Predictability of blood pressure response to isometric stress.

Isometric exercise causes transient systemic hypertension, but with individual differences. An attempt was made to delineate predictors of those differences by analyzing the blood pressure (BP) response in terms of variables readily measured in clinical practice. For each of 270 office patients, we determined blood pressure, heart rate (HR), electrocardiographic findings, and symptoms in response to maximal isometric and maximal dynamic exercise. For systolic BP response as the predicted measure, 4 predictor variables in combination, including age, sex, resting systolic BP, and maximal treadmill systolic BP, yielded 70% predictability. For diastolic BP, 5 predictors in combination, including handgrip strength, resting diastolic BP, treadmill HR, systolic BP, and diastolic BP, allowed 66% prediction. Not predictive of either were resting HR, abnormality of treadmill test, presence of heart disease, and certain other medical diagnoses.

Blood pressure at rest and during maximal dynamic and isometric exercise as predictors of systemic hypertension.

This study sought to verify evidence that transient high blood pressure (BP) at rest and during dynamic and isometric exercise is often predictive of later hypertension. In addition these 3 predictors were compared. One hundred office patients (all men) with BPs less than 140/90 mm Hg, ages 28 to 79 years, who had little or no heart disease and were not taking medication, had BPs taken at rest and during treadmill and handgrip dynamometer. Within 14 years, 16 subjects developed hypertension and 84 remained normotensive. Multivariate statistical comparisons for systolic and diastolic BPs and their interactions were used to discriminate between later hypertensive and normotensive subjects. The best single predictor was resting diastolic BP, classifying 88% of hypertensive and 69% of normotensive subjects correctly, followed closely by handgrip and treadmill diastolic BP and resting, treadmill and handgrip systolic BP. The best prediction was by the interaction between resting diastolic BP X handgrip diastolic BP; this classified 88% of hypertensive and 80% of normotensive subjects correctly. Of the few known precursors of hypertension, high BP at rest and during dynamic and isometric stress provides a means of alerting to careful follow-up and early treatment.

Birth injury as the cause of mental retardation.

Mental retardation, on initial impression, may appear to be caused by the birth process, but may be disproved by later clinical or autopsy examination. However, information often is lacking as to the basic pathology that may have been responsible for attributing the cause of the mental retardation to traumatic birth. From a 39-year period (1944 to 1983) 1146 records were evaluated at a state hospital for mentally retarded persons to determine how the intake impression compared with the final clinical and autopsy diagnoses of perinatal damage. Clinical evaluations provided some corrections of the intake diagnoses; autopsies provided more, but a combination provided the most reliable final diagnoses. Of 258 patients diagnosed as birth injury on intake, only 49.2% were confirmed by the best clinical and/or autopsy diagnoses. Although the cause of mental retardation was not ascertainable by either clinical or autopsy studies in 14.8% of cases, 31.4% were corrected to prenatal influences, and 4.6% to postnatal brain damage. Patients with perinatal cause of mental retardation usually were institutionalized at a young age and died young. If they do not require institutionalization until they are older, their life expectancy is longer, although still much less than that of normal persons.

Inability to cope with environmental stress: peptic ulcers in mentally retarded persons.

Mentally retarded persons in the protective environment of an institution developed more peptic ulcers than the general population. We sought to determine whether their physical and mental handicaps may have a relationship to this disease. Thirty seven mentally retarded institutionalized ulcer patients were compared to 37 non-ulcer controls matched for age and sex, who were also similar in IQ and mental retardation diagnoses. A stepwise discriminant analysis demonstrated that the ulcer group was more limited by chronic diseases and inability to ambulate. Also differentiating the groups were ulcer patients having more cerebral palsy, more visual deficit, and more limited motor and sphincter control than non-ulcer subjects. We conclude that helplessness in responding to environmental demands produces stress sufficient to induce peptic ulcers, even in severely mentally retarded persons.

Does gastrostomy and fundoplication prevent aspiration pneumonia in mentally retarded persons?

