Evans Ratio Research Articles

The Effect of Hydrocephalus on the Optic Nerve in the Presence of Intracranial Mass

The measurement of optic nerve sheath diameter is a noninvasive, practical, and economical method used to identify increased intracranial pressure. The purpose of this study is to detect the preoperative and postoperative changes in optic nerve sheath diameter in patients with intracranial mass, to correlate these changes with optic nerve diameter variations, and to evaluate the impact of hydrocephalus on these alterations. This study was conducted with patients who presented to our clinic with complaints of intracranial mass, were decided for surgery, and underwent surgical procedures. The optic nerve and optic nerve sheath diameter measurement values were different preoperatively and postoperatively, with a significant decrease in the optic nerve sheath diameter in all groups in postoperative measurements, while the optic nerve diameter significantly increased. Although there was no significant difference between the effects of hydrocephalus and intracranial mass-related increase in intracranial pressure on the optic nerve and optic nerve sheath, it was observed that hydrocephalus increased intracranial pressure when considering the Evans ratio. It has been determined that as ventricular dilatation increases, so does intracranial pressure, which leads to an increase in the diameter of the optic nerve sheath, resulting in papilledema and thinning of the optic nerve. These findings indicate the importance of early cerebrospinal fluid diversion and monitoring optic nerve sheath diameter in the management.

Microcirculatory Impairment and Cerebral Injury in Hydrocephalus and the Effects of Cerebrospinal Fluid Diversion.

Hydrocephalus is characterized by progressive enlargement of cerebral ventricles, resulting in impaired microvasculature and cerebral hypoperfusion. This study aimed to demonstrate the microvascular changes in hydrocephalic rats and the effects of cerebrospinal fluid (CSF) release on cerebral blood flow (CBF). On postnatal day 21 (P21), male Wistar rats were intracisternally injected with either a kaolin suspension or saline. On P47, Evan's ratio (ER) was measured using MRI. On P49, the arteriolar diameter and vascular density of the pia were quantified using a capillary video microscope. The CBF was measured using laser Doppler flowmetry. The expressions of NeuN and glial fibrillary acidic protein determined by immunochemical staining were correlated with the ER. The CBF and rotarod test performance were recorded before and after CSF release. The expressions of 4-hydroxynonenal (4-HNE) and c-caspase-3 were studied on P56. Ventriculomegaly was induced to varying degrees, resulting in the stretching and abnormal narrowing of pial arterioles, which regressed with increasing ER. Quantitative analysis revealed significant decreases in the arteriolar diameter and vascular density in the hydrocephalic group compared with those in the control group. In addition, the CBF in the hydrocephalic group decreased to 30%-50% of that in the control group. In hydrocephalus, the neurons appear distorted, and the expression of 4-HNE and reactive astrogliosis increase in the cortex. After CSF was released, improvements in the CBF and rotarod test performance were inversely associated with the ER. In addition, the levels of 4-HNE and c-caspase-3 were further elevated. Rapid ventricular dilatation is associated with severe microvascular distortion, vascular regression, cortical hypoperfusion, and cellular changes that impair the recovery of CBF and motor function after CSF release. Moreover, CSF release may induce reperfusion injury. This pathophysiology should be taken into account when treating hydrocephalus.

Correlation between smoking and brain atrophy detected by cross sectional imaging

Background and objectives: Smoking have effect on many organs in human body, we are focusing on its relation with brain atrophy. We aimed to determine whether there is an association between smoking and brain atrophy by using certain parameters from CT scan or MRI of brain. Methods: This is a case control study done from December 2019 to May 2021, a total of 100 cases of CT scans and MRI brain which is randomly selected reviewed by taking certain measurements like frontal horn index, Evans ratio, bicaudate index, huckman number, cella media. Results: Brain atrophy group involved 50 cases and control non-atrophy group 50 cases both group with equal number of male and female, there is statistically significant difference between smokers with brain atrophy 30% and smokers with no brain atrophy 6% with p-value 0.027, also the mean duration of smoking among brain atrophy was 17.83 years while among non-atrophic brain was 9.83 years. Number of cigarettes smoked per day showed statistically significant difference as it was 21.07 cigarettes among smokers with brain atrophy versus 13.83 cigarettes in non –brain atrophy smokers. Conclusions: Current brain imaging demonstrate that chronic tobacco smoking is associated with significant increase in prevalence of brain atrophy than non-smokers, smoking can be considered a risk factor for brain atrophy.

