Brain ventricular size in healthy elderly: comparison between Evans index and volume measurement

Optimal Diagnostic Indices for Idiopathic Normal Pressure Hydrocephalus Based on the 3D Quantitative Volumetric Analysis for the Cerebral Ventricle and Subarachnoid Space

BACKGROUND AND PURPOSE

Despite the remarkable progress of 3D graphics technology, the Evans index has been the most popular index for ventricular enlargement. We investigated a novel reliable index for the MR imaging features specified in idiopathic normal pressure hydrocephalus, rather than the Evans index.

MATERIALS AND METHODS

The patients with suspected idiopathic normal pressure hydrocephalus on the basis of the ventriculomegaly and a triad of symptoms underwent the CSF tap test. CSF volumes were extracted from a T2-weighted 3D spin-echo sequence named "sampling perfection with application-optimized contrasts by using different flip angle evolutions (SPACE)" on 3T MR imaging and were quantified semiautomatically. Subarachnoid spaces were divided as follows: upper and lower parts and 4 compartments of frontal convexity, parietal convexity, Sylvian fissure and basal cistern, and posterior fossa. The maximum length of 3 axial directions in the bilateral ventricles and their frontal horns was measured. The "z-Evans Index" was defined as the maximum z-axial length of the frontal horns to the maximum cranial z-axial length. These parameters were evaluated for the predictive accuracy for the tap-positive groups compared with the tap-negative groups and age-adjusted odds ratios at the optimal thresholds.

RESULTS

In this study, 24 patients with tap-positive idiopathic normal pressure hydrocephalus, 25 patients without response to the tap test, and 23 age-matched controls were included. The frontal horns of the bilateral ventricles were expanded, with the most excessive expansion being toward the z-direction. The CSF volume of the parietal convexity had the highest area under the receiver operating characteristic curve (0.768), the z-Evans Index was the second (0.758), and the upper-to-lower subarachnoid space ratio index was the third (0.723), to discriminate the tap-test response.

CONCLUSIONS

The CSF volume of the parietal convexity of <38 mL, upper-to-lower subarachnoid space ratio of <0.33, and the z-Evans Index of >0.42 were newly proposed useful indices for the idiopathic normal pressure hydrocephalus diagnosis, an alternative to the Evans Index.

Comparision between Brain Atrophy and Subdural Volume to Predict Chronic Subdural Hematoma: Volumetric CT Imaging Analysis

Objective

Brain atrophy and subdural hygroma were well known factors that enlarge the subdural space, which induced formation of chronic subdural hematoma (CSDH). Thus, we identified the subdural volume that could be used to predict the rate of future CSDH after head trauma using a computed tomography (CT) volumetric analysis.

Methods

A single institution case-control study was conducted involving 1,186 patients who visited our hospital after head trauma from January 1, 2010 to December 31, 2014. Fifty-one patients with delayed CSDH were identified, and 50 patients with age and sex matched for control. Intracranial volume (ICV), the brain parenchyme, and the subdural space were segmented using CT image-based software. To adjust for variations in head size, volume ratios were assessed as a percentage of ICV [brain volume index (BVI), subdural volume index (SVI)]. The maximum depth of the subdural space on both sides was used to estimate the SVI.

Results

Before adjusting for cranium size, brain volume tended to be smaller, and subdural space volume was significantly larger in the CSDH group (p=0.138, p=0.021, respectively). The BVI and SVI were significantly different (p=0.003, p=0.001, respectively). SVI [area under the curve (AUC), 77.3%; p=0.008] was a more reliable technique for predicting CSDH than BVI (AUC, 68.1%; p=0.001). Bilateral subdural depth (sum of subdural depth on both sides) increased linearly with SVI (p<0.0001).

Conclusion

Subdural space volume was significantly larger in CSDH groups. SVI was a more reliable technique for predicting CSDH. Bilateral subdural depth was useful to measure SVI.

