Moderate correlation between breath-holding and CO(2) inhalation/hyperventilation methods for transcranial doppler evaluation of cerebral vasoreactivity.

BACKGROUND: Both CO(2) inhalation followed by hyperventilation and breath-holding have been utilized to measure cerebral vasomotor reactivity (VMR) but their correlation has been poorly studied and understood. METHODS: A retrospective study was conducted in 143 subjects (62.6 ± 15.8 years old, 64% men) with transcranial Doppler ultrasonography measurement of mean flow velocity (MFV) at baseline, after 30 seconds of breath-holding, and after CO(2) inhalation followed by hyperventilation, in the left and right middle cerebral artery. Breath-holding index (BHI) was calculated as the percentage of MFV increase from baseline per second of apnea. CO(2) inhalation/hyperventilation index (CO(2) /HV) was calculated as the percentage of MFV difference between CO(2) inhalation and hyperventilation. RESULTS: There were 75 carotid arteries with >70% stenosis or occlusion, and 18 middle cerebral arteries with >50% stenosis or occlusion. The mean BHI was 0.93 ± 0.7 and 0.89 ± 0.6, whereas the mean CO(2) /HV was 61 ± 26% and 60 ± 26%, respectively, on the right and left sides. The correlation between BHI and CO(2) /HV was moderate on the right (r = 0.33; p < 0.01) and left sides (r = 0.38; p < 0.01). Multivariate linear regression analysis indicated that age (p = 0.01) and history of stroke (p = 0.007) were associated independently with an impaired VMR on the right as measured by CO(2) /HV. No predictors for impaired VMR by CO(2) /HV on the left and by BHI on either side were found. CONCLUSIONS: CO(2) /HV and BHI are only moderately correlated. Further studies are necessary to determine which method more accurately predicts clinical morbidity. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound 2012; Published online in Wiley Online Library.

Burden of stroke in Puerto Rico.

Stroke is the fifth leading cause of death and the first cause of long-term disability in Puerto Rico. Trained staff reviewed and independently validated the medical records of patients who had been hospitalized with possible stroke at any of the 20 largest hospitals located in Puerto Rico during 2007, 2009, and 2011. The mean age of the 5005 newly diagnosed stroke patients (51·2% female) was 70 years. At the time of hospitalization, women were 4½ years older, were less likely to be married (60·2% vs. 39·9%, P < 0·001), smoked less (5·8% vs. 13·4%, P < 0·001), and had significantly higher proportion of diabetes (56·0% vs. 54·8%), hypertension (89·1% vs. 85·0%), and low density lipoprotein-cholesterol (LDL-Chol) > 100 mg/dL (65·7% vs. 57·5%) P < 0·05. Ischemic stroke represented 75% of all types of strokes. Atrial fibrillation was mentioned in 7·9% of the medical records. The risk for dying before discharge was similar for both genders, but was 40% higher for women than for men at one-year follow-up: age-adjusted odds ratio = 1·4 (95% confidence interval = 1·2-1·5).

Hypotension and transient renal impairment induced by lumbar puncture.

INTRODUCTION: Raised intracranial pressure (ICP) may induce hypertension through sympathetic mechanisms. METHODS: Case report. RESULTS: A 55-year-old man was admitted with a symptomatic intracerebral mass and new refractory arterial hypertension. Several antihypertensive medications were necessary to control his blood pressure. A lumbar puncture was performed for diagnostic purposes and raised opening pressure (42 cm H2O) denoted raised ICP. After cerebrospinal fluid extraction, the closing pressure dropped to normal level. Shortly after the lumbar puncture, a sudden and pronounced drop in blood pressure was noted. Over the next day, the patient's serum creatinine rose from 0.9 to 1.9 mg/dL. Blood pressure normalized after discontinuation of all antihypertensive drugs and administration of intravenous fluids. Renal function also completely recovered within 2 days. The patient remained spontaneously normotensive thereafter. CONCLUSION: Sudden hypotension may occur after lumbar puncture in patients with raised ICP receiving treatment for arterial hypertension.