Aqueductal stenosis and neurofibromatosis: a rare association.

Three cases with rare association of neurofibromatosis, hydrocephalus, and aqueductal stenosis seen at the University of Iowa during the past 20 years are presented. The literature on nontumoral hydrocephalus and aqueductal stenosis in neurofibromatosis is reviewed. Possible explanations for the association of aqueductal stenosis and neurofibromatosis are discussed. It is concluded that aqueductal stenosis, though not common, should nevertheless be considered in the differential diagnosis of hydrocephalus in neurofibromatosis.

Trigeminal nerve lipoma: MR findings.

Trigeminal nerve lipomas are rare tumors that typically cause progressive focal neurologic symptoms due to their intimate involvement with nerve fascicles and adjacent neural structures. We describe the CT and magnetic resonance (MR) findings of this unusual tumor. The changes in signal intensity on T1 and T2 weighted MR scans provide precise anatomic location and tissue characterization prior to surgical intervention.

Cerebellar atrophy in schizophrenia and affective disorder.

The authors evaluated 108 patients with schizophrenia, 50 patients with affective disorder, and 74 age- and sex-matched control subjects by CAT scan for evidence of global cerebellar atrophy. No difference was found between control subjects and schizophrenic patients or between control subjects and patients with affective disorder. This study does not confirm previous reports linking cerebellar atrophy to schizophrenia.

Accelerated myelination in early Sturge-Weber syndrome demonstrated by MR imaging.

Magnetic resonance imaging of the brain in two infants with Sturge-Weber syndrome has demonstrated a pattern of accelerated myelination in the abnormal cerebral hemisphere. The extent of myelination was most apparent on the T1-weighted inversion recovery sequence while the T2-weighted images demonstrated concomitant changes in hydration of the brain. We propose an explanation for this finding based on cerebral ischemia underlying the leptomeningeal angioma.

Cerebral hemiatrophy, hypoplasia of internal carotid artery, and intracranial aneurysm. A rare association occurring in an infant.

A 4-month-old child with a very rare association of primary (congenital) left cerebral hypoplasia, hypoplasia of the left internal carotid artery, and giant anterior communicating artery aneurysm was seen. The aneurysm was detected and treated before rupture. We briefly reviewed the literature on agenesis (hypoplasia) of the internal carotid artery, intracranial aneurysms in childhood, and primary cerebral hypoplasia. It is proposed that cerebral arteriography, cranial computed tomography, or magnetic resonance imaging be performed in all children with primary cerebral hemihypoplasia to establish an etiologic diagnosis and, more importantly, to detect and treat possible associated intracranial aneurysms before they become symptomatic.

Cerebellopontine angle-petromastoid mass lesions: comparative study of diagnosis with MR imaging and CT.

Capabilities of computed tomography (CT) and magnetic resonance (MR) imaging in the diagnosis of cerebellopontine angle-petromastoid (CPA-PM) lesions were compared in 75 patients. CT and MR demonstrated 95.8% and 98.7% of the lesions, respectively. MR was often more helpful for characterization of neuromas, epidermoid cysts, exophytic gliomas, and vascular lesions, while CT was usually more informative for meningiomas, metastases, and tympanomastoid cholesteatomas. A specific diagnosis could be made with MR for most types of lesions through use of relaxation parameters and characteristic morphologic changes. Size, shape, location, and contour of the lesions, however, were generally more helpful for differential diagnosis than relaxation times. With the exception of metastatic lesions, cholesteatomas, and some meningiomas, MR was usually more helpful than CT in defining the full extent of the lesions and their relationships to contiguous structures. MR, because of its high accuracy in lesion detection, characterization, and localization, is a suitable primary diagnostic modality for evaluating patients with suspected CPA-PM lesions.

Dichotomy between clinical findings and MR abnormalities in pontine infarction.

Comparison between cranial CT and magnetic resonance (MR) imaging in 10 patients with recent pontine infarction indicates a distinct superiority for MR. However, MR changes often failed to correlate with the degree of neurological dysfunction. Regions of abnormal signal intensity appeared to involve areas with normal neurologic function.

Cerebellar infarction: comparison of computed tomography and magnetic resonance imaging.

We correlated clinical, computed tomographic (CT), and magnetic resonance imaging (MRI) findings in 14 patients with cerebellar infarctions. Before MRI, the diagnosis of cerebellar infarction was made in only 7 patients on the basis of clinical and CT evidence. Cerebellar infarction was bilateral in 3 patients and was associated with brainstem infarction in 6. Infarction occurred in the territory of the posterior inferior cerebellar artery (PICA) in 12 patients. The territory of the superior cerebellar artery (SCA) was involved in 1 patient, and 1 infarction encompassed the watershed between the PICA and the SCA. In patients with infarction of the PICA territory, the medial and intermediate hemispheric segments were most frequently involved. Involvement of the lateral hemispheric segment was infrequent and was independent of brainstem involvement. Because of its fine demonstration of anatomical detail, its lack of bony artifact, and its ability to visualize infarctions readily within the first 24 hours, MRI is an excellent method for demonstrating cerebellar infarction.