Intraparenchymal ventricular diverticula in chronic obstructive hydrocephalus: prevalence, imaging features and evolution

BACKGROUND

Intraparenchymal cavities communicating with the ventricles may appear in patients with chronic obstructive hydrocephalus despite no identifiable surgerical, vascular or traumatic causes. The rate, features, pathogenesis, evolution and clinical impact of intraparenchymal diverticula have not been outlined, yet.

METHODS

Brain MRIs of 130 patients (mean age: 11.3 years; age range: 0-67; 60 females) with chronic obstructive hydrocephalus were analyzed. The pathogenesis, neurosurgical treatment, ventricle size, signs of transependymal reabsorption and septum pellucidum integrity of the hydrocephalus were recorded. Subarachnoid outpouching of the ventricles, post-hemorrhagic parenchymal cavities, paths of ventricular shunting and cavities not communicating with the ventricles were excluded. Of patients with intraparenchymal diverticula, all previous available CT and MRI scans were evaluated.

RESULTS

Eight patients (6.2 %, mean age: 18.7 years; age range: 2-42) harbored 11 intraparenchymal diverticula sprouting from the temporal (6), occipital (3) or frontal (2) horns of the lateral ventricles. Intraparenchymal diverticula were more frequent in males (p = 0.04) and older patients (18.7 ± 12.7 vs 11.3 ± 9.8 years, p = 0.04). Their presence or evolution (mean neuroradiological follow-up 3.6 years; range: 0-8) showed a trend of association with hydrocephalus severity (bifrontal index) and did not correlate with the surgical treatment. In three patients the diverticula progressed during follow-up. One patient presented with hemiparesis consistent with the intraparenchymal lesion and improved after ventricular shunting. A DTI study revealed that the cortico-spinal tract was partly included in the septum between the ventricle and the intraparenchymal diverticulum.

CONCLUSIONS

Clinicians dealing with chronic severe obstructive hydrocephalus should be aware of ventricular intraparenchymal diverticulation. Studies aiming at clarifying their pathogenesis and proper management are warranted.

Brain ventricular dimensions and relationship to outcome in adult patients with bacterial meningitis

Background

Experimental studies suggest that changes in brain ventricle size are key events in bacterial meningitis. This study investigated the relationship between ventricle size, clinical condition and risk of poor outcome in patients with bacterial meningitis.

Methods

Adult patients diagnosed with bacterial meningitis admitted to two departments of infectious diseases from 2003 through 2010 were identified. Clinical and biochemical data as well as cerebral computed tomographic images were collected. The size of the brain ventricles were presented as a Ventricle to Brain Ratio (VBR). Normal range of VBR was defined from an age matched control group. A multivariate analysis was performed to identify predictors of 30-day mortality.

Results

One hundred and seven patients were included. Eighty-one patients had a CT scan at the time of diagnosis. VBR was identified as an independent risk factor of 30-day mortality, Mortality Rate Ratio: 6.03 (95 % confidence interval: 1.61-22.64, p = 0.008) for highest versus lowest tertile. A VBR deviating more than 2 standard deviations from the normal range was associated with increased mortality.

Conclusions

Brain ventricles are commonly subject to marked changes in size as a consequence of meningitis. Increased brain ventricle size in the acute phase of bacterial meningitis was associated with increased mortality.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-1097-3) contains supplementary material, which is available to authorized users.

Simple and reproducible linear measurements to determine ventricular enlargement in adults

Background:

Recent studies have suggested that Evan's Index (EI) is not accurate and instead endorse volumetric measurements. Our aim was to evaluate the reproducibility of linear measurements and their correlation to ventricular volume.

Methods:

Using magnetic resonance (MR) images of 30 patients referred for normal pressure hydrocephalus (NPH), EI, frontal-occipital horn ratio (FOR), third ventricular width and height, frontal horn width (FHW), and callosal angle (CA) at the foramen of Monro and the posterior commissure (PC) were independently measured by residents in neurosurgery and radiology, a neurosurgeon and radiologist, and a medical student. Intraclass correlation coefficients (ICC) were calculated to establish inter-rater agreement among the reviewers. Pearson's correlation coefficients were done to assess the relationship of the linear measurements with total ventricular volume. Kappa analyses were performed to assess the degree of agreement between cutpoints determined by the ROC analysis for the linear measurements and reviewers’ gestalt impression about ventricular size with volumetric abnormality.

