An analysis of ischemic stroke in an urban southern California population. The University of California, San Diego, Stroke Data Bank.

BACKGROUND: Stroke databanks may provide important information regarding regional and temporal variations in the causes of stroke. METHODS: Five hundred consecutive patients presenting to the University of California, San Diego, stroke services with acute ischemic stroke were evaluated prospectively. A specific cause of stroke was assigned in each case according to predetermined diagnostic criteria. RESULTS: Relative incidences of ischemic stroke causes were as follows: lacunar, 27%; unknown cause, 23%; cardioembolic, 22%; large-vessel atherothrombotic/embolic, 18%; and miscellaneous, 10%. CONCLUSIONS: These relatively high rates of lacunar stroke and stroke of unknown cause are similar to those from other recent surveys and may reflect an important shift in the pathophysiologic mechanisms that underlie ischemic stroke.

Short-latency somatosensory evoked potentials.

Short-latency components of the somatosensory evoked potential (SEP) were studied in 20 subjects who had median nerve stimulation using knee, forehead, and ear reference recordings. Six potentials were identified (P10, P12, P14, N19, P20, P23). Potential P10 seems to originate in the brachial plexus, P12 most likely is generated in dorsal column nuclei and medial lemniscus, P14 is probably thalamic in origin but is frequently bilobed and may have a second generator source, and N19 may originate in sensory radiation or cortex. The origin of P20 is unclear, and P23 appears to be generated in the contralateral somatosensory cortex. Clinically, we recommend using right, left, and bilateral median nerve stimulation at 4 Hz. Intensity of stimulus should produce at least a small thumb twitch, it was only with knee reference recording that all early potentials were seen.

CNS cysticercosis.

Worldwide, cysticercosis is the most common CNS parasite. Because of immigration from endemic areas, cysticercosis has become more common in the United States. Seventeen cases have been seen at the University of California Medical Center, San Diego (La Jolla) over the last ten years. Eight patients had intracranial hypertension; three, seizures; three, intracranial hypertension; and seizures; two, strokes; and one, retinal involvement. Diagnosis was by surgical biopsy in five cases and by clinical setting plus positive serologic findings in 12. Twelve patients underwent surgical procedures during their illness, one patient died, and five improved with steroid therapy. Clinical, serologic, and pathologic criteria permit definitive diagnosis. Therapy is currently directed toward complications of the primary infection, which usually is inactive at the time of presentation.

Recovery function of short-latency components of the human somatosensory evoked potential.

Short-latency somatosensory evoked potentials were studied in 14 normal human subjects with the technique of paired stimuli with different interstimulus intervals. Interstimulus intervals were 5, 10, 15, 25, 50, 100, 150, and 200 ms. To obtain the response to the second stimulus of the pair, amplitudes of the second responses (R2) were subtracted from those of the first responses (R1) and recovery curves constructed. Results of this study support previous conclusions that P10 is generated in peripheral nerves (brachial plexus), P14 in medial lemniscus, N19 in sensory radiation, and P23 in sensory cortex.

Guillain-Barré syndrome. Clinicoepidemiologic features and effect of influenza vaccine.

A study of the epidemiologic and clinical features of Guillain-Barré syndrome in the population of Olmsted County, Minnesota, over the 46-year period 1935 through 1980 was conducted through the centralized diagnostic index maintained at Mayo Clinic, Rochester, Minn. A total of 48 cases were identified, giving an age- and sex-adjusted incidence of 1.8 per 100,000 person-years. The rate increased over time from 1.2 in the interval 1935 through 1956 to 2.4 in the interval 1970 through 1980. Males were affected more than females (age-adjusted rates of 2.3 and 1.2, respectively). The rate increased with age from 0.8 in those under 18 years old to 3.2 for those 60 years and older. Antecedent infectious diseases were reported in 65% of the cases. Implications with regard to the incidence of Guillain-Barré syndrome associated with the A/New Jersey/76 (swine flu) vaccine are discussed.

Evoked potentials in trigeminal neuralgia associated with multiple sclerosis.

A 49-year-old man with definite multiple sclerosis suffered an episode of right-sided trigeminal neuralgia (TN) of two weeks' duration, unaccompanied by any other clinical symptoms or signs of exacerbation. Serial evoked potentials, obtained before, during, and after TN, demonstrated developing abnormalities in brain-stem auditory evoked potentials from the right ear that disappeared in a delayed fashion after the clinical symptoms of TN had subsided. This rare combination of clinical and electrophysiologic abnormalities suggests a pontine demyelinating plaque involving the right trigeminal sensory root and the right lateral lemniscus.