Ratios of head circumference to ventricular size vary over time and predict eventual need for CSF diversion in intraventricular hemorrhage of prematurity.

Intraventricular hemorrhage (IVH) of prematurity can lead to hydrocephalus, sometimes necessitating permanent cerebrospinal fluid (CSF) diversion. We sought to characterize the relationship between head circumference (HC) and ventricular size in IVH over time to evaluate the clinical utility of serial HC measurements as a metric in determining the need for CSF diversion. We included preterm infants with IVH born between January 2000 and May 2020. Three measures of ventricular size were obtained: ventricular index (VI), Evan's ratio (ER), and frontal occipital head ratio (FOHR). The Pearson correlations (r) between the initial (at birth) paired measurements of HC and ventricular size were reported. Multivariable longitudinal regression models were fit to examine the HC:ventricle size ratio, adjusting for the age of the infant, IVH grade (I/II vs. III/IV), need for CSF diversion, and sex. A total of 639 patients with an average gestational age of 27.5weeks were included. IVH grade I/II and grade III/IV patients had a positive correlation between initial HC and VI (r = 0.47, p < 0.001 and r = 0.48, p < 0.001, respectively). In our longitudinal models, patients with a low-grade IVH (I/II) had an HC:VI ratio 0.52 higher than those with a high-grade IVH (p-value < 0.001). Patients with low-grade IVH had an HC:ER ratio 12.94 higher than those with high-grade IVH (p-value < 0.001). Patients with low-grade IVH had a HC:FOHR ratio 12.91 higher than those with high-grade IVH (p-value < 0.001). Infants who did not require CSF diversion had an HC:VI ratio 0.47 higher than those who eventually did (p < 0.001). Infants without CSF diversion had an HC:ER ratio 16.53 higher than those who received CSF diversion (p < 0.001). Infants without CSF diversion had an HC:FOHR ratio 15.45 higher than those who received CSF diversion (95% CI (11.34, 19.56), p < 0.001). There is a significant difference in the ratio of HC:VI, HC:ER, and HC:FOHR size between patients with high-grade IVH and low-grade IVH. Likewise, there is a significant difference in HC:VI, HC:ER, and HC:FOHR between those who did and did not have CSF diversion. The routine assessments of both head circumference and ventricle size by ultrasound are important clinical tools in infants with IVH of prematurity.

Computerised tomography brain findings in male patients with alcohol dependence syndrome: A hospital based cross sectional study

ABSTRACT Background: Alcohol dependence syndrome (ADS) is a set of mental, emotional and physiological effects of drinking alcohol daily. This study aimed to assess the computerised tomography (CT) brain findings in patients with ADS and to compare it with age-matched controls. Aims: To study the relationship of CT-Brain findings in Male patients with alcohol dependence syndrome and compare it with controls. Materials and Methods: This retrospective study was carried out after obtaining clearance from the institution’s ethics committee between 1 January 2021 and April 2022. Medical records of 64 patients were examined, of which 32 patients with the diagnosis of ADS who had already undergone CT brain Neuroimaging and 32 age- and sex-matched normal controls, were randomly selected and parameters were compared to look at cortical atrophy, cella media index (CMI), the maximum width of the third, fourth ventricle, frontal subarachnoid space, Evans ratio, the maximum width of the anterior interhemispheric fissure and maximum width of the Sylvian fissure (MSF). Results: The study detected that the mean age of cases was 41.96 years, and in controls, it was 40.91 years with no significant difference. There was a significant difference in the mean level of CMI, the maximum width of the third and fourth ventricle, frontal subarachnoid space, the maximum width of the anterior hemispheric fissure and the MSF amongst the cases compared to controls. Conclusion: Compared to controls, there was a significant change in CT brain findings amongst the ADS patients.

