Edwin C. Shuttleworth

Chronic stress and immunity in family caregivers of Alzheimer's disease victims.

&NA; Although acute stress has been associated with transient immunosuppression, little is known about the immunologic consequences of chronic stress in humans. In order to investigate possible health‐related consequences of a long‐term stressor, we obtained blood samples for immunologic and nutritional analyses and psychologic data from 34 family caregivers of Alzheimers disease (AD) victims and 34 sociodemographically matched comparison subjects. Family caregivers for AD victims were more distressed than comparison subjects without similar responsibilities. Greater impairment in the AD victim was associated with greater distress and loneliness in caregivers. Caregivers had significantly lower percentages of total T lymphocytes and helper T lymphocytes than did comparison subjects, as well as significantly lower helper‐suppressor cell ratios; caregivers also had significantly higher antibody titers to Epstein‐Barr virus than did comparison subjects, presumably reflecting poorer cellular immune system control of the latent virus in caregivers. The percentages of natural killer cells and suppressor T lymphocytes did not differ significantly. These data suggest that chronically stressed AD family caregivers do not show immunologic or psychologic adaptation to the level of their well‐matched age peers.

Further observations on the nature of prosopagnosia

Two new cases of prosopagnosia are described and compared with pertinent clinical material from the English language literature. The interpretation of this disorder most compatible with the clinical data appears to us to be that there is an underspecification of visuoperceptive information preventing both the formation of significant face images and the retrieval of well-known face memoranda existing within a relatively intact visual remote memory store. Failure of formation of immediate memoranda of similarly complex visual images is also commonly observed but does not seem to be a requirement for the symptom of prosopagnosia. Conceptualizing this abnormality as simply a material specific visual agnosia of images beyond the classifier level would still appear to be acceptable if less informative.

Magnetic Resonance Imaging and Clinical Correlates of Intellectual Impairment in Myotonic Dystrophy

Although intellectual impairment is common in patients with myotonic dystrophy, this aspect of the disease has received relatively little research attention. We examined 41 patients with myotonic dystrophy using objective neuropsychological procedures and magnetic resonance imaging. Ten patients (24%) had severe and generalized intellectual dysfunction, while lesser or no cognitive impairment characterized the remaining patients. Degree of intellectual impairment was not related to neuromuscular status or sex. Patients with severe intellectual disturbance had significantly earlier onset of both myotonia and weakness and were more likely to inherit the disease from their mother. Magnetic resonance imaging findings indicated that while degree of cerebral atrophy was not related to severity of intellectual impairment, skull thickness, focal white matter lesions, and anterior temporal lobe abnormalities were significantly more common in patients with severely disturbed intellect. This study reports a number of previously unreported cerebral magnetic resonance imaging findings associated with intellectual impairment in myotonic dystrophy, but the etiology of these changes awaits neuropathologic examination.

The naming disorder of dementia of Alzheimer type

We studied the characteristics of the naming disorder of dementia of the Alzheimer type (DAT) in 20 patients, who were divided on the basis of Mini-Mental State scores into a mild and a moderate-severe group. Our results confirmed the presence of a progressive anomia which was sensitive both to word frequency and to image quality. Although DAT patients as a group made a similar proportion of perceptual-recognition and aphasic errors as did our age and education-matched controls, evidence was obtained that suggested that variations in the character of the anomia exist among individual DAT patients.

The wobbler mouse mutant, an animal model of hereditary motor system disease.

SummaryThe homozygous wobbler (wr) mouse mutant manifests shortly after birth a form of progressive neural atrophy characterized pathologically by vacuolization and degeneration of neurons of the brainstem and ventral horn of the spinal cord. Ultrastructural features include the presence of autophagic vacuoles containing tubular structures indistinguishable in appearance from neurotubules. The present study correlates certain of these histological features with the characteristics of axoplasmic flow in the homozygous 5–8 week old (wr) mouse.Slow phase axoplasmic flow was found to be identical in both (wr) mice and normal littermate groups and was estimated to be 1–2 mm per day. However, the homozygous (wr) mouse consistently demonstrated more label in the proximal segments at 7 and 10 days suggesting the presence of an additional population of neurons with impaired flow but with a relatively intact protein synthetic mechanism. This is accompanied by histologic evidence for the elaboration of abnormal neurotubular protein under genetic control. It is hypothesized that the neurotubular transport system underlying the slow phase of axoplasmic flow is thus rendered defective resulting in impairment in axonal continuity and the progressive histologic picture so described.

Fluctuations in plasma dopamine level impair memory in Parkinson's disease

We found a causal relationship between variation in plasma dopamine level and memory impairment in Parkinsons disease. If the level of dopamine was changed between the time of original learning and a later time of attempted memory retrieval, memory performance was impaired when compared with a maintenance of similar dopamine levels on both occasions. The absolute level of dopamine did not influence memory performance. Side-effects of levodopa-carbidopa therapy include variation in dopamine level, parkinsonian symptoms, and possibly “sate-dependent” impairment of memory.

Dose‐dependent memory impairment in Parkinson's disease

Variation in plasma dopamine level between the time of original learning and subsequent memory retrieval causes a state-dependent memory impairment in Parkinsons disease. The occurrence of this phenomenon is not related to either progression of disease or duration of therapy, but is more likely to occur with high-dosage levels of levodopa-carbidopa.

Neuropsychological Similarities in Lateralized Parkinsonism

Parkinsons disease (PD) patients who have left or right predominance of motor symptoms may exhibit cognitive differences. Previous research found greater neuropsychological impairment in patients with both right and left motor predominance, and some found no differences. Variability in overall severity of disease among the patients studied makes evaluation of these reports difficult. We examined the possibility that neuropsychological differences may occur in different stages of disease by comparing patients with mild unilateral disease (Exp. 1) and advanced disease (Exp. 2). Results indicated that while overall cognitive impairment increased with advancing disease, the pattern of neuropsychological impairments were not different with respect to laterality of motor symptoms in either experiment.

Neuropsychological Impairments Associated With Severity of Parkinson's Disease

Intellectual impairment and disease severity tend to parallel one another in patients with Parkinsons disease (PD), but the pattern of development of the neuropsychological impairments contributing to the overall intellectual decline is unknown. This problem was addressed by comparing neuropsychological performance in the early and later stages of PD. Impairment of recent memory, impairment of cognition, and somatic features of depression were seen early and worsened with more advanced disease. Impairment of visuospatial skills, remote memory, language, and mood were observed only in the later stages of PD. These findings suggest that neuropsychological impairments do not develop in a uniform manner with progression of PD.

Atypical presentations of dementia of the Alzheimer type.

Seven patients who eventually met established criteria for dementia of the Alzheimer type are described to illustrate the variety of atypical clinical presentations of this disorder. The value of a careful history, examination, and follow up in reaching the earliest possible diagnosis is emphasized. In the event of the development of adequate therapy this information will become essential in proper management of these patients.