Alcoholic brain damage and reversible deficits

Cognitive dysfunction in recently detoxified female alcoholics

Objective:To assess the extent of cognitive impairment in a group of female alcoholics and to examine if any relationship was present between the degree of cognitive impairment, and the duration of alcohol dependence, impairment of liver function or associated prescribed medication abuse.Method:The subjects were thirty consecutive women in a residential alcoholism treatment programme who were assessed two weeks after detoxification. The visual reproduction subtest of the Wechsler Memory Scale was used, together with four subtests of the Wechsler Adult Intelligence Scale: vocabulary, similarities, block design and object assembly. We examined the effect on these scales of prolonged alcohol abuse (>5 years), abnormal liver function tests and prescribed medication abuse.Results:The group showed a significant impairment on the subtests, similarities, block design and object assembly when compared with the general population mean for the WAIS-R. Analysis of sub-groups showed little statistically significantly greater impairment on cognitive testing then the remainder of the group.Conclusions:The pattern of cognitive dysfunction for the group indicated subjects had deficits in abstraction, visual spatial and visual motor reasoning similar to previous studies involving male alcoholics. The usefulness of the sub-group comparisons was limited by the small numbers involved and larger studies would help clarify the role of contributory factors in the development of cognitive dysfunction in alcoholic subjects.

Brain damage in alcoholism: current concepts

Current views concerning the brain damage occasioned by alcohol abuse are reviewed. Diffuse cerebral changes appear to be common and partially reversible with prolonged abstinence. The possible determinants of such changes, and their relevance to functional deficits are discussed, with illustrations from work currently proceeding at the Institute of Psychiatry. Possible interactions between cortical and subcortical pathologies in contributing to the cognitive deficits shown by alcoholic patients are emphasised.

Alcoholism and dementia

This article reviews epidemiological, neurological, cognitive, and imaging data on alcohol-induced dementia. Recent studies indicate that "heavy alcohol use" (variously defined) is a contributing factor in 21-24% of cases of dementia. Research difficulties include lack of positive diagnostic criteria, few post-mortem studies, and no accepted pathological mechanism. Sulcal widening and ventricular enlargement (occasionally reversible) are the strongest findings in patients with alcohol-induced dementia. There is evidence for peripheral neuropathy, ataxia, sparing of language, and improved prognosis when patients with alcohol-induced dementia are compared to other dements. Case examples, etiologic theories, and recommendations for research, training, and clinical practice are included.

Synapse-to-neuron ratio in the lateral geniculate nucleus of rats exposed chronically to ethanol

Effects of chronic ethanol exposure on synapse-to-neuron ratio in the rat lateral geniculate nucleus were investigated. Male Sprague-Dawley rats were exposed to ethanol, using the Lieber-DeCarli liquid diets, for 4 months starting at the age of 5 weeks. Brains were perfusion-fixed, and the region containing the dorsal lateral geniculate nucleus was cut into slabs (500 microns thick) that were epoxy resin-embedded. From each rat, three slabs containing the structure were serially sectioned for electron microscopy. Using the double disector method, the study shows an unaltered synapse-to-neuron ratio in ethanol-treated rats when compared with controls. The findings are in agreement with previous studies on the visual system using the same exposure model. In contrast, a previous study has shown that the synapse-to-neuron ratio in locus ceruleus of ethanol-treated rats is reduced by 50%. Other studies have shown that, whereas the glutamatergic NMDA receptor is very sensitive to ethanol, the kainate/AMPA type of receptor is very much less so. Thus, the difference in ethanol-induced synapse elimination between the two regions may reflect this different sensitivity of the glutamatergic receptors, which are of the kainate/AMPA type in the lateral geniculate nucleus and of the NMDA type in the locus ceruleus.

