The natural history of intracranial venous angiomas.

Cerebral venous angiomas are congenital anomalies of the intracranial venous drainage. Many believe that they are associated with a high risk of hemorrhage and neurological dysfunction, but newer neurodiagnostic imaging techniques are showing not only that they are more common than previously known but also that many have no associated symptoms. In this retrospective study, the natural history of venous angiomas was examined in 100 patients (48 males and 52 females) with radiographically identifiable lesions treated over a 14-year period. Information on the natural history of the lesion was obtained from clinical records and follow-up data. Imaging studies included angiography, computerized tomography, and magnetic resonance imaging. Angioma locations were classified as frontal (42 cases), parietal (24 cases), occipital (4 cases), temporal (2 cases), basal or ventricular (11 cases), cerebellar (14 cases), or brain stem (3 cases); 47 lesions were on the left side. Headache as a presenting symptom was common (36 patients) and often led to other radiographic studies, but this appeared to be related to the vascular lesion in only four patients. Other possibly related complications were hemorrhage in one patient, seizures in five, and transient focal deficits in eight. Fifteen patients had no neurological signs or symptoms. The mean patient age at last contact was 45.3 years (range 3 to 94 years). All patients have been managed without surgery. It is concluded that significant complications secondary to venous angiomas are infrequent and that surgical resection of these lesions and of surrounding brain is rarely indicated.

Detection of tuberous sclerosis in parents by magnetic resonance imaging.

We performed a detailed physical examination and MRI without gadolinium DTPA contrast in 60 couples with at least 1 child having tuberous sclerosis (TS). Eight parents had TS diagnosed by physical examination, family history, or various diagnostic procedures including MRI. Eight additional subjects and 6 control subjects had nonspecific high-signal white matter changes on MRI. MRI confirmed the diagnosis of TS in only 1 parent without physical findings of the disease, similar to the results of earlier studies using computed cranial tomography. CT may be less sensitive than MRI but is probably more specific for TS. Either CT or MRI may occasionally help substantiate the diagnosis of TS in a parent with few other findings. Both studies may need to be done in some parents to maximize the accuracy of genetic counseling.

Is Gd-DTPA required for routine cranial MR imaging?

Gadopentetate dimeglumine (gadolinium diethylenetriaminepentaacetic acid [DTPA]) was administered prospectively to 500 consecutive children and adults referred for routine cranial magnetic resonance (MR) imaging over a 4-month period. Pre- and postcontrast images were blindly and independently interpreted by two experienced neuroradiologists. Specific criteria were provided to the readers to define objectively when contrast material enhancement (or lack thereof) would be considered "radiologically helpful." Contrast-enhancing lesions were observed in 99 cases (20%). In only 15 cases (3%) did Gd-DTPA permit detection of lesions not also apparent on the precontrast studies. Contrast enhancement was considered radiologically helpful in 74 of the 99 cases. Lack of enhancement was considered helpful in 112 of the 500 cases (22%). Factors that may indicate increased usefulness of Gd-DTPA include increased patient age, definite lesion seen at computed tomography or precontrast MR imaging, prior craniotomy for tumor, and clinically documented systemic or central nervous system disease. Gd-DTPA should probably be used routinely for cranial MR imaging in most patients, except, perhaps, children and young adults with normal precontrast images.

Magnetic resonance imaging of the craniovertebral junction in rheumatoid arthritis.

Conventional radiography and magnetic resonance imaging (MRI) of the craniovertebral junction were evaluated in 12 patients with longstanding rheumatoid arthritis (RA) and neck pain with or without other neurologic signs or symptoms of cervical myelopathy. MRI demonstrated abnormal soft tissue masses thought to represent pannus in 9 patients. Three patients showed cord or brainstem compression due to pannus or atlantoaxial subluxation. The 3 patients with MRI evidence of cord or brainstem compression had neurologic signs or symptoms of cervical myelopathy, and appropriate therapy was instituted based on these findings. This study indicates that MRI is able to detect abnormal soft tissue masses which probably represent pannus and their relationship to the spinal cord or brainstem, and confirms the utility of the procedure in the management of craniovertebral involvement in RA.

Magnetic resonance imaging in pediatric neurologic disorders.

We present our initial experience with magnetic resonance imaging (MRI) in 301 pediatric patients with a variety of neurologic disorders. MRI does not require ionizing radiation and can be done easily and safely in children. It is equal or superior to computed cranial tomographic (CT) scans in demonstrating most types of pediatric neurologic disorders. MRI is often superior to CT scans in demonstrating intracranial tumors, although both studies are usually abnormal in highly malignant tumors. No clear advantage was shown with either MRI or CT scans for fluid-filled intracranial lesions. Lesions of the brain stem and upper cervical region, such as Chiari malformation, are well delineated by MRI. Increased signal from the paranasal sinuses was frequently evident by MRI, but, in most instances, there was no clinical indication of sinus disease. Large arteries can be visualized as an area of diminished signal, and intracranial hemorrhage, dural sinus thrombosis, and cerebral infarction were demonstrated. The increased anatomic detail pictured by MRI allows the diagnosis of congenital defects, such as agenesis of the corpus callosum or septum pellucidum, that are not always apparent with CT scans. Although our experience with spinal cord lesions was not extensive, fluid-filled lesions within the cord can be reliably demonstrated.

