Ventricular Asymmetry Research Articles

Unusual presentation of echogenic bowel: postnatal diagnosis of congenital myofibromatosis

Description of case(s): A 27-year-old primigravid woman presented for ultrasound at 25 weeks for concern over large fetal size. Biometry was appropriate for gestational age. Fluid, movement, and tone were unremarkable. Asymmetry of the cerebral ventricles was noted, 10 mm vs. 5 mm. Additionally, a fairly well-circumscribed cystic and solid area was noted midline within the fetal abdomen below the stomach. The patient underwent an amniocentesis; karyotype and TORCH studies were normal. Subsequent ultrasound examinations at 29 and 33 weeks revealed a decreased prominence of the ventricular asymmetry. The previously noted mass in the abdomen was no longer distinguishable from the normal abdominal contents though the bowel had a stippled appearance. Fetal monitoring was started at 33 weeks for mild growth restriction. Delivery was at 34.4 weeks by Cesarean section due to abnormal Dopplers and a nonreassuring fetal heart tracing.

Quantitative Assessment of Cerebral Ventricular Volumes in Chronic Fatigue Syndrome

Previous qualitative volumetric assessment of lateral ventricular enlargement in chronic fatigue syndrome (CFS) has provided evidence for subtle structural changes in the brains of some individuals with CFS. The aim of this pilot study was to determine whether a more sensitive quantitative assessment of the lateral ventricular system would support the previous qualitative findings. In this study, we compared the total lateral ventricular volume, as well as the right and left hemisphere subcomponents in 28 participants with CFS and 15 controls. Ventricular volumes in the CFS group were larger than in control groups, a difference that approached statistical significance. Group differences in ventricular asymmetry were not observed. The results of this study provide further evidence of subtle pathophysiological changes in the brains of participants with CFS.

Outcome of prenatally diagnosed mild unilateral cerebral ventriculomegaly.

The objective of this study was to determine the frequency of prenatally diagnosed unilateral cerebral ventriculomegaly and also to assess neonatal outcome in infants with this prenatal diagnosis. A computerized ultrasonography database identified fetuses with isolated and nonisolated unilateral cerebral ventriculomegaly from October 1994 to June 1999. The Denver II Developmental Screening Test was used to assess developmental skills. Unilateral cerebral ventriculomegaly was diagnosed in 15 of 21,172 (1 per 1,411) pregnancies. The width of the enlarged lateral ventricle ranged from 1.0 to 1.9 cm. In 10 (67%) of 15 cases unilateral cerebral ventriculomegaly was an isolated finding. Eight of the 14 infants who were born at 36 weeks' gestation or later had postnatal cranial imaging, and ventricular asymmetry was confirmed in 5 (63%). One infant with an arachnoid cyst and cerebral palsy died at 2 years of age. The remaining 11 infants in whom developmental milestones were assessed had age-appropriate skills. Unilateral fetal ventriculomegaly is usually an isolated finding and when isolated has little measurable effect on developmental outcome.

Cerebral ventricular asymmetry in schizophrenia: a high resolution 3D magnetic resonance imaging study

Lateral ventricular volume asymmetries in schizophrenia were studied using high resolution 3D magnetic resonance imaging in conjunction with segmentation and quantitation techniques. Comparisons were made between two clinical syndromes that have been associated with opposite patterns of functional hemispheric activation, namely an active and a withdrawn syndrome. Ratios of both left to right ventricular volume and left to right ventricle-to-brain ratios differed significantly between the two groups. These results primarily reflected differences in the left ventricular volume, in keeping with previous reports which have usually implicated left hemispheric structural abnormalities in schizophrenia. It is suggested that a syndromal approach might help to resolve some of the inconsistencies in the existing literature on lateralised neuroanatomical differences in schizophrenia.

