Imaging findings in patients with clinical anophthalmos.

PURPOSETo review the intracranial and facial imaging features in children with congenital anophthalmos.METHODSWe retrospectively studied eight children with anophthalmos with respect to intraorbital, intracranial, and craniofacial anomalies (six had CT examinations, including the face, orbits, and brain, and four had MR imaging, including the orbits and brain).RESULTSThree patients had primary bilateral anophthalmos on CT (n = 1) and MR (n = 3) studies. In these patients, MR images showed hypoplasia of the optic chiasm and posterior visual pathways (n = 3), agenesis (n = 1) or dysgenesis of the corpus callosum (n = 2), and a mass in the tuber cinereum region (n = 1). One patient had incontinentia pigmenti. Five patients had unilateral anophthalmos on CT (n = 5) and MR (n = 1) studies. One of these patients had a contralateral congenital cystic eye and one had contralateral severe microphthalmia and absent optic chiasm. All had craniofacial anomalies that consisted of midline facial clefts (n = 2) and concomitant hemifacial hypoplasia (n = 2). One had a craniosynostosis. All five had normal-appearing brains.CONCLUSIONPatients with bilateral anophthalmos represent a distinct group from those with unilateral anophthalmos. In our patients, bilateral anophthalmos was associated with absence of the optic chiasm, diminished size of the posterior optic pathways, and agenesis or dysgenesis of the corpus callosum. Patients with unilateral anophthalmos had severe craniofacial anomalies. Imaging of the face is helpful in patients with unilateral anophthalmos.     

Cerebrotendinous xanthomatosis (van Bogaert-Scherer-Epstein disease): CT and MR findings.

PURPOSETo describe the CT and MR findings in the brain and spinal cord of patients with cerebrotendinous xanthomatosis and to seek possible correlations between clinical, biochemical (cholestanol levels), and neuroimaging findings.METHODSTen patients with well-defined clinical and biochemical diagnoses of cerebrotendinous xanthomatosis were examined. Brain CT was performed in eight cases. In all patients MR was obtained using spin-echo and gradient-echo sequences. In eight patients spine MR was also performed.RESULTSNeuroradiologic findings included diffuse cerebral and cerebellar atrophy. In half the cases, atrophy of the brain stem and corpus callosum was also found. In the majority of patients cerebellar bilateral focal lesions and mild white matter signal alterations were present. Spinal cord MR did not show signal abnormalities or atrophy.CONCLUSIONSWe found cranial alterations in patients with severe neurologic impairment, but there was no correlation with cholestanol plasma levels. No spinal cord abnormalities were present.     

Diffuse cortical necrosis in a neonate with incontinentia pigmenti and an encephalitis-like presentation

Incontinentia pigmenti is a rare neurocutaneous disorder that may present with neurologic symptoms, in addition to a characteristic vesicular rash within the first days of life. We describe a neonate girl presenting with a rash and an encephalopathy who was first thought to suffer from a viral infection and was only later recognized as being affected by incontinentia pigmenti. Cerebral MR imaging showed extensive cortical necrosis in the acute period. Incontinentia pigmenti should be included in the differential diagnosis of encephalopathy and cutaneous involvement in neonates, after a viral infection has been ruled out.     

Quantitative cerebral MR in rheumatoid arthritis.