Results:

The overall inter-rater agreement among reviewers was almost perfect for EI (ICC = 0.913), FOR (ICC = 0.830), third ventricular width, FHW (ICC = 0.88), and CA at PC (ICC = 0.865), substantial for temporal horn width (ICC = 0.729) and CA at foramen of Monro (ICC = 0.779), and moderate for third ventricular height (ICC = 0.496). EI, FOR, third ventricular width, temporal horn width, and CA at PC measures correlated with total ventricular volume. There was fair-to-almost-perfect agreement of the individual reviewer's gestalt responses of abnormatility with volumetric abnormality. Gestalt responses were better for more senior raters.

Conclusion:

Linear measurements are reliable and reproducible methods for determining ventricular enlargement.

Long-Term Outcomes After Small-Bone-Window Posterior Fossa Decompression and Duraplasty in Adults with Chiari Malformation Type I

BACKGROUND

Small-bone-window posterior fossa decompression with duraplasty is one of the popular surgical options for Chiari malformation type I, but its efficacy is controversial and the risk factors of clinical outcome remain unclear.

METHODS

The study cohort included 152 patients with Chiari malformation type I who received small-bone-window posterior fossa decompression at Beijing Tiantan hospital from January 2008 to September 2009. All patients underwent combined surgical procedures: a small-bone-window suboccipital decompression (diameter, 2.5-3 cm) and a C1 laminectomy (1.5- to 2-cm wide) followed by a duraplasty with an autologous graft. Clinical manifestations, radiologic features, and follow-up data during a 6-year span were analyzed. Risk factors associated with outcome were investigated by the use of χ(2) analysis and logistic regression analysis.

RESULTS

The average follow-up duration was 74 months. Symptoms were improved in 126 patients (82.9%), remained stable in 21 patients (13.8%), and deteriorated in 5 patients (3.3%). There was no mortality. Postoperative magnetic resonance imaging scans were available for all patients. Preoperatively, 112 patients were associated with syringomyelia, and the follow-up magnetic resonance images showed obvious reduction of syringomyelia in 73 patients (65.2%) and no significant change in 39 patients (34.8%). In addition, enlargement of the cistern magna was observed in 92 patients (85.2%). Regression analysis indicates preoperative motor dysfunction, brainstem herniation and basilar invagination may influence the clinical outcome (P < 0.05).

CONCLUSIONS

Small-bone-window posterior fossa decompression with duraplasty is an effective and safe treatment option with a low complication rate. Motor dysfunction, brainstem herniation, and basilar invagination are predictors of poor clinical prognosis.

Computerized tomographic study of normal Evans index in adult Nigerians

Background:

The evaluation of degree of ventricular enlargement should be based on established indices rather than on personal experience as this is highly subjective. Our aim was to establish normal values for Evans index in a Nigerian adult population as none has been found in the Nigerian medical literature.

Materials and Methods:

Axial computerized tomographic brain scans of 488 normal subjects were reviewed retrospectively. Of them, 319 (65.36%) of the patients were males and 169 (34.63%) were females; their ages ranged from 18 to 84 years with a mean age of 37.26 years. The images were acquired using a multi-slice GE Sigma excite scanner. Evans index was measured as the linear ratio of the total width of the frontal horns of the cerebral lateral ventricles to the maximum intracranial diameter.

Results:

The mean value for Evans index for the studied population was 0.252 ± 0.04. The EI increased with age and it was slightly higher among males. The difference in Evans value in males and females was not statistically significant. Individuals above 60 years old had the highest Evans values in both sexes.

Conclusion:

This study has established ranges of normal value for Evans index in a Nigerian population. It agrees with the diagnostic cut-off value of > 0.3 for hydrocephalus and it compares well with that of the Caucasians.