Brain and craniovertebral junction in patients with achondroplasia using low dose dynamic computed tomography

Purpose: To describe the brain and craniovertebral junction (CVJ) in achondroplasia by dynamic low dose computed tomography (CT). Methods: This paper documents a cross-sectional retrospective study performed between 1998 and 2013. The Ethics and Research Committee approved the project. The investigators reviewed the medical records of 440 patients with skeletal dysplasia and performed flexion-extension CT for 24 patients with achondroplasia confirmed by molecular testing. They were divided in two groups: children younger than eight years old and group 2 with older individuals. Normal scans were selected as controls in proportion 1:4. Three measurements were made by two radiologists using the following parameters: Evans Ratio, cerebroventricular index of the anterior horns and maximum width of the third ventricle; diameters of the foramen magnum (FM), width of the spinal canal, clivus size, basion-axial interval, atlantooccipital interval and Powers ratio, atlantodental interval, distance of the dens tip position above McGregor line and Welcher angle. T-test, Kruskal-Wallis and Fisher statistics were used. P-value&lt;0.05 threshold was considered for statistical significance. Results: The ventricles were greater, and the FM was smaller in achondroplastic patients than in controls scans (p&lt;0.01). Other findings were: ventriculomegaly (30%), hydrocephalus (4%), narrowing of FM (between 96% and 100%), spinal stenosis (92%), clivus hypoplasia (88%), atlantooccipital instability (25%), atlantoaxial instability (13 %), basilar invagination (13%) and platybasia (8%). There was no upper cervical compressive myelopathy. There was no difference of CVJ changes between the groups 1 and 2 (p&gt;0.09). Conclusion: The craniometry showed the most frequent cerebral and CVJ changes in achondroplasia.

The semi-sitting position in patients with indwelling CSF shunts: perioperative management and avoidance of complications

ObjectivePosterior fossa or midline tumors are often associated with hydrocephalus and primary tumor removal with or without perioperative placement of an external ventricular drain (EVD) is commonly accepted as first-line treatment. Shunting prior to posterior fossa surgery (PFS) is mostly reserved for symptomatic cases or special circumstances. There are limited data regarding the anticipated risk for symptomatic pneumocephalus and the perioperative management using the semi-sitting position (SSP) in such a scenario. Here, we therefore assessed the safety of performing PFS in a consecutive series of patients over a period of 15 years to allow the elaboration of recommendations for perioperative management.MethodsAccording to specific inclusion and exclusion criteria a total of 13 patients who underwent 17 operations was identified. Supratentorial pneumocephalus was evaluated with semiautomatic-volumetric segmentation. The volume of pneumocephalus was evaluated according to age and ventricular size.ResultsTen of the 13 patients had a programmable valve (preoperative valve setting range 6–14 cmH20; mean 7.5 cmH20) while 3 patients had non programmable valves. A variable amount of supratentorial air collection was evident in all patients postoperatively (range 3.2–331 ml; mean 122.32 ml). Positive predictors for the volume of postoperative pneumocephalus were higher age and a preoperative Evans ratio > 0.3. In our series, we encountered no cases of tension pneumocephalus necessitating an air replacement procedure as well as no obstruction, disconnection, infection or hardware malfunction of the shunt system.ConclusionsOur findings indicate that a CSF shunt in situ is not a contraindication for performing PFS in the semi-sitting position and it does not increase the pre-existing risk for postoperative tension pneumocephalus. In cases of primary shunting for hydrocephalus associated with posterior fossa tumors a programmable valve set at a medium opening pressure with a gravitational device is a valid option when PFS in the semi-sitting position is opted. In patients with an indwelling shunt diversion system special caution is indicated in order to prevent and detect overdrainage especially in not adjustable valves or shunts without antisiphon devices.

Cerebral Infarction and Evan's Ratio on MRI Affect the Severity and Prognosis of Tuberculosis Meningitis Patients.

