Psychiatric aspects of posttraumatic epilepsy: A still unexplored area

Highlights

• Post-traumatic epilepsy accounts for 10% to 20% of all symptomatic epilepsies but it is still an underappreciated condition

• Data on psychiatric comorbidities of post-traumatic epilepsy are still limited

• People with a psychiatric condition seem to be at increased risk of developing post-traumatic epilepsy

• Genetic and environmental contributors need to be clarified

Abstract

Traumatic brain injury (TBI) represents one of the most common causes of death and disability in young people, and posttraumatic epilepsy (PTE) accounts for 10% to 20% of all symptomatic epilepsies. However, PTE is still a relatively underappreciated condition. This paper aimed at reviewing current knowledge about psychiatric comorbidities of PTE, looking in particular at the nature of the relationship between TBI, psychiatric problems, and epilepsy, at the phenomenology of psychiatric disorders in PTE, and how to manage them. Data on psychiatric comorbidities of PTE are almost nonexistent, and this is a paradox considering that TBI itself is burdened by a number of cognitive and psychiatric sequelae, which can profoundly affect the everyday life of these patients. Preliminary data seem to suggest that the bidirectional relationship between epilepsy and psychiatric disorders is maintained in TBI and people with a psychiatric condition at the time of the TBI, or as a consequence of it, are at increased risk of developing PTE and vice versa. However, a number of questions are still unanswered concerning the genetic and environmental contributors, the phenomenology of psychiatric disorders in PTE, and how to prevent and address them properly. Further research in this area is urgently needed in order to provide the best possible care to people with PTE.

Special Issue: Epilepsy & Behavior's 20th Anniversary.

Introduction

Psychiatric disorders represent a frequent comorbidity in epilepsy with a lifetime history identified in one every three patients [1]. During the last 10 years, research in this area has progressed with good epidemiological studies as well as new data on the role of psychiatric comorbidities on the long-term prognosis of the epilepsy [2]. In fact, it is now established that patients with epilepsy and psychiatric disorders do not only have low quality of life but they are also less likely to be seizure-free [3,4] and they present with increased morbidity and mortality [5].

Despite the fact that posttraumatic epilepsy (PTE) accounts for 10% to 20% of symptomatic epilepsies and 5% of all epilepsies [6], it is still an unappreciated condition. This is probably due to the lack of evidence for the effectiveness of drug treatments for the prevention of seizures in people with traumatic brain injury (TBI) [7,8]. Traumatic brain injury is one of the most frequent causes of disability among young adults, with devastating neurological, cognitive, and psychiatric consequences. Epidemiological studies report 1.4 million cases each year in the United States [9] with a total of 5.3 million people suffering from long-term disabilities because of a TBI, and total annual costs are in the region of 56 billion dollars [10].

It is well-known that TBI is associated with a number of psychiatric disorders and behavioral changes. The famous case of Phineas Gage (Fig. 1), a construction worker who, in 1848, survived a severe frontal lobe damage, is probably the first detailed description of the behavioral consequences of TBI [11]. Phineas Gage developed PTE 12 years later with his first seizure in February 1860. His physical and mental state significantly deteriorated after that as “he continued to work in various places but he could not do much” [12]. On the 20th of May 1860, he suffered a cluster of seizures, and he then developed status epilepticus and died on the subsequent day.

Despite interest of the scientific community on the case of Phineas Gage, a systematic approach to psychiatric problems in TBI comes later on with Adolf Meyer and the concept of “traumatic insanities” [13]. Nowadays, it is established that people with TBI can develop a variety of psychiatric problems including mania, depression, aggressive behavior, dyscontrol disorders, psychosis, obsessive–compulsive behavior, posttraumatic stress disorder (PTSD), and apathy [14]. The prevalence of these conditions varies according to epidemiological studies, and this is probably linked to the site of the injury, the severity of the TBI, the presence and severity of concomitant cognitive problems, and associated comorbidity [15]. At the same time, some studies are suggesting that psychiatric disorders, including depression, anxiety, and conduct disorders, represent a risk factor for TBI itself [16]. However, studies in this area are still limited.

Given that both epilepsy and TBI are strongly associated psychiatric problems, it is obvious to hypothesize that psychiatric disorders should represent an important comorbidity in people with PTE. Nonetheless, research in this area is almost nonexistent. This paper aimed at reviewing current knowledge about psychiatric comorbidities of PTE, emphasizing gaps in the literature, and raising important clinical questions, which urgently need clarification. This paper will focus specifically on the nature of the relationship between TBI, psychiatric problems, and epilepsy, the phenomenology of psychiatric problems in PTE, and how to manage them.