Alcohol Withdrawal Increases Protein Kinase A Activity in the Rat Inferior Colliculus.

BACKGROUND: Cyclic AMP-dependent protein kinase A (PKA) signaling is a key target for the action of alcohol and may therefore play a role in the pathophysiology of alcohol withdrawal seizures (AWSs). Here, we investigated the role of PKA activity with respect to increased seizure susceptibility in rats that were subjected to alcohol withdrawal. METHODS: Adult male Sprague Dawley rats received 3 daily doses of ethanol (EtOH) (or vehicle) for 4 consecutive days. Rats were then tested for susceptibility to acoustically evoked AWSs 3, 24, and 48 hours after the last alcohol dose. In separate experiments, the inferior colliculus (IC) was collected at these same time points from rats subjected to alcohol withdrawal and control rats following alcohol withdrawal. PKA activity, catalytic Cα (PKACα ) protein, regulatory RIIα (PKARIIα ) protein, and RIIß (PKARIIß ) protein were measured in the IC. Lastly, in situ pharmacological studies were performed to evaluate whether inhibiting PKA activity in the IC suppressed AWSs. RESULTS: In the EtOH-treated group, AWSs were observed at the 24-hour time point, but not at the 3-hour or 48-hour time points. In the IC, PKA activity was significantly higher both 3 hours (i.e., before AWS susceptibility) and 24 hours after the last alcohol dose (when AWS susceptibility peaked) than in control rats. Consistent with these findings, protein levels of the PKACα subunit were significantly increased in the IC both 3 and 24 hours after the last alcohol dose. Lastly, in situ inhibition of PKA activity within the IC suppressed AWSs. CONCLUSIONS: The increase in PKA activity and PKACα protein expression in the IC preceded the occurrence of AWSs, and inhibiting PKA activity within the IC suppressed acoustically evoked AWSs. Together, these findings suggest that altered PKA activity plays a key role in the pathogenesis of AWSs.

Predictors of severe alcohol withdrawal syndrome: a systematic review and meta-analysis.

BACKGROUND: Severity of alcohol withdrawal syndrome (AWS) is associated with hospital mortality and length of stay. However, as there is no consensus regarding how to predict the development of severe alcohol withdrawal syndrome (SAWS), we sought to determine independent predictors of SAWS. METHODS: We conducted a systematic review and meta-analysis of studies evaluating hospitalized patients with AWS versus SAWS-delirium tremens (DT) and/or seizures. Random-effects meta-analysis [PRISMA guidelines] was performed on common baseline variables and predictive effects for development of SAWS were calculated using RevMan v5.2. Funnel plots were constructed, and tests of heterogeneity were performed. RESULTS: Of 226 studies screened, 17 met criteria and 15 were included in the meta-analysis. The primary findings were that an incident occurrence of DT or alcohol withdrawal seizures was significantly predicted by history of a similar event (OR 2.58 for DT vs. no-DT, 95% CI 1.41, 4.7; OR 2.8 for seizure vs. no-seizure, 95% CI 1.09, 7.19). Both a lower initial platelet count and serum potassium level were predictive of an incident occurrence of DT (platelet count mean difference [MD] -45.64/mm(3) vs. no-DT, 95% CI -75.95, -15.33; potassium level MD -0.26 mEq/l vs. no-DT, 95% CI -0.45, -0.08), seizures, and SAWS. Higher initial alanine aminotransferase was seen in patients with SAWS (MD 20.97 U/l vs. no-SAWS, 95% CI 0.89, 41.05). Higher initial serum gamma-glutamyl transpeptidase was seen in patients with incident alcohol withdrawal seizures (MD 202.56 U/l vs. no-seizure, 95% CI 3.62, 401.5). Significant heterogeneity was observed, and there was evidence of publication bias. Notably, neither gender nor comorbid liver disease was predictive. CONCLUSIONS: The course of prior episodes of AWS is the most reliable predictor of subsequent episodes. Thrombocytopenia and hypokalemia also correlate with SAWS. We propose further research into drinking patterns, gender, and medical comorbidities.

