The excessively small ventricle on computed axial tomography of the brain

Comparison of acute and chronic traumatic brain injury using semi-automatic multimodal segmentation of MR volumes

Although neuroimaging is essential for prompt and proper management of traumatic brain injury (TBI), there is a regrettable and acute lack of robust methods for the visualization and assessment of TBI pathophysiology, especially for of the purpose of improving clinical outcome metrics. Until now, the application of automatic segmentation algorithms to TBI in a clinical setting has remained an elusive goal because existing methods have, for the most part, been insufficiently robust to faithfully capture TBI-related changes in brain anatomy. This article introduces and illustrates the combined use of multimodal TBI segmentation and time point comparison using 3D Slicer, a widely-used software environment whose TBI data processing solutions are openly available. For three representative TBI cases, semi-automatic tissue classification and 3D model generation are performed to perform intra-patient time point comparison of TBI using multimodal volumetrics and clinical atrophy measures. Identification and quantitative assessment of extra- and intra-cortical bleeding, lesions, edema, and diffuse axonal injury are demonstrated. The proposed tools allow cross-correlation of multimodal metrics from structural imaging (e.g., structural volume, atrophy measurements) with clinical outcome variables and other potential factors predictive of recovery. In addition, the workflows described are suitable for TBI clinical practice and patient monitoring, particularly for assessing damage extent and for the measurement of neuroanatomical change over time. With knowledge of general location, extent, and degree of change, such metrics can be associated with clinical measures and subsequently used to suggest viable treatment options.

Brain atrophy in alcoholics: relationship with alcohol intake; liver disease; nutritional status, and inflammation

OBJECTIVES

Brain atrophy is a common finding in alcoholics. Several mechanisms may be involved, including ethanol itself, malnutrition, liver failure, and, possibly, ethanol-induced hormone and cytokine changes. The aim of this study was to analyse the relation of brain atrophy-assessed by computerized tomography (CT) scan-and the aforementioned alterations.

METHODS

Serum insulin-like growth factor 1 (IGF-1), interleukin (IL)-6, IL-8, IL-10, TNF alpha, PTH, estradiol, free testosterone, and corticosterone were measured in 36 alcoholics, ten of them cirrhotics, who also underwent brain CT, which recorded the presence of cortical atrophy or cerebellar atrophy, Evan's, Huckmann's, cella media, bicaudate, cortical atrophy, bifrontal, and ventricular indices, and diameter of the third ventricle; subjective nutritional assessment, midarm anthropometry, and evaluation of liver function.

RESULTS

Patients showed marked alterations of all the CT indices compared with 12 controls, but poor relations between these indices and the other parameters analysed (IGF-1, handgrip strength and years of addiction with bifrontal index (P < 0.025 in all cases); PTH and Evan's index (r = 0.36, P = 0.032); mean corpuscular volume with cella index and cortical atrophy (P < 0.05). Cerebellar atrophy was associated with a greater daily ethanol consumption (t = 2.19, P = 0.034).

CONCLUSION

Brain atrophy is frequently observed in alcoholics, but relationships with liver function, cytokines, nutritional status, and hormone levels are poor.

Clinical and neuroimaging characteristics of hydrocephalus associated with vestibular schwannoma

OBJECT

The clinical and neuroimaging characteristics of hydrocephalus associated with vestibular schwannoma were retrospectively analyzed to improve the perioperative management of the circulation of cerebrospinal fluid.

METHODS

A retrospective analysis was performed in 236 patients with unilateral vestibular schwannomas. The patients' ages ranged from 17 to 83 years (mean 53.6 +/- 13.2 years), and the diameters of the tumors the patients harbored ranged from 5 to 60 mm (mean 30.5 +/- 12.7 mm). Hydrocephalus was present before tumor resection in 33 patients (14%) and in six of these patients focal dilation of the sylvian fissures was noted. There was a significant correlation between the incidence of hydrocephalus and tumor size. The incidence of preoperative hydrocephalus among elderly patients (> or = 65 years of age) was 28.6% and that among younger patients (< 65 years of age) was 10.8%. Tumors in elderly patients with hydrocephalus (mean tumor diameter 32.8 +/- 11.7 mm; 12 patients) were significantly smaller than those in younger patients (mean tumor diameter 41.7 +/- 10.9 mm; 21 patients). Among patients with tumors smaller than 30 mm (114 patients), the incidence of hydrocephalus in elderly patients (25%) was 12-fold higher than that in younger patients (2.1%). Six patients with hydrocephalus who had focal dilation of the sylvian fissures were significantly older than 27 patients with hydrocephalus in whom there was no focal dilation. The dilated sylvian fissures collapsed in two patients spontaneously after tumor resection and in the other four patients after shunt placement.

