Predicting posttraumatic epilepsy using admission electroencephalography after severe traumatic brain injury

OBJECTIVE

Posttraumatic epilepsy (PTE) develops in as many as one third of severe traumatic brain injury (TBI) patients, often years after injury. Analysis of early electroencephalographic (EEG) features, by both standardized visual interpretation (viEEG) and quantitative EEG (qEEG) analysis, may aid early identification of patients at high risk for PTE.

METHODS

We performed a case-control study using a prospective database of severe TBI patients treated at a single center from 2011 to 2018. We identified patients who survived 2 years postinjury and matched patients with PTE to those without using age and admission Glasgow Coma Scale score. A neuropsychologist recorded outcomes at 1 year using the Expanded Glasgow Outcomes Scale (GOSE). All patients underwent continuous EEG for 3-5 days. A board-certified epileptologist, blinded to outcomes, described viEEG features using standardized descriptions. We extracted 14 qEEG features from an early 5-min epoch, described them using qualitative statistics, then developed two multivariable models to predict long-term risk of PTE (random forest and logistic regression).

RESULTS

We identified 27 patients with and 35 without PTE. GOSE scores were similar at 1 year (p = .93). The median time to onset of PTE was 7.2 months posttrauma (interquartile range = 2.2-22.2 months). None of the viEEG features was different between the groups. On qEEG, the PTE cohort had higher spectral power in the delta frequencies, more power variance in the delta and theta frequencies, and higher peak envelope (all p < .01). Using random forest, combining qEEG and clinical features produced an area under the curve of .76. Using logistic regression, increases in the delta:theta power ratio (odds ratio [OR] = 1.3, p < .01) and peak envelope (OR = 1.1, p < .01) predicted risk for PTE.

SIGNIFICANCE

In a cohort of severe TBI patients, acute phase EEG features may predict PTE. Predictive models, as applied to this study, may help identify patients at high risk for PTE, assist early clinical management, and guide patient selection for clinical trials.

Quantitative epileptiform burden and electroencephalography background features predict post-traumatic epilepsy

BACKGROUND

Post-traumatic epilepsy (PTE) is a severe complication of traumatic brain injury (TBI). Electroencephalography aids early post-traumatic seizure diagnosis, but its optimal utility for PTE prediction remains unknown. We aim to evaluate the contribution of quantitative electroencephalograms to predict first-year PTE (PTE1).

METHODS

We performed a multicentre, retrospective case-control study of patients with TBI. 63 PTE1 patients were matched with 63 non-PTE1 patients by admission Glasgow Coma Scale score, age and sex. We evaluated the association of quantitative electroencephalography features with PTE1 using logistic regressions and examined their predictive value relative to TBI mechanism and CT abnormalities.

RESULTS

In the matched cohort (n=126), greater epileptiform burden, suppression burden and beta variability were associated with 4.6 times higher PTE1 risk based on multivariable logistic regression analysis (area under the receiver operating characteristic curve, AUC (95% CI) 0.69 (0.60 to 0.78)). Among 116 (92%) patients with available CT reports, adding quantitative electroencephalography features to a combined mechanism and CT model improved performance (AUC (95% CI), 0.71 (0.61 to 0.80) vs 0.61 (0.51 to 0.72)).

CONCLUSIONS

Epileptiform and spectral characteristics enhance covariates identified on TBI admission and CT abnormalities in PTE1 prediction. Future trials should incorporate quantitative electroencephalography features to validate this enhancement of PTE risk stratification models.

Chemical Kindling as an Experimental Model to Assess the Conventional Drugs in the Treatment of Post-traumatic Epilepsy

BACKGROUND

Traumatic brain injury (TBI) is one of the leading causes of morbidity and mortality today, which will surpass many infectious diseases in the coming years/decades. Posttraumatic epilepsy (PTE) is one of the most common debilitating consequences of TBI. PTE is a secondary, acquired epilepsy that causes recurrent, spontaneous seizures more than a week after TBI. The extent of head injury in individuals who develop PTE is unknown; however, trauma is thought to account for 20% of symptomatic epilepsy worldwide. Understanding the mechanisms of epilepsy following TBI is crucial for the discovery of new anticonvulsant drugs for the treatment of PTE, as well as for improving the quality of life of patients with PTE.

OBJECTIVE

This review article explains the rationale for the usage of a chemical model to access new treatments for post-traumatic epilepsy.

