Acta Neurochir DOI 10.1007/s00701-014-2339-7
EXPERIMENTAL RESEARCH - PEDIATRICS
Changes of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in the model of experimental acute hydrocephalus in rabbits Maxim A. Shevtsov & Konstantin A. Senkevich & Alexander V. Kim & Kseniia A. Gerasimova & Tatyana N. Trofimova & Galina V. Kataeva & Sviatoslav V. Medvedev & Olga I. Smirnova & Zhanna I. Savintseva & Marina G. Martynova & Olga A. Bystrova & Emil Pitkin & Galina Y. Yukina & William A. Khachatryan
Received: 21 October 2014 / Accepted: 27 December 2014 # Springer-Verlag Wien 2015
Abstract Background To study the integrity of white matter, we investigated the correlation between the changes in neuroradiological and morphological parameters in an animal model of acute obstructive hydrocephalus. Methods Hydrocephalus was induced in New Zealand rabbits (n=10) by stereotactic injection of kaolin into the
M. A. Shevtsov : A. V. Kim : K. A. Gerasimova : W. A. Khachatryan A.L. Polenov Russian Scientific Research Institute of Neurosurgery, 191014Mayakovsky str. 12, St. Petersburg, Russia K. A. Senkevich : G. Y. Yukina I.P. Pavlov State Medical University, 197022L. Tolstoi str. 6-8, St. Petersburg, Russia M. A. Shevtsov (*) : M. G. Martynova : O. A. Bystrova Institute of Cytology of the Russian Academy of Sciences (RAS), 194064Tikhoretsky Ave. 4, St. Petersburg, Russia e-mail: [email protected] T. N. Trofimova : G. V. Kataeva : S. V. Medvedev : O. I. Smirnova : Z. I. Savintseva N.P. Bechtereva Institute of the Human Brain of the Russian Academy of Sciences (RAS), 197376Akademika Pavlova str. 9, St. Petersburg, Russia E. Pitkin The Wharton School, University of Pennsylvania, 3730 Walnut St., Philadelphia, PA 19104, USA
lateral ventricles. Control animals received saline in place of kaolin (n=10). The progression of hydrocephalus was assessed using magnetic resonance imaging. Regional fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) were measured in several white matter regions before and after the infusion of kaolin. Morphology of myelinated nerve fibers as well as of the blood– brain barrier were studied with the help of transmission electron microscopy (TEM) and light microscopy. Results Compared with control animals, kaolin injection into the ventricles resulted in a dramatic increase in ventricular volume with compression of basal cisterns, brain shift and periventricular edema (as observed on magnetic resonance imaging [MRI]). The values of ADC in the periventricular and periaqueductal areas significantly increased in the experimental group (P < 0.05). FA decreased by a factor of 2 in the zones of periventricular, periaqueductal white matter and corpus collosum. Histological analysis demonstrated the impairment of the white matter and necrobiotic changes in the cortex. Microsctructural alterations of the myelin fibers were further proved with the help of TEM. Blood–brain barrier ultrastructure assessment showed the loss of its integrity. Conclusions The study demonstrated the correlation of the neuroradiological parameters with morphological changes. The abnormality of the FA and ADC parameters in the obstructive hydrocephalus represents a significant implication for the diagnostics and management of hydrocephalus in patients.
Acta Neurochir
Keywords Hydrocephalus . Magnetic resonance imaging . Fractional anisotropy . Apparent diffusion coefficient . White matter . Ventriculomegaly
characterization in vivo the anisotropic diffusion in white matter and subsequently compared the evaluated parameters with the electron and light microscopy data. Materials and methods Model of acute obstructive hydrocephalus Animals
Introduction Hydrocephalus represents a common and complex pathology caused by physical or functional obstruction of the cerebrospinal fluid (CSF) flow with an incidence rate of 1.1 in 1,000 infants [40]. Clinically hydrocephalus presents as progressive ventricular dilatation and is typically divided into noncommunicating and communicating subtypes [17]. Noncommunicating hydrocephalus results from the obstruction of the CSF pathways (e.g., tumor, arteriovenous malformation [AVM], etc.). Communicating hydrocephalus mostly occurs following subarachnoid hemorrhage and results from the impaired absorption of CSF at the level of the arachnoid granulations [8]. The predominant mode of hydrocephalus treatment constitutes a ventriculoperitoneal (VP) shunting, though other alternative surgical approaches (e.g., endoscopic ventriculostomy) exist [28, 29, 35, 36]. Several recent models of obstructive hydrocephalus were proposed in various animal species including mice, rats, cats, dogs, and sheep [1, 10, 11, 22–24, 37, 42]. In these models the authors mostly focused on the parameter of the ventricular size for characterization of the hydrocephalus and subsequent surgical treatment. At the same time, other characteristics including neuroradiological parameters are of high importance in the diagnosis and assessment of treatment efficacy of hydrocephalus. Thus, in a recent study of Eskandari et al. [16] in the model of kaolin-induced hydrocephalus in cats, it was shown that fraction anisotropy (FA) significantly decreased in the acute stage (