Central pontine myelinolysis. A clinical reappraisal.

We discuss three patients with clinical findings of central pontine myelinolysis (CPM). Two patients survived with minimal neurological deficits, and one patient died from medical complications while recovering from his neurological deficit. Postmortem examination showed the typical lesion of CPM. Brain stem auditory evoked potential studies in two of our patients indicate that there was impairment of function in auditory pontine pathways that returned to normal as the patients improved clinically. We conclude that CPM can be diagnosed clinically and that patients may recover if intercurrent illnesses are vigorously treated.

Clinical validity of the Mattis Dementia Rating Scale in detecting Dementia of the Alzheimer type. A double cross-validation and application to a community-dwelling sample.

OBJECTIVE: To assess the clinical validity of the Dementia Rating Scale (DRS) in detecting patients with dementia of the Alzheimer type (DAT). BACKGROUND: The DRS is widely used to evaluate cognitive functioning in older adults. Adequate normative data are unavailable; studies addressing the clinical validity of the DRS are limited by small sample sizes. DESIGN AND METHODS: Administered the DRS to 254 outpatients with DAT and 105 healthy elderly subjects. Performed (1) multiple regressions of demographic factors on the DRS and its subscales; (2) derivation of optimal DRS cutoff scores using receiver operating characteristic curves; (3) double cross-validation with stepwise logistic regressions; and (4) application of results to a community-dwelling sample. RESULTS: Age- and education-adjusted DRS scores were computed. The optimal DRS cutoff score for DAT of 129 or less revealed a sensitivity of 98% and a specificity of 97%. The logistic regressions resulted in a combination of the Memory and Initiation/Perseveration subscales that correctly classified 98% of all subjects, 92% of a subsample of 76 patients with mild DAT, and 100% of the 51 patients with autopsy-confirmed DAT. The resultant equation was then applied to a community-dwelling sample (238 healthy elderly subjects and 44 patients with DAT): 91% of patients and 93% of normal subjects were correctly classified. Of an additional 77 individuals with questionable DAT, 43 were classified as demented and 34 were classified as nondemented. CONCLUSIONS: The DRS is a clinically valid psychometric test for the detection of DAT. The Memory and Initiation/Perseveration subscales are its best discriminative indexes for an abbreviated version.

Incidence and prevalence of tuberous sclerosis in Rochester, Minnesota, 1950 through 1982.

The incidence of tuberous sclerosis in Rochester, MN, was 0.56 per 100,000 person-years in 1950 through 1982, and point prevalence on December 31, 1980, was 10.6 per 100,000 persons. The true incidence and prevalence may be even higher, because cases with hypomelanotic macules and no other clinical manifestations are often unrecognized. Pertinent clinical observations in the eight cases identified included familial occurrence in two; hypomelanotic macules in all eight; seizures with onset before age 2 in four, of whom two were mentally retarded; and no neurologic abnormalities in those free of seizures.

'Crescendo' transient ischemic attacks: clinical and angiographic correlations.

Forty-seven consecutive patients presenting acutely with repetitive symptoms indicative of anterior circulation ischemia ("crescendo" transient ischemic attacks) were evaluated to identify clinical features that might reliably predict the presence of significant stenosis, ulceration, or both in the presumably symptomatic internal carotid artery. Angiographic or intraoperative correlation was obtained in all patients, and 26 (55%) were found to have anatomically significant disease. Of 20 patients with signs or symptoms suggestive of cortical ischemia, amaurosis fugax, or both, 17 (85%) had "positive" angiograms; of 18 with numbness/weakness only, 9 (50%) had positive angiograms; of 9 whose symptoms suggested lacunar ischemia, none had positive angiograms.

ApoE and CYP2D6 polymorphism with and without parkinsonism-dementia complex in the people of Chamorro, guam.

Parkinsonism-dementia complex (PDC), a neurodegenerative disorder in the Chamorro, Guam population, has been epidemiologically ascribed to the ingestion of the neurotoxin cycasin. This disease is characterized neuropathologically by the presence of abundant neurofibrillary tangles (NFTs). We analyzed a genetic risk factor of Alzheimer's disease (AD), apolipoprotein E, hypothesized to be linked to NFT formation, and a genetic risk factor of Parkinson's disease (PD), CYP2D6 mutation, linked to slower metabolism of exogenous toxins, in Chamorro, Guam individuals with and without PDC. The representation of the G-to-C mutation in exon 9 of the CYP2D6 gene was higher in Chamorro and Filipino than in Caucasian individuals, but this mutant allele had similar high frequencies in both PDC patients and healthy Chamorro individuals. We found no alleles of these genes associated with AD or PD to be overrepresented among those with PDC.