Structural reorganization in the supraoptic nucleus of withdrawn rats following long-term alcohol consumption

We have recently shown in the supraoptic nucleus (SON) of the rat that prolonged ethanol consumption induces cell degeneration and enlargement of the surviving neurons and of their subcellular organelles. We analyzed the SON of withdrawn rats to evaluate whether it displays any evidence of morphological reorganization following abstinence from ethanol, inasmuch as in this condition the ethanol-induced changes in the plasma levels of neurohormones and plasma osmolality are no longer detectable. A group of 18-month-old withdrawn rats was compared with age-matched, pair-fed control and ethanol-treated rats. To differentiate between the effects of withdrawal and the effects of rehydration, a group of 18-month-old rehydrated rats was also included in this study and compared with age-matched, pair-fed control and dehydrated rats. We estimated the volume of SON, and the total number and mean volume of its neurons. The cross-sectional areas of the vasopressinergic and oxytocinergic populations were also evaluated. At the ultrastructural level, we determined the volumes and surface areas of the rough endoplasmic reticulum and Golgi apparatus, and the volumes of neurosecretory granules and nucleoli. In withdrawn animals, the total number of SON neurons was smaller than in controls, although the neuronal volume was greater. The number of SON neurons did not differ between withdrawn and ethanol-treated rats, despite the reduced volume of SON in the former animals. The decrease of SON volume correlated with and was caused by a reduction in the volume of SON neurons and in the size of the organelles involved in neuro-hormone synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Psychiatry and neuropathology: the maturing of a relationship

Images

The effect of chronic ethanol intake on brain NGF level and on NGF-target tissues of adult mice

The effect of ethanol consumption on the forebrain and hypothalamus of adult mice was investigated. A consistent decrease of biological activity and of nerve growth factor (NGF) immunoreactivity was observed in the hippocampus and hypothalamus of alcohol-treated mice. Biochemical studies also indicate that chronic ethanol intake causes a reduction in the level of choline-acetyltransferase in the septum, hippocampus and striatum, but not in the cortex and other brain regions. This study provides evidence that long-term ethanol intake causes impairment of brain NGF level and of the cholinergic enzyme, regulated by NGF, suggesting that NGF synthesis and/or biological activity is affected in alcohol-related brain neuropathology.

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.

The effect of long-term alcohol intake on brain NGF-target cells of aged rats

It was reported that chronic exposure to ethanol causes a loss of hippocampal pyramidal cells and of brain cholinergic neurons in both laboratory animals and humans. In the present study, it was hypothesized that nerve growth factor (NGF), a trophic agent for the survival and maintenance of basal forebrain cholinergic neurons (FCN), might be affected by the neurodegenerative events which occur during ethanol consumption. To test this hypothesis, we used aged rats (14 months) exposed for 16 weeks to 40 g/kg per day of undiluted wine. Our experiments showed that chronic alcohol consumption causes a reduction of NGF in the hippocampus (HI) and of choline acetyltransferase (ChAT) activity in both the septum and the HI and a reduction in the distribution of NGF-receptors (NGF-R) in the septum and nucleus of Meynert. Intracerebral injection of NGF in alcohol-exposed rats results in a return to normal levels of ChAT enzymatic activity and NGF-R expression. These experiments indicate that the damaging effect of alcohol on the FCN is also associated with impairment of central NGF-target structures.

Effects of chronic alcohol intake and withdrawal on the prefrontal neurons and synapses

Previous studies demonstrated that alcohol induces marked deterioration of the cerebral cortex. However, quantitative evaluations of neurons and synapses of the prefrontal cortex from chronic alcohol-fed and withdrawn animals are nonexistent, in spite of the functional implications that can underlie structural changes in this cortical area. To achieve this evaluation, we used groups of rats alcohol-fed for 6, 12 and 18 months, their respective controls as well as groups of rats alcohol-fed for 6 and 12 months and then switched to water for 6 months--withdrawal groups. The thickness of the prelimbic cortical layers I-III was reduced in the alcohol-fed and withdrawal groups. A significant reduction in the density of cells was found, which was more marked after withdrawal. Conversely, the density of synapses increased after alcohol exposure and withdrawal; such numerical shifts lead to a significant increase in the synapse-to-neuron ratio. These results indicate that the cortical circuitry of the prelimbic cortex is vulnerable to prolonged periods of alcohol exposure and withdrawal and allow to advance the view that the alterations can induce functional implications.