PURPOSETo determine the presence of hyperintense white matter lesions and atrophy reflecting cerebral vasculitis in rheumatoid arthritis.METHODSThirty-three patients with rheumatoid arthritis and 48 control subjects were examined with MR. Mean age was 45.1 years (range, 26 to 55 years) for the patients and 42.2 years (range, 25 to 55 years) in the control group. To determine atrophy we measured the area of corpus callosum, the cerebrum, and the cerebellum on midline sagittal sections. On transverse images, the ventricle-to-brain ratio, the bifrontal ratio, and the bicaudate ratio were selected as atrophy parameters. Area and signal intensity were measured for the biggest and the smallest lesions in both groups.RESULTSNine patients (27%) had hyperintense lesions compared with 15 (31%) of the control subjects. Mean numbers of hyperintense lesions were 1.3 in patients and 2.1 in control subjects. Mean area of the largest lesion in each patient was 27.4 mm2 for the patients and 29.8 mm2 in the control group. In patients with long disease duration (> 15 years) the mean ventricle-to-brain ratio was 0.09 compared with 0.08 in the control subjects. The midsagittal area of the cerebellum was 1349.8 mm2 in the patients with long disease duration and 1573.3 mm2 in the control group. No difference in number of hyperintense white matter lesions was detected between patients with long disease duration and the control subjects. Comparing the total group of patients with the control subjects, no significant differences in atrophy parameters or hyperintense white matter lesions were found. Also, there were no significant differences in relative signal intensity of the hyperintense lesions and corpus callosum between the two groups. We were not able to detect differences between treated versus untreated patients.CONCLUSIONThis study indicates a tendency of more cerebral and cerebellar atrophy in patients with severe rheumatoid arthritis. The number and size of the white matter lesions were not significantly different in the two groups and do not support a higher frequency of even clinically silent infarcts caused by vasculitis in the patients with rheumatoid arthritis compared with control subjects.     

Anomalies of the corpus callosum: correlation with further anomalies of the brain

The MR imaging studies of 68 patients who had brain anomalies were reviewed retrospectively to evaluate specific anatomic abnormalities of the corpus callosum. The corpus callosum was abnormal in 32 (47%) of the 68 patients. Excluding patients with the Chiari I malformation, callosal anomalies were present in 30 (68%) of 44 patients. Callosal dysgenesis was most common, followed by callosal atrophy or hypoplasia and complete agenesis. The anterior commissure was present in all patients. On the basis of the known temporal sequence of brain and callosal embryogenesis, we deduced the following regarding the pathogenesis of developmental anomalies: (1) callosal dysgenesis occurs as a result of insults during the formation of its precursors, not during formation of the corpus callosum itself; (2) the Dandy-Walker malformation sometimes occurs as a result of an insult in the eighth week of gestation, several weeks later than has been generally accepted; (3) sphenoidal encephaloceles probably occur as a result of faulty disjunction of neuroectoderm and cutaneous ectoderm at the anterior neuropore; and (4) a complete but atrophic corpus callosum results from an insult to the cortex or white matter after formation of the corpus callosum is complete (18-20 weeks). Callosal anomalies, easily identified on MR, are an important indicator of additional brain anomalies. Analysis of the corpus callosum provides important information about the embryogenesis of brain anomalies and may assist in distinguishing between in utero and perinatal brain insults.     

Quantitative determination of MS-induced corpus callosum atrophy in vivo using MR imaging

To quantitate the extent of corpus callosum atrophy in multiple sclerosis, midsagittal corpus callosum areas were determined in 48 controls with normal MR scans and 41 patients with definite multiple sclerosis. The mean midsagittal corpus callosum area was 601 mm2 (range 405-791), 641 mm2, and 561 mm2 for all adult controls, for adult males, and for adult females, respectively. Control values were significantly greater than the means determined for all multiple sclerosis (MS) patients (508 mm2, range 281-758), for MS men (528 mm2), or for MS women (498 mm2). The degree of corpus callosum atrophy paralleled the estimated volume of periventricular and corpus callosum high-signal lesions, suggesting a possible cause-effect relationship. The results indicate that corpus callosum atrophy occurs commonly in patients with typical clinical forms of multiple sclerosis.     

Neuroradiologic findings in Marinesco-Sjögren syndrome.

PURPOSEOur purpose was to determine the neuroradiologic findings of Marinesco-Sjögren syndrome on plain skull radiographs, CT, and MR images.METHODSEight patients with proved Marinesco-Sjögren syndrome (age range, 4 to 56 years) had a total of nine CT scans, seven MR imaging studies, and two plain radiographic examinations of the skull. The findings were reviewed retrospectively, with particular attention to the size of the posterior fossa and cerebellum.RESULTSAll patients had hypoplastic cerebellar hemispheres and a hypoplastic vermis in a small posterior fossa. One patient had a midline posterior fossa cyst and another had agenesis of the corpus callosum.CONCLUSIONHypoplasia of the cerebellar hemispheres and the vermis and a small posterior fossa are the most prominent neuroradiologic findings in Marinesco-Sjögren syndrome.     