Short-term outcomes of skull fracture: a population-based study of survival and neurologic complications.

All Olmsted County, Minnesota, residents who experienced brain injury from 1935 through 1979 were identified and their medical records reviewed for survival and neurologic outcome. Minimum inclusion criteria included loss of consciousness or post-traumatic amnesia or neurologic evidence of brain injury or skull fracture. Of 4,660 cases identified, skull fractures were observed in 28%. Over half of brain-injured patients who died did so within 24 hours of trauma; among 1-day survivors, subsequent survival was moderately impaired, especially in older individuals. Mortality was lowest in subjects without a skull fracture and increased with fracture severity. Associated neurologic injuries, complications, and deficits were generally more common in patients with skull fracture than those without and were much more frequent with more severe skull fractures. The types of neurologic deficits differed little between those with and without fractures, except that subjects with complicated skull fractures had higher proportions of special sensory deficits and multiple deficits.

Weight loss precedes dementia in community-dwelling older adults.

OBJECTIVE: To determine whether the weight loss associated with Alzheimer's disease precedes or follows the dementia. DESIGN: Older community-dwelling men (n = 134) and women (n = 165) were followed for 20 years before they were diagnosed as cognitively intact or demented. A repeated measures analysis was used to compare weight change in those who developed Alzheimer's Disease (AD) with those who remained cognitively intact. MEASUREMENTS: Weight was measured at three clinic visits between 1972-74, 1984-87, and 1990-93. Participants were classified as having probable or possible AD or being cognitively intact at the 1990-93 evaluation. Diagnoses were made by two neurologists and a neuropsychometrist, based on neuropsychological tests and physical examination, using NINCDS-ADRDA criteria. RESULTS: There were 36 men and 24 women diagnosed with probable or possible AD; they were considered to have mild to moderate dementia based on their test scores and community-dwelling status. Those who developed dementia were older than those diagnosed as cognitively intact. In age-adjusted analyses, both men and women who were later diagnosed with AD had a significant decrease in weight after the baseline visit (P < .001 and P < .003, respectively), but there was no significant weight loss in the men and women who remained cognitively intact. These differences were not explained by lifestyle, depression, or other illness. CONCLUSION: Weight loss precedes mild to moderate dementia; early weight loss is, therefore, unlikely to be a consequence of AD patients being unable or unwilling to eat.

Cognitive and functional status of the oldest old.

OBJECTIVE: To compare the cognitive performance and functional status of the normal oldest old (85 + years) with that of normal older persons aged 65 to 84 years to identify age-associated changes in cognition in individuals considered clinically normal. BACKGROUND: Advancing age appears to be a risk factor for dementia. DESIGN/METHODS: Analysis of performance on an extensive neuropsychological battery and the Pfeffer Outpatient Disability Scale in 243 normal individuals age 65 to 99 years. RESULTS: Fifty-two normal subjects who were 85 years of age and older (mean age 88.2 +/- 3.1) and 191 normal subjects aged 65-84 years (mean age 75.8 +/- 5.0) were compared. Mean education for both groups was not statistically different. No significant differences in functional disability were found between the two groups. Normal subjects aged 85 years and older performed significantly less well than their younger counterparts on verbal and nonverbal memory, psychomotor/executive tasks, and category verbal fluency. CONCLUSIONS: Advancing age in normal subjects is accompanied by a decrease in cognitive function, measured by various neuropsychological tests, but is not accompanied by functional impairment.

The association of non-insulin-dependent diabetes mellitus and cognitive function in an older cohort.

OBJECTIVE: In this study, we examined the association of non-insulin-dependent diabetes mellitus (NIDDM) and impaired glucose tolerance (IGT) with cognitive function in a population-based sample of older individuals. RESEARCH DESIGN AND METHODS: Subjects were 1509 healthy, community-dwelling men and women aged 55 years and older who were participants in the Rancho Bernardo Study and attended clinic visits in 1984-87 and in 1988-91. An oral glucose tolerance test was administered during the 1984-87 visits. Based on World Health Organization criteria, participants were classified into those with NIDDM, IGT, or normal glucose tolerance. During the 1988-91 clinic visits, 12 tests of cognitive function were administered. RESULTS: Of the participants, 14.3% of the men and 9.9% of the women had NIDDM, and 21.0% of the men and 28.0% of the women had IGT. Multiple regression analysis was used to compare the cognitive function of individuals with NIDDM and IGT with individuals with normal glucose tolerance after adjustment for age, education, obesity, depression, blood pressure, and current estrogen use. In men, there were no statistically significant differences in any of the 12 cognitive function tests by glucose tolerance category. Compared with those with normal glucose tolerance, women with IGT had lower scores on almost every cognitive function test, whereas women with NIDDM had higher scores, but none of these differences were statistically significant after adjustment for multiple comparisons. Furthermore, observed differences by NIDDM or IGT status were small and accounted for < or = 0.6% of the explained variance in cognitive function. CONCLUSIONS: This study shows no strong or consistent association between IGT or mild diabetes with cognitive function in community-dwelling older adults.