Measures of ventricles and evans' index: from neonate to adolescent

Ventricle sizes are important for the early diagnosis of hydrocephalus or for follow-up after ventriculostomy. Diameters of ventricles may change, especially in childhood. This study aims to provide normative data about ventricle diameters. Among 14,854 cranial MRI performed between 2011 and 2013, 2,755 images of Turkish children aged 0-18 years were obtained. After exclusions, 517 images were left. Four radiologists were trained by a pediatric radiologist. Twenty images were assessed by all radiologists for a pilot study to see that there was no interobserver variation. There were 10-22 children in each age group. The maximum width of the third ventricle was 5.54 ± 1.29 mm in males in age group 1 and 4.98 ± 1.08 mm in females in age group 2. The Evans' index was <0.3 and consistent with the literature. The third ventricle/basilar artery width ratio was found to be >1 and <2 in all age groups and both gender groups. Our study showed the ventricle size data of children in various age groups from newborn to adolescent. The ventricle volume/cerebral parenchyma ratio seems to decrease with age. We think that these data can be applied in clinical practice, especially for the early diagnosis of hydrocephalus.

Automatic volumetry of the cerebrospinal fluid space in idiopathic normal pressure hydrocephalus

Objectives

To measure the cerebrospinal fluid (CSF) space volume in idiopathic normal pressure hydrocephalus (INPH), we developed a software that allows us to automatically measure the regional CSF space and compared the volumes of the ventricle systems (VS), Sylvian fissures (SF) and sulci at high convexity and midline (SHM) among INPH patients, Alzheimer's disease (AD) patients and healthy volunteers (HVs).

Methods

Fifteen INPH patients, 15 AD patients and 15 HVs were retrospectively selected for this study. 3D-T1 MR images were obtained. We improved upon an automatic gray matter volume system to measure CSF spaces, adopting new regions for the template of INPH-characteristic CSF spaces and measured them. The VS, SF and SHM volumes were calculated relative to the intracranial volume.

Results

The relative SHM volume of the INPH group (0.0237 ± 0.0064) was the smallest among the 3 groups (AD: 0.0477 ± 0.0109, HV: 0.0542 ± 0.0045). The VS (0.0499 ± 0.0135) and SF (0.0187 ± 0.0037) volumes of the INPH group were significantly larger than those of the AD (VS: 0.0311 ± 0.0075, SF: 0.0146 ± 0.0026) and HV groups (VS: 0.0167 ± 0.0065, SF: 0.0111 ± 0.017).

Conclusion

Automatic volume measurement can be used to delineate the characteristic changes in CSF space in patients with INPH and is useful in the diagnosis of INPH.

Surgical treatment of Chiari I malformation with ventricular dilation

Ventricular dilation affects 7% to 10% of patients with Chiari type I malformation (CIM), but the choice of surgical treatment is controversial. To study the surgical approaches for treating CIM with ventricular dilation and to evaluate the efficacy of posterior fossa decompression (PFD), clinical and imaging data of 38 adult patients who received surgical correction performed at the authors' department from 2004 to 2011 were reviewed. Ventricular dilation was defined as Evans' index > 0.30. Preoperative fundus examinations were done on all patients and no papilledema was found. Surgical procedures included a sub-occipital decompression and a C1 laminectomy, followed by a duraplasty with an autologous graft. Evans' index was measured before and after surgery respectively, and a paired samples t-test was performed to examine the difference. Factors predicting outcomes were investigated using logistic regression analysis. Follow-up was done to all patients with an average duration of 43 months. All postoperative magnetic resonance (MR) images showed a relief of cervicomedullary compression and recreation of the cisterna magna. Symptoms improved in 33 patients (86.8%), remained stable in 5 (13.2%), and no patient deteriorated. No significant change in ventricular size was observed after surgery (P = 0.257). Regression analysis showed duration of illness had a significant effect on clinical outcome (P = 0.034, OR = 12.5, 95% CI: 1.214, 128.661). Our study suggests that the intracranial pressure (ICP) of patients with CIM and ventricular dilation is usually normal. PFD with duraplasty is an effective and safe treatment for CIM with ventricular dilation. Treatment of ventricular dilation is unnecessary before PFD as long as there is no persistent headache, vomiting, and papilledema.