MR imaging of corpus callosotomy

MR findings in 13 patients who underwent corpus callosotomy for medically intractable seizures were reviewed. Preoperative MR studies were available in nine patients: five showed at least one morphological and/or MR signal abnormality including corpus callosal thinning (four cases), cerebellar atrophy (two cases), cortical atrophy (two cases), and periventricular hyperintensity on T2-weighted images (one case). Four patients had normal MR studies. Postoperative MR studies were obtained in 11 patients with subtotal callosotomy and two with total callosotomy. Of all pulse sequences, sagittal T1-weighted images best showed the surgical division, although two cases displayed a coaptation artifact, which was misleading. A surgical clip placed at the posterior extent of the callosotomy was best visualized with sagittal T1-weighted imaging. Two patients (15%) had MR findings consistent with subacute blood in the callosum, and three patients (23%) demonstrated parafalcial hyperintensity on T2-weighted images 1 week after callosotomy. Motion artifact was a significant problem with coronal imaging and T2-weighted pulse sequences in postoperative patients. Patients selected for corpus callosotomy may have a normal baseline MR or show nonspecific abnormalities. MR imaging is an effective method for evaluating callosal division, and in some cases, may demonstrate signal changes consistent with surgically related edema and/or blood.     

The spectrum of brain MR abnormalities in sickle-cell disease: a report from the Cooperative Study of Sickle Cell Disease.

PURPOSETo define the spectrum of abnormalities in sickle-cell disease, including infarction, atrophy, and hemorrhage, that are identified by brain MR imaging.METHODSAll MR studies included T1, T2, and intermediate pulse sequences. Images were interpreted without knowledge of the clinical history or neurologic examination findings. Brain MR imaging was performed in 312 children with sickle-cell disease.RESULTSSeventy patients (22%) had infarction/ischemia and/or atrophy, infarction/ischemia was noted in 39 children (13%) who had no history of a stroke (the "silent" group). The prevalence rates for silent lesions were 17% for sickle-cell anemia and 3% for hemoglobin sickle-cell disease. For patients with sickle-cell anemia and a history of cerebrovascular accident, infarction/ischemia lesions typically involved both cortex and deep white matter, while silent lesions usually were confined to deep white matter. Within the age range studied, the prevalence of infarction/ischemia did not increase significantly with age, although older patients with lesions had more lesions than did younger patients with lesions.CONCLUSIONSBrain MR imaging showed infarction/ischemia in the absence of a recognized cerebrovascular accident in 13% of patients. The prevalence of these lesions did not increase significantly between the ages of 6 and 14 years, suggesting that lesions are present by age 6. However, the increase in the average number of lesions per patient with age may indicate progressive brain injury.     

Cranial MR imaging of sequelae of prefrontal lobotomy

BACKGROUND AND PURPOSE: Although prefrontal lobotomy is an obsolete treatment for schizophrenia, we still encounter patients who have undergone this procedure. The purpose of this study was to describe the MR imaging findings of sequelae of prefrontal lobotomy. METHODS: We retrospectively reviewed cranial MR images of eight patients with schizophrenia who underwent prefrontal lobotomy approximately 50 years previously. RESULTS: In all patients, a bilateral cavitary lesion with a thick wall was found in the frontal white matter. The genu of the corpus callosum was mildly to markedly atrophic. The size and location of the cavity and the degree of callosal atrophy were correlated. CONCLUSION: MR imaging is useful for the diagnosis of sequelae of prefrontal lobotomy, including cavitary lesions with dense walls of gliosis and secondary degeneration of the genu of the corpus callosum.     

Subacute sclerosing panencephalitis: evaluation with CT and MR.