RESULTS

There are multiple methods to control and manage PTE. The essential and available remedy for the management of epilepsy is the use of antiepileptic drugs. Antiepileptic drugs (AEDs) decrease the frequency of seizures without affecting the disease's causality. Antiepileptic drugs are administrated for the prevention and treatment of PTE; however, 30% of epilepsy patients are drug-resistant, and AED side effects are significant in PTE patients. There are different types of animal models, such as the liquid percussion model, intracortical ferric chloride injection, and cortical subincision model, to study PTE and neurophysiological mechanisms underlying the development of epilepsy after head injury. However, these animal models do not easily mimic the pathological events occurring in epilepsy. Therefore, animal models of PTE are an inappropriate tool for screening new and putatively effective AEDs. Chemical kindling is the most common animal model used to study epilepsy. There is a strong similarity between the kindling model and different types of human epilepsy.

CONCLUSION

Today, researchers use experimental animal models to evaluate new anticonvulsant drugs. The chemical kindling models, such as pentylenetetrazol, bicuculline, and picrotoxin-induced seizures, are important experimental models to analyze the impact of putative antiepileptic drugs.

Thyroid function in the subacute phase of traumatic brain injury: a potential predictor of post-traumatic neurological and functional outcomes

PURPOSE

That thyroid hormones exert pleiotropic effects and have a contributory role in triggering seizures in patients with traumatic brain injury (TBI) can be hypothesized. We aimed at investigating thyroid function tests as prognostic factors of the development of seizures and of functional outcome in TBI.

METHODS

This retrospective study enrolled 243 adult patients with a diagnosis of mild-to-severe TBI, consecutively admitted to our rehabilitation unit for a 6-month neurorehabilitation program. Data on occurrence of seizures, brain imaging, injury characteristics, associated neurosurgical procedures, neurologic and functional assessments, and death during hospitalization were collected at baseline, during the workup and on discharge. Thyroid function tests (serum TSH, fT4, and fT3 levels) were performed upon admission to neurorehabilitation.

RESULTS

Serum fT3 levels were positively associated with an increased risk of late post-traumatic seizures (LPTS) in post-TBI patients independent of age, sex and TBI severity (OR = 1.85, CI 95% 1.22-2.61, p < 0.01). Measured at admission, fT3 values higher than 2.76 pg/mL discriminated patients with late post-traumatic seizures from those without, with a sensitivity of 74.2% and a specificity of 60.9%. Independently from the presence of post-traumatic epilepsy and TBI severity, increasing TSH levels and decreasing fT3 levels were associated with worse neurological and functional outcome, as well as with higher risk of mortality within 6 months from the TBI event.

CONCLUSIONS

Serum fT3 levels assessed in the subacute phase post-TBI are associated with neurological and functional outcome as well as with the risk of seizure occurrence. Further studies are needed to investigate the mechanisms underlying these associations.

Automatic Detection of EEG Epileptiform Abnormalities in Traumatic Brain Injury using Deep Learning

Traumatic brain injury (TBI) is a sudden injury that causes damage to the brain. TBI can have wide-ranging physical, psychological, and cognitive effects. TBI outcomes include acute injuries, such as contusion or hematoma, as well as chronic sequelae that emerge days to years later, including cognitive decline and seizures. Some TBI patients develop posttraumatic epilepsy (PTE), or recurrent and unprovoked seizures following TBI. In recent years, significant efforts have been made to identify biomarkers of epileptogenesis, the process by which a normal brain becomes capable of generating seizures. These biomarkers would allow for a higher standard of care by identifying patients at risk of developing PTE as candidates for antiepileptogenic interventions. In this paper, we use deep neural network architectures to automatically detect potential biomarkers of PTE from electroencephalogram (EEG) data collected between post-injury day 1-7 from patients with moderate-to-severe TBI. Continuous EEG is often part of multimodal monitoring for TBI patients in intensive care units. Clinicians review EEG to identify the presence of epileptiform abnormalities (EAs), such as seizures, periodic discharges, and abnormal rhythmic delta activity, which are potential biomarkers of epileptogenesis. We show that a recurrent neural network trained with continuous EEG data can be used to identify EAs with the highest accuracy of 80.78%, paving the way for robust, automated detection of epileptiform activity in TBI patients.