Diagnosis and management of idiopathic normal-pressure hydrocephalus

The diagnosis and management of idiopathic normal-pressure hydrocephalus (iNPH), a disorder of gait impairment, incontinence, and dementia that affects elderly patients, incorporates an organized approach using familiar principles for neurologists. The starting point is a comprehensive history and neurologic examination, review of neuroimaging, and evaluation of the differential diagnosis. Coexisting disorders should be treated before specific iNPH testing is performed. Specific iNPH testing includes assessing patient response to temporary CSF removal and testing CSF hydrodynamics. In properly selected patients, all iNPH symptoms, including dementia, can improve after shunt surgery. The longitudinal care of iNPH patients with shunts includes evaluation of the differential diagnosis of worsening iNPH symptoms and treatment of coexisting disorders. Evaluation of shunt obstruction is often indicated, and if it is found, surgical correction is likely to result in symptomatic improvement.

Voxel-based morphometry of disproportionate cerebrospinal fluid space distribution for the differential diagnosis of idiopathic normal pressure hydrocephalus

OBJECTIVE

To determine whether voxel-based morphometry of the cerebrospinal fluid (CSF) space can accurately differentiate iNPH from other related neurological disorders.

METHODS

Nineteen patients with surgically proven iNPH and 24 patients with Alzheimer's disease (AD), 18 patients with Parkinson's disease (PD), and 14 healthy elderlies were examined. Regions of interest (ROIs) in the ventricular/sylvian (VS) and high convexity/midline (HCM) areas were used in VBM, and differences in CSF volume within these ROIs among the 4 groups were examined.

RESULTS

The relative CSF volume in the VS-ROI in the iNPH group (.64) was significantly higher than that in the AD, PD, and healthy control groups (.26, .29, and .17, respectively; P < .001), whereas the relative CSF volume in the HCM-ROI was significantly reduced in the iNPH (.10) than in the other (.17, .16, and .16, respectively) groups (P < .001). Furthermore, the ratio of the 2 areas (VS/HCM) was markedly higher in the iNPH (6.87) than in the other (1.65, 1.74, .97, respectively) groups (P < .001), with sensitivity and specificity of .89 and 1.00, respectively.

CONCLUSIONS

The VBM-based CSF space analysis can detect disproportionate changes in CSF space and differentiate iNPH patients from those with AD or PD and healthy elderlies accurately.

Measurement of CSF dynamics with oscillating pressure infusion

INTRODUCTION

Infusion tests are used to diagnose and select patients with idiopathic normal pressure hydrocephalus (INPH) for shunt surgery. The test characterizes cerebrospinal fluid dynamics and estimates parameters of the cerebrospinal fluid system, the pressure-volume index (PVI) and the outflow conductance (Cout). The Oscillating Pressure Infusion (OPI) method was developed to improve the test and reduce the investigation time. The aim of this study was to evaluate the new OPI method by comparing it with an established reference method.

METHODS

Forty-seven patients (age 71.2 ± 8.9 years) with communicating hydrocephalus underwent a preoperative lumbar infusion investigation with two consecutive infusion protocols, reference (42 min) and new (20 min), that is, 94 infusion tests in total. The OPI method estimated Cout and PVI simultaneously. A real-time analysis of reliability was applied to investigate the possibility of infusion time reduction.

RESULTS

The difference in Cout between the methods was 1.2 ± 1.8 μl/s/kPa (ΔRout = -0.8 ± 3.5 mmHg/ml/min), P < 0.05, n = 47. With the reliability analysis, the preset 20 min of active infusion could have been even further reduced for 19 patients to between 10 and 19 min. PVI was estimated to 16.1 ± 6.9 ml, n = 47.

CONCLUSIONS

The novel Oscillating Pressure Infusion method produced real-time estimates of Cout including estimates of reliability that was in good agreement with the reference method and allows for a reduced and individualized investigation time.

Childhood hydrocephalus - is radiological morphology associated with etiology

Background

Clinicians use a non-standardized, intuitive approach when correlating radiological morphology and etiology of hydrocephalus.