Reversible brain shrinkage in abstinent alcoholics, measured by MRI

Magnetic resonance imaging of the intracranial CSF volume was compared before and after 5 weeks of confirmed abstinence in 9 alcohol-dependent patients. All patients showed a highly significant reduction in CSF volume in accordance with reexpansion of the brain after alcohol abstinence. T2 values for white matter, estimated by linear regression from 16 echoes of a CPGM sequence, however, showed no significant increase such as occurs in rehydration. This indicates, that alcohol-induced reversible brain atrophy cannot be attributed to fluctuation of free water in the brain only.

Brain computed tomography in morbid obesity before and after gastric restriction surgery: a prospective quantitative study

Linear brain parameters were measured by CT in 19 patients with morbid obesity (mean weight 126.4 +/- 20.5 kg) and 20 age and sex matched normal weight subjects (mean weight 62.6 +/- 14.9 kg). Ventricular parameters were slightly smaller and cortical parameters were slightly larger in the preoperative obese than in control subjects. However, only the four cortical sulci ratio was significantly different in the two groups (P = 0.02). After gastric restriction surgery and drastic weight loss (mean postoperative weight 82.9 +/- 27.4 kg), all the ventricular and cortical parameters increased, with significant change in the frontal interhemispheric fissure ratio (P less than 0.05). Obese patients followed for 23 months after surgery had less striking changes than those followed for 6 months. Morbidly obese subjects have altered brain CT dimensions which are partly reversible after weight correction.

P3 amplitudes in two distinct tasks are decreased in young men with a history of paternal alcoholism

Visual event-related potentials (ERPs) were obtained in two groups of young adult male subjects: One group (N = 24) considered to be at high risk for alcoholism due to paternal alcoholism and the second group (N = 26) with no family history of alcoholism. Results presented here were obtained during a baseline (no drug) condition. The ERP tasks both were target detection paradigms, but differed in several respects. One paradigm involved continuous participation in a distracting tracking task, but used an easily interpreted target stimulus. The second task involved no distractions, but entailed more complex stimuli. Both paradigms utilized level of task difficulty as an experimental variable. The results from both tasks were quite similar and demonstrated significantly lower ERP amplitudes in the high risk compared to the low risk group. Reaction times to target stimuli did not discriminate group membership, but were related to perceived task difficulty. Task difficulty was not a useful variable in discriminating group membership.

Are we drinking our neurones away?

A quantitative neuropathological necropsy study of the human cerebral cortex showed that the number of cortical neurones in the superior frontal cortex in chronic alcoholic patients is significantly reduced compared with that in controls matched for age and sex. The number of neurones in the motor cortex did not differ significantly between the controls and alcoholics, but in both cortical regions there was evidence that alcoholic patients had smaller (shrunken) neurones than controls. Further studies are necessary to identify other regions of the cerebral cortex that are selectively damaged in brain damage associated with alcohol.

The role of essential fatty acids in alcohol dependence and tissue damage

Evidence for the role of essential fatty acids in alcohol dependence is reviewed. If alcohol-induced tissue damage is associated with impaired fatty acid and phospholipid metabolism, supplements of essential fatty acids might be beneficial in the treatment of alcoholics. The evidence for this effect is examined.

The contributions of sex and drinking history to the CT brain scan changes in alcoholics

Consecutive series of male and female alcoholics, Alcoholic Anonymous (AA) members and controls were examined by interview and with a CT brain scan. Male controls were shown to have larger CT brain parameters than healthy females of the same age. Female alcoholics revealed equivalent CT scan abnormalities, apart from less sulcal widening, after a markedly shorter drinking history and at a lower estimated peak alcohol consumption than male alcoholics. The CT scan findings persisted after accounting for body weight and after matching for age and length of drinking history. The CT scan parameters of female AA members approached control values more completely and after briefer abstinence than did those of male AA members. Methodological problems and sex differences in selection and other processes are discussed. The findings are consistent with sex differences in the vulnerability of the brain to alcohol toxicity, and in its recovery with abstinence.

