Examination of alcoholics by computed tomographic (CT) scans: a critical review

Alcoholic dementia

At least four distinct cerebral diseases--Wernicke-Korsakoff, Marchiafava-Bignami, pellagrous encephalopathy, and acquired hepatocerebral degeneration--have a close association with chronic alcoholism. Each is characterized by a distinctive pathologic change and a reasonably well-established pathogenesis; in each the role of alcohol in the causation is secondary. The question posed in this review is whether there is, in addition to the established types of dementia associated with alcoholism, a persistent dementia attributable to the direct toxic effects of alcohol on the brain--i.e., a primary alcoholic dementia. The clinical, psychologic, radiologic, and pathologic evidence bearing on this question is critically reviewed. None of the evidence permits the clear delineation of such an entity. The most serious flaw in the argument for a primary alcoholic dementia is that it lacks a distinctive, well-defined pathology, and it must remain ambiguous until such time as its morphologic basis is established.

Volumetric magnetic resonance imaging quantification of longitudinal brain changes in abstinent alcoholics

Magnetic resonance imaging (MRI) of the brain was performed on a group of 24 recently detoxified, male alcoholics approximately 1 month after their date of last drink. The imaging was repeated 3 months later, at which point 9 subjects had resumed drinking and 15 had maintained abstinence. Contrasts between these two drinking groups revealed that, despite comparable baseline values, the Abstainers exhibited volumetric white matter increases and cerebrospinal fluid reductions over the follow-up interval, whereas the Drinkers did not show significant change on either of these MRI indices. These results provide the first evidence suggestive of significant volumetric white matter increase with abstinence.

Neuropsychological deficits are correlated with frontal hypometabolism in positron emission tomography studies of older alcoholic patients

In an extension of previous work, we studied the behavioral correlates of medial frontal lobe glucose hypometabolism in chronically alcohol-dependent patients. Thirty-one male patients who were detoxified, medically stable, and free of other central nervous system risk factors for neuropsychological impairment were examined with (1) anatomic imaging (CT or MR), (2) functional imaging with [18F] fluorodeoxyglucose (18F-FDG) and positron emission tomography (PET), and (3) a battery of neuropsychological tests, including two measures of abstraction known to be generally sensitive to frontal lobe disease or dysfunction [the Wisconsin Card Sorting Test (WCST) and the Halstead Category Test (HCT)]. 18F-FDG PET data from 18 age- and sex-matched normal control subjects were used for comparison. All patients met criteria for severe alcohol dependence and for at least a mild degree of alcoholic-induced cognitive impairment. Although the mean IQ level of the alcoholic patients was in the average range, the concepts attained and the error scores on the WCST and HCT were significantly impaired in comparison with established norms. Local cerebral metabolic rate for glucose (LCMRglc) was significantly decreased in a sagittal strip of the medial frontal cortex in the alcoholic patients as compared with the normal controls. Comparison of data from PET scans and anatomic images indicated that the reduced LCMRglc could not be attributed to reduced amounts of tissue alone. A statistically significant relationship was found between LCMRglc in the medial frontal region of the cerebral cortex and performance on the WCST, but not the HCT. These findings suggest that chronic alcohol intake results in impaired function of cerebral tissue in the medial frontal region.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcohol, head injury, and neuropsychological function

Evidence is reviewed indicating that the extent of alcohol abuse alone cannot account for the neuropsychological deficits observed in alcoholics, and that alcohol abuse and head injury may interact in some patients to influence neuropsychological status. Alcohol abuse both increases the risk for head trauma and potentiates the resulting brain injury, which can lead to negative neuropsychological consequences. Clinicians involved in the treatment of addiction should assess patients for history of head injury, and neuropsychological deficits consequent to both head injury and ethanol. These deficits may limit patient ability to comply with addiction rehabilitation programs. Conversely, clinicians in acute care and rehabilitation of the sequelae of head trauma should routinely assess their patients for substance abuse, because such abuse can have a significant impact on recovery from brain injury.

