Discussion
One new finding to emerge here was that, independent of any confounding factors, an alcohol-related head trauma was a significant predictor of new-onset seizures among subjects with no TBI or mild TBI. Furthermore, a history of psychiatric disease was also a significant predictor of new-onset seizures in the total cohort and among those without TBI, a finding that was quite likely explained by concomitant alcohol and/or drug abuse.
Our observation that among 45% of the subjects with a new-onset seizure problem the underlying cause was alcohol abuse is in accordance with previous studies. Alcohol-related seizures are a common form of acute non-genetic seizure, accounting for about 41–49% of all ER acute seizure problems. Furthermore, seizures are known to be provoked by long-term heavy drinking and are frequently associated with alcohol dependence. All acute seizure problems reaching the ER, including alcohol-related seizures, require careful evaluation, because they carry a potential for many serious complications, including acute TBI. Also, an alcohol-related seizure is an indicator of alcoholism, which frequently leads to premature death. In the present series, a third of the subjects with new-onset seizures died during the follow-up.
Few studies have dealt with the efficacy and effectiveness of brief interventions among subjects with TBI, although many reports have considered this problem among subjects with trauma and a few with facial trauma. It has been shown, however, that a brief intervention may be effective in reducing alcohol use. The American College of Surgeons requires trauma centres to provide screening and a brief intervention for persons showing a risk of misuse of alcohol or other substances, and it is feasible to assume that a brief intervention provided for subjects with head trauma would also reduce post-traumatic misuse, especially where the trauma is mild and there is no cognitive deficit. Persons who themselves attribute the head trauma to alcohol misuse may be more open to changing their behaviour in future. It is often the case, however, that no intervention is performed because of cynicism or a shortage of time.
We observed a preceding psychiatric disease to be a significant predictor of new-onset seizures in our cohort. Psychiatric problems are often associated with drug and/or alcohol abuse, and this was also the case in our population, but the number of subjects with a preceding psychiatric disease and new-onset seizures was small and our observations should be interpreted with caution. A recent report has observed that new-onset seizures were frequently preceded by psychosis, depression, bipolar disorder and anxiety disorder. We did not evaluate the role of antipsychotics and/or antidepressants in this study.
It has been shown previously that the risk of seizures depends on the severity of TBI, and as expected, the risk was high among our subjects with moderate-to-severe TBI. Even subjects with relatively severe TBI may have prior abuse of alcohol and drugs, and these problems should be tackled during rehabilitation. As emphasised by Corrigan, interventions on account of alcohol and drug problems are largely neglected in cases of subjects with more severe TBI, in spite of the fact that these subjects, too, may suffer from alcohol and drug abuse later on. To prevent future problems, every head trauma subject should be assessed for alcohol consumption and one should try to influence the drinking habits of intoxicated subjects during their visit to the ER no matter how severe the injury is. This is admittedly difficult, because busy ER physicians tend to discharge all those with a minor trauma as soon as possible.
There are several limitations that should be noted when interpreting our results. First, because the number of subjects with alcohol-related seizures was relatively small, all our observations should be interpreted with caution. For example, a larger number of subjects with moderate-to-severe TBI would be needed in order to show whether an alcohol-related index injury will also predict the onset of alcohol-related seizures in this group. Second, register-based data are prone to bias on account of deficient or inaccurate coding. We tried to reduce this type of bias by checking the data against the available hospital charts. Third, some subjects who develop seizures may not seek help from healthcare providers and may therefore remain unrecorded. Finally, the recording of alcohol abuse prior to a seizure problem may remain unnoticed. The strengths of this work lie in the fact that the data in the Finnish registers (NHD and SFCD) are accurate and the baseline data for 1999 were gathered systematically by means of a structured protocol.
In conclusion, we observed a significant role of alcohol abuse as a predictor of new-onset seizures among subjects with minor head trauma. The need for efficient and effective intervention was apparent. Means for tackling alcohol problems are not usually available to ER personnel in our country.