Discriminant Analysis of Intracranial Volumetric Variables in Patients with Normal Pressure Hydrocephalus and Brain Atrophy.

A method was developed for the computerized volumetric assessment of the intracranial cerebrospinal fluid (CSF) distribution. The study involved 62 patients differentiated into two groups: with CSF resorption disorders (normal pressure hydrocephalus - 30 patients) and without CSF resorption disorders (various types of brain atrophy - 32 patients). The goal of the study was to ascertain whether the assessment, depending on the linear discriminant analysis of volumetric brain features, could be an effective tool differentiating the two groups. Volumetric measurements were performed using VisNow software. For each patient, five features were determined and subjected to discriminant analysis: CSF volume in the subarachnoid space and basal cisterns (SV), CSF volume in the intracranial ventricular system (VV), brain volume (BV), total intracranial CSF volume (FV), and total intracranial volume (TV). Discriminant analysis enables the achievement of a high percentage of correct classification of patients to the appropriate group determined on the result of a lumbar infusion test. The discriminator, based on three features: BV, SV, and VV, showed a complete separation of the groups; irrespective of age. The squared Mahalanobis distance was 70.8. The results confirmed the applicability of the volumetric method. Discriminant analysis seems a useful tool leading to the acquisition of a computer-aided method for the differential diagnosis of CSF resorption disorders.

[The usefulness of the evaluation of volumetric and posturographic parameters in the differential diagnosis of hydrocephalus]. / Przydatnosc oceny parametrów posturograficznych i wolumetrycznych w diagnostyce róznicowej wodoglowia.

INTRODUCTION: A variety of diagnostic methods in normal pressure hydrocephalus and brain atrophy, it testifies to the difficulties in contrast to both teams. Develop a safe diagnostic tool having comparable statistical accuracy of the infusion test results would be of great clinical significance. The chances of implementing such a procedure in clinical practice, it may be a combination of these syndromes in the functional assessment (Posturography) the assessment of morphological CNS (volumetric). THE AIM: To evaluate and summary of the results of two non-invasive diagnostic methods morphological (posturography) and functional (volumetric) with results that were obtained from tests infusion. MATERIAL AND METHODS: The evaluation of volumetric and posturographic research was conducted in 39 patients including 27 patients with brain atrophy (BA) and in 12 patients with hydrocephalus (NPH). Volumetric measurements were made using proprietary software VisNow. Posturographic measurements performed using manual posturograph Pro-Med. RESULTS: Both the volume of CSF obtained by volumetric assessment, as well as the values of the analyzed parameters posturographic, highly correlate with the results of resistance resorption (R). The BA radius values sway with eyes open and closed R_OZ R_OO were consistent with test results infusion of 100% in the NPH radius values showed 75% compliance with the test results infusion. Volumetric parameters: the volume of CSF contained in the subarachnoid space and basal cisterns (SV) and the volume of CSF system intracranial ventricular (VV) were found in both patients NPH and BA 100% compatible resorption resistance (R). CONCLUSIONS: Simultaneous use of two non-standard methods of non-invasive (posturographic and volumetric) in the diagnostic process is a proposal to recognize normal pressure hydrocephalus and brain atrophy non-invasive methods, while maintaining very high statistical significance.

Analysis of intracranial volume ratios by means of cerebrospinal fluid deployment indicators.

