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Biomedical subjects

M J Alberts

Publications and source records attributed to M J Alberts.

At least 55 records · Page 3Linked to original sources

Swallowing in Alzheimer's disease.

Using a prospective case series design, we examined the incidence of oropharyngeal swallowing abnormalities in 25 patients with moderate or severe Alzheimer's disease by videofluoroscopy. Aspiration occurred in 6 of 25 (28.6%). Only four patients showed unequivocally normal performance. Exploratory statistical analyses showed that swallowing abnormalities associated significantly with duration of dementia, eating dependency, and abnormal oral praxis. We observed a trend toward a higher incidence of aspiration in patients with more severe dementia. We conclude that oropharyngeal swallowing abnormalities, including aspiration, are more prevalent in patients with Alzheimer's disease than in normal elderly individuals.

Aged↗

Antiphospholipid antibodies in patients without systemic lupus erythematosus: neuroradiologic findings.

PURPOSE: To study neuroradiologic findings in patients with hypercoagulability due to antiphospholipid antibodies (APAs). MATERIALS AND METHODS: Retrospective review of abnormal angiographic, computed tomographic, and magnetic resonance imaging findings was performed over a 14-month period in patients with APAs, no diagnosis of systemic lupus erythematosus, age less than 65 years, and no other cause of a hypercoagulable state. RESULTS: Fourteen patients (age range, 22-62 years) with APAs had abnormal results at neuroradiologic examination. Abnormal findings on cross-sectional imaging studies included large-artery (n = 3), lacunar (n = 5), and venous infarctions (n = 2); cortical atrophy (n = 5); white matter abnormalities (n = 3); and dural sinus thrombosis (n = 4). Abnormal angiographic findings included large-artery occlusions (n = 2), arterial narrowing that simulated vasculitis (n = 2), and transverse sinus thrombosis (n = 1). CONCLUSION: Presence of APAs should be suspected when no cause is apparent for either (a) an ischemic cerebrovascular event in young and middle-aged adults or (b) dural sinus or cerebral venous thrombosis (c) in patients with recurrent systemic arterial or venous thromboses, especially women with recurrent miscarriages.

Adult↗

A follow-up survey of clinical practices for the use of heparin, warfarin, and aspirin.

OBJECTIVE: To determine whether anticoagulation practices have changed when heparin and warfarin are used to treat cerebrovascular disease, and to determine the dosage of aspirin used to treat carotid territory transient ischemic attacks (TIAs). BACKGROUND: A 1987 study documented that neurologists and neurology house officers were using excessive amounts of heparin and warfarin. Recent studies have demonstrated the efficacy and safety of low-intensity anticoagulation for preventing strokes, but no data are available on how these findings have affected the treatment practices of clinicians. DESIGN/METHODS: Questionnaires were sent to neurology staff at 10 medical centers. The questions dealt with the use of heparin, warfarin, and aspirin in stroke/transient ischemic attack patients. The nonparametric Wilcoxon rank sum test was used for analyzing the responses. RESULTS: Ninety-three physicians responded compared with 52 in the prior study. Most (56 of 92; 61%) did not use an IV heparin bolus. The mean partial thromboplastin time (PTT) was 55 seconds, which was significantly less than the mean PTT of 62 seconds (p = 0.006) in the prior study. The mean prothrombin time (PT) fell to 16.0 seconds (range, 12.5 to 20.0) compared with a mean of 19.9 seconds (range, 15.0 to 27.0; p < 0.001) in the earlier study. There was a significant fall in the mean PT ratio from 1.74 (range, 1.20 to 2.25) to 1.49 (range, 1.12 to 2.50; p < 0.001). Most respondents used 325 mg qd of aspirin for treating TIAs. CONCLUSIONS: At the centers studied, neurologists and neurology house officers are using less intense anticoagulation when treating stroke patients now than in 1986. This concurs with recent studies demonstrating the efficacy and safety of low-intensity anticoagulation in some clinical settings. The use of 325 mg/d of aspirin is common, although the data supporting its efficacy compared with higher doses are unclear.

Anticoagulants↗

Evaluation times for patients with in-hospital strokes.