Fetal cardiac asymmetry: a marker for congenital heart disease

Objective: To determine the sensitivity of prenatally detected fetal cardiac asymmetry as a sonographic marker for congenital heart disease. Methods: The normal ratios of pulmonary artery to aorta diameters and of right ventricle to left ventricle diameters were derived from normal fetuses scanned at 17 weeks or more in a 65-month period. Cross-sectional diameters of cardiac ventricles and great arteries were measured at the level of the valves at the time of the scan. Fetuses with confirmed cardiac anomalies detected prenatally during the study were examined to identify how many had cardiac asymmetry, determined by abnormal ratios. Results: Linear regression analysis of the group of 881 normal fetuses showed the normal pulmonary artery to aorta diameter ratio remained constant throughout pregnancy and the normal right ventricle to left ventricle ratio increased slightly with progressing gestational age. The 90% confidence intervals were 0.79, 1.24 for the right ventricle to left ventricle ratio and 0.84, 1.41 for the pulmonary artery to aorta ratio. Of the 73 fetuses with abnormal hearts, 66% had either ventricular or great artery asymmetry (at least one of the two ratios was abnormal). However, if no asymmetry was present, the cardiac defect was more likely to be a minor one. Conclusion: Cardiac asymmetry was present in two-thirds of fetuses with cardiac anomalies diagnosed prenatally. If cardiac asymmetry is found, a more thorough examination of the fetal heart is indicated.

Fetal Cardiac Asymmetry

In Brief Objective To determine the sensitivity of prenatally detected fetal cardiac asymmetry as a sonographic marker for congenital heart disease. Methods The normal ratios of pulmonary artery to aorta diameters and of right ventricle to left ventricle diameters were derived from normal fetuses scanned at 17 weeks or more in a 65-month period. Cross-sectional diameters of cardiac ventricles and great arteries were measured at the level of the valves at the time of the scan. Fetuses with confirmed cardiac anomalies detected prenatally during the study were examined to identify how many had cardiac asymmetry, determined by abnormal ratios. Results Linear regression analysis of the group of 881 normal fetuses showed the normal pulmonary artery to aorta diameter ratio remained constant throughout pregnancy and the normal right ventricle to left ventricle ratio increased slightly with progressing gestational age. The 90% confidence intervals were 0.79, 1.24 for the right ventricle to left ventricle ratio and 0.84, 1.41 for the pulmonary artery to aorta ratio. Of the 73 fetuses with abnormal hearts, 66% had either ventricular or great artery asymmetry (at least one of the two ratios was abnormal). However, if no asymmetry was present, the cardiac defect was more likely to be a minor one. Conclusion Cardiac asymmetry was present in two-thirds of fetuses with cardiac anomalies diagnosed prenatally. If cardiac asymmetry is found, a more thorough examination of the fetal heart is indicated. Asymmetry of the fetal heart is a marker for congenital heart disease.

Ephemeral New Traces and Evaporated Remote Engrams: A Form of Neocortical Temporal Lobe Amnesia? A Preliminary Case Report

We report the case of a patient (GB) with a 2-year history of memory disturbances characterized by forgetting of both recently learned traces and remote information acquired decades before. Forgotten contents involved the episodic aspects of autobiographical and media-mediated information. Moreover, a mild anterograde verbal learning defect was evident. General cognition was normal. In the last months of our observation, GB developed partial complex epilepsy with EEG evidence of a left temporal anterior focus. He never experienced acute transient amnesic episodes. MRI showed normal and symmetrical temporomedial aspects, and a slight ventricular asymmetry with a greater extension of the left ventricle. No brain atrophy was apparent. It is speculated that GB's memory loss is the consequence of a neocortical left temporal lobe dysfunction due to a still obscure underlying degenerative process which produces, as its neurological counterpart, not atrophy, but epilepsy. Temporal epilepsy is cautiously rejected as a crucial determinant of GB's amnesia.

Isolated lateral ventricular asymmetry in very low-birth-weight infants: a left-sided lesion?