[Early predictive biomarkers of posttraumatic epilepsy]

Traumatic brain injury (TBI) affects about 50 million people in the world every year. Posttraumatic epilepsy (PTE) is a significant complication of TBI of any severity. PTE occurs in 20% of patients with TBI. Treatment of patients with PTE is particularly difficult due to obvious tendency towards drug resistance. Currently, there are no validated predictive biomarkers for PTE. Development of a system of validated predictive markers would improve PTE prediction quality and therapeutic approach for these patients. This review is devoted to the current data on the most perspective predictive biomarkers of PTE for clinical practice.

A review of seizures and epilepsy following traumatic brain injury

Traumatic brain injury (TBI) is one of the commonest presentations to emergency departments and is associated with seizures carrying different significance at different stages following injury. We describe the epidemiology of early and late seizures following TBI, the significance of intracranial haemorrhage of different types in the risk of later epilepsy and the gaps in current understanding of risk factors contributing to the risk of post-traumatic epilepsy (PTE). The delay from injury to epilepsy presents an opportunity to understand the mechanisms underlying changes in the brain and how they may reveal potential targets for anti-epileptogenic therapy. We review existing treatments, both medical and surgical and conclude that current research is not tailored to differentiate between PTE and other forms of focal epilepsy. Finally, we review the increasing understanding of the frequency and significance of dissociative seizures following mild TBI.

ADC mapping and T1-weighted signal changes on post-injury MRI predict seizure susceptibility after experimental traumatic brain injury

OBJECTIVE

Post-traumatic epilepsy (PTE) is a serious complication of traumatic brain injury (TBI). This study is designed to determine the feasibility of using multiparametric MRI endpoints to predict differences in seizure susceptibility after experimental TBI.

METHODS

MRI imaging and behavioral measurements were performed at multiple time points after lateral fluid percussion injury (FPI) in rats. Seizure susceptibility was determined by video-electroencephalogram (EEG) monitoring and off-line signal analysis after chemoconvulsant challenge.

RESULTS

Multiple MRI endpoints, including measures of injury-related brain swelling (normalized interhemispheric volume difference, NIVD) and T1-weighted signal change with contrast enhancement (a measure of blood-brain barrier disruption, BBBD), reliably distinguished between injured and sham-injured animals at 72 hours after injury. ADC (apparent diffusion coefficient) values (a measure of water diffusivity) in injured cortex at 72 hours and 1 week after injury, BBBD in injured cortex at 72 hours after injury and NIVD at 72 hours after injury were significantly correlated with EEG-based measures of seizure susceptibility to chemoconvulsant challenge at 3 months after injury.

CONCLUSIONS

The correlations between our MRI quantitative endpoints and EEG-based measures of seizure susceptibility to chemoconvulsant challenge in injured animals versus sham-injured animals support the feasibility of these MRI endpoints as potential biomarkers for post-traumatic epileptogenesis.

Prevalence of epileptic and nonepileptic events after pediatric traumatic brain injury

Though posttraumatic epilepsy (PTE) is a prominent sequela of traumatic brain injury (TBI), other nonepileptic phenomena also warrant consideration. Within two UCLA pediatric TBI cohorts, we categorized five spell types: 1) PTE; 2) Epilepsy with other potential etiologies (cortical dysplasia, primary generalized); 3) Psychopathology; 4) Behavior misinterpreted as seizures; and 5) Other neurologic events. The two cohort subsets differed slightly in injury severity, but they were otherwise similar. Overall, PTE occurred in 40%, other epilepsy etiologies in 14%, and nonepileptic spells collectively in 46%. Among children with spells, PTE was associated with severe TBI (p=0.001), whereas psychopathology (p=0.014) and epilepsy with other etiologies (p=0.006) were associated with milder TBI severity. Posttraumatic epilepsy (p=0.002) and misinterpreted behavior (p=0.049) occurred with younger injury age. Psychopathology (p=0.020) and other neurologic events (p=0.002) occurred with older injury age. In evaluating possible PTE, clinicians should maintain a broad differential diagnosis to prevent misdiagnosis and inappropriate treatment.