Background: Magnetic resonance imaging (MRI) is widely used in the diagnosis of tuberculous meningitis (TBM) and its complications. We aimed to explore the relationship between MRI features and neurological deficits and TBM patients’ prognosis. Methods: patients diagnosed with TBM were subjected to a neurological evaluation on admission and divided into groups based on the Medical Research Council (MRC) scale. After several years of follow-up, the patients were further divided into groups according to the Modified Rankin Score (MRS). Their MR images were analyzed for meningeal enhancement, tuberculomas, infarction, hydrocephalus, and abscess, including the location and size of the lesion. Any changes in MRI features during the follow-up were recorded. MRI features between groups were compared, and the relationship between dynamic changes in images and Rankin grading was explored. Results: We found significant differences in acute cerebral infarction (ACI) and old cerebral infarctions (OCI) between the MRC groups, and the ORs of ACI and OCI were 21.818 (95% CI: 2.440–195.075) and 6.788 (95% CI: 1.516–30.392), respectively. There were significant differences in ACI, OCI, and Evan’s ratio between the MRS groups (p < 0.05), and the ORs of ACI, OCI, and hydrocephalus were 6.375 (95% CI: 1.501–27.080), 5.556 (95% CI: 1.332–23.177), and 9.139 (95% CI: 2.052–40.700), respectively. The changes of Evan’s ratio were related to the MRS grading (r = 0.335, p = 0.040). Conclusions: For patients with TBM, the presence of ACI or OCI is associated with neurological deficits, and ACI, OCI, and hydrocephalus can be regarded as poor prognostic predictors. Changes in Evan’s ratio will affect the outcome.

Periventricular hypodensity is associated with the incidence of pre-shunt seizure in hydrocephalic children.

The seizure incidence in hydrocephalic children has been acknowledged in a lot of studies previously; nonetheless, seizure pathogenesis in these children remains unclear. Its high proportion of hydrocephalic children who underwent shunt surgery suggests that the seizure might be associated with the protocol of shunt placement and/or the shunt existence intracranially; however, this hypothesis could not explain the pre-shunt seizure incidence in hydrocephalic children. This study aims to evaluate the patients' characteristics and CT findings in pre-shunt hydrocephalic children to identify the possible seizure etiology in these patients. Three hundred and thirty-four children with hydrocephalus were included in this study, including 147 hydrocephalic children with the pre-shunt seizure history and 187 hydrocephalic children presented without the pre-shunt seizure history. The following information was retrieved from the patients' medical records: gender, age, pediatric Glasgow Coma Scale (pGCS) upon admission, and hydrocephalus diagnoses. CT findings were re-evaluated to assess the compression association of sulci and gyri, Sylvian fissures, cisterns, FH/ID ratio, Evan's ratio, and periventricular hypodensity with pre-shunt seizure. The results show that the pre-shunt seizure incidence is significantly higher in hydrocephalic children aged 1 to 5years old (63/113 (55%), p = 0.0001), diagnosed with communicating hydrocephalus (97/163 (59%), p = 0.0001) or infectious hydrocephalus (80/109 (73%), p = 0.0001). The presence of periventricular hypodensity is significantly associated with the pre-shunt seizure incidence (132/205 (64.3%), p = 0.0001). Results from univariate analyses suggest significant association between periventricular hypodensity in every location and pre-shunt seizure (p < 0.0001). Multivariate analyses identify that temporal horn in the right lateral ventricle as the location of periventricular hypodensity has the strongest association with the pre-shunt seizure. The presence of periventricular hypodensity in head CT scan is significantly associated with the pre-shunt seizure incidence. Further investigation to confirm this finding and evaluate the possible roles of inflammation in the pre-shunt seizure in hydrocephalic children is important to seek its possible implication on the treatment of pre-shunt seizure in these children.

