Somatosensory potentials, CSF creatine kinase BB activity, and awakening after cardiac arrest

OBJECTIVE: To examine the utility of somatosensory evoked potential (SEP) peaks and CSF creatine kinase BB isoenzyme activity (CKBB) in predicting nonawakening from coma due to cardiac arrest. BACKGROUND: Accurate predictors of neurologic outcome in patients comatose after cardiac arrest are needed to improve medical decision making. METHODS: A total of 72 comatose patients had bilateral median SEPs, and of these, 52 had CSF and CKBB. Awakening was defined as following commands or having comprehensible speech. Both short (N1) and long (N3) latency SEP peaks were analyzed. Nonparametric analyses were used. RESULTS: For patients who had both tests, CKBB > or = 205 U/L predicted nonawakening with a sensitivity of 49% and a specificity of 100%. Bilateral absence of the N1 peak predicted nonawakening with a sensitivity of 53% and a specificity of 100%. Using CKBB > or = 205 U/L, bilaterally absent SEP N1 peaks, or both predicted nonawakening with a sensitivity of 69% and a specificity of 100%. Using CKBB > or = 205 U/L, bilaterally absent N1 peaks, bilateral N3 > or = 176 msec or absent, or some combination predicted nonawakening with a sensitivity of 78% and a specificity of 100%. CONCLUSION: The combination of an absent N1 peak and elevated CKBB performs better than either alone in predicting nonawakening after cardiac arrest. Prolonged or absent N3 latency may increase sensitivity. These results should be interpreted with caution given the small number of patients and the possibility of a self-fulfilling prophecy.     

Antiepileptic drug-induced bone loss in young male patients who have seizures

BACKGROUND: Long-term antiepileptic drug (AED) therapy is a known risk factor for bone loss and fractures. Vitamin D deficiency is frequently cited as a cause for bone loss in patients who have seizures. OBJECTIVE: To determine whether men who have seizures, but who are otherwise healthy, suffer substantial bone loss in the hip while taking AEDs. PATIENTS AND METHODS: We prospectively examined femoral neck bone mineral density (BMD) by dual-energy x-ray absorptiometry in 81 consecutive men, aged between 25 and 54 years old (mean age, 45 years), who were attending an outpatient seizure clinic. Low BMD values were analyzed for known risk factors for bone loss. Dual-energy x-ray absorptiometry scans were repeated in 54 patients, 12 to 29 months later (mean, 19 months), to assess the rate of change in BMD over time. RESULTS: Multivariate linear regression analysis revealed that age (P<.001) and time receiving AEDs (P<.003) were the 2 important risk factors associated with low femoral neck BMD. Neither vitamin D deficiency, hypogonadism, cigarette smoking, nor excess alcohol intake were associated with low BMD after correcting for age and time on AEDs. Longitudinal analysis of femoral neck BMD revealed that only those in the youngest age group (25-44 years) showed significant declines in femoral neck BMD (1.8% annualized loss; 95% confidence interval, -3.1 to -0.9; P<.003) while receiving AED therapy. There was no evidence that a specific type of AED was more causally related to bone loss in this group although most patients were taking phenytoin sodium or carbamazepine during the longitudinal assessment. CONCLUSIONS: Long-term AED therapy in young male patients who have seizures causes significant bone loss at the hip in the absence of vitamin D deficiency. Dual-energy x-ray absorptiometry scanning of the hip is useful in identifying patients who are particularly susceptible to rapid bone loss while taking AEDs.     

Moyamoya disease in Washington State and California

The authors identified 298 diagnoses of moyamoya in California and Washington from hospital discharge databases during the period 1987 to 1998. The incidence was 0.086/100,000 persons. The ethnicity-specific incidence rate ratios compared to whites were 4.6 (95% CI: 3.4 to 6.3) for Asian Americans, 2.2 (95% CI: 1.3 to 2.4) for African Americans, and 0.5 (95% CI: 0.3 to 0.8) for Hispanics. The incidence of moyamoya in Washington and California was lower than reported in Japan, but the rate among US Asians is similar.     

