clock drawing in Alzheimer's disease. A novel measure of dementia severity.

We have tested a simple and reliable measure of visuospatial ability in Alzheimer patients--the Clock Drawing Test. To determine the usefulness of this measure, we asked 67 Alzheimer patients and 83 normal controls to draw the face of a clock reading the time of 2:45. Six independent observers blindly evaluated the results with ratings from 10 (best) to 1 (worst). The mean performance score of Alzheimer subjects was 4.9 +/- 2.7 compared to 8.7 +/- 1.1 for normal controls (P less than .001). Inter-rater reliability for the clocks drawn by Alzheimer patients was highly significant (r = 0.86; P less than .001), and there was relatively little overlap between ratings for Alzheimer patients and normal controls. Furthermore, correlations were highly significant (P less than .001) between the mean score of clock drawings and three independent global measures of dementia severity. Although the Clock Drawing Test is certainly not a definitive indicator of Alzheimer's disease, the test is easy to administer and provides a useful measure of dementia severity for both research and office settings where sophisticated neuropsychological testing is not available.

Aged↗
PubMed1988

Central muscarinic cholinergic antagonists block wet-dog shakes produced by the TRH analog MK-771 in the rat.

Thyrotropin-releasing hormone (TRH) is known to elicit wet-dog shakes in rats through a central mechanism of action. In the present study, the ability of muscarinic cholinergic antagonists to inhibit TRH-mediated wet-dog shakes was examined. The longer-acting TRH analog, MK-771, at doses of 1.0, 1.5 and 3.0 mg/kg elicited wet-dog shakes in a dose-dependent manner. The centrally-acting muscarinic cholinergic antagonists, atropine and scopolamine, at doses of 5 and 0.8 mg/kg, respectively, significantly reduced the ability of only the highest dose of MK-771 to elicit wet-dog shakes. When the peripherally-acting antagonists, methylscopolamine and methylatropine, were examined, they were not found to significantly reduce wet-dog shakes produced by MK-771 at doses of 5 and 0.8 mg/kg, respectively. The results of this study suggest that cholinergic antagonists inhibit MK-771-induced wet-dog shakes in a noncompetitive manner and support the view that TRH-mediated wet-dog shakes are modulated by central muscarinic cholinergic systems.

Animals↗
PubMed1988

Multiple-dose arecoline infusions in Alzheimer's disease.

Twelve patients with dementia of the Alzheimer type received two-hour infusions of placebo and the muscarinic cholinergic agonist arecoline hydrobromide at rates of 1, 2, and 4 mg/h in a double-blind, randomized fashion. These infusions resulted in dose-dependent physiologic and neuroendocrine effects consistent with central cholinergic stimulation. Infusions were generally well tolerated. No statistically significant improvement in performance on most cognitive tasks assessing knowledge memory and episodic learning and memory was observed at any dose, although marginal improvement in picture recognition ability and in ratings of word-finding were observed at the lower doses. Psychomotor activation and slightly improved affect were reliably observed at the lower doses, whereas increasing psychomotor retardation was observed at the highest dose. The data support a role for central cholinergic modulation of some aspects of cognition, behavior, and affect in this population. The apparent greater behavioral sensitivity of patients with Alzheimer's disease in comparison with subject populations previously studied, as well as the altered dose responsiveness, merit further study in relationship to normal aging.

Aged↗
PubMed1988

The effects of acute scopolamine in geriatric depression.

In an intensive multidrug, multidose study, nine elderly depressed patients were administered 0.1, 0.25, and 0.5 mg of scopolamine hydrobromide, 1 mg of oral lorazepam, and placebo in a double-blind investigation aimed at assessing the status of the central cholinergic nervous system in geriatric depression. Significant cognitive and behavioral effects of scopolamine were observed only at the high dose (0.5 mg), while lower doses and lorazepam showed no significant differences from placebo. Cognitive deficits caused by scopolamine were in the areas of new learning, access to semantic memory, vigilance, and continuous performance. Behavioral effects consisted of activation, restlessness, and anxiety, but there was no significant effect on depressed mood. These results suggest that elderly depressed patients with mild to moderate cognitive impairment seem to be more similar to previously studied elderly controls rather than to patients with Alzheimer's disease in their reaction to short-term cholinergic blockade, and suggest that the cognitive and mood changes often seen in geriatric depression may involve factors other than disturbed muscarinic cholinergic mechanisms.

Aged↗
PubMed1988

Antisomatostatin IgG in major depressive disorder. A preliminary study with implications for an autoimmune mechanism of depression.

IgG reactive with somatostatin 1-14 was identified in human plasma by enzyme linked immunosorbent assay. From a sample of 25 subjects, six (60%) of ten individuals with major depressive disorder demonstrated antibody reactive with somatostatin 1-14, in contrast to one (7%) of 15 controls. Overall, antisomatostatin reactivity was significantly higher in patients with major depressive disorder (0.233 +/- 0.177) than in the normal volunteers (0.084 +/- 0.039; t = 3.18, P less than .01). Antisomatostatin IgG was isolated by affinity chromatography. The recognition site for somatostatin was retained by F(ab)'2 fragments. Although there has been little previous exploration of the existence of antibodies to endogenous neuropeptides, such antibodies could prove of relevance to neuropsychiatric and other human disorders.

Adult↗
PubMed1988

Intravenous nicotine in Alzheimer's disease: a pilot study.

In the first study to examine direct nicotinic augmentation of central cholinergic functioning in Alzheimer's disease, six patients were studied in an intensive pilot study with three doses (0.125, 0.25, and 0.5 microgram/kg/min) of intravenous nicotine and placebo. Cognitive tests showed a decrease in intrusion errors on the middle (0.25 microgram) dose. Prominent behavioral effects were noted, with significant dose-related increases in anxiety and depressive affect. These results suggest that central nicotinic cholinergic stimulation deserves further investigation as a treatment in Alzheimer's disease and that nicotine may also be a useful investigative tool in other populations as a probe of central cholinergic function, especially in regard to the modulation of affect.

Aged↗
PubMed1988

Differential responsivity of mood, behavior, and cognition to cholinergic agents in elderly neuropsychiatric populations.

To evaluate the possible differential responsivity of Alzheimer patients to cholinergic agents, a series of pharmacologic challenge studies in 83 neuropsychiatric patients and controls were performed contrasting a cholinergic antagonist (scopolamine) with two cholinergic agonists (arecoline and nicotine). Alzheimer patients displayed significantly greater behavioral and cognitive responses to central cholinergic blockade at lower scopolamine doses than age-matched controls or elderly depressives. These differential changes could not be explained by group differences in the sedative, physiologic, or pharmacokinetic effects of the drug. In addition, the elderly, age-matched control subjects did reveal a profile of cognitive deficits at the highest dose (0.5 mg), which temporarily mimicked the baseline impairments found in early Alzheimer's disease. Together, these findings with scopolamine suggest an increased sensitivity to cholinergic blockade in Alzheimer's disease and demonstrate the first direct evidence of anticholinergic modelling of dementia in normal elderly subjects. To investigate further the postsynaptic cholinergic responsivity in Alzheimer's disease, patients were studied with arecoline and nicotine. While the cognitive effects of both agents were modest at best, there were significant differences in mood and behavioral responses between arecoline and nicotine in Alzheimer subjects. These behavioral changes occurred at much lower doses in the Alzheimer patients than those required in normal controls, once more supporting the notion of increased behavioral sensitivity to cholinergic agents in Alzheimer's disease. In addition, the differential mood effects between these two cholinergic agonists raise new questions about receptor selectivity in the cholinergic regulation of mood.

Aged↗