CONCLUSIONS

The incidence of associated hydrocephalus is higher in older patients. Communicating hydrocephalus tends to occur in elderly patients. Enlargement of the ventricles with focal dilation of the sylvian fissures should not be misinterpreted as physiological brain atrophy.

Successful neuroendoscopic third ventriculostomy for hydrocephalus and syringomyelia associated with fourth ventricle outlet obstruction. Case report

The authors report the use of neuroendoscopic third ventriculostomy to treat successfully both hydrocephalus and syringomyelia associated with fourth ventricle outlet obstruction. A 27-year-old woman presented with dizziness, headache, and nausea. Magnetic resonance (MR) imaging demonstrated dilation of all ventricles, downward displacement of the third ventricular floor, obliteration of the retrocerebellar cerebrospinal fluid (CSF) space, funnellike enlargement of the entrance of the central canal in the fourth ventricle, and syringomyelia involving mainly the cervical spinal cord. Cine-MR imaging indicated patency of the aqueduct and an absent CSF flow signal in the area of the cistema magna, which indicated obstruction of the outlets of the fourth ventricle. Although results of radioisotope cisternography indicated failure of CSF absorption, neuroendoscopic third ventriculostomy completely resolved all symptoms as well as the ventricular and spinal cord abnormalities evident on MR images. Neuroendoscopic third ventriculostomy is an important option for treating hydrocephalus in patients with fourth ventricle outlet obstruction.

Area and volume measurement of posterior fossa structures in MRI

This study was undertaken to determine the extent to which area measures of posterior fossa structures can be used confidently to represent structure volumes. MRI scans were obtained from three groups: fragile X males, males with other developmental disabilities, and males with normal IQ. The areas of the midbrain, pons, medulla, cerebellar vermis, and fourth ventricle were measured in midsagittal sections. Volumes of midbrain, pons, medulla, cerebellum, fourth ventricle, and third ventricle were obtained by measuring these structures in contiguous axial slices. In addition, the largest axial area for each structure was identified. Analysis revealed that midsagittal area measures for pons, medulla, and fourth ventricle were significantly correlated with structure volumes, and that all of the largest axial area measures were significantly correlated with structure volumes. However, only the midsagittal area measure of fourth ventricle and the largest axial area measures of fourth ventricle and cerebellum were correlated with volume measures with an r of .80 of greater. Results of this study suggest that area measures may not accurately represent three-dimensional structure size.

Neuropsychological deficits and morphological MRI brain scan abnormalities in apparently healthy non-encephalopathic patients with cirrhosis. A controlled study

By means of psychometric testing, we have determined the frequency of latent hepatic encephalopathy in a group of 19 cirrhotics with no clinical evidence of encephalopathy. Magnetic resonance imaging (MRI) of the brain was performed in order to determine whether morphological cerebral abnormalities were associated with latent encephalopathy. Nineteen age and educationally matched patients with normal liver function acted as controls. Significant differences (P less than 0.05) between cirrhotics and controls were found in tests of short-term visual memory and speed of reaction to light (cirrhotics 316 +/- 132 ms vs. controls 225 +/- 36 ms), sound (cirrhotics 361 +/- 152 ms vs. controls 236 +/- 52 ms) and choice (cirrhotics 651 +/- 190 ms vs. controls 406 +/- 101 ms) stimuli (all values mean +/- S.D.). Reitan trail test performance, however, was similar in both groups. (Trail A: cirrhotics 43 +/- 19 s vs. controls 35 +/- 13 s; Trail B: cirrhotics 105 +/- 66 s vs. controls 93 +/- 36 s.) In patients with cirrhosis, MRI revealed statistically significant increases in the maximum fissure width of right frontal sulci, right and left parietal sulci, inter-hemispheric fissure width and in bicaudate index. These changes, indicating cerebral atrophy, were largely confined to alcoholics. There was poor correlation between measurements of cerebral morphology and neuropsychological performance, only 10% of associations achieving statistical significance.

