Sequential pituitary MR imaging in Sheehan syndrome: report of 2 cases.

We present the evolution of pituitary changes in the cases of 2 patients with Sheehan syndrome as assessed by MR imaging. Both patients had severe postpartum hemorrhage, symptoms of pituitary gland apoplexy, and hypopituitarism. Sequential MR imaging demonstrated evidence of ischemic infarct in the pituitary gland with enlargement followed by gradual shrinkage during several months, to pituitary atrophy.

Herniation of the buccal fat pad into the maxillary antrum: CT findings in three cases.

We report the first 3 cases in which CT disclosed herniation of the body of the buccal fat pad into the maxillary antrum. Only 20 cases of traumatic herniation of the buccal fat pad have been described in the literature. In all except one instance, the buccal fat pad herniated into the oral cavity. The only previous report of herniation of the buccal fat pad into the maxillary antrum is in an article published before modern cross-sectional imaging, and the diagnosis was not made preoperatively in that case.

fMRI of triggerable aurae in musicogenic epilepsy.

The authors studied a patient with musicogenic epilepsy triggered by one specific musical piece using 3D PRESTO fMRI. During epileptic aurae initiated by the stimulus, signal increases were found in the left anterior temporal lobe, correlating with ictal EEG and SPECT showing a left anterior temporal focus, and the right gyrus rectus. Because fMRI indicated a cascade of recruitment of the ventral frontal lobes by epileptogenic music, left anterior temporal lobe activity could be secondary to a right gyrus rectus focus, possibly triggered by emotional processing of music.

Dynamic neuroimaging of brain function.

To fully characterize the brain processes underlying sensorimotor and cognitive function, the spatial distribution of active regions, their interconnected regions must be measured. We describe methods for imaging brain sources from surface-recorded EEG and magnetoencephalographic data, called electromagnetic source imaging (EMSI). EMSI provides brain source locations within the common framework of magnetic resonance (MR) images of brain anatomy. This allows integration of data from other functional brain imaging methods, like positron emission tomography and functional MR imaging, which can improve the accuracy of EMSI localization. EMSI also provides submillisecond temporal resolution of the dynamic processes within brain systems. Examples are given of applications to visual perceptual and attentional studies.

Cerebellar atrophy in patients with long-term phenytoin exposure and epilepsy.

OBJECTIVE: Cerebellar atrophy has been noted in patients with phenytoin exposure. This finding has been attributed by some investigators to seizures, but by others to phenytoin. Previous studies included patients with mental retardation and convulsive seizures. We undertook a study in a group of nonretarded patients with partial epilepsy to better elucidate the cause of the cerebellar atrophy. DESIGN: Case control study. SETTING: Referral population from an epilepsy center. PATIENTS: Thirty-six patients with partial epilepsy and long-term phenytoin exposure were selected from a consecutive sample of admissions to an epilepsy center. Patients with histories of ethanol abuse, perinatal distress, anoxia, status epilepticus, or neurodegenerative disorders were excluded. Age- and sex-matched controls were selected from a pool of healthy volunteers and patients who had undergone magnetic resonance imaging for complaints of headache and dizziness. INTERVENTIONS: All patients and controls underwent magnetic resonance imaging. MAIN OUTCOME MEASURE: Degree of cerebellar atrophy. RESULTS: The magnetic resonance imaging scans were reviewed in a blind fashion. A rating was assigned to each scan based on the degree of cerebellar atrophy. Cerebellar atrophy was significantly more pronounced in patients than in controls. No correlation was found between cerebellar atrophy and variables reflective of seizure severity or degree of phenytoin exposure. CONCLUSIONS: Cerebellar atrophy may be seen in phenytoin-exposed patients with epilepsy in the absence of generalized tonic-clonic seizures or preexistent brain damage. Whether it is the phenytoin or the seizures that play the primary etiologic role remains unanswered. These factors may be synergistic.

Association of Wilms' tumor and intracranial hemorrhage due to arteriovenous malformation.

A high incidence of congenital malformations associated with Wilms' tumor has been recognized lately. Aniridia, hemihypertrophy, and urinary tract anomalies are among the most frequently reported. Anomalies of the central nervous system associated with Wilms' tumor are rare. We report a previously healthy 4-year-old girl who presented with an intracranial hemorrhage secondary to a ruptured arteriovenous malformation. A routine abdominal examination revealed a large right-sided Wilms' tumor. The question generated by the coexistence of these two uncommon disorders in one individual is whether there is a genetic or other relationship between them, or whether this is merely a coincidental occurrence. The question at this point is unanswered and must await demonstration of additional, similar cases.

Qualitative assessment of brain morphology in acute and chronic schizophrenia.

OBJECTIVE: Neuroimaging studies of brain morphology in schizophrenia have used predominantly morphometric techniques to assess brain scans. However, as currently implemented, such methods are not particularly helpful in the routine assessment of individual patients. The purpose of this study was to evaluate brain morphology seen with magnetic resonance imaging (MRI) by qualitative assessment, the most frequently used method in clinical practice for evaluating brain scans. METHOD: First-episode (N = 62) and chronic, multi-episode (N = 24) schizophrenic patients and healthy comparison subjects (N = 42) underwent MRI of the whole head in a sequence that provided 63 contiguous brain slice images. Each subject received a rating of normal, questionably abnormal, or definitely abnormal for four brain regions (lateral ventricles, third ventricle, medial temporal lobe structures, and frontal/parietal cortex) and a global rating. RESULTS: The schizophrenic patients had significantly higher global rates of abnormal morphology (first-episode group, 31%; chronic group, 42%) than the normal subjects (5%). The highest regional rates of abnormalities were seen in the lateral ventricles and the lowest in the frontal/parietal cortex. Although the chronic patients had generally higher abnormal rates than the first-episode patients, these differences were not statistically significant. The qualitative ratings of brain morphology were significantly correlated with quantitative assessments performed in separate studies. CONCLUSIONS: Despite its limits in sensitivity (and until quantitative morphometric techniques are made practical and more widely available), qualitative evaluation of MRI scans can be a useful technique in research and clinical evaluation of patients with schizophrenia.