PURPOSETo evaluate the progression of CT and MR changes of the brain in subacute sclerosing panencephalitis (SSPE) as a basis for assessing the effects of different types of therapy.METHODSFifty-two patients with SSPE were examined, 44 with MR imaging and 42 with CT of the brain on one or more occasions. A total of 92 MR and 67 CT studies were performed.RESULTSCorrelation between the clinical status and the MR findings in admission was poor. Of 20 patients with clinically advanced disease, only 8 had marked MR abnormalities; 6 had normal or almost normal findings on MR examinations. Two of 4 patients with clinically mild disease had advanced MR changes. The progression of the MR findings appeared to follow a constant pattern. The earliest pathologic finding was focal, high-T2-intensity white matter changes; later atrophic changes followed. The atrophy lagged behind the white matter changes and was thus mild when white matter changes were moderate or severe. In the most advanced stage, when the patient was in a neurovegetative state, an almost total loss of white matter had usually taken place. At this stage, the corpus callosum was also thin. Basal ganglia changes, usually involving the putamina, were seen in one third of patients and cortical gray matter changes were seen in one fourth of patients examined with MR imaging. In 2 of 20 patients, MR changes regressed in parallel with clinical improvement following therapy, but in 5 patients clinical improvement was accompanied by progression of MR changes.CONCLUSIONThe progress of MR abnormalities seen in patients with SSPE seems to follow a constant pattern, but the severity of MR changes does not always correlate well with the clinical findings. Caution must therefore be used when evaluating the effects of therapy.     

Traumatic brain stem injury: MR imaging

Eighty-seven patients with acute (n = 70) or chronic (n = 17) head injuries were prospectively studied with magnetic resonance (MR) imaging and computed tomography (CT) to characterize the frequency and nature of traumatic brain stem injury (BSI). Forty-eight traumatic lesions were identified in 36 patients. Of 36 patients, 35 had neurologic findings that corroborated the radiographic impression of BSI. T1- and T2-weighted MR images demonstrated a significantly higher number of lesions than did CT. Patients with BSI had a significantly higher frequency of corpus callosum and diffuse axonal "shear" lesions. The number of cortical contusions and extraaxial hematomas was similar in both groups. The mean Glasgow Coma Scale (GCS) scores at admission were significantly lower in patients with evidence of BSI on MR images. Patients with primary BSI had lower initial GCS scores, a longer duration of coma, more diffuse axonal "shear" lesions, and a higher frequency of corpus callosum injury than patients with secondary BSI. The location of primary and secondary lesions was significantly different. Overall, MR imaging was more helpful than CT in detecting, localizing, and characterizing BSI.     

Nearly completely reversible brain abnormalities in a patient with incontinentia pigmenti

SUMMARY: We report a case of incontinentia pigmenti with reversible cortex and subcortical white matter necrosis-like presentation by MR imaging. The reversible changes in follow-up imaging of the patient with incontinentia pigmenti suggest a course of natural repair of inflammation or cerebrovascular disease.     

MR and cerebrospinal fluid enzymes as sensitive indicators of subclinical cerebral injury after open-heart valve replacement surgery.

PURPOSETo evaluate MR imaging and lumbar cerebrospinal fluid enzymes as potential sensitive indicators of cerebral injury after open-heart valve replacement surgery.METHODSThirty-four patients with cardiac valvular disease were prospectively entered into this study and then underwent valve replacement or repair under cardiopulmonary bypass using a membrane oxygenator. In 26 patients, MR head images were obtained 12 to 24 hours before surgery; repeat MR images were obtained between 1 and 2 weeks after surgery. In 18 patients, lumbar puncture cerebrospinal fluid was analyzed 24 to 48 hours after surgery; the analyses included measurement of lactic dehydrogenase, creatine phosphokinase, adenylate kinase, and neuron-specific enolase.RESULTSAfter surgery, MR imaging showed new ischemic lesions in 15 (58%) of 26 patients: 7 with deep white matter hyperintense lesions; 5 with brain stem, caudate, cerebellar, or thalamic/basal ganglia infarcts; 1 with intraparenchymal hemorrhage; 1 with a subdural hematoma and cortical infarct; and 1 with a corpus callosum lesion consistent with calcium or air. These new ischemic lesions seen on MR images were associated with a focal neurologic deficit in only 4 (27%) of the 15 patients. Neuron-specific enolase and lactic dehydrogenase were abnormally elevated after surgery in 5 (28%) of 18 patients. Adenylate kinase and creatine phosphokinase (brain isozymes) were elevated in one (67%) of the patients. Two (40%) of the five patients with abnormally high neuron-specific enolase or lactic dehydrogenase after surgery also showed a new focal neurologic deficit.CONCLUSIONSMR imaging is a sensitive measure of subclinical cerebral ischemia after cardiac valve replacement under cardiopulmonary bypass. Cerebrospinal fluid neuron-specific enolase and lactic dehydrogenase are less sensitive than MR imaging for detecting subclinical cerebral ischemia, but these values were elevated after surgery more frequently than was adenylate kinase in our patients.     