Cortical blindness caused by acute general cerebral swelling

A 7-year-old girl who suffered from acute general cerebral swelling as a result of a traffic accident showed cortical blindness. Computed tomography (CT) scan on admission revealed marked slitlike ventricles and narrowing of the perimesencephalic cisterns, which indicated general cerebral swelling. While hospitalized, the patient developed transtentorial herniation twice on day 3, and CT scans at herniation episodes showed disappearance of the perimesencephalic cisterns. After recovery of consciousness, the patient showed cortical blindness, and during gradual recovery she showed pure alexia without agraphia. The visual evoked potentials at 8 weeks, 16 weeks, and 3 years 4 months after trauma showed normalization of the pattern, but revealed left occipital inactivity.

Colpocephaly: frequency and associated findings

Colpocephaly is an abnormal enlargement of the occipital horn of the lateral ventricle, also described as persistence of the fetal configuration of the lateral ventricles. Since it was first described, colpocephaly has been found in association with a number of abnormalities of the brain. In order to determine the frequency of this ventricular configuration at our hospital, we reviewed 3,411 computed tomographic (CT) scans done over a 26-month period. Fourteen cases were identified in which the CT scan had the appearance of colpocephaly. These CT scans were performed during the evaluation of a number of different clinical problems. Agenesis of the corpus callosum was the most frequently associated malformation. The types of malformations commonly associated with colpocephaly suggest that colpocephaly is merely a marker of disordered brain formation and that insults occurring anytime between one and four months of gestation may result in this anomaly.

Cerebral CT scan abnormalities in cholestatic and hepatocellular disease and their relationship to neuropsychologic test performance

Forty-nine nonalcoholic cirrhotic patients, on whom cranial CT scans were available, were administered a battery of neuropsychological tests. Although none of the subjects exhibited clinical signs or symptoms of hepatic encephalopathy, quantification of the CT scan image implicated cerebral edema and cortical atrophy. In addition numerous significant correlations were observed between the CT variables and neuropsychological test performance. The findings are conjectured to reflect previously unrecognized cerebral morphologic changes associated with chronic subclinical portal-systemic encephalopathy.

The excessively small ventricle on cranial computed tomography: clinical correlation in 75 patients

Excessively small ventricle (ESV) was demonstrated in 75 (8.3%) of 9,000 patients over 15 years of age examined by cranial computed tomography (CT). The patients had no other CT abnormality except for ESV. Detailed retrospective analysis of clinical records of these 75 patients revealed four major groups of patients: 1) those with seizures (24%); 2) those with headaches (24%); 3) those with acute non-penetrating head trauma (21.5%); and 4) those with benign increased intracranial pressure (8%). The remaining patients (22.5%) had a variety of cerebral derangements.

A computed tomographic prolective trohoc study of chronic schizophrenics

The maximal width of the third ventricle, the maximal distance between the outer tips of the anterior horns, and the number of enlarged cerebral sulci on the two highest CT slices were measured in 68 chronic schizophrenic patients on cranial computed tomograms in order to detect a possible enlargement of the cerebrospinal fluid (CSF) filled intracranial spaces. These results were compared with values obtained from a control group which was formed in accordance with definite exclusion criteria and matched-pair parameters (sex, age and maximal inner diameter of the skull). In a prolective trohoc study no difference was found in the size of the CSF spaces of schizophrenics and the controls. The psychopathological condition of the patients, which was classified in a semistandardized dialogue, also showed no correlation with the ventricular size or the number of enlarged cerebral sulci.