We prospectively performed serial cranial ultrasonography to determine the incidence of asymmetry of the lateral ventricles in very low-birth-weight (VLBW) infants (500-1500 g) who did not have evidence of other intracranial pathology. Of the 490 babies scanned, 354 were free of other pathology and 41 (11.6%) had isolated ventricular asymmetry. In 10 infants, the asymmetry was seen on the initial scan and in 31, it developed subsequently. In 19 infants, the ventricular asymmetry resolved and in 22 infants it persisted until hospital discharge. In no case was progressive enlargement of the ventricles noted. There was a striking tendency of the larger ventricle to be on the left side (33 L>R, 8 R>L). Compared with a control group of babies matched for birth weight and gestational age who had persistently negative scans, there were no differences in Apgar scores, cesarean section rate, gender distribution, prenatal steroid exposure, or complications of prematurity except for an increased incidence of respiratory distress syndrome requiring surfactant in the group with ventricular asymmetry (63% vs. 29%, p = 0.04). Ventricular asymmetry is common in VLBW infants, but whether it is an incidental finding or represents subtle brain injury is unknown.

Magnetic resonance imaging of the lateral ventricles in beagle-type dogs.

Magnetic resonance (MR) imaging was performed on 21 presumed normal Beagle-type dogs. The size and symmetry of their lateral ventricles were evaluated and dogs were categorized on the basis of the percentage of their ventricular height (Vh) to brain height (Bh) and the ratio of the largest to the smallest ventricular area (rVA). Eleven dogs had lateral ventricles classified as normal sized (0-14% Vh/Bh) while 10 of 21 dogs had moderate enlargement (15-25% Vh/Bh) of one or both lateral ventricles. None of the dogs had severe lateral ventricular enlargement. Degree of asymmetry was also arbitrarily categorized on basis of rVA as normal to minimal (rVA < 1.5), mild (1.5 < rVA < 2.0), or severe (2.0 < rVA). Of the dogs having normal-sized lateral ventricles, six of eleven had symmetric, three of eleven had mildly asymmetric and two of eleven had severely asymmetric lateral ventricles. Of the dogs having at least one moderately enlarged lateral ventricles, five of ten had symmetric lateral ventricles, and two of ten had mild asymmetry and three of ten had severe asymmetry. Gender and body weight had no statistical relationship to lateral ventricle symmetry. Clinically insignificant ventricular enlargement and asymmetry was common in this group of Beagle dogs.

Ventricular volume and asymmetry in schizotypal personality disorder and schizophrenia assessed with magnetic resonance imaging

Magnetic resonance imaging (MRI) was performed in 12 patients with schizotypal personality disorder (SPD), 11 patients with chronic schizophrenia, and 23 age-and sex-matched normal volunteers. MRI slices were acquired in the axial plane at 1.2-mm intervals, and the ventricles were traced on every other slice. The lateral ventricular system was divided into the anterior horn, temporal horn, and dorsal lateral ventricle. Schizophrenic patients had larger left anterior and temporal horns than the normal volunteers. Size of the left anterior and temporal horn in SPD patients was intermediate between those of normal volunteers and schizophrenic patients and differed significantly from schizophrenic patients. The left-minus-right difference was larger in schizophrenic patients than in normal volunteers or SPD patients. Thus, in their structural brain characteristics, as well as in their clinical symptomatology, SPD patients evidence, in attenuated form, abnormalities resembling those found in full-fledged schizophrenia. The findings suggest that decreased left hemispheric volume, in frontal and temporal regions, may characterize both psychotic and non-psychotic disorders of the schizophrenia spectrum.

The fornix of the human brain: evidence of left/right asymmetry on axial MRI scans.

This article reports the observation that there is a left/right asymmetry of the anterior columns of the fornix in the human brain. This asymmetry is present in the position of the two columns of the fornix in relation to the septum pellucidum. The left columna fornicis was found to be located caudal to the right, and this can be readily visualized on axial MRI scans. This difference was seen in most of the subjects, but in some subjects there was no left/right-difference and in a few the asymmetry was inverse. The asymmetry of the fornix with respect to the anterior-posterior axis was independent of the well-known dissimilar lateral ventricular volumes. However, the left/right difference in the position of the fornix was evident in subjects with or without differences in ventricular volumes. This suggests that the mechanism underlying the development of asymmetry of the fornix is independent of the mechanism leading to ventricular asymmetry. So far, no functional relevance has been ascribed to such differences in location. The finding is gaining interest in connection with recent reports of asymmetries in hippocampal subfields. Studies of fornical lesions should therefore give attention to possible side-to-side differences.