MR and cognitive testing of patients undergoing osmotic blood-brain barrier disruption with intraarterial chemotherapy.

PURPOSETo determine whether osmotic blood-brain barrier disruption is associated with MR abnormalities or cognitive deterioration and, if so, whether the MR findings correlate with cognitive test results.METHODSFifteen brain tumor patients who had a complete tumor response (nine central nervous system lymphoma, three germ cell and two astrocytoma, and one primitive neuroectodermal tumor) treated with blood-brain barrier disruption procedures (318 total procedures) with intraarterial chemotherapy were included. MR images were evaluated for the development of white matter hyperintensity, vascular lesions, or atrophy. Cognitive testing was performed to assess deterioration caused by this therapy.RESULTSIn two patients white matter hyperintensity developed, in two small vascular lesions developed, and in one mild atrophy developed. One infarct was asymptomatic and the second one resulted in mild dysesthesia in one upper extremity. No patient showed diminished cognitive function on the posttherapy evaluation.CONCLUSIONIn patients undergoing blood-brain barrier disruption with intraarterial chemotherapy, new abnormalities on MR imaging may develop. These patients maintain the same level of cognitive and neurologic function and MR findings do not correlate with the results of cognitive testing.     

White matter changes caused by chronic solvent abuse.

PURPOSETo examine the brain damage of solvent abusers in Japan, where pure industrial toluene is frequently abused.METHODSTwenty solvent abusers 17 to 33 years of age with 7.2 +/- 4.0 years of abuse were examined with a 1.5-T MR imaging system.RESULTSWhite matter hyperintensities in cerebrum, brain stem, and cerebellum on T2-weighted images were found in seven cases. The extent of white matter change was most clearly shown on proton density-weighted images. The patients with restricted white matter change and intermediate white matter change showed white matter hyperintensities in the brain stem and cerebellum on T2-weighted images, in some cases, with additional hypointensities in the corresponding T1-weighted images. These patients had mainly abused pure toluene. The patients with diffuse white matter change showed obvious brain atrophy, including hippocampal atrophy and thinning of the corpus callosum. These patients had mainly abused lacquer thinner.CONCLUSIONThere are some patients with restricted but severe enough change to cause the neurologic symptoms in specific regions, such as the brain stem and/or cerebellum, before the brain atrophy becomes apparent. This suggests that the restricted white matter change represents not only an early change of diffuse white matter change, but at least in some cases also represents a qualitatively different change than that of diffuse white matter change. We suggest that pure toluene has a possible relation to this qualitative difference.     

MR evaluation of hydrocephalus

An analysis of sagittal T1-weighted MR studies was performed in 23 patients with hydrocephalus, 58 patients with atrophy, and 100 normal patients. The average mamillopontine distance was 1.15 cm for the normal group, 1.2 cm for patients with atrophy, and 7.5 mm for patients with hydrocephalus. A reduction of the mamillopontine distance below 1.0 cm was found in 22 patients with hydrocephalus, 5 patients with atrophy, and 15 normal patients. Dilatation of the anterior third ventricle was noted in 21 patients in the hydrocephalus group and in none of the patients in the atrophy and normal groups. The average thickness of the corpus callosum at the level of the foramen of Monro was 6 mm in normal subjects and was reduced below 6 mm in 16 of the hydrocephalus patients. Smooth elevation of the corpus callosum was noted in 20 hydrocephalus patients, in 2 patients with atrophy, and in none of the normal patients. MR improves the accuracy of diagnosis in patients with hydrocephalus both because of its ability to show small obstructing lesions that are not depicted by CT and because the mass effect of the distended supratentorial ventricles produces anatomic changes that are delineated with precision by MR.     