Serum potassium and stroke risk among treated hypertensive adults

BACKGROUND: In prospective studies, hypokalemia has been shown to be associated with a subsequent increase in stroke risk in treated hypertensive adults after 4 to 16 years of follow-up. Stroke risk associated with more recent assessments of hypokalemia has not been examined. METHODS: We used data from an on-going, population-based, case-control study of incident stroke at Group Health Cooperative (GHC). Cases were treated hypertensive adults, 30 to 79 years old, who sustained an incident ischemic or hemorrhagic stroke between July 1989 and December 2000. Controls were GHC members without a history of stroke who met same inclusion criteria as cases. Serum potassium (K(+)) levels were collected from GHC laboratory database. Hypokalemia (< or =3.4 mM/L) was defined using the most recent serum K(+) measure in the year before the index date (event date for cases; random date within calendar year of identification for controls). Multivariate logistic regression estimated the relative risk of ischemic and hemorrhagic stroke. RESULTS: Among 593 ischemic and 125 hemorrhagic stroke cases, and 2397 controls, few subjects were hypokalemic: 3%, 6%, and 2%, respectively. Using the normal range of serum K(+) as a reference (3.5 to 5.0 mM/L), hypokalemia was associated with an elevated risk of ischemic (odds ratio [OR]: 2.04; 95% confidence interval [CI]: 1.14-3.64) and hemorrhagic stroke (OR: 3.29; 95% CI: 1.45-7.48) in adjusted analyses. Associations were not modified by diuretic use. CONCLUSIONS: In adults with treated hypertension, hypokalemia in the year before a stroke was associated with an increased risk of incident ischemic and hemorrhagic stroke independent of diuretic use when compared to normal serum K(+) levels.     

Risk factors for incident stroke among patients with end-stage renal disease

Although patients with ESRD experience markedly higher rates of stroke, no studies in the US have identified risk factors associated with stroke in this population. It was hypothesized that black race, malnutrition, and elevated BP would be associated with the risk of stroke among patients with ESRD. Data from the United States Renal Data Systems were used. Adult Medicare-insured hemodialysis and peritoneal dialysis patients without a history of stroke or transient ischemic attack (TIA) were considered for analysis. The primary outcome was hospitalized or fatal stroke. Cox proportional hazards models were used to determine the associations between the primary predictor variables and stroke. The rate of incident stroke was 33/1,000 person-years in the study sample. After adjustment for age and other patient characteristics, three markers of malnutrition were associated with the risk of stroke-serum albumin (per 1 g/dl decrease, hazard ratio [HR] = 1.43), height-adjusted body weight (per 25% decrease, HR = 1.09), and a subjective assessment of undernourishment (HR = 1.27)-as was higher mean BP (per 10 mmHg, HR = 1.11). The association between black race varied by cardiac disease status, with blacks estimated to be at lower risk than whites among individuals with cardiac disease (HR = 0.74), but at higher risk among individuals without cardiac disease (HR = 1.24). This study confirms the extraordinarily high rates of stroke in ESRD patients on dialysis and identifies high mean BP and malnutrition as potentially modifiable risk factors. The association between black race and stroke differs by cardiac disease status; the reasons for this differing effect of race deserve further investigation.     

Extravasation of radiographic contrast is an independent predictor of death in primary intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Hematomas that enlarge following presentation with primary intracerebral hemorrhage (ICH) are associated with increased mortality, but the mechanisms of hematoma enlargement are poorly understood. We interpreted the presence of contrast extravasation into the hematoma after CT angiography (CTA) as evidence of ongoing hemorrhage and sought to identify the clinical significance of contrast extravasation as well as factors associated with the risk of extravasation. METHODS: We reviewed the clinical records and radiographic studies of all patients with intracranial hemorrhage undergoing CTA from 1994 to 1997. Only patients with primary ICH were included in this study. Univariate and multivariate logistic regression analyses were performed to determine the associations between clinical and radiological variables and the risk of hospital death or contrast extravasation. RESULTS: Data were available for 113 patients. Contrast extravasation was seen in 46% of patients at the time of CTA, and the presence of contrast extravasation was associated with increased fatality: 63.5% versus 16.4% in patients without extravasation (P=0.011). There was a trend toward a shorter time (median+/-SD) from symptom onset to CTA in patients with extravasation (4.6+/-19 hours) than in patients with no evidence of extravasation (6.6+/-28 hours; P=0.065). Multivariate analysis revealed that hematoma size (P=0.022), Glasgow Coma Scale (GCS) score (P=0.016), extravasation of contrast (P=0.006), infratentorial ICH (P=0.014), and lack of surgery (P<0.001) were independently associated with hospital death. Variables independently associated with contrast extravasation were hematoma size (P=0.024), MABP >120 mm Hg (P=0.012), and GCS score of 相似文献