Voluntary wheel running attenuates ethanol withdrawal-induced increases in seizure susceptibility in male and female rats.

We recently found that voluntary wheel running attenuated ethanol withdrawal-induced increased susceptibility to chemoconvulsant-induced seizures in male rats. Since female rats recover from ethanol withdrawal (EW) more quickly than male rats across several behavioral measures, this study was designed to determine whether the effects of exercise on EW seizures also exhibited sex differences. Animals were maintained under no-wheel, locked-wheel or free-wheel conditions and ethanol was administered by liquid diet for 14 days with control animals pair-fed an isocaloric diet, after which seizure thresholds were determined at 1 day or 3 days of EW. Consistent with previous reports, females ran significantly more than males, regardless of diet condition. Introduction of the ethanol-containing liquid diet dramatically increased running for females during the day (rest) phase, with little impact on night phase activity. Consistent with previous reports, EW increased seizure susceptibility at 1 day in non-exercising males and females and at 3 days in males. These effects were attenuated by access to running wheels in both sexes. We also assessed the effects of sex, ethanol diet and exercise on ethanol clearance following an acute ethanol administration at 1 day EW in a separate set of animals. Blood ethanol concentrations at 30 min post-injection were lower in males, ethanol-exposed animals, and runners, but no interactions among these factors were detected. Interestingly, females displayed more rapid ethanol clearance than males and there were no effects of either diet or wheel access on clearance rates. Taken together, these data suggest that voluntary wheel running during ethanol administration provides protective effects against EW seizures in both males and females. This effect may be mediated, in part, in male, but not in female rat, by effects of exercise on early pharmacokinetic contributions. This supports the idea that encouraging alcoholics to exercise may benefit their recovery.

Indicators for elevated risk factors for alcohol-withdrawal seizures: an analysis using a random forest algorithm.

Alcohol-withdrawal seizures (AWS) are an important and relevant complication during detoxification in alcohol-dependent patients. Therefore, it is important to evaluate the individual risk for AWS. We apply a random forest algorithm to assess possible predictive markers in a large sample of 200 alcohol-dependent patients undergoing alcohol withdrawal. This analysis showed that the combination of homocysteine, prolactin, blood alcohol concentration on admission, number of preceding withdrawals, age and the number of cigarettes smoked may successfully predict AWS. In conclusion, the results of this analysis allow for origination of further research, which should include additional biological and psychosocial parameters as well as consumption behaviour.

Biological markers for alcohol withdrawal seizures: a retrospective analysis.

AIMS: Alcohol withdrawal seizures (AWS) are among the most important possible complications during the detoxification treatment of alcohol-dependent patients. Pharmacological therapy is often used during detoxification, but can cause dangerous side effects [Eur Addict Res 2010;16:179-184]. In separate studies several biological markers have been described as being associated with AWS risk. We investigated the role of homocysteine (HCT), carbohydrate-deficient transferrin (CDT) and prolactin (PRL) as biological markers for the risk of developing AWS. METHODS: The present study included 189 alcohol-dependent patients of whom 51 had a history of AWS. We investigated the HCT, CDT and PRL levels of all patients and calculated sensitivity and specificity. Bayes' theorem was used to calculate positive (PPV) and negative (NPV) predictive values. RESULTS: The highest combined sensitivity and specificity for %CDT was reached at a plasma cutoff value of 3.75%. The combination of HCT at a cutoff value of 23.9 µmol/l and %CDT at a cutoff value of 3.75% showed the best predictive values (sensitivity 47.1%, specificity 88.4%, PPV 0.504, NPV 0.870). CONCLUSION: A combined assessment of HCT and CDT levels can be a useful method to identify patients at a higher risk of AWS, which may lead to a more individualized therapy.

Withdrawal severity after chronic intermittent ethanol in inbred mouse strains.

