Neuroimaging Reports Research Articles

HMO membership and patient age and the use of specialty care for hospitalized patients with acute stroke: The Minnesota Stroke Survey.

The number of older patients enrolling in health maintenance organizations (HMOs) is increasing. Concerns have been raised that older patients may be targeted by HMOs for more stringent cost-containment mechanisms, including reduced access to expensive specialty care. We investigated the relationship between membership in an HMO and the decision to consult with a neurologist or admit to a neurology ward for patients hospitalized with acute stroke. We then compared 1-year mortality of patients who received neurology care to the 1-year mortality of those who did not receive neurology care. Retrospective medical record review. A sample of hospitalized acute stroke patients (age range, 30-79 years) who were discharged from Minneapolis-St. Paul metropolitan hospitals with a diagnosis code of acute cerebrovascular disease from 1991 to 1993. Trained nurses abstracted the medical records. Stroke events (n = 2,320) were validated using clinical criteria and neuroimaging reports. Mortality data were obtained from the Minnesota Death Index. Among patients enrolled in HMOs, 30% of validated stroke patients did not receive neurology care in comparison with 19% of patients not enrolled in HMOs. After adjusting for patient mix and hospital characteristics, the odds of receiving neurology care were half as great for patients enrolled in HMOs as compared with patients not enrolled in HMOs (odds ratio [OR] = 0.52, 95% confidence interval [CI] 0.36-0.74). The association of membership in HMOs with lower use of neurology care was concentrated in older patients. Within each age group, the odds ratios and 95% CI of receiving neurology care for patients enrolled in HMOs versus patients not enrolled in HMOs were: < 55 years (1.06, 0.42-2.67), 55 to 64 years (0.54, 0.34-0.87), 65 to 74 years (0.51, 0.36-0.71), and >75 years (0.40, 0.24-0.68). Using Cox regression, 30-day mortality did not differ between patients who received neurology care and those who did not. Among 30-day survivors, the mortality hazards ratio (HR) during the next 11 months for patients who received neurology care was 71% of the hazard for patients who did not receive neurology care (HR = 0.71, 95% CI = 0.55-0.91). These data suggest that membership in an HMO was associated with reduced access to neurology care for older patients with acute stroke and that patients who received neurology care had a lower risk of death during the year after their stroke. It remains to be determined if these differences in outcome are caused by true differences in stroke management or by unmeasured characteristics.

Abstracts of literature

Abstracts of literature

Delayed hospital arrival for acute stroke: the Minnesota Stroke Survey.

Although recent advances have been made in the treatment of acute stroke, patients often arrive at the hospital too late to receive the maximum benefit from these new therapies. To investigate characteristics that influence the time from symptom onset to hospital arrival (delay time) for patients with acute stroke. Retrospective medical record review. Minneapolis-St. Paul metropolitan hospitals. A 50% random sample of all patients 30 to 79 years of age who were hospitalized with acute stroke from 1991 to 1993. Patients were identified through discharge diagnosis lists by using the International Classification of Diseases, 9th Revision. Trained nurses abstracted the medical records. Stroke events were validated by using neuroimaging reports and additional clinical criteria (1895 patients). An accelerated failure time model was used to identify patient characteristics that independently predicted delay time. For 70% of patients (n = 1334), delay time was calculated from the medical record by subtracting the recorded time of symptom onset from the admission time. For the remaining 30% of patients (n = 561), the time of symptom onset was not recorded, and an approximate delay time was estimated from all available information. Among patients with a calculated delay time, half arrived within 3 hours of symptom onset and 90% arrived within 24 hours. Patients with approximated delay times tended to have longer delays, and less than 40% of these patients arrived within 24 hours of symptom onset. Some characteristics associated (P < 0.05) with longer delay included Asian/Pacific Islander ethnicity, dependence in any activities of daily living before stroke, and several symptoms at stroke onset. Characteristics associated (P < 0.05) with shorter delay included admission through the emergency department, presence of syncope or seizures at stroke onset, previous myocardial infarction, abnormal mental status, and greater disability at presentation (measured by the Rankin scale). Most patients arrive at the hospital too late to receive the maximum benefit from emerging stroke therapies. Efforts to reduce delays in hospital arrival after acute stroke can maximize the effectiveness of these therapies by specifically targeting persons at risk for longer delay.

Neuroimaging and Case Reports 3 November 1997, Monday

Neuroimaging and Case Reports 3 November 1997, Monday

Cognitive and language functions of the human cerebellum.

Traditionally, the human cerebellum has been regarded as a motor mechanism, but this view of its function is being challenged by a growing body of data on the non-motor functions of the cerebellum. Some of these data are presented in this article, which reviews neuroanatomical, neuroimaging and behavioral reports of cerebellar involvement in cognitive and language functions. The article proposes that this functional expansion is a consequence of specific cerebellar structural changes that evolved during hominid evolution and that could have been a prerequisite for the evolution of human language.

Blood glucose and stroke.

Current recommendations for the treatment of abnormal blood glucose levels for stroke rely on evidence-based guidelines. Ongoing advances in neuroimaging, tissue studies, animal studies, and case series and reports present findings that expose additional variables to be considered in the causal analysis of the role of diabetes and glucose control for stroke occurrence and outcome. The physician when treating the individual patient must fold this information into that provided by large clinical trials. Consideration of all information available without limitation to results from large, double-blind randomized trials allows the physician to expect and thus forecast the result of clinical action by understanding the complexity of the situation. Avoiding hypoglycemia and levels of hyperglycemia able to produce symptoms of stroke and cerebral damage by themselves would seem common sense. The plethora of evidence consistent with worse outcome and increased mortality in acutely ill and stroke patients with hyperglycemia also would call for treatment, with prudent avoidance of hypoglycemia. These rules appear to apply for hemorrhage as well as ischemia, and aggressive recommendations for lowing blood glucose caution against hypoglycemia.