BACKGROUND: Each year at least 35,000 people suffer a stroke while hospitalized, but little is known about the clinical characteristics of such patients or how rapidly they are identified and evaluated. With a recent emphasis on the very early treatment of stroke, in-hospital stroke patients may be candidates for some early interventions. METHODS: This was a retrospective study using the stroke registries at two academic medical centers. Data were collected about the clinical characteristics of patients with an in-hospital stroke and who recognized the stroke. Detailed time data were analyzed to determine the time of stroke recognition, medical evaluation, and neurological evaluation. These specific time epochs were analyzed to determine which were responsible for any delays in stroke identification and assessment. Data were analyzed using nonparametric methods, including the Wilcoxon rank sum and Kruskal-Wallis procedure. RESULTS: Sixty-three patients were identified with in-hospital strokes and adequate time data. In-hospital stroke patients were recognized most frequently by nurses (63%) and by the patient (16%). Patients on a cardiology service and general surgery service accounted for 48% of all in-hospital strokes. The mean and median times from stroke recognition to a neurology evaluation were 14.5 and 2.5 hours, respectively. Total delays differed significantly with service and locale (P = .004). Patients on the Duke neurology service were evaluated significantly sooner (median delay, 0.5 hour) than patients on the Duke medical (median delay, 5.8 hours) or Duke surgical (median delay, 20.5 hours; P < .01 by Wilcoxon rank sum) services. Patients on the Yale surgical service were evaluated significantly sooner than patients on the Duke medical (P = .0006) or surgical (P = .0001) services. The time between physician notification and calling for a neurology evaluation accounted for > 60% of the total time delay for patients not on a neurology service. CONCLUSIONS: A substantial number of in-hospital stroke patients experience a long delay between symptom recognition and a neurological evaluation. While medical personnel are usually notified very soon after an in-hospital stroke is recognized, such patients often do not receive a rapid neurological evaluation. Additional education of hospital staff may reduce these time delays.

Cerebral Infarction↗

TPA in stroke.

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Brain Ischemia↗

Association of apolipoprotein E allele epsilon 4 with late-onset familial and sporadic Alzheimer's disease.

Apolipoprotein E, type epsilon 4 allele (APOE epsilon 4), is associated with late-onset familial Alzheimer's disease (AD). There is high avidity and specific binding of amyloid beta-peptide with the protein ApoE. To test the hypothesis that late-onset familial AD may represent the clustering of sporadic AD in families large enough to be studied, we extended the analyses of APOE alleles to several series of sporadic AD patients. APOE epsilon 4 is significantly associated with a series of probable sporadic AD patients (0.36 +/- 0.042, AD, versus 0.16 +/- 0.027, controls [allele frequency estimate +/- standard error], p = 0.00031). Spouse controls did not differ from CEPH grandparent controls from the Centre d'Etude du Polymorphisme Humain (CEPH) or from literature controls. A large combined series of autopsy-documented sporadic AD patients also demonstrated highly significant association with the APOE epsilon 4 allele (0.40 +/- 0.026, p < or = 0.00001). These data support the involvement of ApoE epsilon 4 in the pathogenesis of late-onset familial and sporadic AD. ApoE isoforms may play an important role in the metabolism of beta-peptide, and APOE epsilon 4 may operate as a susceptibility gene (risk factor) for the clinical expression of AD.

Aged↗

Recombinant tissue plasminogen activator in acute thrombotic and embolic stroke.

An open angiography-based, dose rate escalation study on the effect of intravenous infusion of recombinant tissue plasminogen activator (rt-PA) on cerebral arterial recanalization in patients with acute focal cerebral ischemia was performed at 16 centers. Arterial occlusions consistent with acute ischemia in the carotid or vertebrobasilar territory in the absence of detectable intracerebral hemorrhage were prerequisites for treatment. After the 60-minute rt-PA infusion, arterial perfusion was assessed by repeat angiography and computed tomography scans were performed at 24 hours to assess hemorrhagic transformation. Of 139 patients with symptoms of focal ischemia, 80.6% (112) had complete occlusion of the primary vessel at a mean of 5.4 +/- 1.7 hours after symptom onset. No dose rate response of cerebral arterial recanalization was observed in 93 patients who completed the rt-PA infusion. Middle cerebral artery division (M2) and branch (M3) occlusions were more likely to undergo recanalization by 60 minutes than were internal carotid artery occlusions. Hemorrhagic infarction occurred in 20.2% and parenchymatous hematoma in 10.6% of patients over all dose rates, while neurological worsening accompanied hemorrhagic transformation (hemorrhagic infarction and parenchymatous hematoma) in 9.6% of patients. All findings were within prospective safety guidelines. No dose rate correlation with hemorrhagic infarction, parenchymatous hematoma, or both was seen. Hemorrhagic transformation occurred significantly more frequently in patients receiving treatment at least 6 hours after symptom onset. No relationship between hemorrhagic transformation and recanalization was observed. This study indicates that site of occlusion, time to recanalization, and time to treatment are important variables in acute stroke intervention with this agent.

Acute Disease↗

Aspiration after stroke: lesion analysis by brain MRI.

Aspiration is a common problem following stroke, resulting in feeding difficulties and aspiration pneumonia. Despite past studies using clinical assessments and computed tomographic (CT) scans of the head, the correlation of stroke location with aspiration remains unclear. Since brain magnetic resonance imaging is more sensitive than CT for many stroke types, we have correlated MRI lesions with aspiration in patients who have sustained a stroke. We selected patients with acute stroke who underwent brain MRI and a swallowing evaluation. Aspiration was present in 21 of 38 patients (55%). Patients with just small vessel infarcts had a significantly lower occurrence of aspiration (3 of 14, 21%) compared to those with both large- and small-vessel infarcts (15 of 20, 75%, p = 0.002). Multivariate analysis of several specific brain areas failed to identify a significant association between stroke location and the occurrence of aspiration. These findings suggest that patients who have experienced stroke should be individually evaluated for swallowing dysfunction regardless of stroke location or size, since even small-vessel strokes can be associated with aspiration in greater than 20% of cases.