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.

Correlates of increased risk for alcoholism in young men

Healthy men, aged 21-28, were divided into two groups according to the DSM-III diagnosis of alcoholism in their biological fathers. Evoked potentials from each subject were measured according to a visual odd-ball paradigm designed to elicit large responses in the midline parietal, Pz, lead. Subjects with alcoholic fathers produced significantly smaller amplitudes of the P3 component compared to subjects with non-alcoholic fathers. Reaction time, task difficulty and subject drinking history did not distinguish the groups. Subject's drinking history was not related to P3 amplitude.

Cerebral atrophy and hypoperfusion improve during treatment of Wernicke-Korsakoff syndrome

Nineteen patients with sudden onset of impaired recent memory, cerebellar ataxia, peripheral neuropathy, and other signs of Wernicke-Korsakoff syndrome (WKS) were treated and examined prospectively for 3 months. Serial studies included histories, neurological examinations, cognitive capacity screening examinations (CCSE), computed tomography (CT) scans, and measurements of regional CBF. Patients were detoxified and withdrawn from sedatives before CBF measurements were examined. Treatment included alcohol withdrawal, nutritious diet, and 300 mg thiamine daily. Before treatment CCSE scores and blood flow values of both white and gray matter were reduced, particularly within both temporoparietal regions. After treatment of compliant patients (n = 10), white and gray matter blood flow increased concurrently with improved CCSE scores. Abnormal eye signs, ataxia, peripheral neuropathy, and performance of activities of daily living also improved. Cerebral atrophy and ventricular enlargement measured by CT decreased. Early recognition and treatment of WKS in compliant patients permit rapid reversals of cognitive and neurological impairments associated with increased blood flow of gray and white matter and improvements of brain atrophy measured by CT scanning.

Reversible and non-reversible enlargement of cerebrospinal fluid spaces in anorexia nervosa

Brain CT studies of 35 patients with anorexia nervosa confirmed the observations of other authors: cerebral dystrophic changes correlate with weight loss and the reversibility of these changes also correlates with the normalization of body weight. Other corroborated facts are: the most numerous and most pronounced enlargements are of the cortical sulci and the interhemispheric fissure, moderate widening affects the ventricles and the rarest and most insignificant changes are those of the cerebellum. The reversibility of the changes showed a parallel to the extent of the changes themselves and to the duration of improvement of the body weight. The reversibility of the enlargement of the cortical sulci and of the distances between the frontal horns of the lateral ventricles was more often significant than that of the abnormal measurements of the cella media. This difference is based on minimal early acquired brain damage which occurs in 60% of our patients. This high incidence of early acquired minimal brain disease in patients with anorexia nervosa is here discussed as a nonspecific predisposing factor. Although there is no exact explanation of the etiology of the reversible enlargement of cerebrospinal fluid (CSF) spaces in anorexia nervosa, the changes resemble those in alcoholics. The mechanisms of brain changes in alcoholism, as shown experimentally, seem to us to throw light on the probable mechanism of reversible dystrophic brain changes in anorexia nervosa.

Effect of chronic alcohol consumption on rat brain microsome lipid composition, membrane fluidity and Na+-K+-ATPase activity

