Intracranial Pressure Waveform and Hypertension

Abstract

Objective: Noninvasive intracranial pressure waveforms for estimation of intracranial hypertension have been previous validated and a P2/P1 ratio over 1,2 shows a good correlation with this damage. 1,2,3 In animal models, with induced hypertension, it has been observed a significative increase in P2/P1 ratio 2 weeks later. 4 Our objective, as a proof of concept, was to observe followed treated hypertensive patients concerning the rate of P2/P1 behavior. Design and method: The evaluation procedure of noninvasive intracranial pressure waveforms have been performed in 62 treated hypertensive patients with 7 minutes length. First and last minutes were discarded as well any test with poor quality wave signal at any moment. Data concerning systolic and diastolic blood pressure (BP) measured with OMRON automatic device HBP 1100 were obtained at the same moment as well the variables of age, body mass index (BMI), anti-hypertensive drugs and a history of diabetes (DM), stroke (ST) or myocardial infarction (MI). Descriptive statistics tests were used through the measurement of central tendency (mean), dispersion (standard deviation) and frequency (percentage). T Student and ANOVA as parametric tests and qui squared for categorical variables. Results: Data from 52 patients were validated. Mean age of 64,6 years, 63,5% female, BMI 28,4 +- 5,4 Kg/m2, 48,1% with diabetes. Mean systolic and diastolic office BP measurements of 141,6 +- 25,4 mmHg and 85,2 +- 14,7 mmHg respectively and 53,8% with controlled hypertension (systolic BP < 140 mmHg and diastolic BP < 90 mmHg). P2/P1 ratio over 1,2 has been found in 75% of the sample and there were no differences concerning controlled and non-controlled hypertension, number of anti-hypertensives drugs, or comorbidities as DM, ST or MI but at this moment we have to consider the small size of the sample to achieve enough power to detect these differences or correlations. Conclusions: The prevalence of 75% of P2/P1 ratio over 1,2 (equivalent to intracranial hypertension) deserves attention from scientific community since it raises a question about blood-brain barrier protection and can help to explain the huge association between hypertension and cerebrovascular diseases.