Transient global amnesia after cerebral angiography. Report of seven cases.

Because of a case of typical transient global amnesia following cerebral angiography, the records of all patients undergoing cerebral angiography during a seven-year period were reviewed. Six other cases were discovered. All patients had either transfemoral catheter or brachial angiograms performed immediately before the development of amnesia. Spasm of a vertebral artery was noted in one case. None had clinically obvious seizures. All recovered within 24 hours. This only recently reported complication of cerebral angiography is consistent with a vascular etiology of the syndrome of transient global amnesia when not associated with angiography, although a direct toxic effect of the contrast material cannot be excluded.

Central nervous system magnetic resonance imaging findings in myotonic dystrophy.

We evaluated findings in 14 patients with myotonic dystrophy (MD) using magnetic resonance imaging of the brain and compared them with those in age-matched controls with headache. There was an increased incidence of ventriculomegaly and a lumpy and/or thick pattern of periventricular hyperintensity in patients with MD as compared with the age-matched controls. These white matter abnormalities do not appear to be etiologically specific, but some possible explanations for these frequent findings in MD are discussed.

Cerebellar atrophy demonstrated by computed tomography.

We studied 55 cases of cerebellar atrophy identified by computerized tomography. Atrophy was determined by subjective assessment and objective measurements (superior cerebellar cistern, fourth ventricle, and brainstem). Different patterns of cerebellar atrophy were related to clinical diagnoses. A high incidence of vermal atrophy was observed in primary cerebellar degeneration and chronic alcoholism. More than half the patients with alcoholism had hemispheral atrophy. Vermal atrophy and enlargement of superior cerebellar cisterns (but not hemispheral atrophy) were associated with carcinomatous cerebellar degeneration. Atrophy caused by chronic phenytoin usage showed a specific pattern of enlargement of the cisterna magna, cerebellopontine angle, and superior cerebellar cisterns. Supratentorial atrophy was increased significantly only in the alcoholics. In general, limb ataxia, dysarthria, and nystagmus were related to hemispheral but not to vermal atrophy.

Cerebellar atrophy: relationship to aging and cerebral atrophy.

We studied the incidence of computed tomography evidence of cerebellar atrophy in 20 elderly patients with dementia, 20 age-matched controls, and 40 younger normal subjects. Cerebellar vermian atrophy was present in 6 of 20 demented patients, 7 of 20 elderly controls, and 1 of 40 younger controls. There was no other atrophy of infratentorial structures except for occasional enlargement of the cisterna magna and cerebellopontine angle cisterns. Vermian atrophy did not correlate with cerebral atrophy (enlargement of either lateral ventricles or cortical sulci). None of these patients had clinical signs of cerebellar dysfunction. Therefore, atrophy of the cerebellar vermis may occur selectively with aging, without atrophy of the cerebral cortex, and without clinical manifestations.

Safety and efficacy of sodium and meglumine ioxaglate (Hexabrix) and Hypaque M60% in contrast-enhanced computed cranial tomographic scanning. A double-blind clinical study.

The safety and efficacy of sodium and meglumine ioxaglate (Hexabrix, Mallinckrodt, Inc., St. Louis, MO), a new low-osmolality contrast agent, and Hypaque Meglumine 60% (Wintrop-Breon, Inc., New York, NY) were compared for contrast-enhanced computed cranial tomographic scanning. Fifty-two patients with possible enhancing lesions of the brain received a total of 59 injections of either Hexabrix or Hypaque M60 in a double-blind, randomized fashion. Hexabrix was superior to Hypaque M60 in both subjective and objective patient tolerance. A lower incidence of heat and pain in patients receiving Hexabrix was believed to be related to its lower osmolality. Lesion enhancement with both Hexabrix and Hypaque M60 was excellent. There was a statistically significant increase in the degree of enhancement immediately after injection with Hexabrix. Hexabrix had less effect on the cardiovascular system than Hypaque M60. No neurologic complications or adverse reactions requiring treatment occurred in either group. Hexabrix is a suitable agent for intravenous contrast-enhancement for cranial CT.

Clinical correlates of high signal lesions on magnetic resonance imaging in Alzheimer's disease.

The pathophysiology and clinical significance of high signal lesions, visualized on magnetic resonance imaging (MRI) in patients with Alzheimer's disease (AD), remain controversial. Since they are known to correlate with vascular disease and vascular risk factors, we reviewed the clinical correlates of periventricular high signal (PVH) and subcortical white matter lesions (WML) in a sample of 106 patients with probable AD, excluding persons with treated vascular risk factors or symptomatic cerebrovascular and cardiovascular disease. Grade 2 PVH were seen in 26 (25%) and scattered WML were identified in 29 (18%). PHV were associated with advancing age and gait disturbance. WML were associated with gait disturbance and incontinence. Neither radiologic finding was related to dementia severity. The findings suggest that these lesions are common in patients with AD even when those with evidence of cerebrovascular disease are excluded; their presence, therefore, should not preclude a diagnosis of AD. Additionally, the data suggest that HSL on MRI may be one of many risk factors associated with functional disability in persons with probable AD.