The present study reports differences in phospholipid classes, fatty acids of individual phospholipids, and changes in membrane fluidity and Na+-K+-ATPase activity in brain microsomes of rats maintained on an alcohol diet for 35 days compared to sex, age and weight-matched control rats maintained on a calorically-equivalent, non-alcohol diet. Although no difference in Na+-K+-ATPase activity was found in microsomes from alcohol vs control rats when measured in the absence of added alcohol, the presence of low concentrations of ethanol (less than 100 mM) stimulated, while high concentrations (greater than 100 mM) inhibited enzyme activity. The stimulation was differentially expressed in that the microsomal enzyme from alcohol rats was stimulated to a lesser extent than the enzyme from control rats. However, the inhibiting effect of high concentrations of alcohol was similar in microsomes from both alcohol and control rats. Also in membranes from alcohol rats, there was a lower quantity of phosphatidylethanolamine (PE) and higher quantities of phosphatidylserine (PS) and phosphatidylinositol (PI) compared to membranes from control rats. The major change in fatty acid composition was a reduction in the level of polyunsaturated fatty acids, which was particularly evident in PI and PS. The linoleic acid: arachidonic acid ratio (18:2/20:4) and the saturation:unsaturation ratio were also increased in PI and PS in membranes from alcohol animals. However, the ratio of n-6/n-3 fatty acids remained the same or was reduced in membranes from alcoholic animals. Although no difference in the inherent "fluidity" of membranes from alcohol vs control rats could be demonstrated by electron paramagnetic resonance, molecular tolerance to ethanol was demonstrated in the membranes from alcohol rats by the resistance to the disordering effects of added ethanol.

Behavioral correlates of computed tomographic (CT) scan changes in older psychiatric patients

Fifty psychiatric inpatients aged 50 and over, with no hard neurologic findings, and with a variety of DSM-III diagnoses (adjustment disorder, affective illness, and dementia), were rated for behavioral and psychiatric symptoms using the Geriatric Rating Scale and the Nurse's Assessment of Global Symptomatology-Elderly. These clinical ratings were correlated with computed tomographic (CT) scan assessments of various superficial cerebral regions as well as with linear measures of ventricular size. Behavioral deficits in activities of daily living (ADL) plus an interactional variable, inability to respond to requests, were correlated with superior temporal and inferior parietal CT abnormalities, particularly on the left side. Suspiciousness and peculiar thinking, mood lability and irritability, as well as impaired memory with confusion, perplexity, and disorientation were also associated with atrophy in these same regions. Prefrontal area defects correlated with mood lability and deficits in visual-interactional responsiveness. Statistically controlling for effects of age and alcohol abuse did not alter the basic nature of these results. Regional cerebral specialization in relation to these results are discussed using concepts developed by Luria.

CT demonstration of the early effects of alcohol on the brain

CT evidence of brain damage has been sought in subjects consuming alcohol between 10 g/day to over 200 g/day. Dietary contributing factors have been evaluated. The level of atrophy (shrinkage) has been correlated with intellectual performance. To establish a relationship between alcohol intake and brain structure and function, re-examination of subjects over a 6- to 12-month period of abstinence has been undertaken to examine any reversibility features. A record of liver function showed that brain damage always precedes liver damage. Subjects were re-examined a second time, who had initially abstained for six months and then had returned either to their original level of consumption or to one that was somewhat reduced. A regression in initial improvement was considered evidence of reversible brain damage that had originally been related to alcohol. The threshold consumption for CT damage was 40 g/day, but the level of CT atrophy at which cognitive dysfunction appeared has still to be established.

Partially reversible cerebral atrophy and functional improvement in recently abstinent alcoholics

52 recently abstinent chronic alcoholics were given repeated psychological tests and 20 of these had repeated CT scans. The first scan was done within 5 weeks of the last drink. The degree of measurably reversible cerebral atrophy on CT scan correlated negatively with the interval between the last drink and the first CT scan. Significantly more reversibility of cerebral atrophy was noted in those subjects claiming interscan abstinence. There were positive correlations between functional improvement scores on neurological exam and reversible cerebral atrophy measurements. Significant improvement on psychological test performance was restricted to patients tested initially within 3 weeks of the last drink. Both the CT results and the psychological test results suggest that reversible changes occur soon after the cessation of drinking.

Peripheral neuropathy, cerebral atrophy, and intellectual impairment in chronic alcoholics

Peripheral neuropathy, cerebral atrophy, and intellectual impairment was investigated in 46 males with alcoholic nervous system damage. An overall correlation was found between peripheral neuropathy and cerebral atrophy and between several of the individual neurophysiological and neuroradiological variables examined. There was also a correlation between cerebral atrophy and intellectual impairment. The findings support the view that alcohol in itself is toxic to central and peripheral nervous tissues, although a dose-response dependence could not be established.