Magnetic resonance imaging in tuberous sclerosis.

Twenty-five patients with tuberous sclerosis were studied with magnetic resonance imaging (MRI), and these findings were compared with those of computed cranial tomography (CCT) and with the clinical severity of the disease. Multiple high-signal MRI lesions involving the cerebral cortex are characteristic of tuberous sclerosis and probably correspond to the hamartomas and gliotic areas seen pathologically. These cortical lesions were only occasionally seen with CCT. The periventricular calcific lesions characteristic of tuberous sclerosis are better visualized with CCT than with MRI, but the larger periventricular calcifications produce low-signal MRI abnormalities. Seven patients had high-signal MRI lesions of the cerebellum; small calcific cerebellar lesions were also noted with CCT in three patients. As in earlier studies, no clear correlation was seen between the number of abnormalities visible with CCT and the clinical severity of the disease. By contrast, the more severely affected patients tend to have a higher number of cerebral cortical lesions detected with MRI. Thus, MRI may be useful in predicting the eventual clinical severity of younger children with newly diagnosed tuberous sclerosis.

Magnetic resonance imaging and complex partial seizures.

Magnetic resonance imaging (MRI) is a new imaging modality with potential usefulness in the evaluation of patients with seizure disorders. We studied 100 consecutive patients with complex partial seizures comparing computerized cranial tomography (CCT) with MRI. Our study revealed 36 patients with CCT abnormalities. Of these, 30 (83%) had focal abnormalities. MRI demonstrated 45 patients with abnormalities, 34 (76%) were focal. Intracranial calcifications were not visualized by MRI, but were easily demonstrated by CCT. MRI was more sensitive in visualizing cerebral atrophy, abnormal cerebral vasculature, and lesions in the posterior fossa and suprasellar region. Most importantly, several patients who had normal CCTs had abnormal MRIs consistent with neoplastic lesions. As MRI becomes more available, this imaging modality along with EEG, should be the studies of choice in evaluating patients with partial epilepsy.

Subtemporal decompression: radiological observations and current surgical experience.

Subtemporal decompression, although seldom used today for the management of hydrocephalus, pseudotumour cerebri, or premature closure of cranial sutures, is still used in many centres to alleviate intracranial hypertension caused by tumour, trauma, or severe intracranial haemorrhage. The charts of 50 patients undergoing subtemporal decompression for either severe head trauma or severe intracranial haemorrhage were reviewed. Preoperative and postoperative computed axial tomographic scans were available in 15 patients for analysis of the effects of decompression on the underlying temporal lobe. Calculation of the additional space provided by subtemporal decompression ranged from 26 to 33 cm3.

MRI of corpus callosal syndromes.

Six patients, 6 to 13 years old, with corpus callosal abnormalities diagnosed by electroencephalography or CT were studied with a 0.15 T MR imager to determine the effectiveness of MRI in evaluating midline anomalies. Spin-echo images in the coronal, axial, and sagittal planes were obtained in two patients with Aicardi's syndrome and partial agenesis of the corpus callosum, in one patient with Dandy-Walker syndrome, and in two patients with septooptic dysplasia. Inversion recovery and spin-echo images were obtained in one patient with lipoma of the corpus callosum. Partial agenesis of the corpus callosum was seen in septooptic dysplasia, an association that has not been reported previously in the radiologic literature. Direct sagittal and coronal MRI provided better anatomic visualization of the brain and ventricles than did reformatted CT. T1-weighted images are sufficient to diagnose and delineate the extent of midline cerebral abnormalities. The unique capability of direct sagittal imaging makes MRI the best procedure for evaluating corpus callosal and other midline abnormalities.

MRI of radiation injury to the brain.

Nine patients with a history of radiation of 2400-6000 rad (24-60 Gy) to the brain were examined by magnetic resonance imaging (MRI) and computed tomography (CT). MRI demonstrated abnormalities in the periventricular white matter in all patients. The abnormal periventricular signal was characterized by a long T2 and was demonstrated best on coronal spin-echo (SE) 1000/80 images. A characteristic scalloped appearance at the junction of the gray-white matter was seen on MR images of seven patients, and represented extensive white-matter damage involving the more peripheral arcuate fiber systems. This differs from transependymal absorption, which is seen best on SE 3000/80 images and has a smooth peripheral margin. Cranial CT demonstrated white-matter lucencies in six cases but generally failed to display the extent of white-matter injury demonstrated by MRI. MRI is uniquely suited to detect radiation injury to the brain because of its extreme sensitivity to white-matter edema.