Objective

To investigate the possibility of categorizing hydrocephalus in different groups based on radiological morphology, to analyze if these proposed groups relate to the location and type of underlying pathology, and if this can be of use in clinical practice.

Methods and material

A retrospective cohort study including 110 hydrocephalus patients below age seven seen at Rigshospitalet University Hospital, Denmark. Their neuro-imaging was analyzed and categorized based on radiological morphology. Patient charts were reviewed and possible association between the underlying cause of hydrocephalus and the proposed groups of radiological morphology was evaluated.

Results

Radiological appearance varied distinctively between patients. A classification system was created based on the morphology of the lateral ventricles from axial sections at the level of maximal ventricular width. No statistically significant association was found between the suggested groups of morphology and the location and type of pathology.

Conclusion

Distinguishable patterns of radiological morphology exist. The proposed classification system cannot in its current form indicate type and location of the underlying cause of hydrocephalus. A clear need exists for a standardized approach when evaluating etiology and treatment options based on radiological results.

Microglia and a functional type I IFN pathway are required to counter HSV-1-driven brain lateral ventricle enlargement and encephalitis

HSV-1 is the leading cause of sporadic viral encephalitis, with mortality rates approaching 30% despite treatment with the antiviral drug of choice, acyclovir. Permanent neurologic deficits are common in patients that survive, but the mechanism leading to this pathology is poorly understood, impeding clinical advancements in treatment to reduce CNS morbidity. Using magnetic resonance imaging and type I IFN receptor-deficient mouse chimeras, we demonstrate HSV-1 gains access to the murine brain stem and subsequently brain ependymal cells, leading to enlargement of the cerebral lateral ventricle and infection of the brain parenchyma. A similar enlargement in the lateral ventricles is found in a subpopulation of herpes simplex encephalitic patients. Associated with encephalitis is an increase in CXCL1 and CXCL10 levels in the cerebral spinal fluid, TNF-α expression in the ependymal region, and the influx of neutrophils of encephalitic mouse brains. Reduction in lateral ventricle enlargement using anti-secretory factor peptide 16 reduces mortality significantly in HSV-1-infected mice without any effect on expression of inflammatory mediators, infiltration of leukocytes, or changes in viral titer. Microglial cells but not infiltrating leukocytes or other resident glial cells or neurons are the principal source of resistance in the CNS during the first 5 d postinfection through a Toll/IL-1R domain-containing adapter inducing IFN-β-dependent, type I IFN pathway. Our results implicate lateral ventricle enlargement as a major cause of mortality in mice and speculate such an event transpires in a subpopulation of human HSV encephalitic patients.

Evaluation of automatic measurement of the intracranial volume based on quantitative MR imaging

BACKGROUND AND PURPOSE

Brain size is commonly described in relation to ICV, whereby accurate assessment of this quantity is fundamental. Recently, an optimized MR sequence (QRAPMASTER) was developed for simultaneous quantification of T1, T2, and proton density. ICV can be measured automatically within minutes from QRAPMASTER outputs and a dedicated software, SyMRI. Automatic estimations of ICV were evaluated against the manual segmentation.

MATERIALS AND METHODS

In 19 healthy subjects, manual segmentation of ICV was performed by 2 neuroradiologists (Obs1, Obs2) by using QBrain software and conventional T2-weighted images. The automatic segmentation from the QRAPMASTER output was performed by using SyMRI. Manual corrections of the automatic segmentation were performed (corrected-automatic) by Obs1 and Obs2, who were blinded from each other. Finally, the repeatability of the automatic method was evaluated in 6 additional healthy subjects, each having 6 repeated QRAPMASTER scans. The time required to measure ICV was recorded.