Impairment of long-term potentiation in rat hippocampus following chronic ethanol treatment

The effect of chronic ethanol treatment on long-term potentiation (LTP), a possible substrate for memory, was studied in rats using the in vitro hippocampal slice preparation. Rats were provided ad libitum access to an ethanol-containing or control liquid diet. One group of animals received the diet for a total period of 9 months before testing, while a second group received the diet for 7 months and was allowed a 2 month ethanol-free period before testing. LTP was induced in the CA1 region by orthodromic stimulation of the stratum radiatum with 4 stimulus trains of 200 pulses each at 25, 50, 100 and 200 Hz separated by 10 min intervals. The number of slices with potentiation greater than 15% was significantly smaller in the ethanol-fed animals both before and following the 2 month withdrawal period. However, the average percent increase in the amplitude of the population spike was significantly decreased in the ethanol-fed animals when tested before withdrawal but no significant difference was detected following the 2 month withdrawal period, suggesting some recovery. The possible mechanisms mediating the chronic ethanol-induced depression of LTP are discussed.

Increased cerebral ventricular volume in monozygotic twins discordant for alcoholism

21 pairs of monozygotic twins discordant for alcoholism and heavy drinking were examined by computerised tomography. Brain and ventricular volumes were calculated by the use of a semiautomated method with the rater blind to twinship and drinking history. 11 severely dependent alcoholics had larger ventricular volumes and ventricle/brain ratios than did their normal cotwins. These changes correlated best with the length of time the alcoholic twin had been drinking eight centilitres pure alcohol, equivalent to a bottle of wine, a day.

Morphological alterations in rat CA1 hippocampal pyramidal cell dendrites resulting from chronic ethanol consumption and withdrawal

Hippocampal CA1 pyramidal cell dendrites were studied in rats after 5 months of consumption of an ethanol liquid diet and 5 months of ethanol diet followed by 2 months of withdrawal. Morphometric data were compared with those obtained from matched littermate, yoke -fed control animals. Dendritic branching in Golgi-Cox-stained tissues was assessed by standard and modified Sholl analysis techniques and basilar dendrites were analysed three-dimensionally by computer. Five months of chronic ethanol consumption caused a significant decrease in the number of second-order basilar dendrites, 60-90 micron from the apical border of the cell layer. No significant changes in the neuronal density of CA1 or CA3 cells were found; however, the thickness of the strata oriens and radiatum of the CA1 field was significantly decreased in the ethanol-fed group. After 5 months of chronic ethanol consumption and 2 months of withdrawal, the thickness of the strata returned to control sizes and the frequency of proximal basilar branching recovered. Evidence of lengthening and new branching of distal basilar dendrites occurred in the third-, fourth-, and fifth-order segments when control animals 6 and 8 months of age were compared. During the 2-month period of withdrawal, the number and length of third-, fourth-, and fifth-order segments of basilar dendrites increased when compared to the nonwithdrawn ethanol group while the number and length of second- and third-order segments decreased. This is comparable to the changes seen during normal aging and suggests that withdrawal may interact with aging to produce enhanced dendritic growth in "compensation" for the developmental retardation induced by chronic ethanol intake.

The assessment of changes in brain volume using combined linear measurements. A CT-scan study

All linear measurements employed for evaluation of brain atrophy, were performed on 148 computed tomograms of patients aged 28 to 84 without evidence of any nervous system disorder. These included size of lateral, third and fourth ventricles, width of the Sylvian and frontal interhemispheric fissures and cortical sulci and size of the pre-pontine cistern. Various parameters indicated decrease in brain mass with age. Since the atrophic process is a diffuse phenomenon, integration of several measurements evaluating separate brain regions was made. The bicaudate ratio and the Sylvian fissure ratio (representing both central and cortical atrophy) were combined arithmetically, resulting in a correlation of 0.6390 with age (P less than 0.0005). With a computed canonical correlation analysis; a formula was obtained which combined measurements of the lateral and third ventricles, the Sylvian fissure and the pre-pontine cistern. This formula yielded a correlation of 0.67795 (P less than 0.0005). These linear measurements will allow simple and reliable assessement of reduction in brain volume during the normal aging process and in disorders accompanied by brain atrophy.