To determine whether gastrostomy and fundoplication prevent aspiration pneumonia in mentally retarded individuals, 105 cases of feeding gastrostomy were examined; 21 subjects had preoperatively diagnosed gastroesophageal reflux. Thirty-nine patients had gastrostomy and fundoplication, 66 patients had gastrostomy alone, and 60 subjects had had aspiration pneumonia before surgery. Recurrent aspiration pneumonia was least in those without preoperative gastroesophageal reflux and who had gastrostomy and fundoplication. Feeding gastrostomy does not prevent aspiration pneumonia. Gastrostomy with fundoplication reduces the likelihood of aspiration pneumonia but still allows a significant number to develop it.

Comparison of blood pressure and rate-pressure product responses in maximal dynamic and isometric exercise.

The relationship between hemodynamic responses to maximal dynamic and isometric exercise have not been clearly established. We monitored heart rate (HR), systolic and diastolic blood pressure (SBP, DBP), electrocardiogram (ECG), as well as symptoms and signs, during both maximal treadmill test (GXT) and one-minute maximal handgrip dynamometry (HG) in the same individuals. Subjects were 164 adult male office patients, ages 20-79 years, who were not on medication. There was a wide range of responses in HR, SBP, DBP, and heart rate-systolic blood pressure product (MTTI), but with significant differences in mean values between GXT and HG as follows. SBP absolute value and percent increase over resting level were higher on GXT than on HG, DBP was higher on HG than GXT. HR was greater on GXT than on HG, MTTI was greater on GXT than on HG, both for mean absolute value and percent increase over resting level. Normal GXT related to lower SBP response on HG, abnormal GXT to higher. Normal vs abnormal GXT did not correlate significantly with MTTI. SBP on maximal HG was greater than it was for low levels of GXT, less than for high levels of GXT. DBP increase was greater for maximal HG than for any level of GXT. BP response is critical in monitoring HG, as HR is for GXT. Both GXT and HG are useful tests, without undue risk if contra-indications are observed and patients are properly monitored. There are notable HR, BP and MTTI differences in the two tests, which can only be determined by monitoring each individual.

Pupillary responses in recognizing awareness in persons with profound mental retardation.

Pupil-size changes have been shown to indicate positive or negative reactions to several sensory and psychologic stimuli in normal persons. Whether this could be extended to mentally retarded patients who lack ability for verbal or motor behavior was tested by pupillary responses to several visual, tactile, and auditory stimuli. 24 institutionalized severely and profoundly retarded patients were examined by video camera in their usual environments rather than in a controlled laboratory setting. The videotapes were later projected onto a screen for pupil-size measurements. Pupils dilated with pleasant stimuli, including visualizing a familiar person, soft touch to the arm, music, and soft compliments. There was constriction with presenting an unfamiliar person, rough grasp of the arm, and abrasive noise and harsh commands. The findings demonstrate the existence of pupil reactivity in profoundly retarded persons and suggest such testing as a means of determining which elements of their environment are pleasing or aversive to them.

Psychological stress in people with profound mental retardation.

Does emotional stress in people with profound mental retardation occur and does it result from simple stimuli of daily living? Can this be measured by recording vital signs? To obtain answers, the histories of stress and stress diseases, and the behavioral characteristics of 163 institutionalized adults with developmental disabilities were evaluated; vital signs, temperatures and bodily expressions of 35 subjects from this sample were monitored. All but two of the 35 subjects had elevations of heart rate, blood pressure, respiration rate, core body temperature, and changes in peripheral temperature. Reactions occurred with unpleasant and pleasurable stimuli, and were greatest at clinical examinations and when the subjects were stared at. Responses were best demonstrated by heart rate, respiration rate, blood pressure and temperature. Such reactions result from the insecurity of people whose disabilities prevent them from adjusting to perceived threats.

Neurogenic atherosclerosis in mentally retarded persons.

