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P A Engel

Publications and source records attributed to P A Engel.

15 recordsLinked to original sources
PubMed2000

Atypical dementia and spastic paraplegia in a patient with primary lateral sclerosis and numerous necortical beta amyloid plaques: new disorder or Alzheimer's disease variant?

Primary lateral sclerosis (PLS) and hereditary spastic paraplegia (HSP) are clinically similar disorders in which progressive lower limb spasticity and corticospinal tract degeneration are characteristic. We report the occurrence of progressive spastic paraplegia and frontal systems dementia in a patient with postmortem features of PLS combined with moderate Alzheimer-like changes in neocortex and hippocampus. This combination of clinical and neuropathologic findings has not been described in PLS or HSP and varies from other cases in which spastic paraplegia, dementia, and Alzheimer neuropathology occurred concurrently. This 69-year-old woman developed spastic quadriplegia and dementia over 12 years. Left leg weakness progressed over 7 years to paraplegia, then quadriplegia by age 68. Sensory and cerebellar function were preserved and fasciculations were absent. Dementia characterized by concrete thinking, perseveration, and impaired executive function appeared in the seventh year and remained relatively stable until 6 months before death at age 69. Degeneration of the lateral corticospinal and dorsal spinocerebellar tracts confined to the spinal cord was evident at postmortem examination. Brain stem, midbrain, and cerebellum were normal. Numerous beta/A4 amyloid positive diffuse plaques (10-15/200x field) were apparent in neocortex, and neurofibrillary tangles immunopositive for paired helical filament were detected in hippocampus. This case broadens the spectrum of disorders associated with Alzheimer neuropathologic changes. The relationship between PLS, HSP, and Alzheimer's disease requires further study.

Aged↗
PubMed1997

Primary progressive aphasia, left anterior atrophy, and neurofibrillary hippocampal pathology: observations in an unusual case.

A 71-year-old, right-handed woman experienced onset of a slowly progressive, nonfluent language disorder. She maintained normal cognitive abilities until age 80 and developed a mild spastic right hemiparesis the following year. By age 82, she had become severely demented, mute, and akinetic. Postmortem brain examination showed moderate asymmetric atrophy (wt = 1000 g), which was most prominent in the left perisylvian and posterior frontal regions, with disproportionate enlargement of the left lateral ventricle. Microscopically, a high density of neurofibrillary tangles was present in the hippocampal pyramidal cell layer and entorhinal cortex (up to 45/400 x field, R > L). Gliosis and patchy neuronal loss were symmetrically present in the frontal and parietal lobes including speech areas, but neurofibrillary tangles and neuritic plaques were present in only small numbers (0-1/400 x field). In this case of primary progressive aphasia, pathologic changes associated with Alzheimer's disease occurred in allocortex but not in neocortex. These clinical and neuropathologic findings expand on those previously reported in primary progressive aphasia and suggest a need for further study of this syndrome.

Aged↗
PubMed1996

Treatment of progressive supranuclear palsy with amitriptyline: therapeutic and toxic effects.

BACKGROUND: Progressive supranuclear palsy (PSP) is a parkinsonian-like disorder characterized by postural instability, rigidity, bradykinesia, supranuclear ocular palsy, dysarthria, dysphagia, and dementia. There is no satisfactory treatment. Two patients with advanced (PSP) reported here had clinically meaningful improvement in motor function on low dose amitriptyline (AMI) but developed cognitive and behavioral disturbances at higher doses. CASE REPORTS: During 11 weeks of upward dose titration, a 65-year-old man was partially relieved of severe bradykinesia, dysarthria, and dysphagia at an optimal dose of 40 mg bid (plasma AMI 39 ng/mL) such that he could feed himself, swallow easily, and transfer from wheelchair to toilet. Nocturnal confusion and urinary incontinence appeared at 70 mg bid, then resolved at 40 mg bid. Benefits were sustained during the next 14 months. A 77-year-old man had substantial relief of severe rigidity, bradykinesia, poor balance, and blepharospasm at 10 mg bid, such that he could feed himself and walk independently. At 40 mg bid (plasma AMI 62 ng/mL) 3 weeks later, he became aggressive, irritable, and increasingly confused. He reverted to his untreated state with drug withdrawal, then improved when AMI was reintroduced at 10 mg bid (plasma AMI 17 ng/mL). CONCLUSION: Low dose AMI may improve severe motor dysfunction in PSP significantly. Dosing must be individualized for optimal response and minimal toxicity.