EXPERIMENTAL RESEARCH - PEDIATRICS
Changes of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in the model of experimental acute hydrocephalus in rabbits Maxim A. Shevtsov & Konstantin A. Senkevich & Alexander V. Kim & Kseniia A. Gerasimova & Tatyana N. Trofimova & Galina V. Kataeva & Sviatoslav V. Medvedev & Olga I. Smirnova & Zhanna I. Savintseva & Marina G. Martynova & Olga A. Bystrova & Emil Pitkin & Galina Y. Yukina & William A. Khachatryan
Received: 21 October 2014 / Accepted: 27 December 2014 # Springer-Verlag Wien 2015
Abstract Background To study the integrity of white matter, we investigated the correlation between the changes in neuroradiological and morphological parameters in an animal model of acute obstructive hydrocephalus. Methods Hydrocephalus was induced in New Zealand rabbits (n=10) by stereotactic injection of kaolin into the
M. A. Shevtsov : A. V. Kim : K. A. Gerasimova : W. A. Khachatryan A.L. Polenov Russian Scientific Research Institute of Neurosurgery, 191014Mayakovsky str. 12, St. Petersburg, Russia K. A. Senkevich : G. Y. Yukina I.P. Pavlov State Medical University, 197022L. Tolstoi str. 6-8, St. Petersburg, Russia M. A. Shevtsov (*) : M. G. Martynova : O. A. Bystrova Institute of Cytology of the Russian Academy of Sciences (RAS), 194064Tikhoretsky Ave. 4, St. Petersburg, Russia e-mail: [email protected] T. N. Trofimova : G. V. Kataeva : S. V. Medvedev : O. I. Smirnova : Z. I. Savintseva N.P. Bechtereva Institute of the Human Brain of the Russian Academy of Sciences (RAS), 197376Akademika Pavlova str. 9, St. Petersburg, Russia E. Pitkin The Wharton School, University of Pennsylvania, 3730 Walnut St., Philadelphia, PA 19104, USA
lateral ventricles. Control animals received saline in place of kaolin (n=10). The progression of hydrocephalus was assessed using magnetic resonance imaging. Regional fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) were measured in several white matter regions before and after the infusion of kaolin. Morphology of myelinated nerve fibers as well as of the blood– brain barrier were studied with the help of transmission electron microscopy (TEM) and light microscopy. Results Compared with control animals, kaolin injection into the ventricles resulted in a dramatic increase in ventricular volume with compression of basal cisterns, brain shift and periventricular edema (as observed on magnetic resonance imaging [MRI]). The values of ADC in the periventricular and periaqueductal areas significantly increased in the experimental group (P < 0.05). FA decreased by a factor of 2 in the zones of periventricular, periaqueductal white matter and corpus collosum. Histological analysis demonstrated the impairment of the white matter and necrobiotic changes in the cortex. Microsctructural alterations of the myelin fibers were further proved with the help of TEM. Blood–brain barrier ultrastructure assessment showed the loss of its integrity. Conclusions The study demonstrated the correlation of the neuroradiological parameters with morphological changes. The abnormality of the FA and ADC parameters in the obstructive hydrocephalus represents a significant implication for the diagnostics and management of hydrocephalus in patients.
Acta Neurochir
Keywords Hydrocephalus . Magnetic resonance imaging . Fractional anisotropy . Apparent diffusion coefficient . White matter . Ventriculomegaly
characterization in vivo the anisotropic diffusion in white matter and subsequently compared the evaluated parameters with the electron and light microscopy data. Materials and methods Model of acute obstructive hydrocephalus Animals
Introduction Hydrocephalus represents a common and complex pathology caused by physical or functional obstruction of the cerebrospinal fluid (CSF) flow with an incidence rate of 1.1 in 1,000 infants [40]. Clinically hydrocephalus presents as progressive ventricular dilatation and is typically divided into noncommunicating and communicating subtypes [17]. Noncommunicating hydrocephalus results from the obstruction of the CSF pathways (e.g., tumor, arteriovenous malformation [AVM], etc.). Communicating hydrocephalus mostly occurs following subarachnoid hemorrhage and results from the impaired absorption of CSF at the level of the arachnoid granulations [8]. The predominant mode of hydrocephalus treatment constitutes a ventriculoperitoneal (VP) shunting, though other alternative surgical approaches (e.g., endoscopic ventriculostomy) exist [28, 29, 35, 36]. Several recent models of obstructive hydrocephalus were proposed in various animal species including mice, rats, cats, dogs, and sheep [1, 10, 11, 22–24, 37, 42]. In these models the authors mostly focused on the parameter of the ventricular size for characterization of the hydrocephalus and subsequent surgical treatment. At the same time, other characteristics including neuroradiological parameters are of high importance in the diagnosis and assessment of treatment efficacy of hydrocephalus. Thus, in a recent study of Eskandari et al. [16] in the model of kaolin-induced hydrocephalus in cats, it was shown that fraction anisotropy (FA) significantly decreased in the acute stage (