The question is raised whether arteriosclerosis (AS) may be induced in man by chronic central nervous system injury. In an institutionalized population of mentally retarded children, more AS than expected was observed. Of 1173 residents with detailed clinical and autopsy records over 40 years, 78 of them, aged 1-21 years, showed mild to moderate coronary or aorta AS. Thirty control subjects without AS, matched for sex, age and IQ, were studied in comparison. In 65 of the probands, the condition could not be explained by predisposing diseases or known risk factors. There were more lesions in those with convulsive disorder; this was felt to reflect arterial changes due to neuronal-sympathoadrenal hyperactivity. In addition, more disease occurred in physically restricted patients; this appeared related to the stress of handicap and inability to respond to psychosocial needs. It is concluded that certain areas of brain defect predispose to atherogenesis. Down's syndrome provides a different set of influences on AS, yet the frequency of AS in these patients was similar to that of non-Down's.

Risk of pulmonary edema in mentally retarded persons.

Pulmonary edema is an important medical risk for mentally retarded persons. To evaluate the predisposing conditions and their influence on clinical management, I analyzed 1,197 records with autopsy findings over a 40-year period in a state hospital. Of these, 220 subjects had severe pulmonary edema, and 433 had no pulmonary edema. There was more frequent occurrence in patients who were older, had higher IQs, and were ambulatory, as well as in those with epilepsy. Sudden death also predisposed to pulmonary edema. Atelectasis related prominently, but aspiration and pulmonary emphysema did not. Cardiovascular lesions were not a significant cause of pulmonary edema in this population. The underlying conditions must be considered in individualizing treatment.

Twenty-year tuberculin testing in an institution for persons with mental retardation.

Tuberculin Purified Protein Derivative skin test conversions and reversions were followed over 20 years in 363 patients in an institution for persons with mental retardation. Of these, 88.7% remained negative and 5.2% remained positive. Changes included 2.7% reverting to negative, 0.3% converting to positive, and 3.1% showing two to five negative-positive changes, with varying degrees of positivity over the years. Some patients showed only transient positive reactions. Most changes could not be explained by clinical evidence of infection, but multiple causes were felt to be likely. The discovery of converters was minimal, and the usefulness of routine skin testing in such institutions is doubtful.

Hypothalamic dysthermia in persons with brain damage.

Brain injury causing dysthermia has appeared to be not uncommon in institutionalized people with mental retardation. We sought to determine the characteristics and risks of patients of one institution. Of 1100 residents surveyed over 10 years 92 were reported to have unexplained high or low body temperatures, and 48 were monitored. Core temperatures were taken by non-invasive thermometers recording continuously for 24 h. Results were related to clinical conditions and aetiologies of mental retardation. Twenty-one per cent of the residents monitored showed hyperthermia, often related to prenatal metabolic or chromosomal abnormalities. Forty-two per cent had hypothermia, related to other causes of brain injury. Seventy-five per cent had abnormal patterns, including flat or exaggerated rhythms, reversed day-night cycle, unusual fluctuations, or sleep phase delay. Sixty-two per cent of 21 deaths to date have occurred in hypothermic patients. Occasional discrepancies between history of dysthermia and monitored results are best explained by fluctuations of temperature control over several days, probably due to changes in timing of hypothalamic rhythmicity. This could be better delineated by longer periods of monitoring.

Comparison of cardiovascular risk in maximal isometric and dynamic exercise.

With the hypothesis that isometric exercise testing offers important clinical information yet is neglected because of overemphasis on its risk, we compared it with dynamic testing for variables indicative of myocardial ischemia. In a medical office, 287 patients were each subjected once to both a one-minute maximal handgrip stress test and maximal treadmill test while monitored noninvasively for cardiovascular responses. Systolic blood pressures usually increased more with the treadmill test, diastolic more with the handgrip. The treadmill tests caused greater mean heart rate and rate-pressure products, as well as more ST segment displacements, arrhythmias, and symptoms and signs. However, there were some unpredictable individual differences in the isometric blood pressure responses. Isometric testing is easy and useful and, if properly monitored, causes less risk to the patient than dynamic testing.

Patterns in mortality over 60 years among persons with mental retardation in a residential facility.

Records of 2,444 decreased institutionalized persons with mental retardation were examined for etiologies, disabilities, causes of death, and life expectancies over 60 years. Participants at most risk tended to have prenatal etiology of brain damage, to be young, and have the lowest IQs, epilepsy, poor mobility and feeding skills, and more medical complications. Most mortality was from respiratory infections. Epilepsy was present in 57.2% but was rare in people with Down syndrome. Sudden death occurred in 22.2% of these deceased residents. Over the years generally more residents had prenatal etiology of mental retardation, lower IQ, epilepsy, and were nonambulatory and older when they died.

