NMR T1 relaxation time of the brain during alcohol withdrawal and its lack of relationship with symptom severity

Significant reversibility of alcoholic brain shrinkage within 3 weeks of abstinence

Chronic alcoholism is often associated with brain shrinkage or atrophy. During recent years, it has been demonstrated that this shrinkage is, at least in part, reversible when abstinence is maintained. There are different hypotheses concerning the mechanisms for this reversibility, but many questions are still open. Especially the time conditions for these reversible changes are subject of discussion. Twenty-eight male patients with severe alcohol dependence were investigated in a computed tomographic study at the beginning of abstinence and 3 weeks later. Planimetric evaluation of 5 selected slices revealed a significant decrease in liquor areas and an increase of brain volume. The densitometric analysis showed an increase in brain tissue density. In a multiple regression approach it was shown that the reversibility was mostly influenced by the age of the patients. Our results support neither the hypothesis of an increase in brain water as the most important principle for reversibility in alcoholic brain shrinkage nor the hypothesis of augmented dendritic growth. Other mechanisms like reduced (during chronic intoxication) and normalized (during abstinence) cerebral hemoperfusion have to be considered as possible mechanisms for the reversibility of alcoholic brain shrinkage.

Neuroimaging in alcoholism: CT and MRI results and clinical correlates

For more than a century we have known the deleterious effects of alcohol on the brain regions surrounding the third ventricle and on the cerebellum. But it was only recently that we gained clearer evidence that the cortex is affected as well. Our imaging studies show that brain shrinkage is at least partially reversible once abstinence is maintained. They confirm results obtained in different laboratories from all over the world. Although our data contradict the rehydration hypothesis and thus lend credence to the idea of regeneration and neuroplasticity, the nature of reversibility is still a matter of debate.

A critique of instruments and methods to detect, diagnose, and rate delirium

This document reviews existing instruments for evaluation of delirium. Instruments have been grouped into four categories: tests that screen for cognitive impairment, delirium diagnostic instruments, delirium-specific numerical rating scales, and laboratory and paraclinical exams. Analysis of instruments was based on comparison of their psychometric properties as well as subjective judgment. Guidelines are suggested for choosing the appropriate instrument according to the type of clinical evaluation or delirium research envisaged. Important factors in choosing an instrument, besides the appropriateness of its psychometric characteristics, include administration time constraints, level of rater expertise, and patient capabilities. By familiarizing investigators with the variety of evaluation instruments available, this work should permit more appropriate instrument selection in future studies on delirium.

The reversibility of alcoholic brain damage is not due to rehydration: a CT study

Alcoholic brain damage is reversible when the patients are continually abstinent. An increase of brain water content was the putative explanation for this phenomenon. We tested the rehydration hypothesis using CT density measurements in 29 alcohol-dependent male inpatients. During a 5-week period of controlled abstinence, CT density measures did not decrease in any of the investigated regions of the brain as one would expect with an increase in brain water. Although the volumetry of the ventricular system and the subarachnoidal spaces revealed a significant reduction of CSF volume, we found a slight increase in CT density measures. Thus, our results are in contradiction to the rehydration hypothesis. Under discussion is whether neuronal plasticity might be the explanation of the reversibility of alcoholic brain damage in abstinent patients.

Inappropriate vasopressin secretion in severe alcohol withdrawal

Forty-one male alcoholics suffering from alcohol withdrawal syndrome were investigated to assess the relationship between vasopressin (ADH), water homeostasis and alcohol withdrawal. During 10 d, we found a significant decrease in serum vasopressin, from 3.08 +/- 0.61 to 1.71 +/- 0.22 pg/nl. There were no concomitant changes in osmolality, so that a general dysregulatory state of vasopressin secretion during alcohol withdrawal cannot be assumed. Only patients with delirium tremens (8/41) had higher vasopressin levels despite lowered serum osmolalities. These findings support the hypothesis of an inappropriate rebound secretion of vasopressin in severe alcohol withdrawal. Furthermore, they may contribute to the pathogenesis of focal alcoholic brain damage, because rapid and/or profound changes in osmolality are suspected to cause circumscribed cerebral demyelinization.

T1 and T2 relaxation time estimates and brain measures during withdrawal in alcoholic men

Twenty-four chronic alcoholic men were investigated with 0.02 Tesla/0.8 MHz magnetic resonance imaging on days 7-9 of acute alcohol withdrawal state. Estimates of T1 and T2 relaxation times were obtained from the white matter and basal ganglia nuclei in an axial section. This section was also used for area measurements of intracranial structures using computer-assisted tissue classification. The relation between T1 and age was more marked in the alcoholic patients than in the control group. Mean values of T1 and T2 did not differ between the two groups, but differences in the age dependence of T1 were highly significant for all regions. The number of years of drinking was influential to T1, but to a lesser extent than age. Lateral ventricular area correlated significantly with T1 of the white matter in the alcoholic patients. Using visual ratings of the entire intracranial volume the alcoholic patients demonstrated wider lateral ventricles and cortical sulci, but there was no increased frequency of white matter lesions.