Effects of age, gender and education on selected neuropsychological tests in an elderly community cohort.

OBJECTIVE: To establish population-based data, with special emphasis on the effects of age, gender, and education, for eight, widely used neuropsychological tests in a community-dwelling cohort of normal and cognitively impaired older adults. DESIGN: A population-based observational study. SETTING: Examinations were performed in a research clinic by specially trained staff during a 1988-1992 evaluation for osteoporosis. PARTICIPANTS: 1,692 community-dwelling subjects, aged 55 to 94 years, who were members of the Rancho Bernardo Heart and Chronic Disease Study initiated in 1972. The mean age for men was 73.9 years (SD 9.3) and for women, 73.5 (SD 9.1). OUTCOME MEASURES: Eight neuropsychological tests were used to measure cognitive functions. Analysis of variance and post hoc contrasts were performed to determine the effects of age, gender, education, and their interactions on performance on these tests. RESULTS: Performance on all tests decreased progressively, without leveling off, from the youngest, age 55, to the oldest, age 94. Women performed better on verbal tasks and men on tests of visuospatial, visuoconceptual, and mental control functions. Performances of men on several tests declined more rapidly with advancing age than those of women. Both men and women with some college education performed better on most tests than men and women with high school educations, and the rate of decline with age was sometimes slower in the college-educated group. Only the savings score from the Visual Reproduction Test, which is a measure of rate of forgetting, and the scores of short-term recall derived from the Selective Reminding Test (Buschke-Fuld) were unaffected by educational attainment. CONCLUSIONS: In a community-dwelling cohort, including normal and cognitively impaired elderly men and women, advancing age is accompanied by decline in cognitive functions as measured by neuropsychological tests. This decline is slower in women and in college-educated subjects. Two cognitive indices were unaffected by education, and these may be especially useful in cross-cultural studies.

Serial recordings of multimodality evoked potentials in multiple sclerosis: a four year follow-up study.

Pattern reversal visual, brain-stem auditory, and short latency median nerve somatosensory evoked potentials (EPs) were evaluated in a prospective study over 4 years in 20 patients with clinically definite sclerosis (MS). Standardized neurological examinations were done at regular intervals and correlated with EP findings. The highest incidence of EP abnormalities occurred in the visual system followed by the somatosensory and auditory systems. Clinical relapse was usually accompanied by EP deterioration, but clinical improvement often occurred without parallel EP recovery. EP changes were not always related to clinical symptoms and often took place during remission periods in the absence of clinical changes. There was no significant correlation between clinical and electrophysiological progression within any given sensory modality. The progression of clinical disability, however, showed a fairly good correlation with the overall progression of EP abnormalities. We conclude that EPs complement the neurological exam in the evaluation of MS and may have a place in the investigation of the effects of therapeutic agents on the neurological status in MS.

Screening for dementia of the alzheimer type in the community: the utility of the Clock Drawing Test.

This study reports the sensitivity and specificity of the Clock Drawing Test (CDT) for detecting dementia of the Alzheimer type in a community-dwelling sample of elderly subjects. Forty-two patients with clinically diagnosed Alzheimer's disease and 237 cognitively intact subjects were administered the CDT as part of an epidemiological study of aging and dementia. Three individual measures of clock drawing performance (quantitative score, qualitative score, and combined quantitative and qualitative score) were determined for each participant. When qualitative elements such as errors and strategies were incorporated into the CDT score, the sensitivity was 84% and the specificity was 72%. The findings suggest that a CDT score which evaluates qualitative and quantitative features provides reasonably good discrimination between normal elderly individuals and DAT patients. However, the CDT appears to have limited utility as a single screening instrument in the community. Instruments such as the Dementia Rating Scale (Mattis, 1976) provide better discrimination of DAT, indicating that functions such as memory and verbal fluency need to be assessed during screening.