Activities of Daily Living↗
PubMed1996

Surface and edge wear of Björk-Shiley Delrin heart valve discs.

BACKGROUND AND AIMS OF THE STUDY: Wear of Björk-Shiley Delrin (BSD) heart valve discs is known to have occurred in some patients, possibly contributing to increased regurgitation. This paper specifically addresses surface and edge wear that have been observed on some discs of explanted BSD valves after implant durations up to 22.4 years. METHODS: The wear patterns have been documented using either photographic or scanning electron microscopic methods for 42 out of 73 explanted BSD valve discs. The remainder of the 73 discs were not available for analysis. RESULTS: One form of surface wear found on 18 out of 42 of the Delrin discs was the concentric wear of mild abrasive origin along the surface near the disc edge due to contact with the inlet and outlet struts. In five instances, surface anomalies were observed, primarily in the areas of high velocity blood flow. This paper also describes two Delrin discs with non-concentric edge wear patterns: (a) one which appears to be due to fatigue micro-chipping and abrasive wear of the disc of a 20 year BSD explant, which had fibrous tissue ingrowth, causing abnormal rotation of the disc during valve closure, and (b) a second one which is thought to have been caused by a cutting action of the knife-like stub of one inlet strut leg which had separated. Cross-sectional analyses of two explanted BSD discs, with full indent grooves on the inflow side, indicated that the Delrin material was primarily compressed under these wear grooves, rather than removed by abrasion. Hardness profiles indicated that the Delrin 150 microns below the surface was harder and would tend to prevent further deformation. A simple model describing the compound impact (impact with sliding) phenomenon is introduced to explain abrasive wear found on some explanted BSD discs. CONCLUSION: Based on the studies here and reports in the literature, the BSD heart valve appears to present a design which provides many years of service and, when wear occurs, it occurs in a manner that provides easily recognized clinical symptoms, which allow time for diagnosis and treatment.

Aortic Valve↗
PubMed1996

Theory of wear as related to the Björk-Shiley Delrin disc heart valve.

BACKGROUND AND AIMS OF THE STUDY: Mechanical wear is an important consideration for the Björk-Shiley Delrin (BSD) heart valve, the disc of which is periodically impacted against the inlet strut by the momentum of the blood flow during closure. Impact wear theory was used in designing experiments as well as establishing theoretical evaluation and projections of wear life. MATERIALS AND METHODS: The experimental apparatus involved a pivotal hammer device where the striking face could be varied by the inclusion of distinct spherical shapes; the sharper the radius, the higher the contact stress induced. The striking speed could be varied between one and three m/s, and the repetition rate between 2-50 Hz. Blood was simulated with an aqueous 42% glycerol solution. The same wear mechanism was induced on Delrin occluder disc specimens as the one governing the wear observed in Delrin occluder discs of some of the explanted BSD heart valves; thus two wear parameters, c and g, were established for the prediction of wear in BSD implants. The experimental runs were repeated on as many as four simultaneous specimens, for up to 7.5 x 10(7) cycles. RESULTS: The wear history was found to comprise three distinct regions, corresponding to (a) initial plastic deformations; (b) zero wear; and (c) measurable wear. The zero wear region produced very little change in the contact dimensions, and represented a fatigue threshold to the progress of a wear scar. Procedures for analytical establishment of the zero wear limit are outlined in the paper. Measurable wear was governed by the process of increasing conformance between the repetitively contacting surfaces. The differential equation of wear was then used with the physical parameters c and g previously determined experimentally. CONCLUSION: The maximum depth of the wear scar after cycling the equivalent of 20 years was predicted to be 278 microns. This value appears to represent a safe dimension for BSD heart valves.

Biocompatible Materials↗
PubMed1992

Does computed tomographic brain imaging have a place in the diagnosis of dementia?