Cerebral lateral ventricular asymmetry: Is this a normal ultrasonographic finding in the fetal brain?

To evaluate the clinical significance of in utero detection of fetal cerebral lateral ventricular asymmetry. We used high resolution ultrasonography to study asymmetries of the fetal lateral ventricles in the human brain. A retrospective survey was conducted on 7200 pregnant women who presented at two large district hospitals in Israel. Only fetuses with a difference of greater than 2.4 mm (two standard deviations) in the width of the lateral ventricles, with no known brain pathology, were included in the study. Index cases were evaluated regarding maternal complications, prenatal ultrasound examinations, postnatal imaging studies, and neonatal outcome up to 6 months of age. Lateral ventricular asymmetry was found in 21 subjects, all with available clinical data. In 15 fetuses (71%), the body or the occipital horn of the left lateral ventricle was larger than the right, whereas in six fetuses (29%), the right was larger than the left. In four cases (20%), serial scans noted resolution of asymmetry; in 15 (75%), it was persistent; and in one (5%), asymmetry increased. In one case, termination of pregnancy was performed; however, pathologic examination of the fetal brain failed to detect any structural abnormality. Underlying cerebral pathology was later found only in three fetuses (14%); one had subclinical cytomegalovirus ventriculitis, one had insidious periventricular hemorrhage, and in one fetus with increased asymmetry, trisomy 21 was verified. All the remaining 17 cases had normal neurologic development. Some degree of asymmetry of the lateral ventricles exists in the human fetal brain and is detectable in utero. Lateral ventricular asymmetry alone is probably not clinically significant, and it may be considered as a normal variant, rather than a pathologic finding.

Quantitative brain magnetic resonance imaging in attention-deficit hyperactivity disorder.

Anatomic magnetic resonance imaging (MRI) studies of attention-deficit hyperactivity disorder (ADHD) have been limited by small samples or measurement of single brain regions. Since the neuropsychological deficits in ADHD implicate a network linking basal ganglia and frontal regions, 12 subcortical and cortical regions and their symmetries were measured to determine if these structures best distinguished ADHD. Anatomic brain MRIs for 57 boys with ADHD and 55 healthy matched controls, aged 5 to 18 years, were obtained using a 1.5-T scanner with contiguous 2-mm sections. Volumetric measures of the cerebrum, caudate nucleus, putamen, globus pallidus, amygdala, hippocampus, temporal lobe, cerebellum; a measure of prefrontal cortex; and related right-left asymmetries were examined along with midsagittal area measures of the cerebellum and corpus callosum. Interrater reliabilities were .82 or greater for all MRI measures. Subjects with ADHD had a 4.7% smaller total cerebral volume (P = .02). Analysis of covariance for total cerebral volume demonstrated a significant loss of normal right > left asymmetry in the caudate (P = .006), smaller right globus pallidus (P = .005), smaller right anterior frontal region (P = .02), smaller cerebellum (P = .05), and reversal of normal lateral ventricular asymmetry (P = .03) in the ADHD group. The normal age-related decrease in caudate volume was not seen, and increases in lateral ventricular volumes were significantly diminished in ADHD. This first comprehensive morphometric analysis is consistent with hypothesized dysfunction of right-sided prefrontal-striatal systems in ADHD.

P300 lateral asymmetries in schizophrenic syndromes

Lateral ventricular volume asymmetries in schizophrenia were studied using high resolution 3D magnetic resonance imaging in conjunction with segmentation and quantitation techniques. Comparisons were made between two clinical syndromes that have been associated with opposite patterns of functional hemispheric activation, namely an active and a withdrawn syndrome. Ratios of both left to right ventricular volume and left to right ventricle-to-brain ratios differed significantly between the two groups. These results primarily reflected differences in the left ventricular volume, in keeping with previous reports which have usually implicated left hemispheric structural abnormalities in schizophrenia. It is suggested that a syndromal approach might help to resolve some of the inconsistencies in the existing literature on lateralised neuroanatomical differences in schizophrenia.