Cortical atrophy in young adults with a history of hyperactivity in childhood.

A computed tomographic (CT) brain scan study was conducted in 24 young males treated and followed up for hyperactivity since childhood. Compared to 27 matched controls, adults with a history of hyperactivity had a significantly greater frequency of cerebral atrophy. No differences in cerebellar atrophy frequency or in lateral cerebral ventricle-to-brain ratio (VBR) were found. The possible associations of hyperactivity or perhaps stimulant drug treatment to atrophic brain changes are discussed.

Cerebral ventricular enlargement in schizophrenia. A preliminary follow-up study.

Lateral cerebral ventricular enlargement is now known to occur in some schizophrenic patients. To determine whether ventriculomegaly in schizophrenia is a static vs progressive process, we conducted a follow-up computed tomographic brain scan study on 11 young male patients, three years after initial scans were obtained. No significant change was found in the mean ventricles-brain ratio of this small schizophrenic sample after three years. Four of 11 patients showed noticeable increases (greater than 50%) in individual ratio. Methodologic problems are discussed and the need for follow-up studies as a research strategy is emphasized.

Third ventricular enlargement on CT scans in schizophrenia: association with cerebellar atrophy.

The width, length, and ventricle-to-brain area ratio (VBR) of the third ventricle were measured in 55 consecutive young male schizophrenic patients and 27 matched control subjects. No differences in third ventricular dimensions were found between the two groups. However, schizophrenic patients with cerebellar atrophy had a significantly greater mean third ventricular length. Correlations of third ventricular VBR with lateral ventricular VBR, but not with sulcal widening, were found. The possible existence of a subset of schizophrenic patients defined by cerebellar atrophy and third ventricular enlargement is discussed.

Spatial perception testing in diagnostic radiology.

A test predictive of ultimate radiologic expertise could be of great value in the selection of individuals entering the field. Some individuals have an aptitude superior to others to perceive three-dimensional spatial relations from two-dimensional data. This may enhance their ability to draw radiologic conclusions from clinical images and may favorably affect their performance as radiologists. To test cognitive perceptual ability, a three-dimensional Visual Form Reconstruction Test (form test) was developed and administered to residents and faculty members. All subjects also completed the Thurstone Surface Development Test, a standardized test of spatial visualization ability. The form test results correlated well with resident performance, as measured by overall faculty ratings (predictive validity). Although form test and Thurstone test performance were highly correlated with each other (concurrent validity), the form test was better correlated with resident performance. Intercorrelations among the three subsections of the form test demonstrated high split-part reliability. Performance on the form test was unaffected by level of training. This suggests that an underlying aptitude was measured. These preliminary results indicate that testing of spatial visualization aptitude is predictive of resident performance in radiology. A test such as this could be useful in selection and self-selection of resident candidates.

Cerebral asymmetry in subtypes of schizophrenia.

CT scans of 26 nonparanoid and 10 paranoid right-handed male schizophrenics were examined. Multiple measurements were made of each region of the brain and a standard error of measurement with a confidence level of p less than .01 was used to define significant asymmetry. Three aspects of cerebral asymmetry, i.e., local hemispheric width, local hemispheric protrusion, and regional hemispheric size, were examined. Paranoid and nonparanoid patients were similar in their patterns of frontal asymmetries. However, a substantial proportion of nonparanoid schizophrenics had wider, longer, and larger right parieto-occipital lobes compared to paranoid patients.

An evaluation of computer-assisted instruction in radiology.

The effectiveness of computer-assisted instruction in two radiologic topics was investigated. A group of fourth-year medical students received computer-assisted instruction while a control group received the same material by way of a conventional lecture. Each group was tested before and after instruction, and the group mean scores were compared. Student attitudes were elicited by questionnaire. Computer-assisted instruction was as effective as the lecture in improving the students' test performance. Subjectively, computer-assisted instruction was rated superior by the students because of its interactive nature. Applications of computer-assisted instruction in radiology education are discussed.

Orbital hypotelorism. An isolated autosomal dominant trait.

Four patients from three consecutive generations of a family with ocular hypotelorism are described. Radiographs document a subnormal distance between the medial orbital walls. To our knowledge, this is the first report of heritable isolated orbital hypotelorism. The pedigree is consistent with an autosomal dominant disorder.

Clinical correlates of sulcal widening in chronic schizophrenia.

Fifty-five chronic schizophrenic males who consented to have a computed tomographic (CT) brain scan were divided into those with cerebral atrophy evidenced by sulcal widening (n = 22) and those with normal sulci (n = 33). The two groups were compared on several clinical variables obtained from medical records by psychiatrists who were unaware of the CT results. Schizophrenic men with sulcal enlargement were significantly less likely to show agitation as a clinical symptom during an acute relapse and had significantly worse cognitive test scores on admission to the hospital. The implications of these findings are compared to the literature on ventricular enlargement and their clinical applications are discussed.