RESULTS

No significant difference was found between reference and automatic (and corrected-automatic) ICV (P > .25). The mean difference between the reference and automatic measurement was -4.84 ± 19.57 mL (or 0.31 ± 1.35%). Mean differences between the reference and the corrected-automatic measurements were -0.47 ± 17.95 mL (-0.01 ± 1.24%) and -1.26 ± 17.68 mL (-0.06 ± 1.22%) for Obs1 and Obs2, respectively. The repeatability errors of the automatic and the corrected-automatic method were <1%. The automatic method required 1 minute 11 seconds (SD = 12 seconds) of processing. Adding manual corrections required another 1 minute 32 seconds (SD = 38 seconds).

CONCLUSIONS

Automatic and corrected-automatic quantification of ICV showed good agreement with the reference method. SyMRI software provided a fast and reproducible measure of ICV.

Automated determination of brain parenchymal fraction in multiple sclerosis

BACKGROUND AND PURPOSE

Brain atrophy is a manifestation of tissue damage in MS. Reduction in brain parenchymal fraction is an accepted marker of brain atrophy. In this study, the approach of synthetic tissue mapping was applied, in which brain parenchymal fraction was automatically calculated based on absolute quantification of the tissue relaxation rates R1 and R2 and the proton attenuation.

MATERIALS AND METHODS

The BPF values of 99 patients with MS and 35 control subjects were determined by using SyMap and tested in relationship to clinical variables. A subset of 5 patients with MS and 5 control subjects were also analyzed with a manual segmentation technique as a reference. Reproducibility of SyMap was assessed in a separate group of 6 healthy subjects, each scanned 6 consecutive times.

RESULTS

Patients with MS had significantly lower BPF (0.852 ± 0.0041, mean ± SE) compared with control subjects (0.890 ± 0.0040). Significant linear relationships between BPF and age, disease duration, and Expanded Disability Status Scale scores were observed (P < .001). A strong correlation existed between SyMap and the reference method (r = 0.96; P < .001) with no significant difference in mean BPF. Coefficient of variation of repeated SyMap BPF measurements was 0.45%. Scan time was <6 minutes, and postprocessing time was <2 minutes.

CONCLUSIONS

SyMap is a valid and reproducible method for determining BPF in MS within a clinically acceptable scan time and postprocessing time. Results are highly congruent with those described using other methods and show high agreement with the manual reference method.

[A biomechanical analysis of cyclical hand motor function: a pilot study in different Parkinsonian syndromes]

INTRODUCTION

Clinical assessment of hand bradykinesia in Parkinson's disease (PD) focuses mainly on the frequency, amplitude and rhythm of movements, thereby subjectively evaluating the correct performance of hand movements. The aim of the study was to quantify hand bradykinesia with kinematic data in different Parkinsonian syndromes.

PATIENTS AND METHODS

This retrospective study compared patients with idiopathic PD (IPD, n = 18), atypical Parkinson's syndrome (APS, n = 17), secondary Parkinson's syndrome (SPS, n = 18) and healthy controls (C, n = 18). All patients were receiving the best medical treatment. Hand movements were recorded using an ultrasound-system (Zebris®, Isny, Germany). Subjects were asked to perform pronation/supination of the forearm (diadochokinesis), flexion/extension of the hand (hand tapping) and tapping of the index finger. Mean amplitude, mean frequency and mean variability of movements were determined.

RESULTS

APS patients had significant complex hand movement disability with reduced amplitude and frequency in combination with increased motion variability in all movement tasks. The key disturbance in the IPD group concerned the rhythm in hand tapping and index finger tapping in combination with moderately reduced velocity and range of motion in all conditions. The cyclical hand movement characteristics in SPS patients showed movement slowness with normal amplitude and variability in all motor conditions.

CONCLUSION

Our results suggest that computerized quantitative analysis of cyclical hand movements can characterize and identify different representations of hand bradykinesia in different Parkinsonian disorders and hence may help clinicians to accurately assess therapeutic targets and outcome of interventions.

Ventriculomegaly and balance disturbances in patients with TIA

OBJECTIVES

Dilated ventricles and gait disturbances are common in the elderly, and these are also features of the treatable syndrome idiopathic normal pressure hydrocephalus (INPH). Many studies report an association between hypertension, vascular disease and INPH. The objective of this study was to study the frequency of ventriculomegaly, with or without hydrocephalic symptoms, in patients who had suffered from a transitory ischaemic attack (TIA).