Increased prevalence of the cavum septum pellucidum in magnetic resonance scans and post-mortem brains of schizophrenic patients.

A cavum septum pellucidum (CSP) has been regarded as an incidental finding of little clinical importance. However, an association between this developmental anomaly and a diagnosis of psychosis has previously been reported. We determined the prevalence of the CSP in parallel studies of brain scans obtained with magnetic resonance (MR) imaging and in the post-mortem brains of schizophrenic patients compared with normal controls. We found a significantly increased prevalence of the CSP in both the MR scans and post-mortem brains of schizophrenic patients compared with controls. In the MR study, 17 of 81 (21%) schizophrenic patients but only 1 of 46 (2%) control subjects had a CSP. In the post-mortem study, 17 of 28 (61%) schizophrenic patients and 12 of 39 (31%) normal controls had a CSP. The increased prevalence of a CSP in schizophrenic patients further indicates that anomalous development of the limbic system is an important aspect of this disorder.

Abnormalities of the septum pellucidum on MR scans in first-episode schizophrenic patients.

PURPOSE AND METHODS: Cavities in the septum pellucidum have been widely regarded in clinical neurology or in autopsy series as incidental findings of little clinical importance; however, an association between this developmental anomaly and a diagnosis of psychosis has been reported. We compared MR brain scans of schizophrenic patients with normal control subjects to determine the prevalence of this finding in the two groups: RESULTS: A cavum septum pellucidum was found in 14 of 62 (23%) schizophrenic patients and only one of 46 control subjects (2%). Pronounced enlargement of the cavum septum and a cavum vergae were seen only in two schizophrenic subjects. A partial agenesis of the corpus callosum was also seen in one of the schizophrenic cases with the largest cavum septum pellucidum. CONCLUSIONS: The increased prevalence of a cavum septum pellucidum, the cavum vergae, and partial callosal agenesis in schizophrenics support the hypothesis that anomalous development of the brain is an important aspect of this disorder. The disturbed structures are closely linked developmentally to the limbic system which has been implicated etiologically in studies of schizophrenia.

Localized proton NMR observation of [3-13C]lactate in stroke after [1-13C]glucose infusion.

To assess whether elevated lactate in stable stroke is being actively produced from blood glucose localized 1H NMR stimulated echo spectra were obtained from a patient in the region of a 32-day-old cortical infarct before and 60-100 min after infusion of [1-13C]glucose. Prior to the infusion the spectrum from the region of the infarct contained an elevated resonance from C3 lactate and a greatly reduced resonance from N-acetyl groups relative to an unaffected contralateral region. After the infusion two additional resonances were observed at 62 and -64 Hz relative to the unlabeled resonance of C3 lactate which were assigned on the basis of chemical shift and relative intensity to [3-13C]lactate. The [3-13C]lactate fractional enrichment in the infarct region was measured to be 32% which is within error one-half the average [1-13C]plasma glucose enrichment during the postinfusion NMR measurement. The result suggests that the stroke lactate pool was completely derived from infused glucose.

Stroke in pediatric acquired immunodeficiency syndrome.

In a 4 1/2-year period, 4 of 68 children in a longitudinal study of neurological complications of human immunodeficiency virus (HIV) infection had clinical and/or neuroradiological evidence of stroke, yielding a clinical incidence of stroke in this population of 1.3% per year. During this period, 32 subjects died, and permission for autopsy was granted in 18 of the patients, including 3 of 4 who had clinical evidence of stroke. The prevalence of cerebrovascular pathological features in our consecutive autopsy series was higher than the clinical incidence. At autopsy cerebrovascular disease was documented in 6 (24%) of 25 children with HIV infection, including all 3 children who had clinical evidence of stroke. Four patients had intracerebral hemorrhages, 6 patients had nonhemorrhagic infarcts, and 3 had both. Hemorrhage was catastrophic in 1 child and clinically silent in 3 children, all of whom had immune thrombocytopenia. One child had an arteriopathy that affected meningocerebral arteries. In another child, the arteries of the circle of Willis were aneurysmally dilated. Two children had coexisting cardiomyopathy and subacute necrotizing encephalomyelopathy with vascular proliferation. These results suggest that stroke should be considered when children with HIV infection develop focal neurological signs.

Brain white-matter changes in the elderly prone to falling.

Falls and impaired gait are a major source of morbidity in the elderly. Why some elderly become prone to falling is often unclear. We analyzed the gait, equilibrium, and brain computed tomography results of 40 elderly subjects without evidence of neurologic disease known to be associated with falls. Twenty of these subjects were prone to falling and the remaining 20 were nonfalling controls. These two groups were comparable in terms of age and sex (mean age, 83.3 years [SE, 1.7 years]). The group of fallers had significantly worse gait and equilibrium scores and a greater degree of white-matter hypodensity on computed tomography. White-matter hypodensity correlated with impaired gait and equilibrium scores but not with impaired performance on cognitive testing. This study reveals the association of white-matter disease with gait and balance impairment leading to falls in the elderly.