Normal pressure hydrocephalus: evaluation of diagnostic and prognostic tests.

This paper reviews the clinical findings in the Hakim-Adams syndrome and distinguishes it from the more general term of normal pressure hydrocephalus. The radiographic tests to diagnose these entities are discussed in their historical context. Computed tomography has recently replaced the pneumoencephalogram for evaluating ventricular size and configuration and computed tomographic metrizamide cisternography is beginning to replace the more traditional radionuclide studies of cerebrospinal fluid dynamics. A protocol is suggested for the future study of Hakim-Adams syndrome which emphasizes strict adherence to clinical criteria for the diagnosis. Studies of the microanatomic and physiologic condition of the underlying brain seem to be emerging as more reliable predictors of the success of shunt procedures than those of cerebrospinal fluid dynamics which have heretofore dominated treatment planning.

Precise placement of sphenoidal electrodes via fluoroscopic guidance.

Fluoroscopically guided placement of sphenoidal electrodes for the assessment of epileptiform activity in the mesial-basal-temporal lobes offers distinct advantages over standard techniques, such as more precision in placement, reduced likelihood of facial pain, and fewer complications (vessel perforation or nerve injury). We describe our instrumentation, technique, and results in over 40 patients.

Chemonucleation and changes observed on lumbar MR scan: preliminary report.

This study examines the relation between the postchemonucleation clinical outcome and changes observed on the lumbar MR scan. Eight of 12 chemonucleated disks showed clinical improvement at the last follow-up, while the other four showed no improvement. In the cases that showed improvement there was a decrease in one or both dimensions of the defect in the thecal sac. Seven of eight showed an increase in the peridisk signal. Where there was no clinical improvement there were fewer decreases in the size of the defect, and three of four showed no increase in the peridisk signal.

The role of facet joint tropism and facet angle in disc degeneration.

In this study, the relationship between facet geometry (joint angle and tropism) and disc degeneration was analyzed. Magnetic resonance imaging and computed tomographic scans of 46 subjects less than 50 years of age were evaluated. Magnetic resonance imaging was used to determine disc degeneration, and computed tomography was used to measure facet joint angles and determine tropism. Subjects with tropism had a significantly higher prevalence of disc degeneration at all three lumbar levels examined (L3-4, L4-5, L5-S1). The average facet angles increased from L3-4 to L4-5 and further to the L5-S1 level. There was no statistically significant relationship between the magnitude of the angle and the presence of disc degeneration at any of the three levels. It was concluded that the risk of disc degeneration is increased in the presence of facet joint tropism.

Discs degenerate before facets.

The purpose of this study was to determine the relationship between facet joint osteoarthritis and disc degeneration in subjects in whom both MRI and CT scans had been obtained. The MRI scans were used to determine disc degeneration, the CT scans to determine facet joint osteoarthritis. It was hypothesized that disc degeneration would sometimes occur without the presence of facet joint osteoarthritis, but that facet joint osteoarthritis would only occur in the presence of disc degeneration. Sixty-eight sets of scans were included and 330 discs and 390 facet joints were evaluated. There were 144 degenerated discs and 41 levels with facet osteoarthritis. Disc degeneration without facet osteoarthritis was found at 108 levels, while all but one of 41 levels with facet degeneration also had disc degeneration. That one exception occurred in a patient with advanced Paget's disease. Disc degeneration and facet osteoarthritis both were found to increase with increasing age. There was no difference between women and men. Degeneration at the L4-5 and L5-S1 levels was significantly more prevalent than at the L3-4 levels, while degeneration at the L3-4 level was significantly more common than at the L1-2 and L2-3 levels. We conclude that disc degeneration occurs before facet joint osteoarthritis, which may be secondary to mechanical changes in the loading of the facet joints.

Clinical experience with the intravenous infusion of iodinated contrast material as an adjunct to computed tomography.

The intravenous infusion of iodinated contrast material is an important adjunct to computed tomography with a wide variety of lesions. Some arteriovenous malformations, metastatic lesions and tumors of the sella turcica and cerebellopontine angle which are undetectable by conventional computed tomography may be visualized by this method. Certain other metastatic lesions, primary tumors, abscesses and infarcts which are detectable in the preinfusion tomogram become better defined following infusion. The indications for this examination and the procedures involved are discussed.