Study of Normal Values of Evan’s Index on Brain CT Scan in Individuals attending Nepal Medical College Teaching Hospital, Kathmandu, Nepal

Ventriculographic indices are obtained by using Evan’s Index. Evan’s Index is a ratio which compares the maximum width of the frontal horns of the lateral ventricle to the maximum transverse diameter of the inner table of the skull and serves as an indirect marker of ventricular volume. Evan’s Index has been extensively used in the diagnosis of idiopathic normal pressure hydrocephalus, in the assessment of outcome of patients having shunt placement which is the primary mode of treatment. This study was aimed to find out the normal values of Evan’s Index on brain CT scan in individuals attending Nepal medical college teaching hospital, Kathmandu, Nepal. A total of 500 individuals CT (250 males and 250 females) were finally selected. The ages were ranged between 5 to 80 years old. The mean Evan’s Index in the studied population was 0.253 ± 0.037 in males, 0.250 ± 0.034 in the females and an overall mean of 0.251 ± 0.035. There was no significant statistical difference in the Evans ratio between male and females (P = 0.274). This study shows that Evan’s Index was higher in individuals who were 60 years and above in both males and females. The very small standard deviations appreciated in the result suggest that Evan’s index can be calculated fairly accurately.

Treatment Outcome of Hydrocephalus Associated with Vestibular Schwannoma.

Background and PurposeManaging hydrocephalus in patients with vestibular schwannoma (VS) is controversial. We evaluated the clinical factors associated with hydrocephalus.MethodsBetween 2000 and 2019, 562 patients with VS were treated at our institute. We applied endoscopic third ventriculostomy (ETV), external ventricular drainage (EVD), and ventriculoperitoneal (VP) shunts to patients with hydrocephalus. The relationships of patient, tumor, and surgical variables with the hydrocephalus outcome were assessed.ResultsPreoperative hydrocephalus (Evans ratio ≥0.3) was present in 128 patients. Six patients who received a preresectional VP shunt were excluded after analyzing the hydrocephalus outcome. Seven of the remaining 122 patients had severe hydrocephalus (Evans ratio ≥0.4). Primary tumor resection, VP shunting, ETV, and EVD were performed in 60, 6, 57, and 5 patients, respectively. The hydrocephalus treatment failure rate was highest in the EVD group. Persistent hydrocephalus was present in five (8%) and seven (12%) patients in the primary resection and ETV groups, respectively. Multivariate analysis revealed that severe hydrocephalus, the cystic tumor, and the extent of resection (subtotal resection or partial resection) were associated with hydrocephalus treatment failure.ConclusionsLarger ventricles and a higher cystic portion are predictive of persistent hydrocephalus. We recommend attempting near-total tumor resection in patients with VS.

Acute Management of Gamma Knife Radiosurgery for Asymptomatic Obstructive Hydrocephalus Associated with Posterior Fossa Metastases

We retrospectively assessed the effectiveness and safety of Gamma Knife radiosurgery (GKRS) for asymptomatic obstructive hydrocephalus associated with posterior fossa metastases, which was known empirically but not well discussed. We reviewed the medical records of 27 patients who underwent GKRS for asymptomatic obstructive hydrocephalus related to posterior fossa metastases. Cumulative control rates of hydrocephalus were 11.1%, 51.9%, 70.4%, and 74.6% at 1, 2, 3, and 6 months after GKRS. Primary gastrointestinal tract cancer (P= 0.001) was significantly correlated with unfavorable management. Evans ratio at GKRS (median 0.31) improved significantly compared with that at 1-3 months after GKRS (median 0.26) (P < 0.0001) and maintained at 6 to 12 months. Cumulative local tumor control rates were 91.7%, 70.8%, and 64.4% at 3, 6, and 12 months after GKRS. Primary gastrointestinal tract cancer (P= 0.018) and no conventional systemic agents (P= 0.027) were significantly correlated with unfavorable control. Cumulative incidence rates of adverse radiation effects were 0.0%, 16.7%, and 24.2% at 6, 9, and 12 months after GKRS. Primary gastrointestinal tract cancer (P < 0.0001) and single and 2- or 3-fraction GKRS (P < 0.0001) were significantly correlated with unfavorable outcomes. All but 1 patient avoided surgical procedure for hydrocephalus after GKRS. The present findings suggest that GKRS is an effective and safe treatment for asymptomatic obstructive hydrocephalus caused by posterior fossa metastases, and all but 1 could avoid invasive surgical procedures for hydrocephalus. Posterior fossa metastases from gastrointestinal tract cancer resulted in unsatisfactory outcomes for control of hydrocephalus, tumor progression, and adverse radiation effects.