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.

CT scan studies of superficial cerebral regions: frequency and distribution of abnormalities in elderly psychiatric patients

The CT scans of 50 elderly psychiatric patients were evaluated for the presence of discrete cerebral abnormalities. The prefrontal, superior temporal and inferior parietal areas showed the most frequent occurrence of defects. Motor, sensory and tertiary visual cortical regions, on the other hand, did not commonly exhibit signs of atrophy or sulcal widening. Clinical diagnoses of depression and dementia occurred in patients whether or not specific gyral defects were present, and therefore did not predict their presence. Patients with regional cerebral defects, however, were more likely to be older and to have sustained severe neurological insults. Patients with affective disorders who were treated with ECT showed no differences in the occurrence of superficial cerebral defects.

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.

The alcoholic brain: CT scan and psychological findings

One hundred male alcoholics without overt clinical signs of brain damage were interviewed, psychologically tested and scanned by means of a CT 1010 EMI scanner. Fifty age-matched controls, lifelong abstainers or light drinkers, were used for comparison. Fifty-six alcoholics from the initial sample were followed up after periods varying from 30 to 152 weeks, and radiological changes during the follow-up were assessed. The main results of the study can be summarized as follows: (1) All CT scan indices were significantly different in alcoholics and controls. Alcoholics had larger ventricles, wider cerebral sulci and wider Sylvian and interhemispheric fissures. Cerebellar sulci were visible only in alcoholics. These differences were greater for older alcoholics and controls, but were also present in the younger subjects. (2) In the alcoholic group the size of the ventricular system, and the width of the sulci, Sylvian and interhemispheric fissures were positively and significantly correlated with age. The duration of the drinking history and the age of onset were not significantly correlated with CT scan indices. (3) In those alcoholics whose age was greater than the mean for the whole group, the size of the ventricular system and width of the Sylvian fissure were significantly and negatively correlated with the duration of abstinence prior to scanning. (4) Other features such as decreased tolerance, a positive family history of alcoholism and 'social decline' were not significantly related to the severity of CT scan abnormalities. (5) When the effects of age and premorbid intelligence were controlled, alcoholics showed significant cognitive impairment when compared with controls. The differences in the scores of psychological tests and CT scan indices were greater between alcoholics and controls of high IQ than between those of low IQ. This discrepancy is likely to be due to a selection bias. (6) No significant correlations were found between the degree of cognitive impairment and clinical features. The size of the ventricular system was positively and significantly correlated with the discrepancy between immediate and delayed recall of verbal material. There were no other significant correlations between cognitive impairment and CT scan indices. (7) Those subjects who had remained abstinent during the follow-up period, when considered as a group, showed a significant reduction in the size of the ventricular system. When cortical indices and V/B ratio were combined, patients whose scans had improved at follow-up differed from the rest with regard to the length of abstinence prior to re-scanning.

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

Neuroradiological studies have consistently demonstrated that alcoholics have morphological abnormalities of cortical, ventricular, and cerebellar structures suggesting brain atrophy. This atrophy is weakly correlated with impaired psychological test performance. Because brain atrophy and intellectual impairment can also be found in normal aging it is necessary to compare alcoholics with age-matched control subjects. It is currently unknown if alcohol-associated brain atrophy and intellectual impairment are the result of conditions preceding alcohol consumption or conditions only indirectly related such as head trauma or other associated diseases. Direct alcohol toxicity would be supported by quantitative alcohol-atrophy dose-response relationships and by a partial reversal of atrophy and functional impairment following abstinence from alcohol. Because of methodological difficulties inherent in neuroradiological research, data on the exact pathogenesis of abnormalities in alcoholics have not been produced. The design of such studies can be improved to increase the probability that the causes of brain atrophy will be elucidated.