Early Magnesium Treatment After Aneurysmal Subarachnoid Hemorrhage: Individual Patient Data Meta-Analysis.

BACKGROUND AND PURPOSE: Delayed cerebral ischemia (DCI) is an important cause of poor outcome after aneurysmal subarachnoid hemorrhage (SAH). Trials of magnesium treatment starting <4 days after symptom onset found no effect on poor outcome or DCI in SAH. Earlier installment of treatment might be more effective, but individual trials had not enough power for such a subanalysis. We performed an individual patient data meta-analysis to study whether magnesium is effective when given within different time frames within 24 hours after the SAH. METHODS: Patients were divided into categories according to the delay between symptom onset and start of the study medication: <6, 6 to 12, 12 to 24, and >24 hours. We calculated adjusted risk ratios with corresponding 95% confidence intervals for magnesium versus placebo treatment for poor outcome and DCI. RESULTS: We included 5 trials totaling 1981 patients; 83 patients started treatment<6 hours. For poor outcome, the adjusted risk ratios of magnesium treatment for start <6 hours were 1.44 (95% confidence interval, 0.83-2.51); for 6 to 12 hours 1.03 (0.65-1.63), for 12 to 24 hours 0.84 (0.65-1.09), and for >24 hours 1.06 (0.87-1.31), and for DCI, <6 hours 1.76 (0.68-4.58), for 6 to 12 hours 2.09 (0.99-4.39), for 12 to 24 hours 0.80 (0.56-1.16), and for >24 hours 1.08 (0.88-1.32). CONCLUSIONS: This meta-analysis suggests no beneficial effect of magnesium treatment on poor outcome or DCI when started early after SAH onset. Although the number of patients was small and a beneficial effect cannot be definitively excluded, we found no justification for a new trial with early magnesium treatment after SAH.

Validity of the NIHSS in predicting arterial occlusion in cerebral infarction is time-dependent.

BACKGROUND: The NIH Stroke Scale (NIHSS) is used to assess acute ischemic stroke severity and outcome. High NIHSS scores are usually associated with arterial occlusion but it is unknown what the effect of time to clinical evaluation (TTCE) in this association is. We tested the NIHSS scores as an instrument to determine vessel occlusion (VO) at different time points from symptom onset. METHODS: Patients were selected from our prospective stroke database if they had admission NIHSS scores and intracranial vessel neuroimaging studies. We dichotomized patients according to VO and TTCE. Receiver operating curves, c statistics, and odds ratios were calculated to study the validity of the NIHSS score. RESULTS: Among 463 patients (mean age 70.2 years, 53.1% male, median NIHSS 4, median TTCE 3.3 hours), 22.5% had arterial occlusion. Median NIHSS scores were higher in patients with VO, 10.5 (interquartile range 5-18) vs 3 (2-7), p<0.001, and in those with TTCE<6 hours, 15 (interquartile range 7-19) vs 4 (2-8) if ≥6 hours, p<0.001. Receiver operating characteristic curves showed that the validity of NIHSS in predicting VO was higher in patients with TTCE<6 hours, p=0.03. The best cutoff point in patients evaluated before 6 hours was an NIHSS of 7 (76.2% sensitivity, specificity 70.1%), while in patients evaluated after 6 hours the best cutoff point was 4 (sensitivity 65.4%, specificity 62.0%). CONCLUSIONS: Our study shows that the validity of NIHSS scores in predicting arterial occlusion is time-dependent, decreasing with increasing time from symptom onset to clinical evaluation.

[Neurological diagnostics in primary health care in Santiago, Chile]. / Diagnósticos neurológicos en la atención primaria de salud en Santiago, Chile.

INTRODUCTION: Neurological diseases are a growing concern for public health planners. The purpose of this study was to determine the burden of neurological diagnosis in a primary health care setting in the East Metropolitan Health Service in Santiago, Chile. PATIENTS AND METHODS: A random blocked sample of diagnosis in a one year period was obtained balanced by each of the fourteen clinics in the area. This corresponded to 3% of all visits. A total of 72 diagnosis corresponding to diseases of the nervous system were selected according to ICD 9 definitions. RESULTS: Of a total of 13,388 visits, 705 (5.3%) corresponded to disease or disorders attributable to the nervous system or that frequently mean consultation with neurologists. Of these, 63.5% were women. The highest rates were found between the second and fourth decades. The most frequent diagnosis were attention deficit disorder in children, headache in adults and spinal pain in the elderly. CONCLUSIONS: The demand for care for syndromes that affect the nervous system in the primary health care setting in a sample of visits is concentrated in chronic disease that require a multidisciplinary approach. The finding are similar to other studies. The data help in defining were to concentrate efforts in health planning and education for the care of neurological disorder in the primary care setting.

Consulting behaviour in migraine and tension-type headache sufferers: a population survey in Santiago, Chile.

Migraine and tension-type headaches are the most frequent types of headaches in Santiago. The purpose of this paper is to describe the patterns of health care utilization in migraine and compare them with tension-type headache sufferers in a community-based study of the prevalence of headache in Santiago, Chile. A two-step questionnaire was administered to an age- and gender-representative sample of 1540 eligible subjects who were aged 15 years or older. Of these, 1385 (89.9%) responded. Cases were defined according to the most frequent type of headache experienced in the last year. Migraine and tension-type headaches were diagnosed according to a questionnaire-based algorithm constructed using the IHS criteria. Consultation rates in migraneurs were significantly (P < 0.01) higher (63%) than in tension-type headache suffers (39%). Migraneurs were more likely to be female, younger and less educated, and had more severe attacks than those with tension-type headache. Female sex, younger age, fewer years of education in migraneurs and younger age and moderate or severe headache in tension-type headache sufferers were found to be independently associated with the likelihood of ever consulting, respectively. Migraneurs are more likely to consult than tension-type headache suffers in this population.