The role of early MR in the evaluation of the term infant with seizures.

PURPOSETo define the role of MR in evaluating term neonates with seizures the most common clinical manifestation of cerebral injury in neonates.METHODSFifteen term infants with seizures underwent MR imaging. The presence and pattern of MR findings were compared with clinical markers of perinatal distress, cause of cerebral injury, and short-term neurologic outcome.RESULTSSeizures were caused by hypoxic-ischemic encephalopathy in three patients, bacterial meningitis in three, and prenatal cocaine exposure in one. Nine patients had no identifiable risk factors. By MR, five patients had focal ischemic injury of the cerebral hemispheres and/or basal ganglia and brain stem. Six patients had diffuse cerebral edema: of these, five had basal ganglia edema; one had brain stem edema. One patient had superior sagittal sinus thrombosis with venous infarcts. Three patients had normal MR studies. There was no correlation between markers of perinatal distress, risk factors for seizures, and presence or pattern of MR findings. There was some correlation between MR findings of diffuse cerebral injury and neurologic outcome, and between MR findings of basal ganglia and brain stem abnormalities and neurologic outcome; these findings correlated with spasticity and hemiplegia at 6 to 24 months follow-up.CONCLUSIONThe presence or pattern of MR findings does not appear to correlate with with clinical signs of perinatal distress or presumed causes of perinatal cerebral injury. Further investigation is needed to identify prospectively neonates with seizures who are at risk for significant neurologic morbidity.     

Partial development of the corpus callosum.

PURPOSETo determine whether the MR findings of callosal dysgenesis suggest that the partially formed corpus callosum in humans is the result of arrested growth or delayed continued development.METHODSThe MR scans of 25 patients with callosal dysgenesis were reviewed to determine whether the observed corpus callosum corresponded to the form and position of a portion of a normal corpus callosum, as suggested by a theory of arrested growth.RESULTSIn 10 of the 25 cases, the partially formed corpus callosum corresponded to a portion of a normal corpus callosum. In the remaining 15 cases, the partially formed corpus callosum was located posterior to the expected location of a normal genu and inferior to the expected location of a normal body.CONCLUSIONSCorpus callosum dysgenesis in humans may be caused by arrested growth in some cases; in other cases it is most likely caused by delayed continued development that attempts to compensate for earlier abnormalities in the evolution of midline structures.     

Venous congestion: an MR finding in dural arteriovenous malformations with cortical venous drainage.

PURPOSETo present the MR findings of intracranial dural arteriovenous malformations with cortical venous drainage, emphasizing the parenchymal changes.METHODSConventional MR and x-ray angiograms in 13 patients with dural arteriovenous malformations and cortical venous reflux were reviewed. The site of the shunt, location of the venous reflux, and presence of venous stenosis were assessed on the angiograms. Parenchymal changes, dilated vessels, and venous occlusive disease were assessed on MR.RESULTSOn MR, 10 of the 13 patients (77%) had dilated pial vessels. Two patients had hydrocephalus. Two patients presented with parenchymal bleeds, one with a subdural component, both remote from the nidus. Two patients presented with subarachnoid hemorrhage. One patient had a parenchymal bleed 9 months after presentation. Venous occlusion was evident on MR in 2 patients. Diffuse white matter edema in the cerebellar or cerebral hemispheres was present on MR in 4 patients and correlated with neurologic deficits. In 2 of these 4 patients, gadolinium enhancement was seen in the periphery of the involved hemisphere.CONCLUSIONSOn MR a surplus of pial vessels suggests a dural arteriovenous malformation with cortical venous drainage. The MR finding of white matter edema deep in the cerebral or cerebellar hemispheres is direct evidence of a venous congestion.