Effects of substance abuse on ventricular and sulcal measures assessed by computerised tomography

Computerised tomography (CT) was used to assess the possible effects of substance abuse on brain morphology. Polydrug abusers had significantly wider third ventricles than normal controls, with a positive correlation between age and ventricle:brain ratio (VBR). Assuming no effect of age, estimated quantity of substance abuse was not significantly related to ventricular and sulcal measures, except that alcohol consumption correlated positively with VBR and severity of cocaine use correlated negatively with sulcal width. When age of the subjects was partialled out, alcohol use showed a tendency for association with VBR; however, severity of cocaine use did not remain a significant predictor of cortical sulcal width. The findings suggest that chronic use of alcohol, but not necessarily of other commonly abused substances, produces brain atrophy.

Reduced cerebral grey matter observed in alcoholics using magnetic resonance imaging

Twenty-eight chronic alcoholics and 36 age- and sex-matched non-alcoholic controls were examined with magnetic resonance imaging and brain morphometric analyses. Results confirmed large increases in subarachnoid cerebrospinal fluid (CSF) volume and mild ventricular enlargement in the alcoholics and revealed associated volume reductions of localized cortical and subcortical cerebral structures. Volume losses in the diencephalon, the caudate nucleus, dorsolateral frontal and parietal cortex, and mesial temporal lobe structures were the most prominent. Significant correlations between increments in cortical and ventricular CSF and decrements in the volume of cortical and subcortical grey matter were noted. Although there was little evidence for relationships between performance on neuropsychological tests and volume of grey matter structures, significant correlations between some cognitive measures and subcortical and cortical fluid volumes were found. The parallels between this pattern of affected structures and recent neuropathological findings are discussed.

Brain CT changes in alcoholics: effects of age and alcohol consumption

A computerized tomographic (CT) brain scan and assessments of lifetime alcohol consumption, body size, and cognitive performance were performed in 37 male alcoholics, aged 26-62 years. Hematocrit and mean corpuscular volume (MCV) were also measured. CT data were analyzed using a semiautomated scoring system yielding measures of percentage of fluid at the ventricles and cortical sulci. Normative brain CT data from 57 community controls spanning the adult age range allowed Z-score assessment of deviation from age norms for each alcoholic. Across the entire group, alcoholics had significantly enlarged ventricles and sulci for their age. Enlargement at both sites correlated significantly with lifetime alcohol consumption. Sulcal enlargement in alcoholics was found across all ages. In contrast, ventricular enlargement was apparent only in older alcoholics and became increasingly exaggerated with age. Measures of body size, hematocrit, and MCV correlated with ventricular but not sulcal enlargement, suggesting that nutritional factors play a role in ventricular enlargement. Associations between neuropsychological performance and CT changes or alcohol consumption were less pronounced and at times counterintuitive. The findings support a modest dose-effect relationship between ethanol exposure and changes in brain morphology, and suggest that ventricles and sulci show a different time course of response. The role of nutritional status needs to be more closely investigated.

[Is the increase in brain volume of abstinent alcoholics a sequela of rehydration?]

A group of 30 alcoholics as identified using the MALT score were examined both within the first 36 h of alcohol withdrawal and then again at the end of a 10-day treatment in hospital. We looked for clinical signs of dehydration, water and electrolyte imbalance, and concentration of steroid metabolites in the urine. Cranial computed tomography was also performed twice, again at the beginning and end of the 10-day period. The size of cerebrospinal fluid spaces was calculated through measuring the frontal interhemisphere distance, the width of cortical sulci, the ventricle III diameter, the Cella media index and also the number of vermal sulci. All patients had a brain atrophy which did not disappear within the 10 days. The neuroradiological parameters remained completely unchanged in the control examination. However, the laboratory parameters of the internal milieu had normalized. Therefore, it is submitted that the shrinkage of the brain of alcoholics cannot be due to a reversible intra- or extracellulary dehydration. There was also no proof of a hormonal cause for the brain shrinkage. As a consequence other etiological factors gain importance, such as malnutrition or a toxic alcohol effect.

Normalization of regional cerebral blood flow in alcoholics during the first 7 weeks of abstinence

Twenty-two institutionalized alcoholics were studied after 1, 3, 5 and 7 weeks of abstinence with measurements of the regional cerebral blood flow (rCBF), psychometric testing and clinical ratings. Twenty-two healthy volunteers served as age-matched controls. Mean rCBF was significantly reduced in the alcoholics at all measurements compared to the controls. The older alcoholics (median cut) showed a 9% increase of rCBF from the 1st to the 7th week (P less than 0.01). The mean rCBF in these alcoholics also increased more in the right than in the left hemisphere (P less than 0.05) during the investigation. The differences between the alcoholics and the controls were most pronounced in the right frontal lobe. The mean flow changes were correlated to improvement in clinical state. Right hemisphere and frontal lobe flow decreases were more accentuated in older alcoholics.