INTRODUCTION: Imaging studies make it possible not only to visualize the general structure of the brain but also to take precise measurements of brain tissue volume and the size of individual lobes and their structure. The aim of this study was to determine the ratio of cerebrospinal fluid (CSF) volume contained in the intracranial ventricular system to the brain tissue volume and the ratio of CSF volume in the subarachnoid space and basal cisterns to the brain tissue volume. MATERIAL AND METHODS: The evaluation of volumetric measurements of computed tomographic (CT) images was undertaken on 23 male and female patients (average age 56.9 ± 6.1) diagnosed with normal pressure hydrocephalus (NPH) and 27 male and female patients (average age 70.6 ± 5.2) diagnosed with brain atrophy (BA). In the CT imaging studies, the total brain tissue volume and CSF volume collected in the intracranial fluid cavities were mapped to a colour scale. The VisNow software was used for volumetric evaluation. The groups were compared by means of the non-parametric Kolmogorov-Smirnov test (K-S) for independent samples. Paired data were compared by means of the nonparametric Wilcoxon test. RESULTS: The volumes of brain (brain volume - BV) and cerebrospinal fluid (fluid volume - FV) differ greatly from each other in both groups BA and NPH. The SBR (subarachnoid space and basal cisterns-to-brain ratio) and VBR (ventricle-to-brain ratio) indicators differ significantly and very much within the NPH group as well as within the BA group. In the NPH group a clearly higher value of VBR can be observed in comparison with the BA group. There was a higher value of SBR in the BA than the NPH group. CONCLUSIONS: The simultaneous use of two indicators, VBR and SBR, on a study group of 50 patients enabled the total separation of NPH and BA groups. This differentiation can have real diagnostic value. Thus the volumetric assessment of the volume of CSF and brain tissue based on CT of the head can become an important part of the differential diagnosis of hydrocephalus and brain atrophy.

[Diffusion tensor imaging (DTI) in the differential diagnosis of normal pressure hydrocephalus and brain atrophy]. / Obrazowanie tensora dyfuzji (DTI) w diagnostyce róznicowej wodoglowia normotensyjnego i zaniku mózgu.

UNLABELLED: Clinical symptomatology of idiopathic normal pressure hydrocephalus, due to its overlap with dementias and neurodegenerative brain disorders, makes diagnosis challenging. As the neurological deficits are reversible there is a need for prompt and reliable noninvasive testing. The aim was to try to use and introduction into clinical practice of new non-invasive method--diffusion tensor imaging (DTI-Diffusion Tensor Imaging) discriminating patients classified as normal pressure hydrocephalus and patients diagnosed with brain atrophy. MATERIAL AND METHODS: Using magnetic resonance-diffusion tensor imaging, we examined white matter changes within the brains of patients diagnosed with idiopathic normal pressure hydrocephalus, cerebral atrophy and controls. Diffusion tensor brain images were obtained with 3Tesla and 1.5 Tesla MR-scanners. Fractional anisotropy brain maps were generated using a computer-automated method, and tract-based spatial statistics were then applied to compare the fractional anisotropy values in the clinical groups. The fractional anisotropy data were further investigated using region-of- interest analysis set within: fibre commissural the lateral ventricles (Fclv), forceps minor of corpus callosum (Fmin), cingulum (Cg), optic radiation (Orad), superior cerebellarpeduncle (Scp), substantia nigra (nucleus ruber) (Sn). RESULTS: Compared with the cerebral atrophy or control group, the FA values in the hydrocephalus group were significantly different in the posterior cingulate (Cg) and the forceps minor of the corpus callosum (Fmin). CONCLUSION: The pattern of white matter tracts changes in select brain regions distinguishes it from cerebral atrophy and control brains. Our pilot study adds to the body of knowledge advancing the understanding of the white matter pathology of idiopathic normal- pressure hydrocephalus.

Posturography in differential diagnosis of normal pressure hydrocephalus and brain atrophy.

Differentiation between normal pressure hydrocephalus (NPH) and brain atrophy is difficult in clinical practice. The purpose of this paper was to apply two advanced statistical, pattern recognition methods: discriminant analysis (DA) and k-nearest neighbour (K-NN) for the classification of NPH and atrophy patients to approach computer aided differential diagnosis. The classification is based on a few measures of the center of foot pressure (COP) movements (radius, area, and length). The posturography method gives a measure of current postural stability by a quantitative evaluation of postural sways. Measurements have been performed in the standing upright position in two conditions: with eyes open (EO) and closed (EC). The study comprises 18 patients (mean age 64 ±13 years) diagnosed as normal pressure hydrocephalus and qualifying for shunt implantation. The patients were evaluated by static posturography twice: before and after surgery. The NPH patients were compared with 36 atrophy patients (mean age 64±13 years) and 47 healthy persons (mean age 60 ±7 years). There were two basic dissimilarities in the NPH patients before surgery in comparison with the other groups: very large sways and their independence from vision. Over 90% of the NPH cases both before and after surgery were correctly classified. There also were over 90% of correctly classified patients if we compared the before surgery NPH and atrophy patients. Further posturographic measurements and data collection are needed to verify these results.