The pathogenesis of pseudotumor cerebri--a mathematical analysis

Although the clinical and laboratory features of pseudotumor cerebri have been clearly delineated, the pathogenesis of idiopathic pseudotumor remains a mystery. A number of pathogenetic mechanisms have been proposed to account for some or all of the observed cases. We describe a model relating changes in CSF outflow resistance and/or dural sinus venous pressure to observed changes in (i) CSF pressure, (ii) cerebral blood volume and (iii) the volume and hydrodynamic flow resistance of the ventriculosubarachnoid space.

Isodense subdural hematoma presenting with paraparesis: case report

Computerized tomography (CT) has replaced cerebral angiography in many institutions as the diagnostic test of choice in cranial trauma. However, isodense subdural hematomas can be a source of false-negative results on CT scans, resulting in omissions in therapy. The authors report a patient with bilateral isodense subdural hematomas who presented with paraparesis but was otherwise alert and fully oriented. The CT findings caused an initial diagnostic dilemma before being resolved.

The outcome from acute subdural haematoma following decompressive hemicraniectomy

Retrospective analysis of 15 cases with acute subdural haematoma receiving decompressive hemicraniectomy was carried out in an effort to clarify the beneficial effect and limitation of this operative procedure. The patients in this series were divided into three groups according to postoperative intracranial pressure (ICP). Decompressive hemicraniectomy was effective in lowering ICP in all patients except for the cases that developed acute brain swelling. Overall mortality rate was 66.7% in this series. Preoperative clinical status, and intra- and postoperative ICP and CT findings obtained within 24 hours of operation were correlated with the operative outcome.

Measurement of the normal ventricular system and supratentorial subarachnoid space in children with computed tomography

The normal ventricular system and subarachnoid space were evaluated on the CT scans of 155 children chosen from 1,400 pediatric CT examinations, and linear measurements were made. The left septum-caudate distance was greater than the right, and the width of the left anterior horn and size of the skull were larger in boys. The interhemispheric and sylvian fissures, the third ventricle and Evans' ratio were larger in the younger group (less than 3 years) than in the older (greater than or equal to 3 years), while the opposite was found for the cella media index and size of the skull. The size of the lateral ventricles (expressed by anterior horn width, septum-caudate distance and width of cella media) was not different in the two age groups of children. Normal limits for the linear measurements and indices are given in Table 2.

Benign intracranial hypertension. A retrospective and follow-up study

Thirty-six patients with benign intracranial hypertension (BIH) were reviewed. Follow-up was obtained on 33 patients (91%) after a mean period of 7 1/2 years. Precipitating factors were found in 27 patients (75%). On admission, 5 patients had retro-ocular pain, especially on eye movements, a complaint not yet described in BIH. Seven patients had nystagmus, two of them horizontal positional nystagmus. It is questionable whether all signs in BIH are caused by the raised CSF pressure. The general outcome was good. Only two patients sustained severe ultimate visual impairment. Both presented with retro-ocular pain and sudden loss of vision on admission. Papilloedema can persist for years in BIH without serious visual impairment. Sometimes "causal" treatment is possible. No symptomatic treatment which is free from complications has been proved to prevent visual failure.

Calculation of cerebral tissue and cerebrospinal fluid space volumes from computer tomograms

The volumes of the cerebral tissue, and internal and external cerebrospinal fluid spaces were calculated from the computer tomograms of 28 patients. On the basis of their different absorption coefficients, cerebral tissue and CSF space were outlines and their volumes calculated by computer. The ratio of cerebral tissue volume to CSF space volume was expressed as an index. This correlated well with an objective grading of severity of hydrocephalus. The index in patients without pathology was between 10.5 and 18.4. In cerebral atrophy the index was between 2.1 and 6.7 depending upon the severity. In occlusive hydrocephalus it was between 1.0 and 5.6. The changes in the volume of the CSF space after treatment can easily by demonstrated by appropriate changes in the index.

Age and sex dependence of the size of normal ventricles on computed tomography

Several parameters of the normal ventricular size have been measured routinely on more than 170 computed tomographic scans of patients with normal neurological findings. All patients have been classified into age groups of 15 years each. Means and further statistical values, separate for male and female, have been calculated and figured in a table and histograms.