Asking the right questions: problem solving in male alcoholics and male alcoholics with Korsakoff's syndrome

The performance of alcoholics and alcoholics with Korsakoff's syndrome was compared with that of nonalcoholic controls on a task which required the generation of a series of questions for the solution of object and digit/letter identification problems. Each subject attempted to determine which of a set of stimuli (objects, letters, or numbers) the examiner had arbitrarily preselected as correct. The nonalcoholic control subjects asked constraint-seeking questions which reduced alternatives by inquiring about general categories (e.g., "Is it a tool?"). In contrast, the two groups of alcoholic patients assumed the far less efficient strategy of asking hypothesis-scanning and pseudo-constraint questions which provided information only about one of the possible stimuli (e.g., "Is it the saw?"). This similarity in the problem-solving strategies of alcoholics both with and without Korsakoff's syndrome is consistent with the hypothesis that the problem-solving deficits of Korsakoff patients are apparent before the acute onset of their amnesic symptoms. These deficits may be due to alcohol-induced damage to the anterior and posterior cerebral cortical association areas which mediate problem-solving and visuoperceptual functions.

The effect of ethanol and sex on radial arm maze performance in rats

A daily dose of 1.5 g/kg of ethanol interfered with radial arm maze performance in rats. Ethanol inhibited the acquisition of a new win-shift response to obtain a food reward, especially when a previously learned response was present. This effect was greater in females than in males. Ethanol appears to suppress flexibility in the development of optimal performance of goal-directed behavior.

The chronic cerebral effects of cannabis use. I. Methodological issues and neurological findings

This paper examines the research evidence relating sustained use of marijuana to chronic cerebral impairment. Evidence from both American and cross-cultural studies is reviewed, with a particular emphasis on methodological problems in the research. The focus of this paper is on neurological findings while another paper focuses on neuropsychological findings. On the basis of available research, it was concluded that there is no evidence that marijuana produces gross structural cerebral changes and little evidence that it leads to functional impairment, although subtle impairment cannot be ruled out.

The chronic cerebral effects of cannabis use. II. Psychological findings and conclusions

This paper examines the research evidence on the question of whether sustained use of marijuana may produce chronic cerebral impairment as measured by neuropsychological measures. Evidence from both American and cross-cultural studies suggests that marijuana probably does not produce chronic cerebral impairment, although subtle impairment cannot be ruled out. Several suggestions for new lines of research are discussed including prospective studies, effects of cannabis use on later aging processes, and true experimental studies.

Computerized tomographic scan assessment of alcoholic brain damage and its potential reversibility

The assessment of alcoholic brain damage by computerized tomographic (CT) scanning is reviewed and discussed. Alcoholics showed greater cerebral atrophy than aged-matched neurological controls. Supratentorial atrophy measurements correlated significantly with some neurobehavioral assessment measures. The cerebral atrophy reversed in some subjects with maintained abstinence. Computerized assessment of cerebral spinal fluid volume (cerebral atrophy) and mean cerebral density showed decreased cerebral spinal fluid volume and increased cerebral density with maintained abstinence over 4 weeks in a group of 20 alcoholics. CT cerebellar measurements demonstrated atrophy in many subjects, but these measurements did not correlate with measures of ataxia, cognitive impairment, supratentorial atrophy measurements, or age. An example of a magnetic resonance imaging scan of an alcoholic is given. Its advantages in avoiding bony artifact for posterior fossa atrophy estimations and its potential for in vivo description and localization of central nervous system metabolic abnormalities in alcoholism are discussed.

Abstinence improves cerebral perfusion and brain volume in alcoholic neurotoxicity without Wernicke-Korsakoff syndrome

Twenty severe chronic alcoholic patients with signs of neurotoxicity but without Wernicke-Korsakoff syndrome were treated by abstinence from alcohol and examined prospectively at intervals thereafter. Serial examinations included detailed medical histories, neurological examinations, cognitive capacity screening examinations, computed tomography scans with measurements of sulcal and ventricular volume, and measurements of regional CBF. All sedatives were withdrawn before CBF measurements were made. Before treatment, gray matter blood flow values were significantly reduced compared with those of age-matched normal volunteers, but white matter blood flow values were normal and the ventricles were enlarged. After abstinence from alcohol, mean gray matter blood flow values and brain volume both increased significantly.