The relationship of congenital heart disease and respiratory infection mortality in patients with Down's syndrome.

Is respiratory infection mortality in Down's syndrome (DS) individuals due mainly to their congenital heart disease (CHD) or to other factors which subject most mentally retarded persons to risk? Detailed clinical and autopsy records of 137 institutionalized DS patients and 480 non-DS controls over 31 years yielded 42 DS subjects and 13 non-DS controls with congenital heart disease. These were compared to 20 DS patients and 20 controls without CHD. The DS and non-DS patients were matched for age, sex and IQ. DS patients had more CHD; controls had more pulmonary oedema. In neither group was there association between heart disease and death from respiratory infection. Nor did pulmonary oedema contribute importantly to such deaths. Such mortality, however, was associated with young age, short institutionalization and bedridden status. We conclude that respiratory infection death in DS individuals is due not primarily to heart disease but to factors which lead to mortality in the general population of retarded people.

Comparison of respiratory mortality in the profoundly mentally retarded and in the less retarded.

Autopsy records of 600 profoundly retarded and 405 less retarded were examined for a thirty-one-year period at Pacific State Hospital. The profoundly retarded were found to have more respiratory infections at autopsy, and more deaths of such infections. Profound retardation was a particularly outstanding risk when in combination with epilepsy, inability to ambulate, and developmental cranial anomalies. Non-infectious respiratory morbidity and mortality are more common in the less retarded, apparently because of their living longer to develop these complications.

Survival of profoundly disabled people with severe mental retardation.

OBJECTIVE: To define further the association between survival and clinical disabilities in profoundly disabled people with mental retardation in an 11-year period. RESEARCH DESIGN: An 11-year follow-up study of the survival of six mutually exclusive subgroups. The presence of severe, profound, or suspected mental retardation and incontinence were considered in all individuals when forming the subgroups. Varying combinations of abilities in mobility, rolling, feeding, and arm-hand use were also considered. PARTICIPANTS: Six subgroups of severely disabled subjects. Included were 128,248 of 155,851 persons who received services from the California Department of Developmental Services between January 1980 and March 1991. MEASUREMENTS/MAIN RESULTS: Survival estimates for individuals who were immobile and could not roll over were short regardless of arm-hand use or feeding status, as were estimates for people who were tube fed. For individuals who could roll over, but were otherwise immobile, survival was relatively improved. CONCLUSION: Individuals who are unable to move their extremities or bodies voluntarily or who require tube feeding have very shortened life expectancies.

The life expectancy of profoundly handicapped people with mental retardation.

BACKGROUND: The life expectancy of people with mental retardation is shorter than that of the general population. Exact estimates of the length of survival for mentally retarded persons at especially high risk are not available, however. METHODS: We collected data on mortality and other factors for 99,543 persons with developmental disabilities, including mental retardation, who received services from the California Department of Developmental Services between March 1984 and October 1987. Three subgroups were selected on the basis of the four characteristics identified in previous studies as the best predictors of mortality among mentally retarded people (deficits in cognitive function, limitations on mobility, incontinence, and inability to eat without assistance). In all three subgroups, the subjects had severe deficits in cognitive function and were incontinent; the subjects in subgroup 1 (n = 1550) were immobile and required tube feeding; those in subgroup 2 (n = 4513) were immobile but could eat with assistance; those in subgroup 3 (n = 997) were mobile (but not ambulatory) and could eat with assistance. Life tables were generated for each of the three subgroups. RESULTS: Immobile subjects were found to have a much shorter life expectancy than those who could move about. Those who also required tube feeding (subgroup 1) had a very short life expectancy (i.e., four to five additional years). Those who could eat if fed by others (subgroup 2) had an average life expectancy of approximately eight additional years. In contrast, those who were mobile though not ambulatory (subgroup 3) had a life expectancy of about 23 additional years. CONCLUSIONS: Severe mental retardation is associated with a decrease in life expectancy, particularly for those who were immobile.