[Nootropics and antioxidants in the complex therapy of symptomatic posttraumatic epilepsy]

To study the possibility of application of nootropics and antioxidants in the complex antiepileptic therapy, we examined 75 patients with symptomatic focal posttraumatic epilepsy. A statistically significant reduction in the number of epileptic seizures, improvement of cognitive function and quality of life of the patients as well as a decrease in the severity of depression and epileptic changes in the EEG were identified. The potentiation of antiepileptic activity of basic drugs, normalization of brain's electrical activity and reduction in EEG epileptiform activity, in particular coherent indicators of slow-wave activity, were noted after treatment with the antioxidant mexidol. A trend towards the improvement of neuropsychological performance and quality of life was observed. There was a lack of seizure aggravation typical of many nootropic drugs. Thus, phenotropil and mexidol can be recommended for complex treatment of symptomatic posttraumatic epilepsy.

Lamotrigine treatment of a patient affected by epilepsy and anxiety disorder

Epilepsy often occurs in comorbidity with mental diseases and disorders. Early detection and/or treatment of such disorders in patients affected by epilepsy, as well as their socialisation are crucially important since epileptic patients tend to suffer more due to lack of social support than to frequent epileptic seizures. Prevalence of psychiatric disorders is higher in patients with epilepsy than in general population, the most frequent being: anxiety, depression, panic attacks, behavioural disorders as well as psychotic states with paranoid elements. The efficacy of AE treatment of patients affected by epilepsy and mood disorders has also directed clinicians to investigate possible AE benefits in treating other mental disorders such as anxiety states, depression and bipolar disorder. The examined case displays complex partial epilepsy and comorbid mental disorder. The use of lamotrigine, a fourth-generation antiepileptic, which is also a mood stabilizer, has assured a favourable remission of symptoms related to both epilepsy and mood disorders. Side-effects caused by lamotrigine were only temporary and dose reduction was sufficient to eliminate their symptoms.

Wearable sensor platform and mobile application for use in cognitive behavioral therapy for drug addiction and PTSD

We present a wearable sensor platform designed for monitoring and studying autonomic nervous system (ANS) activity for the purpose of mental health treatment and interventions. The mobile sensor system consists of a sensor band worn on the ankle that continuously monitors electrodermal activity (EDA), 3-axis acceleration, and temperature. A custom-designed ECG heart monitor worn on the chest is also used as an optional part of the system. The EDA signal from the ankle bands provides a measure sympathetic nervous system activity and used to detect arousal events. The optional ECG data can be used to improve the sensor classification algorithm and provide a measure of emotional "valence." Both types of sensor bands contain a Bluetooth radio that enables communication with the patient's mobile phone. When a specific arousal event is detected, the phone automatically presents therapeutic and empathetic messages to the patient in the tradition of Cognitive Behavioral Therapy (CBT). As an example of clinical use, we describe how the system is currently being used in an ongoing study for patients with drug-addiction and post-traumatic stress disorder (PTSD).

[Posttraumatic epilepsy: the theory and the practice]

One hundred and sixty-one patients with the diagnosis of "posttraumatic epilepsy" have been studied. A study of anamnesis, a clinical and neurological examination, routine EEG and/or video-EEG-monitoring, MRI of the brain have been performed. The period of observation was 1-5 years (on average 3 years). The diagnosis has been confirmed in 123 cases. It has been shown that patients with mild head injury have temporal lobe epilepsy in most cases. In patients with severe injury, the localization of epileptic center was associated with a pathology in the neocortex. The duration of latency period, clinical features and prognosis in patients with mild and severe brain injury were similar. The high frequency of seizures and long duration of epilepsy were associated with the poor prognosis.

Epileptic seizure, cataract, and tongue atrophy during the 8 years after electrical brain injury

As a delayed neurologic complication following a high-voltage electrical injury, motor neuron disease-like spinal cord injury has often been reported. However, epileptic seizure as a delayed complication of electrical brain injury has not been reported. We report a 32-year-old man, who developed epilepsy 8 years after electrical brain injury. His electroencephalogram (EEG) recordings showed focus on the right side, in which the electrical current passed during the accident eight years earlier. He experienced cataract during these 8 years. On examination, the right side of his tongue was found to be atrophic, and he was unaware when it had started. Systemic EMG examination revealed neuropathic changes in both (interossei dorsalis) IODs, the right biceps, right tongue, and right masseter muscles.

[The neurophysiological analysis of symptomatic post-traumatic epilepsy]

To identify correlates of epilepsy development in patients after brain injury, the authors carried out a comparative assessment of the spatial organization of brain electrical activity in patients with consequences of closed craniocerebral injury without epilepsy (53 patients) and in patients with post-traumatic epilepsy (43 patients). A control group included 15 subjects. The EEG study with spectral coherent analysis allows to predict post-traumatic epilepsy and to use a differential approach in prescribing the appropriate anticonvulsive therapy to people after head injury.