Improvement in ventriculomegaly following cervicomedullary decompressive surgery in children with achondroplasia and foramen magnum stenosis.

The role of cervicomedullary decompression (CMD) in the care of hydrocephalic achondroplastic children who present with simultaneous foramen magnum stenosis is not well understood. We sought to determine the percentage of symptomatic achondroplastic children with foramen magnum stenosis who had stabilization or improvement in ventriculomegaly following CMD. The authors retrospectively reviewed the records of pediatric patients at Cedars-Sinai Medical Center with achondroplasia and signs of progressive ventriculomegaly who underwent CMD for symptomatic foramen magnum stenosis between the years 2000 and 2018. Clinical outcomes included changes in fontanelle characteristics, head circumference (HC) percentile, and incidence of ventriculoperitoneal (VP) shunting. Radiographic outcomes measured included changes in Evans ratio. We excluded individuals who were shunted before CMD from our study. Sixteen children presented with symptomatic foramen magnum stenosis and full anterior fontanelle or jump in the HC percentiles. Two children underwent placement of a VP shunt before decompressive surgery and were excluded from further analysis. Of the remaining 14 children who underwent CMD, 13 (93%) showed softening or flattening of their fontanelles post-operatively. Ten of these 14 children had both pre- and post-operative HC percentile records available, with 8 showing increasing HC percentiles before surgery. Seven of those eight children (88%) showed a deceleration or stabilization of HC growth velocity following decompression of the foramen magnum. Among 10 children with available pre- and post-operative brain imaging, ventricular size improved in 5 (50%), stabilized in 2 (20%), and slightly increased in 3 (30%) children after decompression. Two children (14%) required a shunt despite decompression of the foramen magnum. A significant proportion of children with concomitant signs of raised intracranial pressure or findings of progressive ventriculomegaly and foramen magnum stenosis may have improvement or stabilization of these findings following CMD. CMD may decrease the need for VP shunting and its associated complications in the select group of hydrocephalic children with achondroplasia presenting with symptomatic foramen magnum stenosis.

Freehand Insertion of External Ventricular Drainage Catheter: Evaluation of Accuracy in a Single Center.

Introduction:External ventricular drain (EVD) placement is the gold standard for managing acute hydrocephalus. Freehand EVD, using surface anatomical landmarks, is performed for ventricular cannulation due to its simplicity and efficiency. This study evaluates accuracy and reason(s) for misplacements as few studies have analyzed the accuracy of freehand EVD insertion.Patients and Methods:Preoperative and postoperative computed tomography scans of patients who underwent EVD insertion in 2014 were retrospectively reviewed. Diagnosis, Evans ratio, midline shift, position of burr hole, length of the catheter, and procedural complications were tabulated. The procedures were classified as satisfactory (catheter tip in the frontal horn ipsilateral lateral ventricle) and unsatisfactory. Unsatisfactory cases were further analyzed in relation to position of burr hole from midline and length of the catheter.Results:Seventy-seven EVD placements in seventy patients were evaluated. The mean age of the patients was 57.5 years. About 83.1% were satisfactory placements and 11.7% were unsatisfactory in the contralateral ventricle, corpus callosum, and interhemispheric fissure. Nearly 5.2% were in extraventricular locations. Almost 2.6% EVD placements were complicated by hemorrhage and 1 catheter was reinserted. Suboptimal placements were significantly associated with longer intracranial catheter length. The mean length was 66.54 ± 10.1 mm in unsatisfactory placements compared to 58.32 ± 4.85 mm in satisfactory placements. Between the two groups, no significant difference was observed in Evans ratio, midline shift, surgeon's experience, distance of burr hole from midline, and coronal suture.Conclusion:Freehand EVD insertion is safe and accurate. In small number of cases, unsatisfactory placement is related to longer catheter length.

