Michael S. Huckman

The validity of criteria for the evaluation of cerebral atrophy by computed tomography.

Computed tomography of the brain was used in evaluating demented and nondemented elderly people. The incidence of convulutional atrophy and ventricular enlargement correlated well with pathologic and pneumoencephalographic examination of a similar population. Computed tomography also showed certain instances of dementia without atrophy and evidence of atrophy without dementia. The absence of brain atrophy in a demented patient should prompt a search for a potentially treatable cause of the dementia. The authors discuss criteria for diagnosing atrophy by computed tomography and conclude that, because of its noninvasive nature, it is a valuable aid in screening demented patients for treatable diseases.

Cerebral atrophy, EEG slowing, age, education, and cognitive functioning in suspected dementia

Seventy-eight hospital patients, 50 years of age or older, were selected for suspected changes in mentation and for the absence of focal or other organic brain disease. They were studied in relation to education, age, cerebral atrophy (by computerized tomography), electroencephalographic (EEG) slowing, and performance in several neuropsychologic tests. Adequate test-retest reliability of the cognitive measures and interjudge reliability of the cerebral atrophy and EEG measures were demonstrated. Stepwise multiple regression analyses suggested the following: (1) EEG slowing is the strongest and most general pathologic influence on cognition in elderly persons without overt brain disease. (2) Cerebral atrophy independently affects primarily the verbal recall of recent and remote information. (3) Age independently affects primarily recent memory for both verbal and nonverbal material. (4) Formal education is a powerful influence that must be accounted for in all studies of the effects of age on cognition.

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.

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

SummaryThe pathophysiology and clinical significance of high signal lesions, visualized on magnetic resonance imaging (MRI) in patients with Alzheimers 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.

Computed topography in dementia

We examined CTs of patients with senile dementia of the Alzheimer type and age-matched normal controls. Cerebral atrophy was associated with advancing age and the presence, but not the degree, of dementia. CT density numbers in 14 separate brain regions were not related to age or to the presence or degree of dementia. The findings failed to support other reports of decreased CT density in dementia and suggest that the role of CT scan in the evaluation of dementia is limited to ruling out mass lesions.

Computed Tomography in the Diagnosis of Pseudotumor Cerebri

The authors reviewed 17 patients with the clinical diagnosis of benign intracranial hypertension (pseudomotor cerebri). All of these patients underwent CT scans of the head which were interpreted as normal. Comparison of mean ventricular size with that of a group of control subjects showed no significant difference. On the basis of this study and others cited, there would appear to be almost no instances in which invasive neuroradiological procedures would be required to confirm the diagnosis of pseudotumor cerebri.

Transfemoral Cerebral Arteriography versus Direct Percutaneous Carotid and Brachial Arteriography: A Comparison of Complication Rates1

Cerebral arteriograms in 1,141 consecutive patients, which were done either as direct percutaneous carotid or brachial studies or as transfemoro-cerebral catheter studies, were reviewed. While the overall complication rate for the direct percutaneous studies was higher, the incidence of neurologic complications, both transient and permanent, was higher in the transfemoral group. This higher incidence of neurologic complications may be related to the frequent irrigation of the catheter, which increases the probability of embolism. The incidence of serious complications was lower than in previous studies, perhaps because gravely ill patients are more likely to undergo computed tomographic scanning.

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.

Computed tomography of porencephaly and other cerebrospinal fluid-containing lesions.

The EMI head scanner was used to review a large number of cases of porencephaly; computed tomographic scanning was found to be the most satisfactory method of evaluating these lesions. The nuclide brain scan has not usually been of significant value for diagnosis, and although angiography and pneumoencephalography were used for correlation in some cases, the CT scan is often the only neuroradiological procedure necessary to achieve the correct diagnosis. Porencephalic areas usually have a well-defined border, have the density of cerebrospinal fluid, and do not change in density following the use of contrast medium enhancement.

The magnetic resonance hypointense spine of AIDS

The T1-weighted magnetic resonance examinations in 11 acquired immunodeficiency syndrome patients showed substantial reduction in signal intensity of vertebral bodies. Review of bone marrow aspirates and biopsies that were available in eight patients suggested that the abnormality resulted from markedly increased amounts of storage iron within the bone marrow, probably secondary to the anemia of chronic disease.