BACKGROUND: To study withdrawal, ethanol is usually administered chronically without interruption. However, interest has recurred in models of episodic exposure. Increasing evidence suggests that chronic intermittent exposure to ethanol leads to a sensitization effect in both withdrawal severity and ethanol consumption. The goal of the present study was to examine mouse inbred strain differences in withdrawal severity following chronic intermittent exposure using the handling-induced convulsion as the behavioral endpoint. We also sought to compare the withdrawal responses of inbred strains across acute, chronic continuous, and chronic intermittent exposure regimens. METHODS: Male mice from 15 standard inbred strains were exposed to ethanol vapor for 16 hours each day for 3 days and removed to an air chamber during the intervening 8 hours. Mice in the control groups were handled the same, except that they were exposed only to air. Daily blood ethanol concentrations were averaged for each mouse to estimate total dose of ethanol experienced. RESULTS: Across strains, mice had an average daily blood ethanol concentration (BEC) of 1.45 +/- 0.02 mg/ml and we restricted the range of this value to 1.00-2.00 mg/ml. To evaluate strain differences, we divided data into two dose groups based on BEC, low dose (1.29 +/- 0.1 mg/ml) and high dose (1.71 +/- 0.02 mg/ml). After the third inhalation exposure, ethanol-exposed and air-exposed groups were tested hourly for handling-induced convulsions for 10 hour and at hour 24 and 25. Strains differed markedly in the severity of withdrawal (after subtraction of air control values) in both dose groups. CONCLUSION: The chronic intermittent exposure paradigm is sufficient to elicit differential withdrawal responses across nearly all strains. Data from the high-dose groups correlated well with withdrawal data derived from prior acute (single high dose) and chronic continuous (for 72 hours) ethanol withdrawal studies, supporting the influence of common genes on all three responses.

An open trial of gabapentin in acute alcohol withdrawal using an oral loading protocol.

AIMS: Anticonvulsants are increasingly being advocated for the treatment of acute alcohol withdrawal syndrome (AWS) to avoid the addictive properties of established medications. Because earlier works showed that moderate gabapentin doses were too low to clearly ameliorate severe AWS, we tested a higher gabapentin entry dose. METHODS: Inpatients (n = 37) with severe alcohol withdrawal symptoms (Clinical Institute Withdrawal Assessment for Alcohol revised (CIWA-AR) score > or =15 points) were given gabapentin 800 mg, and if their symptom score reduced within 2 h, they were termed 'early responders' and were then treated for 2 days with 600 mg gabapentin q.i.d. (i.e. a total of 3200 mg in the first 24 h) before beginning a taper. RESULTS: Twenty-seven (73%) were early responders (baseline CIWA-AR improved from 17.3 +/- 2.6 to 8.0 +/- 3.6 points). In the remaining 10 patients, baseline CIWA-AR deteriorated within 2 h (from 20.1 +/- 4.6 to 21.5 +/- 4.65 points). These patients were switched to clomethiazole (n = 4) or clonazepam (n = 6), which is the usual treatment. Three of the 'early responders' worsened in the next 36 h and were then reclassified and treated as 'non-responders'. Among them, two developed an epileptic seizure. CONCLUSION: Oral 800 mg gabapentin (loaded up to 3200 mg in the first 24 h) is helpful only in reducing less severe and less complicated acute AWS.

Acamprosate attenuates the handling induced convulsions during alcohol withdrawal in Swiss Webster mice.