Effect of adenosine on cerebral blood flow velocity.

BACKGROUND AND PURPOSE: Evidence suggests that adenosine (ADN) is a potent vasodilator of cerebral vessels. However, the feasibility of manipulating human cerebral vascular resistance with ADN has not been assessed by means of TCD. The purpose of this study was to quantitatively estimate the change in middle cerebral artery cerebral blood flow velocity (CBFV) in response to intravenous ADN infusion in humans. METHODS: Eleven patients with subacute cerebrovascular events (ischemic stroke, transient ischemic attack, or hemorrhage) undergoing adenosine-thallium stress testing were studied before, during, and after ADN infusion to evaluate the effect of ADN on cerebral blood flow velocity. Continuous blood pressure (BP), heart rate (HR), respiration rate (RR), end-tidal CO2 (ET-CO2), and transcranial Doppler ultrasonography monitoring of CBFV and pulsatility index (PI) in both middle cerebral arteries were performed. RESULTS: The mean CBFVs were 65.4 +/- 19.2 cm/s before, 55.4 +/- 18.1 cm/s during, and 64.1 +/- 22.5 cm/s after ADN infusion, which represents a statistically significant decrease during ADN test compared with both baseline (P = .007) and posttest levels (P = .017). The PI was increased during the test (0.91 +/- 0.2) when compared with baseline (0.71 +/- 0.1) (P = .007). During ADN injection, mean HR increased (P = .004) and mean ET-CO2 levels decreased significantly (P = .003). Mean BP and RR did not change significantly. CONCLUSIONS: The authors hypothesize that any direct vasodilatory effect of ADN on the distal cerebral peripheral vasculature may be negated by an effect of ADN on depth of respiration resulting in hypocapnia and secondary distal vasoconstriction.

Epidemiology of tension-type headache in Santiago, Chile: a prevalence study.

OBJECTIVE: To describe the importance of tension-type headache (TTH) in Santiago, Chile, by analyzing its prevalence, clinical features, and impact by age, gender, and socioeconomic status, using widely accepted international diagnostic criteria. METHODS: In 1993, a representative sample of 1540 adults (older than 14) of the province of Santiago were interviewed using a standard questionnaire. A total of 1385 (89.9% response rate) subjects responded to the survey. Initially, a designated member of each household responded to the questionnaire. Subsequently, each household member with headache was asked to respond to questions about the severity, frequency, location, duration, associated symptoms, and impact in work and social activities of their most frequent headaches. TTH diagnoses were determined in accordance with the International Headache Society criteria of 1988. RESULTS: Total prevalence was found to be 26.9% (95% CI: 24.6-29.3%); 35.2% in females (95% CI: 31.7-38.8%) and 18.1% in males (95% CI: 15.2-21.3%). The prevalence of episodic TTH was 24.3% (95% CI: 22.1-26.7%) and of chronic TTH 2.6% (95% CI: 1.8-3.6%). Overall, and by subtype, prevalence was significantly higher in females (ratio 1:9). There was no significant variation in prevalence by socioeconomic or age group except in chronic TTH, in which there was an increase with age. CONCLUSIONS: TTH is a prevalent condition in a sample of adults of Santiago, similar to that reported in previous studies using similar methodologies. Overall, TTH represents 72.3% of all recurrent headaches.

Epidemiology of migraine headache in Santiago, Chile: a prevalence study.

OBJECTIVE: To describe the importance of migraine in Santiago, Chile, by analyzing its prevalence, clinical features and impact by age, gender and socioeconomic status. METHODS: In 1993, a representative sample of 1,540 adults of the province of Santiago were interviewed using a standard questionnaire. A total of 1,385 (89.9%) subjects responded to the survey. Initially, a designated member of each household responded to the questionnaire. Subsequently, each household member with headaches was asked to respond to questions about severity, frequency, location, duration, associated symptoms and impact in work and social activities of their most frequent headaches. Migraine diagnoses were determined in accordance with the International Headache Society (IHS) criteria of 1988. RESULTS: Recurrent headaches in the past year were found in 516 (36.82%) respondents, 145 (28.1%) males and 371 (71.9%) females. Total prevalence of migraine was found to be 7.3% (95% CI 5.9-8.6); 11.9% (95% CI 9.6-14.2) in females and 2.0% (95% CI 0.9-3.0) in males. Overall, migraine constituted 19.6% (101/516) of all headaches reported in this sample. The prevalence did not vary significantly by age groups or socioeconomic status (SES). Migraine with aura had an overall prevalence of 3.5% (CI 0.8-7.1), and was significantly more frequent in females. In 60-70% of cases the attacks lasted 2-6 h and the frequency was 3.3 and 3.4 per month in females and males respectively. Both males and females reported significantly high percentages of attacks during work. CONCLUSIONS: Migraine prevalence in a sample of adults of Santiago is similar to that reported in previous studies using IHS criteria. Women of all socioeconomic levels are at an increased risk.