The relationship of minor physical anomalies and other putative indices of developmental disturbance in schizophrenia to abnormalities of cerebral structure on magnetic resonance imaging

Minor physical anomalies, together with obstetric complications, family history, and handedness status, were assessed to explore putative neurodevelopmental disturbance(s) in patients with schizophrenia whose cerebral structure had been examined previously by magnetic resonance imaging. Minor physical anomalies were related to negative symptoms in males and to premorbid intellectual function in females, but not to ventricular volume; however, three patients with evident neurodevelopmental anomalies of the ventricular system showed prominent minor physical anomalies. In exploratory analyses, obstetric complications were associated with left ventricular asymmetry, and a positive family history with inverse profiles of asymmetry in males vs. females; non-right-handedness was associated with increased ventricular volume in males but with poorer premorbid intellectual function in females. This nexus of relationships and their gender specificities suggest early dysmorphogenesis in schizophrenia that is related to sexual dimorphism.

Cerebral morphometric abnormalities in Tourette's syndrome

Although the pathologic substrate of Tourette's syndrome (TS) is unknown, studies have implicated subtle changes in the basal ganglia. To further investigate structural basal ganglia pathology in TS, we performed morphometric analyses of MRIs of 10 monozygotic twin pairs discordant for severity of TS but concordant for the presence of tic disorders (mean age, 16.3 years; range, 9 to 31 years). Right caudate volume was slightly but significantly reduced in the relatively more severely affected twins as a group compared with the less affected twins (mean difference = 6%, p < 0.01). Most of this difference was attributable to volume reduction in the anterior right caudate (p < 0.02), which was smaller in the more severely affected twin in nine of 10 twin sets. The mean volume of the left lateral ventricle was 16% smaller in the more severely affected twins than in the less severely affected twins (p < 0.01). The normal asymmetry of the lateral ventricles (left greater than right) was not present in the more severely affected twins, who had a trend toward a larger right lateral ventricle. Moreover, the difference within a pair in the degree of loss of the normal ventricular asymmetry correlated with the difference within a pair in the severity of the tic disorder (r = 0.75, p < 0.02). There were no other basal ganglia, ventricular volumetric, or asymmetry abnormalities. These findings partially replicate other MRI studies and suggest that subtle structural abnormalities in the CNS, particularly in the caudate, may play a role in the pathophysiology of TS.(ABSTRACT TRUNCATED AT 250 WORDS)

Congenital Fibrosis of the Vertically Acting Extraocular Muscles: A New Group of Dominantly Inherited Ocular Fibrosis with Radiologic Findings

The authors studied a family with a form of congenital fibrosis of the extraocular muscles different from any group previously reported. A careful examination was done of all affected and all, except one, unaffected members of a family of 15 members extending over three generations. The authors performed computed tomography on five affected and four unaffected family members. All affected family members showed complete loss of vertical ocular movement but largely free horizontal movement except for variable restriction of adduction in some members. A variable degree of ptosis was present, ranging from gross to nil, but with poor levator function and an absent Bell phenomenon in all affected members. All affected members showed superficial keratopathy, many with corneal scarring. Ocular alignment showed considerable variation. Refractive error and amblyopia also were variable. Computed tomographic scan indicated reduction in size of the extraocular muscles, particularly the superior recti with intracranial ventricular asymmetry in three of five patients examined, and abnormality in shape of the eye globes in two patients. The findings indicate a new group best described as dominantly inherited congenital fibrosis of the vertical-acting extraocular muscles, which is part of the syndrome of congenital ocular fibrosis. Computed tomographic scanning suggested that the clinical picture was produced by changes present in the orbit, but intracranial ventricular asymmetry also was present in some patients and asymmetry of the eye globes in others.