In the present study, we examined the effects of acamprosate for its ability to reduce handling induced convulsions (HICs) during alcohol withdrawal. Diazepam was used as a positive control. Swiss Webster male mice received three daily IP injections of alcohol (2.5 g/kg) or alcohol (2.5 g/kg)+methylpyrazole (4-MP) (9 mg/kg). (4-MP, being an alcohol dehydrogenase inhibitor slows down the breakdown of alcohol. 4-MP in combination with alcohol exhibits a dramatic increase in blood alcohol level compared to alcohol alone). Ten hours following the last alcohol injection, the mice were picked up by the tail and examined for their seizure susceptibility (HICs). Diazepam, a benzodiazepine known to reduce seizures during alcohol withdrawal, significantly reduced these HICs at doses of 0.25, 0.5 and 1 mg/kg (p's<0.001). Acamprosate, an anti-relapse compound used clinically in newly abstinent alcoholics, also reduced these HICs at doses of 100, 200 and 300 mg/kg (p's<0.05). This study supports the use of acamprosate during periods of alcohol withdrawal as well as during abstinence.

Elevated prolactin serum levels and history of alcohol withdrawal seizures.

BACKGROUND: Prolactin has been discussed to be useful for differential diagnosis in epilepsia. Aim of the present study was to investigate the association between prolactin serum levels and previous alcohol withdrawal seizures. METHODS: We assessed 118 male patients admitted for detoxification treatment. Previous withdrawal seizures were recorded and prolactin serum levels were measured using an enzymatic immunoassay. RESULTS: Patients with a history of alcohol withdrawal seizures had significantly higher prolactin levels (17.8 ng/ml, SD=12.1) than patients without previous seizures (13.0 ng/ml, SD=8.1, p<0.05). Logistic regression revealed significant predictive qualities for prolactin serum levels (B=0.05, Wald=5.30, p=0.021, OR=1.06, 95%CI=1.01-1.11). CONCLUSIONS: The present findings show an association between elevated prolactin serum levels and a history of withdrawal seizures. Hence, the results suggest that prolactin elevation at admission may be a clinical marker for an increased risk of withdrawal seizures.

Biological markers to predict previous alcohol withdrawal seizures: a risk assessment.

Recent studies have shown that both, elevated homocysteine and prolactin plasma levels are associated with a higher risk of alcohol withdrawal seizures. The aim of this study was to evaluate the predictive qualities of a combined assessment of homocysteine and prolactin for previous alcohol withdrawal seizures. Therefore, 117 male patients suffering from alcohol dependency were included into the study. Homocysteine was measured directly at admission, prolactin the morning following admission for detoxification treatment. Pearson's chi(2)-test showed significant results for the combined assessment of both parameters (chi(2) = 14.71, p = 0.001). Multivariate logistic regression also revealed significant predictive qualities (p = 0.001, OR = 9.23, 95%CI = 2.36-36.05). A combination of both, homocysteine and prolactin, may help to assess the individual risk of alcohol withdrawal seizures in clinical practice.

An assessment of the potential value of elevated homocysteine in predicting alcohol-withdrawal seizures.

PURPOSE: Higher homocysteine levels were found in actively drinking patients with alcohol dependence. Recent studies have shown that high homocysteine levels are associated with alcohol-withdrawal seizures. The aim of the present study was to calculate the best predictive cutoff value of plasma homocysteine levels in actively drinking alcoholics (n = 88) with first-onset alcohol-withdrawal seizures. METHODS: The present study included 88 alcohol-dependent patients of whom 18 patients had a first-onset withdrawal seizure. All patients were active drinkers and had an established diagnosis of alcohol dependence, according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Sensitivity and specificity were calculated by using every homocysteine plasma level found in the study population as cut-off value. A Bayes theorem was used to calculate positive (PPV) and negative (NPV) predictive values for all cutoff values used. RESULTS: The highest combined sensitivity and specificity was reached at a homocysteine plasma cutoff value of 23.9 microM. Positive predictive values ranged from 0.23 to 0.745; the maximum was reached at a homocysteine plasma level of 41.7 microM. Negative predictive values ranged from 0.50 to 0.935, with a maximum at a homocysteine plasma level of 15.8 microM. CONCLUSIONS: Homocysteine levels above this cutoff value on admission are a useful screening tool to identify actively drinking patients at higher risk of alcohol-withdrawal seizures. This pilot study gives further hints that biologic markers may be helpful to predict patients at risk for first-onset alcohol-withdrawal seizures.