MR evaluation of Chiari I malformations at 0.15 T.

Twelve patients with known or presumed Chiari I malformations and two with clinical diagnoses of multiple sclerosis were examined by magnetic resonance (MR) imaging. MR confirmed or established the diagnosis of Chiari I malformation in all 14 cases. The spin-echo technique with a short time to echo (TE = 40 msec) and a short time to recover (TR = 1000 msec) provided optimum imaging of tonsillar position, hydromyelia cavities, and cervicomedullary "kinking." Long TE (greater than 80 msec) and TR (greater than 2000 msec) increase the signal intensity of cerebrospinal fluid and may obscure the pathology. Sagittal, transaxial, and coronal images provided complementary data; sagittal and coronal views best imaged the abnormal spinal cord and tonsils, but slitlike cavities were best seen on transaxial images. Cervicomedullary kinking was found in 10 (71%) of 14 patients and in 90% of the hydromyelic patients. This high incidence suggests that in other radiologic techniques tonsillar herniation masks the kinking. Symptoms of the Chiari I malformation overlap those of demyelinating diseases and brain tumors. Our early experience suggests MR is the preferred noninvasive procedure for identifying Chiari I malformation. Moreover, the ability to portray the variable cavity morphology of hydromyelia directly offers the potential for improved shunt placement.

Left atrial myxoma with cerebral emboli.

Infarction of the central nervous system secondary to embolism from left atrial myxoma is a recognized phenomenon. However, myxoma as the source of an embolus may be overlooked if an index of suspicion is not present during the evaluation of the patient with a stroke without a known cause. We present a case report that illustrates some of the pitfalls and characteristic findings present in the evaluation of these patients. The magnetic resonance image of multiple cerebral aneurysms and infarction associated with this condition is presented along with a unique, arteriographically proven resolution of a fusiform cerebral aneurysm after the removal of the cardiac tumor. A review of published case reports suggests that, if the cardiac tumor is recognized and treated quickly, the ultimate prognosis, while uncertain, is usually good. However, because the potential exists for recurrence of the cardiac tumor, for enlargement of the cerebral lesions, or for late development of cerebral lesions, long term follow-up is mandatory and a vigorous work-up must be pursued if the patient again becomes symptomatic or develops central nervous system manifestations for the first time.

Chronic seizure disorders: contribution of MR imaging when CT is normal.

One hundred consecutive patients with complex partial seizures were studied by magnetic resonance (MR) imaging and computed tomography (CT). Thirty-four patients had seizures of more than 5 years' duration, yet neurologic examinations and previous pre- and postinfusion CT scans had been normal. MR imaging demonstrated surgical lesions of potentially therapeutic significance in four of these 34 patients. Two patients underwent surgery with removal of a thrombosed arteriovenous malformation and a glioma. Although CT has been found to detect structural abnormalities, its yield of therapeutically significant abnormalities has been low.

Results of nuclear magnetic resonance with cerebral glioma. Comparison with computed tomography.

Our experience using nuclear magnetic resonance (NMR) in eight patients with abnormalities on computed tomography (CT) scans suggesting glioma is reported. Three patients underwent biopsies. Two patients had grade II astrocytomas. Difficulty was encountered confirming the diagnosis of astrocytoma on frozen sections in one patient, and permanent sections were required for diagnosis in the other. The third patient to undergo biopsy had a grade III anaplastic mixed glioma. Biopsy of subsequent patients with probable gliomas was not done because of the risk of producing neurological deficit. The NMR images suggest that lower-grade astrocytomas are well circumscribed, whereas higher-grade gliomas affect adjacent association bundles by direct extension of tumor cells or vasogenic edema.

Cranial computerized tomography in carotid artery transient ischemic attacks.

32 of 45 (71.1%) patients with carotid artery distribution transient ischemic attacks had normal cranial computerized tomography (CCT). 9 (20%) had cerebral atrophy. Incidental abnormalities were found in 3 (6.6%) patients, while a hypodense lesion corresponding to the site of neurological dysfunction was seen in only 1 (2.2%) patient. The latter showed a persistent abnormality in follow-up studies on the 8th and the 23rd day after the initial event. Our clinical CCT correlation did not demonstrate the frequency of hypodense lesions reported by some authors. Furthermore an increased incidence of cerebral atrophy was found compared to the one reported previously.

Prolonged course of meningitis due to an arachnoid cyst.

An infected arachnoid cyst was found in a child with bacterial meningitis and prolonged fever. Surgical drainage of the cyst resulted in rapid improvement.

Monocular blindness in nasopharyngeal cancer.

The sudden onset of painless monocular blindness was the initial manifestation of a nasopharyngeal cancer in a 78-year-old woman. Computerized cranial tomography demonstrated encasement of the optic nerve by tumor. Examination of the nasopharynx and paranasal sinuses is important in patients with primary neuro-ophthalmologic complaints.