METHODS

Gait, Romberg sign, tandem standing and one-leg stance were consecutively evaluated in elderly > 24 h after a TIA. Ventricular size, white matter lesions and atrophy were assessed on computed tomography scans. Exclusion criteria were conditions possibly influencing the balance tests.

RESULTS

eventy-six patients with TIA out of 105 were included. Ventriculomegaly [Evans Index (EI) > 0.30] was observed in 19.7% and very large ventricles (EI > 0.33) in 7.9%. Ventriculomegaly was found in 58% of the patients with a previous 'history of balance or gait disturbance', but only in 12% of those without any prior disturbance (chi-square test; P = 0.0009). Three out of 76 patients with TIA (3.9%) fulfilled both radiological and clinical criteria for 'possible INPH'.

CONCLUSION

Ventriculomegaly is a common finding in elderly. One out of 20 patients with TIA may suffer from INPH, existing before and independent of the TIA diagnosis. Therefore, patients presenting with ventriculomegaly and gait/balance disturbances not attributable to other causes should be referred to a hydrocephalus centre or a neurologist with special interest in INPH.

Virtual cerebral ventricular system: an MR-based three-dimensional computer model

The inherent spatial complexity of the human cerebral ventricular system, coupled with its deep position within the brain, poses a problem for conceptualizing its anatomy. Cadaveric dissection, while considered the gold standard of anatomical learning, may be inadequate for learning the anatomy of the cerebral ventricular system; even with intricate dissection, ventricular structures remain difficult to observe. Three-dimensional (3D) computer reconstruction of the ventricular system offers a solution to this problem. This study aims to create an accurate 3D computer reconstruction of the ventricular system with surrounding structures, including the brain and cerebellum, using commercially available 3D rendering software. Magnetic resonance imaging (MRI) scans of a male cadaver were segmented using both semiautomatic and manual tools. Segmentation involves separating voxels of different grayscale values to highlight specific neural structures. User controls enable adding or removing of structures, altering their opacity, and making cross-sectional slices through the model to highlight inner structures. Complex physiologic concepts, such as the flow of cerebrospinal fluid, are also shown using the 3D model of the ventricular system through a video animation. The model can be projected stereoscopically, to increase depth perception and to emphasize spatial relationships between anatomical structures. This model is suited for both self-directed learning and classroom teaching of the 3D anatomical structure and spatial orientation of the ventricles, their connections, and their relation to adjacent neural and skeletal structures.

MR imaging of brain volumes: evaluation of a fully automatic software

BACKGROUND AND PURPOSE

Automatic assessment of brain volumes is needed in research and clinical practice. Manual tracing is still the criterion standard but is time-consuming. It is important to validate the automatic tools to avoid the problems of clinical studies drawing conclusions on the basis of brain volumes estimated with methodologic errors. The objective of this study was to evaluate a new commercially available fully automatic software for MR imaging of brain volume assessment. Automatic and expert manual brain volumes were compared.

MATERIALS AND METHODS

MR imaging (3T, axial T2 and FLAIR) was performed in 41 healthy elderly volunteers (mean age, 70 ± 6 years) and 20 patients with hydrocephalus (mean age, 73 ± 7 years). The software Q(Brain) was used to manually and automatically measure the following brain volumes: ICV, BTV, VV, and WMHV. The manual method has been previously validated and was used as the reference. Agreement between the manual and automatic methods was evaluated by using linear regression and Bland-Altman plots.

RESULTS

There were significant differences between the automatic and manual methods regarding all volumes. The mean differences were ICV = 49 ± 93 mL (mean ± 2SD, n = 61), BTV = 11 ± 70 mL, VV = -6 ± 10 mL, and WMHV = 2.4 ± 9 mL. The automatic calculations of brain volumes took approximately 2 minutes per investigation.

CONCLUSIONS

The automatic tool is promising and provides rapid assessment of brain volumes. However, the software needs improvement before it is incorporated into research or daily use. Manual segmentation remains the reference method.