Alcoholic Korsakoff's syndrome: some unresolved issues concerning etiology, neuropathology, and cognitive deficits

Recent neuropsychological and neuropathological investigations with long-term alcoholics suggest that the etiology and neuropathology of the Wernicke-Korsakoff syndrome are more complex than previously believed. While problem solving and visuoperceptual deficits seem to develop slowly during decades of alcoholism, the amnesic symptoms associated with Korsakoff's syndrome may appear acutely when severe malnutrition and alcoholism are combined. Furthermore, the report that alcoholic Korsakoff patients, like patients with Alzheimer's Disease, have endured a substantial neuronal loss in the nucleus basalis of Meynert has questioned the role of the medial diencephalon in the alcoholic patients' amnesic syndrome. Some initial demonstrations of similarities in the memory disorders of alcoholic Korsakoff and Alzheimer patients indicate that Korsakoff's syndrome may be more accurately characterized as a "basal forebrain" than as a "diencephalic" amnesia.

Cerebral dysfunction in alcoholism related to mortality and long term social adjustment

All 1312 first-admitted alcoholics at the Department of Psychiatry, University Hospital, Lund (120 women) during 1949-1969 were followed until December 31, 1980. There were 537 deaths. All patients had been rated at discharge with a multidimensional rating scale including signs of cerebral dysfunction. Thirty-three per cent of the total patient group had signs of cerebral dysfunction, increasing with age up to 64% in those over 50 years. Men younger than 50 years with brain dysfunction had a higher mortality caused by alcohol-related physical disorders in relationship to violent deaths compared with the others. The main finding in those over the age of 50 was the increased number of deaths caused by circulatory disorder in the brain dysfunction group. The social prognosis was similar in all groups. It is suggested that a continuous and heavy drinking pattern in the young dysfunctional group and an accelerated aging in the old dysfunctional group could explain the differences found.

The continuity hypothesis: the relationship of long-term alcoholism to the Wernicke-Korsakoff syndrome

Although alcoholic Korsakoff's syndrome has traditionally been considered an acute disorder related to a nutritional deficiency, recent evidence demonstrating that ethanol may be neurotoxic has raised the possibility that the perceptual, problem-solving, and memory deficits associated with this chronic neurological disorder may develop slowly over decades of alcohol abuse. A review of the recent cognitive literature provides only limited support for this "continuity hypothesis." Long-term alcoholics, as with patients with alcoholic Korsakoff's syndrome, are impaired on numerous visuoconceptual and learning tasks, but there is little or no evidence that the information-processing deficits underlying the two patient groups' anterograde memory problems are similar. Furthermore, experimental and clinical studies of retrograde amnesia have noted only mild remote memory impairments in non-Korsakoff alcoholics as well as clear indications that alcoholic Korsakoff patients' severe loss or access to remote memories occurs acutely with the onset of Wernicke's encephalopathy. It is concluded that while the continuity hypothesis has heuristic value, there is still insufficient evidence to place the Korsakoff patient, the detoxified long-term alcoholic, and the heavy social drinker at different points on a single continuum of cognitive impairment.

Computerized measures of CT scans of alcoholics: thalamic region related to memory

CT scans of 24 chronic alcoholics were analyzed by computer. Measures of thalamic CT density numbers and third ventricle/intracranial width ratio, as well as supraventricular measures of frontal and parietal CT density numbers, sulcal fluid area, and sulcal fluid volume, were obtained. Tests of long- and short-term memory and visuoperceptive functions were also administered. Results showed that alcoholics' long-term (but not short-term) memory performance correlates significantly with thalamic CT density numbers in the region of the dorsomedial nucleus and with third ventricle/intracranial width ratio, but not with supraventricular CT measures. These findings support the conclusions that (1) the midline thalamic region is involved in the mediation of long-term memory; (2) long- and short-term memory are separable on an anatomical as well as psychological basis; (3) there is a continuum of cognitive impairment encompassing alcoholic Korsakoff patients at one end of the spectrum and alcohol abusers at the other end and (4) computerized CT scan measures, including CT density numbers, contribute significantly to alcoholic CT research methodology.

