Аннотация:AbstractIntroduction: Cerebral autoregulation is an essential mechanism for maintaining cerebral blood flow stability. Thephenomenon of transtentorial intracranial pressure (ICP) gradient after neurosurgical operations, complicated byedema and intracranial hypertension in the posterior fossa, has been described in clinical practice but is still underinvestigated.The aim of the study was to compare autoregulation coefficients (i.e., pressure reactivity index [PRx]) intwo compartments (infratentorial and supratentorial) during the ICP gradient phenomenon.Methods: Three male patients, aged 24 years, 32 years, and 59 years, respectively, were involved in the study afterposterior fossa surgery. Arterial blood pressure and ICP were invasively monitored. Infratentorial ICP was measured inthe cerebellar parenchyma. Supratentorial ICP was measured either in the parenchyma of the cerebral hemispheresor through the external ventricular drainage. Cerebral autoregulation was evaluated by the PRx coefficient (ICM + ,Cambridge, UK).Results: In all patients, ICP was higher in the posterior fossa, and the transtentorial ICP gradient in each patient was5 ± 1.6 mm Hg, 8.5 ± 4.4 mm Hg, and 7.7 ± 2.2 mm Hg, respectively. ICP in the infratentorial space was 17 ± 4 mm Hg,18 ± 4.4 mm Hg, and 20 ± 4 mm Hg, respectively. PRx values in the supratentorial and infratentorial spaces had thesmallest difference (− 0.01, 0.02, and 0.01, respectively), and the limits of precision were 0.1, 0.2, and 0.1 in the first,second, and third patients, respectively. The correlation coefficient between the PRx values in the supratentorial andinfratentorial spaces for each patient was 0.98, 0.95, and 0.97, respectively.Conclusions: A high degree of correlation was established between the autoregulation coefficient PRx in two compartmentsin the presence of transtentorial ICP gradient and persistent intracranial hypertension in the posterior fossa.Cerebral autoregulation, according to the PRx coefficient in both spaces, was similar.Keywords: Cerebral autoregulation, Pressure reactivity, Fossa posterior, Transtentorial gradient, Intracranialhypertension, Gradient intracranial pressuredoi:10.1007/s12028-023-01696-3. Epub ahead of print. PMID: 36890339.