Adult↗

Effects of public and professional education on reducing the delay in presentation and referral of stroke patients.

BACKGROUND AND PURPOSE: Several emerging stroke therapies require patients to be treated within several hours of symptom onset. Past studies have documented a significant delay between symptom onset and hospital presentation. As part of an experimental treatment study using tissue-type plasminogen activator, we began a multifaceted program of public and professional education to reduce the delay in presentation and referral of acute stroke patients. METHODS: The educational efforts focused on improving the recognition of stroke symptoms, the study enrollment criteria, and the need for rapid treatment of stroke patients. This program included 1) interviews on television and radio, 2) newspaper articles, 3) lectures to local and regional primary care and emergency department physicians, 4) mailings to several thousand local physicians, 5) having neurologists on-call for referrals 24 hrs/day, and 6) use of the Duke Life-Flight helicopter. RESULTS: Since starting our program, 139 of 159 (86%) patients with cerebral infarction presented primarily to our were referred to our facility within 24 hours of symptom onset, compared with 70 of 187 (37%) before our educational efforts (p less than 0.00001). No significant change was seen in patients with intracerebral hemorrhage (23 of 30 +AD77%+BD within 24 hours after program, compared with 25 of 40 +AD63%+BD before educational efforts; p = 0.30). CONCLUSIONS: These findings suggest that educational efforts aimed at the public and health professionals may increase recognition of stroke symptoms and reduce the delay in presentation and referral of stroke patients.

Cerebral Hemorrhage↗

Stroke with negative brain magnetic resonance imaging.

BACKGROUND AND PURPOSE: Magnetic resonance imaging (MRI) of the brain is replacing computed tomography in the diagnostic evaluation of acute ischemic strokes. Past studies have suggested that MRI may not visualize all acute strokes, but few clinical details were included. To better understand the clinical characteristics of strokes not detected by MRI, we collected and reviewed case histories of several patients with acute stroke who had negative MRI scans. METHODS: Patients with a clinical diagnosis of stroke and negative brain MRI scans were ascertained from hospital records dating from 1989 to mid-1991. Patients with transient ischemic attacks, postictal paralysis, functional examinations, central nervous system infections, other nonstroke diagnoses, or equivocal findings were excluded. The MRI scans were performed with a GE Signa 1.5-T magnet in an axial plane (spin-echo repetition time/echo time: 500 msec/20 msec; 2,500 msec, 30 msec/80 msec). One patient received contrast material. RESULTS: We identified seven patients with clinically diagnosed ischemic stroke and negative brain MRI scan. Six of seven patients were scanned within 7 days of symptom onset and two patients within 24 hours. One patient was scanned 3 months after symptom onset. The strokes not detected by MRI were clinically localized to the cortex (n = 3), brain stem (n = 3), and subcortical/lacunar area (n = 1). One patient underwent two MRI scans, one with gadolinium. CONCLUSIONS: These cases, while selected, illustrate some potential limitations of MRI for diagnosing stroke.

Aged↗

Dysphagia following brain-stem stroke. Clinical correlates and outcome.

We studied 23 individuals (16 men, seven women; mean age 57 years) who had brainstem strokes confirmed by computed tomography of the head or magnetic resonance imaging. Videofluoroscopic modified barium-swallowing examination showed aspiration in 15 of 23 patients. Of the 15 aspirating patients, the majority had bilateral strokes with multiple lesion loci, most often in association with large-vessel disease. All 15 patients had involvement of the pons or medulla. Statistical analyses revealed a significant association between aspiration and pharyngeal residue observed under videofluoroscopy, cranial nerve IX abnormality, vocal fold weakness, and severe dysarthria. Despite initial severity, recovery was good. Following an aggressive program of aspiration prevention, over 80% of patients resumed full oral nutrition at the last follow-up.

Adult↗

Genetic linkage analysis of nerve growth factor (beta) in familial Alzheimer's disease.

Recent studies have not shown linkage of late-onset (mean age, greater than 60 years) familial Alzheimer's disease (FAD) to the chromosome 21 locus reported linked to early-onset FAD. Beta nerve growth factor (beta-NGF) has been considered a candidate gene in the pathogenesis and therapy of FAD, based on its localization in the cortex and hippocampus and its ability to enhance the growth and survival of cholinergic neurons. A 1.5-kb fragment of the beta-NGF gene was used to detect a BglII restriction fragment length polymorphism, which was then used for linkage analysis. A total of 30 families (27 late onset) with 147 affected members were studied. Close linkage (theta less than or equal to 0.03, z less than or equal to -2.00) of late-onset FAD with beta-NGF was excluded. Two apparent obligate crossovers between affected members were detected in different autopsy-confirmed families. Based on these results, beta-NGF is not the gene responsible for late-onset FAD in the families analyzed.

Aged↗