A preliminary exploration of acute intracranial pressure-cerebrospinal fluid production relationships in experimental hydrocephalus.

CONTEXT:By occluding the fourth ventricle simultaneously obtaining telemetric data on intracranial pressure (ICP) and cerebrospinal fluid (CSF) production, the authors of this study investigate a variety of physiologic parameters in cases of experimental hydrocephalus.AIMS:The aim of this study is to provide a new context on the disrupted homeostasis in hydrocephalus and guide toward improved treatment based on multiple physiological parameters.MATERIALS AND METHODS:Hydrocephalus was induced in ten 21-day-old Sprague–Dawley rats by blocking the flow of CSF to the fourth ventricle with kaolin. Ten days post induction, when physical signs of ventriculomegaly reached Evan's ratio (ER) of ≥0.46, CSF flow and ICP were measured while manipulating body position (0°, 45°, 90°) and heart rate.RESULTS:In hydrocephalic animals (ER ≥0.46), we found a near-steady average acute ICP (13.638 ± 2.331) compared to age-matched controls (ER <0.30) (13.068 ± 8.781), whose ICP fluctuated with the position. Hydrocephalic and controls exhibited an insignificant degree of parabolic shifts in CSF production when body position was changed from prone to 90° and again when moved back to the prone position, a trend more noteworthy in controls (P = 0.1322 and 0.2772). A Pearson's Correlation found CSF production and ICP to be correlated at baseline 0° posture (P = 0.05) in the control group, but not the hydrocephalic group. Weight appeared to play a role when animals were held at 90°. No significant changes in ICP or CSF flow patterns were observed when the heart rate was increased within either group.CONCLUSIONS:These preliminary findings suggest that our standard assumptions of posture-dependent changes in ICP created using data from physiologic data may be inaccurate in the hydrocephalic patient, and thus describe a need to further explore these relationships.

Incidence, diagnostic criteria and outcome following ventriculoperitoneal shunting of idiopathic normal pressure hydrocephalus in a memory clinic population: a prospective observational cross-sectional and cohort study

ObjectiveTo evaluate diagnostic criteria for idiopathic normal pressure hydrocephalus (INPH) among patients with memory impairment, and to estimate the incidence of INPH.DesignProspective observational cross-section and cohort study of diagnostic accuracy.SettingMemory...

Comparison of morphometric parameters in prediction of hydrocephalus using random forests

Ventricles of the human brain enlarge with aging, neurodegenerative diseases, intrinsic, and extrinsic pathologies. The morphometric examination of neuroimages is an effective approach to assess structural changes occurring due to diseases such as hydrocephalus. In this study, we explored the effectiveness of commonly used morphological parameters in hydrocephalus diagnosis. For this purpose, the effect of six common morphometric parameters; Frontal Horns' Length (FHL), Maximum Lateral Length (MLL), Biparietal Diameter (BPD), Evans' Ratio (ER), Cella Media Ratio (CMR), and Frontal Horns’ Ratio (FHR) were compared in terms of their importance in predicting hydrocephalus using a Random Forest classifier. The experimental results demonstrated that hydrocephalus can be detected with 91.46 % accuracy using all of these measurements. The accuracy of classification using only CMR and FHL reached up to 93.33 %. In terms of individual performances, CMR and FHL were the top performers whereas BPD and FHR did not contribute as much to the overall accuracy.

Relationships between Head Circumference Percentile, Lumbar Puncture Pressure, and Cerebrospinal Fluid Space in Young Children: Increased Cerebrospinal Space and Pressure May Result in Compensatory Enlargement of Head Circumference Only in the Infant Period