Alcoholism-associated hyperhomocysteinemia and previous withdrawal seizures.

BACKGROUND: Higher homocysteine levels were found in actively drinking alcoholics as well as in early abstinent patients. Furthermore, it has been shown that high homocysteine levels predicted first-onset alcohol withdrawal seizures. The aim of the present study was to determine plasma homocysteine levels in actively drinking alcoholics and patients with early abstinence in order to evaluate whether there is an additional association between elevated plasma homocysteine levels and a history of alcohol withdrawal seizures. METHODS: Two groups of patients with an established diagnosis of alcohol dependence were studied. Group A comprised 56 consecutively admitted alcoholics who had been abstinent from alcohol between 24 to 72 hours before hospitalization. Group B consisted of 144 consecutively recruited alcoholics who were admitted - acutely intoxicated - for withdrawal treatment. Furthermore, groups were divided into two subgroups: patients with and without a history of alcohol withdrawal seizures. RESULTS: Alcoholics of GROUP B with a history of withdrawal seizures had significantly (p<.0001) higher homocysteine levels than actively drinking patients without seizures in their history: 42.0 micromol/l (SD 26.4) versus 22.5 micromol/l (SD 11.4). Using a logistic regression analysis, history withdrawal seizures in Group B but not in Group A patients were best predicted by a high homocysteine level at admission (Wald chi2=15.5, p<.0001; odds ratio 1.11, 95% CI 1.05-1.20). CONCLUSIONS: Homocysteine levels on admission may be a useful screening method to identify actively drinking patients with a higher risk of alcohol withdrawal seizures.

Low sodium excretion in SIADH patients with low diuresis.

UNLABELLED: It is well known that during low diuresis or low effective circulating volume, salt excretion is low. The aim of this study was to find out whether salt excretion, expressed as either urinary sodium concentration (UNa) or fractional sodium excretion (FENa), and the combined use of FENa and fractional urea excretion (FEurea) still differentiate between hyponatremic SIADH and hyponatremic salt depletion (SD) patients when diuresis is low. The relationships between UNa, FENa and diuresis, indirectly estimated by the urinary to plasma creatinine ratio (U/P creat), were studied in 42 hyponatremic SIADH patients, 21 hyponatremic SD patients and 66 normonatremic controls (CO) of similar age and sex ratio. There was no significant relationship between UNa and U/P creat either in SIADH or in SD or CO patients. FENa and U/P creat were inversely correlated, both in CO (r = -0.72; p < 0.001) and in SIADH (r = -0.68; p < 0.001). SIADH and SD patients can be fairly well differentiated from one another using FENa and U/P creat. Even with high U/P creat values, SIADH patients, despite a sharp decrease in their FENa values, presented still higher FENa values than SD patients did (mean FENa = 0.3 +/- 0.2% in SIADH and 0.1 +/- 0.04% in SD; p < 0.05). However, FENa values of SIADH patients with low diuresis (mean FENa = 0.3 +/- 0.2% for a mean U/P creat = 191 +/- 40) are indistinguishable from those of SD patients with normal urine volumes (mean FENa = 0.2 +/- 0.2% for a mean U/P creat = 92 +/- 30). The combined use of FENa and FEurea remains a reliable way to discriminate SD patients and SIADH patients, as far as the differential limit value for FENa is narrowed to a value of 0.15%, for hyponatremic patients with U/P creat >140. CONCLUSION: In SIADH, FENa values are lower than 0.5%, as soon as U/P creat exceeds a value of 180. In SD patients with U/P creat values exceeding 140, FENa is lower than 0.15% and FEurea lower than 45%.

ERK regulation in chronic ethanol exposure and withdrawal.