BACKGROUND: Computed tomographic (CT) scanning of the head is an accepted routine in the evaluation of dementia. This study attempted to identify a patient group in which brain imaging adds meaningful data to the clinical picture. METHODS: One hundred patients who met criteria for dementia as defined in the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, underwent computed tomographic imaging. From clinical data alone, 56 of these patients also met the following strict criteria for the diagnosis of probable Alzheimer's disease (PAD): the McKhann criteria for PAD, Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, criteria for primary degenerative dementia, a score of less than 4 on the modified Hachinski Ischemia Scale, a normal neurologic examination and symptoms for at least 1 year. RESULTS: In the PAD group, eight scans (14%) had abnormalities other than atrophy; only three (two showing lacunae and one showing infarct) were of possible clinical significance. In the 44 patients not meeting PAD criteria, 23 scans (52%) were abnormal, including 15 with infarcts, two with periventricular lucencies, three showing tumors, and one showing hydrocephalus. CONCLUSIONS: These results support the diagnostic value of computed tomographic scanning in atypical dementia and its limited utility in PAD. The data indicate that clinical guidelines can be developed for the application of CT in the diagnosis of dementia.

Aged↗
PubMed1991

Wernicke-Korsakoff syndrome complicating T-cell lymphoma: unusual or unrecognized?

Malnutrition rather than alcohol abuse is the common element in most cases of WKS. Our report may be the first to identify both the clinical and neuropathologic features of the syndrome in a patient with T-cell lymphoma. The coincidence of these two illnesses underscores a need to consider Wernicke's encephalopathy in debilitated individuals with malignancy or other chronic illnesses, highlights an atypical presentation of acute Wernicke's encephalopathy, and demonstrats the precipitation of that syndrome by glucose feeding. Attention to a patient's nutritional status and the liberal use of thiamine may prompt early recognition of the syndrome or prevent it entirely.

Alcohol Amnestic Disorder↗
PubMed1984

Effect of exogenous vasopressin on vasopressin release.

To characterize the influence of extracellular volume status on vasopressin pharmacokinetics, eleven young (aged 19-31 yr) and four old (aged 62-80 yr) subjects received bolus injections of 1 mU/kg Pitressin or synthetic arginine vasopressin following 6 days of sodium depletion (10 meq Na/day) or sodium loading (250 meq Na/day). In six young subjects the rapid decline in plasma vasopressin (pAVP) following the initial peak was interrupted by a second peak 5-30 pg/ml in magnitude 7.5-20 min after injection. In four of these subjects the second peak was larger following sodium depletion as compared with sodium loading. In the elderly a small (4 pg/ml) second peak was present in one sodium-depleted subject. Of five sodium-depleted subjects with central diabetes insipidus, none showed a secondary rise in pAVP. These results indicate that exogenous vasopressin may stimulate the release of endogenous AVP, an effect that appears to be enhanced by sodium depletion and is virtually absent in the elderly. There was no effect of age, volume status, or diabetes insipidus on AVP pharmacokinetics.

Adult↗
PubMedDate not supplied

Alzheimer's disease or plaque disease? Two cases at the frontier of a definition.

Atypical dementias confront the adequacy of current diagnostic concepts. The two patients with atypical dementia syndromes described here shared common postmortem features of numerous neocortical neuritic (senile) plaques and microvascular amyloid, sparing of hippocampus and substantia nigra, and the virtual absence of neurofibrillary tangles. Microscopically, the two differed only by the presence of a few subcortical Lewy bodies in case 1. These similar morphologic features were associated with dramatically different clinical presentations. In the first patient, visual hallucinations, Capgras' syndrome, cognitive slowing, myoclonus, parkinsonism, and primitive reflexes evolved over 3 years. Memory and language were relatively spared. In the second, dysphagia, nonfluent aphasia, hypophonia, motor perseveration, and a severe disorder of attention developed during this 18-month illness. At autopsy, an unrecognized colon malignancy was found. Despite high neuritic plaque counts in cortex, neither the clinical nor the pathologic criteria for Alzheimer's disease adequately describe either case. The cases will be examined first as clinical, then as neuropathologic, entities. From this approach, we conclude that a specific clinical dementia syndrome may be expressed by several neuropathologic "diseases" and that a variety of clinical syndromes may represent a single neuropathologic diagnosis. This strategy identifies a conceptual dichotomy between Alzheimer's syndrome and postmortem Alzheimer's disease. Meticulous clinical and neuropathologic observation is essential in advancing an understanding of the relationship between the two.

Aged↗