Magnetic resonance imaging in familial versus sporadic cases of schizophrenia

Magnetic resonance imaging findings were compared in 22 familial and 29 sporadic cases with DSM-III-R diagnosis of schizophrenia, schizoaffective, or schizophreniform disorders. Volumetric measurements were used to assess the size of brain structures, including the cranium, cerebrum, lateral ventricles, temporal horns, third ventricle, lenticular nuclei, amygdaloid-hippocampal complex, and cerebellum, as well as the asymmetry of the lateral ventricles. Increased volume of the lenticular nuclei and greater ventricular asymmetry (the left ventricle being larger) were found in familial cases compared with sporadic cases and normal control subjects. It is possible that increased lenticular nuclei volume and greater lateral ventricular asymmetry reflect the role of genetic factors in schizophrenia.

NORMAL VARIATION IN SIZE OF THE LATERAL VENTRICLES OF THE LABRADOR RETRIEVER DOG AS ASSESSED BY MAGNETIC RESONANCE IMAGING

Detecting canine brain lesions on computed tomography (CT) or magnetic resonance (MR) scans can be difficult if the lesions do not enhance well following administration of intravenous contrast material. Changes in the shape and position of the ventricular system can be important in the diagnosis of such lesions. Normal variation within the canine ventricular system has not been documented. MR scans from 62 normal Labrador retriever type dogs were evaluated. Five dogs had symmetric enlargement of the ventricles, while nineteen dogs had mild to severe ventricular asymmetry. The incidence of asymmetry in normal dogs must be considered when using ventricular configuration as an indication of central nervous system abnormality.

Phasic coronary flow characteristics in patients with hypertrophic cardiomyopathy: a study by coronary Doppler catheter.

Abnormal patterns of coronary flow velocity have been observed in patients with symmetric left ventricular hypertrophy in conditions such as aortic stenosis and systemic hypertension. However, phasic coronary flow characteristics have not been investigated in patients with asymmetric left ventricular hypertrophy in hypertrophic cardiomyopathy. The purpose of this study was to assess phasic coronary flow characteristics and their relation to echocardiographic and hemodynamic parameters in patients with hypertrophic cardiomyopathy. Coronary flow velocity was recorded in the left anterior descending artery with a 20 MHz Doppler catheter in eight patients with hypertrophic nonobstructive cardiomyopathy and eight control subjects with normal coronary arteries. Flow reversals observed in systole in all patients with hypertrophic cardiomyopathy, and the time velocity integrals of systolic flow were significantly smaller in patients with hypertrophic cardiomyopathy than in control subjects (-1.5 +/- 1.7 versus 4.3 +/- 1.2 cm; p < 0.01). The time from the beginning of diastole to peak diastolic velocity corrected by the square root of R-R interval (square root of RR) was prolonged significantly, and the velocity half-time from peak diastolic velocity corrected by square root of RR was shorter in the patients with hypertrophic cardiomyopathy compared with those in the control subjects (6.8 +/- 2.0 msec versus 4.0 +/- 0.6 msec [p < 0.01] and 9.2 +/- 4.9 msec versus 13.9 +/- 2.0 msec [p < 0.05], respectively). Peak velocity and time velocity integral of flow reversal showed significant correlations with anterior ventricular septal thickness (y = -0.5x + 13.5, r = 0.8, and p < 0.01; y = -1.3 +/- 16.8, r = 0.8, and p = 0.024, respectively), the septal/free wall thickness ratio (y = -0.1x + 1.1, r = 0.8, and p < 0.01; y = -0.2x + 1.4, r = 0.9, and p < 0.01, respectively), and the degree of narrowing of the first septal perforator arteries (y = 1.9x + 91.6, r = 0.8, and p = 0.012; y = 6.1x + 80.6, r = 0.9, and p < 0.01, respectively). In conclusion, flow reversal in systole and slow acceleration and rapid deceleration in diastole were characteristics in patients with hypertrophic cardiomyopathy. Flow reversal might be related to the degree of left ventricular asymmetry and compression of the septal perforator arteries.