The extracellular signal regulated protein kinases (ERKs), also known as mitogen-activated protein kinases (MAPK) of 42 and 44 kd, play a crucial role in the induction of various forms of neural plasticity. Ethanol induces long-lasting functional changes that are more severe following repeated exposure and may involve intracellular signal transduction mechanisms. Therefore, we investigated the regulation of the ERK signal transduction pathway in models of continuous and intermittent ethanol exposure and withdrawal. Moderate blood alcohol levels (BALs) reduced ERK activation in most of the brain regions studied. Conversely, during withdrawal, activation of ERK was increased in most areas with some regional variations in the levels and kinetics of induction. The most dramatic effects were observed in the amygdala, the cerebellum, the striatum and the hippocampus. In the amygdala and the cerebellum, the activation of ERK observed during withdrawal was significantly higher after intermittent ethanol exposure than after continuous exposure, suggesting the establishment of a form of sensitization to the effects of withdrawal on ERK regulation. Thus the dysregulation of the ERK pathway could contribute to escalation of withdrawal symptoms induced by repeated withdrawal and possibly to the neuroadaptative changes believed to underlie progression towards addiction.

Risk assessment of alcohol withdrawal seizures with a Kohonen feature map.

Recently, it has been suggested that alcohol-induced hyperhomocysteinaemia in patients suffering from chronic alcoholism might be a risk factor for alcohol withdrawal seizures. In the present follow-up study 12 patients with chronic alcoholism who suffered from withdrawal seizures had significantly higher levels of homocysteine (Hcy) on admission (71.43 +/- 25.84 mol/l) than patients (n = 37) who did not develop seizures (32.60 +/- 24.87 mol/l; U = 37.50, p = 0.0003). Using a logistic regression analysis, withdrawal seizures were best predicted by a high Hcy level on admission (p < 0.01; odds ratio 2.07). Based on these findings we developed an artificial neural network system (Kohonen feature map, KFM) for an improved prediction of the risk of alcohol withdrawal seizures. Forty-nine patients with chronic alcoholism (12 with alcohol withdrawal seizures and 37 without seizures) were randomized into a training set and a test set. Best results for sensitivity of the KFM was 83.3% (five of six seizure patients were predicted correctly) with a specificity of 94.4% (one false positive prediction of 19 patients). We conclude that in patients with alcohol-induced hyperhomocysteinaemia the KFM is a useful tool to predict alcohol withdrawal seizures.

Diazepam during prior ethanol withdrawals does not alter seizure susceptibility during a subsequent withdrawal.

The number of cycles of alcohol detoxification is suggested to be an important variable in the predisposition to severe withdrawal seizures in alcohol-dependent individuals. Several clinical studies have suggested that exposure to repeated alcohol withdrawals may lead to increased severity of subsequent withdrawal episodes. Consistent with these observations, exposure to multiple cycles of ethanol withdrawal in our previous study significantly increased sensitivity to the convulsive effects of the GABA(A) receptor inverse agonist, Ro15-4513, in comparison to continuous ethanol exposure with no intermittent withdrawals. There was also a selective increase in the occurrence of spontaneous spike and sharp wave (SSW) activity in the EEG recorded from hippocampal area CA(3) in proportion to the number of withdrawal episodes experienced. It is hypothesized that during such repeated episodes of ethanol intoxication and withdrawal, changes in neuronal excitation during prior withdrawals could serve as initially subconvulsive kindling stimuli that might eventually result in the increased severity of the withdrawal syndrome. There is some evidence of the successful suppression of such neuronal excitation during acute ethanol withdrawal by positive modulators of the GABA(A) receptor. In the present study, the benzodiazepine agonist, diazepam, at a dose (4.0 mg/kg) that suppresses acute withdrawal symptoms, when administered during intermittent withdrawals, did not alter seizure sensitivity during a subsequent nonmedicated withdrawal. Diazepam treatment during prior withdrawals also did not have any effect on the multiple withdrawal-associated increase in SSW activity in hippocampal area CA(3) during an untreated withdrawal. This finding suggests that suppression of acute withdrawal symptoms by diazepam does not prevent long-lasting changes in CNS function resulting from repeated exposures to ethanol withdrawal.