Chapter 43. Neuroepidemiology Flashcards
Question 43-1: What is the change in stroke death rate for the US and western Europe? A. Rates are continuously decreasing B. Rates decreased until the mid 1990’s, and are now increasing C. Rates are continuously increasing D. There has been no consistent change
Answer 43-1: A. Death rate from stroke has been decreasing in US and western Europe. However, in some eastern European countries the rate is now rising. The decrease in death rate in the US is across major ethnic boundaries as well. indicating that the change is not due to population demographic shifts. (p764)
Question 43-2: The figure shows a graph of stroke incidence rates in blacks and whites. The data on blacks was obtained in 1993 whereas the data for whites was obtained from 1985-1989. What conclusions can be made on the basis of these data? A. Stroke rate is higher among blacks B. Stroke rate is age-independent C. The difference in stroke rate betweenblacks and whites is due to location, Cincinnati versus Rochester, MN. D. The difference in stroke rate between blacks and whites is due to hypertension E. AIl are true
Answer 43-2: A. The only conclusions which can be drawn from these data are that the stroke rate is higher among blacks than whites and the discrepancy is age dependent with less of a difference at greater age. There are no presented data in this graph to indicate causation, and one must exhibit great caution in inserting personal opinions and knowledge in interpretation of epidemiologic data. The cause of the discrepancy is likely to be due to vascular risk factors rather than location, but there is no way to identify the cause in this graph. (p765)
Question 43-3: Which is the most common malignant primary brain neoplasm? A. Anaplastic astrocytoma B. Glioblastoma (GBM) C. Malignant meningioma D. Primitive neuroectodermal tumor (PNET)
Answer 43-3: B. Glioblastoma is the most common malignant primary brain tumor. Anaplastic astrocytoma is less common, and is a less malignant form in the same line as GBM. Meningiomas are common but malignant varieties are rare. PNETs including medulloblastomas are common in children, yet they still represent a small proportion of brain tumors. (p767)
Question 43-4: What effect does epilepsy have on mortality rates? A. No change in mortality B. Higher mortality mainly due to motor vehicle accidents C. Higher mortality due to multiple causes D. Lower mortality since they have ongoing medical care
Answer 43-4: C. Patients with epilepsy have a higher mortality rate, and the Stockholm County Inpatient Registry indicated a mortality ratio of3.6, meaning that patients with epilepsy had a 3.6- fold increased risk of death. Driving motor vehicles was not the cause in this population. Causes of the increased death rate included complications of status epilepticus, accidents, pneumonia, and even suicide. (p768)
Question 43-5: Which is the most common cause of epilepsy in the world? A. Trauma 8. Genetic inheritance C. Benign tumor D. Neurocysticercosis
Answer 43-5: D. 284 Neurocysticerosis is the most common cause of epilepsy in the world, although this is a very uncommon cause in the developed countries. Neurocysticercosis is most common in Latin America, Asia, and Athca. Neurologists in developed countries need to be vigilant to the possibility of this diagnosis in immigrant peoples. (p768)
Question 43-6: A patient recently diagnosed with multiple sclerosis bas a monozygotic twin plus three other siblings. How do you advise her about the risk of her other family members developing MS? A. The risk for the twin is 50%, but the risk to the others is about the same as the general population B. The risk for the twin is about 30010, and the risk for the other siblings is 34% C. The risk for the twin is 2-3% and the risk for the other siblings is about the same as in the general population
Answer 43-6: B. MS epidemiology shows a combination of genetic and environmental factors, and families will share both of these. The risk for the monozygotic twin is about 30%. The risk for primary relatives is 3-4%, and while this is low. it is still much higher than the average of 0.11 %, for the population at large. (p 772)
Question 43-7: Migration studies have shown that there is an effect of location for the incidence of multiple sclerosis. Which of the following statements about migration are generally accepted? A. Migration before the age of 15 years results in adoption of the risk of the new environment B. Migration after the age of 15 years results in maintenance of the risk of the initial environment C. Risk is greater in UK, US, Canada, Australia, and South Africa than in other areas . D. All are true
Answer 43-7: D. All of these statements are true. Migration prior to age IS results in adoption of tile new location’s risk, whereas migration after that results in maintenance of the native location’s risk. There is geographic clustering, probably indicating that the disease began in western Europe, but the regions of highest incidence are those listed. Even within these regions, such as the US, there is a wide variation in risk. (p772)
Question 43-8 Which of the following are early complications of HIV infection’? A. Cryptococcal meningitis B. Toxoplasmosis C. Acute demyelinating neuropathy D. Progressive multifocal leukoencephalopathy E. All of these
Answer 43-8: C. Acute and chronic demyelinating neuropathy are among the early complications ofHIV infection when the CD4 counts are at least 200 cells/mm). The other listed complications are typically seen later in the course, especially when the counts are less than this. HIV dementia and primary CNS lymphoma are also conditions which develop later in the course. (p774)
Question 43-9: Which of the following statements are true regarding epidemiology of epilepsy? 1. Seizures are more likely at the extremes of age, in infancy and with advanced age 2. Myoclonic seizures are most common in infancy 3. Absence seizures do not begin after young adult life 4. Simple partial seizures peak in middle age Select: A = 1.2.3. B = 1.3. C = 2. 4. D = 4 only. E = All
Answer 43-9: E. All ofthese statements are true. Whereas the data has differed somewhat between reports, most studies agree that the incidence of epilepsy is greatest in infancy, with myoclonic predominating at this age, and partial seizures predominating in elderly patients. (p769)
Question 43-10: The risk of stroke and stroke death rates have fallen in the US. Which of the following statements are true regarding epidemiology of stroke? 1. Mortality from stroke has declined about 70% in the past 40 years 2. Age-adjusted stroke death rate is higher for blacks than other ethnic groups in the US 3. Stroke death rate for American Indians increased rather than decreased 4. Incidence of cerebral hemorrhage is greatest in Hispanics and blacks Select: A = 1,2.3. B = 13. C = 24. D = 4 only. E = All
Answer 43-10: E. All of these are true. There has been about a 70% reduction in stroke mortality and about a 50% reduction in stroke incidence in recent decades, although there have been some epochs of stroke Increase. American Indian and Alaskan natives have actually had an increase in stroke death rate, unfortunately. (p76S)