Background: The aim of this study was to retrospectively evaluate and analyze the relationships between head circumference percentile (HCP), lumbar puncture pressure (LPP), and cerebrospinal fluid (CSF) space. Methods: The 88 patients were divided into 3 age groups (group 1, up to 12 months; group 2, 12–36 months; group 3, 36–72 months). Results: In group 1 (n = 40), there was a significant positive correlation of the HCP with the LPP (r =0.414, p =0.008), Evans ratio (r =0.365, p =0.021), and thickness of subdural hygroma (SDHG; r =0.403, p =0.010). Group 2 (n = 29) revealed a significant positive correlation between the LPP and the thickness of SDHG (r =0.459, p =0.012). Group 3 (n = 19) showed no significant correlation among these factors. Overall, age was related with SDHG thickness both in infants and toddlers, while HCP was related with LPP, Evans ratio, and SDHG thickness only in infants, and LPP was related with SDHG thickness only in toddlers. Conclusion: We suggest that increased cerebrospinal space and pressure may result in compensatory enlargement of head circumference only in the infant period, and the SDHG thickness decreases with age during the infant and toddler phases.

Freehand Insertion of External Ventricular Drainage Catheter–Evaluation of Accuracy in a Single Centre

Abstract INTRODUCTION External ventricular drain (EVD) placement is the gold standard for managing acute hydrocephalus. Freehand EVD, using surface anatomical landmarks is performed for ventricular cannulation due to its simplicity and efficiency. This study evaluates accuracy and reason(s) for misplacements as few studies have analyzed the accuracy of freehand EVD insertion. METHODS Preoperative and postoperative computed tomography (CT) scans of patients who underwent EVD insertion in 2014 were retrospectively reviewed. Diagnosis, Evan's ratio, midline shift, position of burr hole, length of the catheter and procedural complications were tabulated. The procedures were classified as satisfactory (catheter tip in the frontal horn ipsilateral lateral ventricle) and unsatisfactory. Unsatisfactory cases were further analyzed in relation to position of burr hole from midline and length of the catheter. RESULTS A total of 77 EVD placements in 70 patients were evaluated. Mean age of the patients was 57.5 yr. About 83.1% were satisfactory placements and 11.7% were unsatisfactory in the contralateral ventricle, corpus callosum and interhemispheric fissure. About 5.2% were in extra ventricular locations. About 2.6% EVD placements were complicated by hemorrhage and 1 catheter was reinserted. Suboptimal placements were significantly associated with longer intracranial catheter length. The mean length was 66.54 ± 10.1 mm in unsatisfactory placements compared to 58.32 ± 4.85 mm in satisfactory placements. Between the 2 groups, no significant difference was observed in Evan's ratio, midline shift, surgeon's experience, distance of burr hole from midline and coronal suture. CONCLUSION Freehand EVD insertion is safe and accurate. In small number of cases, unsatisfactory placement is related to longer catheter length.

Morphometric analysis of lateral and third ventricles by computerized tomography for early diagnosis of hydrocephalus

IntroductionBrain ventricles are dilated with accumulation of excess cerebrospinal fluid in it, which can cause the pressure damage to the surrounding structures. This study aims to highlight the reference range values for lateral and third ventricles of brain for easy diagnosis and management of hydrocephalic patients. Material and methodsWe calculated the frontal horn ratio(FHR), bi- caudate ratio(BCR), Evan’s ratio(ER), cella media ratio(CMR), bi-frontal index(BFI), bi- occipital index(BOI), third ventricle width(TVW), third ventricle sylvian fissure ratio index (TSFI), and third ventricle ratio (TVR) in 120 apparently normal CT-Head images and forty hydrocephalic images by taking linear measurements withdicom image software. Descriptive statistics –mean, standard deviation, standard error, 95% confidence interval were calculated for each parameter. Independent student t- test, age regression analysis, and Spearman’s rank correlation coefficient were applied accordingly. ResultsBCR, ER, TSFI showed significant correlation with the age and anteroposterior diameter of brain. BCR and TVW were significantly higher in males. In normal images, 95% confidence limits for FHR [0.295-0.309], TVW [6.104–6.92], TSFI [0.538–0.558] were found. The mean FHR and TVR in hydrocephalic patients were 0.42 and 0.072. DiscussionSince Frontal horn ratio and Third ventricle ratio do not depend upon the age, sex and size of brain, these two parameters can be used as the screening and monitoring tools in patients with hydrocephalus.