Posturography in differential diagnosis of patients with enlargement of brain ventricles.

BACKGROUND AND PURPOSE: This study aimed to quantitatively evaluate balance disturbances by means of static posturography in patients with enlargement of the ventricular system (Evans ratio > 0.3). MATERIAL AND METHODS: Fifty-four patients were diagnosed and treated in our Department of Neurosurgery. Thirty-six of them were qualified as patients with brain atrophy and 18 others were identified as patients with normal pressure hydrocephalus (NPH). Average sway radius and developed area of the posturogram were evaluated with eyes open and closed. These parameters constituted a base to calculate vision indices related to radius and area as a result of division of the difference of a given parameter (radius or area) measured with eyes closed and open by its corresponding sum. RESULTS: The sway range was significantly greater in patients with NPH in comparison to the control group. In NPH, there were no differences of sways observed with eyes open or closed - the vision indices were not statistically different from zero (vision index related to radius: -6.1 ± 18.9%, vision index related to area: -5.1 ± 34.7%). This may indicate no participation of sight in postural stability control. Values of the vision index related to radius (9.3 ± 19.4%) and to area (22.1 ± 28.2%) in the atrophy group significantly differed from zero, which indicated the participation of sight in postural stability control. CONCLUSIONS: Introduction of a new measure called the 'vision index' seems to be a promising clinical practice method of differentiation of hydrocephalus and brain atrophy.

[Posturography and computerized gait analysis in the Computer Dyno Graphy system as non-invasive methods for evaluation of normal pressure hydrocephalus progression]. / Badanie posturograficzne i komputerowa analiza chodu w systemie Computer Dyno Graphy jako nieinwazyjne metody oceny zaawansowania wodoglowia normotensyjnego.

Disturbances of gait and balance are important clinical problems in patients with normal pressure hydrocephalus. A considerable degree of locomotor disability and increased risk of falls are present in many cases. Accordingly, attempts to develop effective evaluation methods of gait and balance disturbances are made. Posturography and the Computer Dyno Graphy (CDG) system appear to be useful in diagnosis and evaluation of treatment in patients with normal pressure hydrocephalus. Both are non-invasive and repeatable methods that enable accurate evaluation of analyzed parameters at time intervals.

Gait disturbances in Computer Dyno Graphy examination in patients with normal pressure hydrocephalus before and after surgery.

BACKGROUND AND PURPOSE: Gait disturbances resulting from the normal pressure hydrocephalus (NPH) syndrome significantly restrain locomotion, which in serious cases can lead to a total loss of the ability to move. Hence the need to create an objective method of evaluating gait disturbances described by values of gait parameters and changes of these parameters resulting from neurosurgical treatment. The aim of this project is to create an effective, non-invasive diagnostics method describing movement disorders in patients with NPH before and after surgery. MATERIAL AND METHODS: An evaluation of the effectiveness of gait analysis was carried out with Ultraflex, which uses the Computer Dyno Graphy (CDG) system to measure the distribution of forces of reaction on the ground during walking. The control group consisted of 17 healthy individuals (age range 50-65 years) and the treatment group included 17 patients with enlargement of the ventricular system (9 females and 8 males, mean age 58.6 years, range 50-65 years), 8 of whom were qualified for surgical treatment. Analyzed parameters: ground reaction force, single and double support, stance. RESULTS: Changes of parameters reflected gait improvement. CONCLUSIONS: The results obtained indicate that gait analysis using the CDG system might be a good method for assessing the effectiveness of NPH surgery.