Neurobiological relationships between aging and alcohol abuse

Both biological aging and chronic exposure to alcohol may cause impaired learning and memory in man and animals. The chains of processes beginning with molecular changes that in turn alter electrophysiology and morphology and finally culminate in changes of behavior (individual and social) are largely unknown. While these chains originating with molecular events leading to the same behavioral end result may be totally different, they may also overlap at any one of these levels of biological organization, accentuate, attenuate each other, to branch again and to develop parallel to each other. There is currently some evidence from observations in humans and animals that both aging and chronic alcohol toxicity induce the following changes: brain atrophy measured in vivo by computerized tomography, histological loss of the dendritic tree of neurons in various brain regions including hippocampus and cerebellum, and a variety of chemical changes of brain synaptic function, such as loss of benzodiazepine receptors.

Alcohol consumption and premature aging. A critical review

Research conducted during the past ten years has demonstrated that alcoholics resemble yet older nonalcoholics on a variety of behavioral, radiological, electrophysiological, and regional blood flow measures of brain function. These similarities have led to speculation that excessive alcohol consumption causes a premature aging of the brain that, in turn, is responsible for the characteristic structural and functional changes seen in detoxified alcoholics. In this chapter, we discuss some of the conceptual and methodological problems associated with what has become known as the premature-aging hypothesis and review a series of recent studies that have used neuropsychological, computerized-tomography, and evoked-potential techniques to test its validity. We conclude that there is very little compelling empirical support for this intriguing hypothesis and suggest that the neurobehavioral changes seen in alcoholics are merely the reflection of a diffusely distributed pattern of brain damage.

Do brain damage and liver disease interrelate in advanced abusers of alcohol?

In a consecutive material comprising 43 alcoholics immediately prior to pension, due to their abuse, the interrelations between different symptoms of dysfunction of the brain and liver were studied. Signs of brain damage used were: psychometric test, delirium tremens and withdrawal seizures. Liver disease was examined by biopsy and liver function tests. The signs of dysfunction were compared with drinking pattern, amount of alcohol consumption and duration of abuse. The group was fairly homogeneous with respect to these variables. The patients showed a considerable degree of brain and liver damage, but relevant significant correlations between the criteria of brain and liver disease could not be demonstrated. This may support the hypothesis that the brain and the liver, in the same individual, react differently to alcohol.

A comparison of the effects of long-term alcohol abuse and aging on the performance of verbal and nonverbal divided attention tasks

The purpose of this study was to assess two versions of the hypothesis that alcohol abuse results in premature aging of the brain and of cognitive functioning. The performances of detoxified long-term alcoholic was compared with that of nonalcoholic controls on three divided attention tasks known to be sensitive to aging. While both forms of the premature aging hypothesis predicted that alcoholics should perform more poorly than controls, the hypotheses differed in their predictions of the interactions between the effects of alcohol and normal aging. The results showed that while all three tasks were sensitive to age, only two were affected by long-term alcohol abuse. On one of the tests affected by both age and alcohol abuse, the performance of both young and old alcoholics was equally impaired whereas on the other, only the older alcoholics had significant difficulties. Based on these findings it was concluded that there was only partial overlap between the effects of alcohol and aging, and that neither of the two forms of the premature aging hypothesis could predict the observed pattern of results.

The effect of verbal mediators on the pictorial memory of brain-damaged patients

Patients with alcoholic Korskoff's syndrome, Huntington's Disease, Alzheimer's Disease or right-hemisphere damage were administered a picture recognition task in which they attempted to associate specific human and animal figures with particular scenic backgrounds. Under one condition (no-story), no explicit verbal cues were provided to help the patients associate the figures with the scenes; in a second condition, stories, stories linking the figures to the background scenes were read to the patients during the study period. Although all four patient groups were impaired in picture-context recognition under the no-story condition, the groups differed significantly in their ability to use the stories to improve their pictorial memory. The Huntington and right-hemisphere patients' picture recognition showed significant improvement when stories were provided, whereas the Korsakoff and Alzheimer patients failed to use this verbal material in a productive manner. The groups also differed in their tendency to make intrusion (i.e., perseverative) errors on the picture-context recognition task. These group differences may be related to the combination of language, cognitive and motivational deficits associated with each disease.