[Driver and epilepsy]

A family physician managing a 54-year-old patient with a past cranio-cerebral trauma in his medical history, followed by an intracerebral hematoma in the right frontal lobe, with secondary posttraumatic epilepsy, repeatedly prescribed anti-epileptic drugs (recommended by a consulting neurologist) and described in the patient's medical records frequent generalized seizures as reported by the patient and his wife. The doctor himself witnessed the patient driving a car, despite the fact that he received a disability pension resulting from frequent epileptic seizures. According to the doctor, he was "shocked" by the patient driving a car and felt obliged to report the matter to the Transport Division Administration, suggesting that the driving license should be revoked. The patient's driving license had been withdrawn, what caused considerable resentment in the individual, who, in turn, filed a suit against the physician for violating professional medical secrecy by informing the Transport Division Administration about his suffering from epilepsy. The described situations point to the necessity of: 1) striving for the highest possible objectivity of diagnosing epilepsy, and 2) standardization of criteria for certification of epilepsy.

[The clinical forensic medicine identification on pseudoseizures after head trauma]

Two pseudoseizures after head trauma are reported. We summarize the clinical manifestation of pseudoseizures, and identify difference of pseudoseizures and Seizures after head trauma. The forensic identification of pseudoseizures after head trauma should base on the extend and position of cerebral trauma, sequelae focus in cerebral, and the clinical manifestation.

Hippocampal Cell Loss in Posttraumatic Human Epilepsy

PURPOSE

We performed this study to determine whether significant head trauma in human adults can result in hippocampal cell loss, particularly in hilar (polymorph) and CA3 neurons, similar to that observed in animal models of traumatic brain injury. We examined the incidence of hippocampal pathology and its relation to temporal neocortical pathology, neuronal reorganization, and other variables.

METHODS

Twenty-one of 200 sequential temporal lobectomies had only trauma as a risk factor for epilepsy. Tissue specimens from temporal neocortex and hippocampus were stained with glial fibrillary acidic protein (GFAP) and hematoxylin and eosin (H&E). Eleven hippocampal specimens had additional analysis of neuronal distributions by using cresyl violet and immunolabeling of a neuron-specific nuclear protein.

RESULTS

The median age at onset of trauma was 19 years, the median time between trauma and onset of seizures was 2 years, and the median epilepsy duration was 16 years. The length of the latent period was inversely related to the age at the time of trauma (r=0.75; Spearman). The neocortex showed gliosis in all specimens, with hemosiderosis (n=8) or heterotopias (n=6) in some, a distribution differing from chance (p=0.02; Fisher). Hippocampal neuronal loss was found in 94% of specimens, and all of these had cell loss in the polymorph (hilar) region of the dentate gyrus. Hilar cell loss ranged from mild, when cell loss was confined to the hilus, to severe, when cell loss extended into CA3 and CA1. Some degree of mossy fiber sprouting was found in the dentate gyrus of all 10 specimens in which it was evaluated. Granule cell dispersion (n=4) was seen only in specimens with moderate to severe neuronal loss.

CONCLUSIONS

Neocortical pathology was universally present after trauma. Neuronal loss in the hilar region was the most consistent finding in the hippocampal formation, similar to that found in the fluid-percussion model of traumatic head injury. These findings support the idea that head trauma can induce hippocampal epilepsy in humans in the absence of other known risk factors.

Posttraumatic Seizures in Survivors of Torture: Manifestations, Diagnosis, and Treatment

Survivors of torture are very likely to have been beaten repeatedly around the head. Apparent brief losses of consciousness are not uncommon following torture, and they may be associated with signs that suggest temporal lobe epilepsy (TLE). The relative risk of developing posttraumatic seizures (PTS) is increased by about 50% after a single head injury involving a brief loss of consciousness. It is 2.9 if that loss of consciousness lasts for more than about 30 min. Thus, patients who have been tortured are at increased risk of seizures. TLE is difficult to diagnose and needs specialist investigations, and other conditions that are not uncommon in survivors of torture, such as panic attacks, posttraumatic stress disorder, dissociation, and syncope can all present with similar pictures. This paper addresses the differential diagnosis of posttraumatic epilepsy in survivors of torture.

Evaluation of seizure-like episodes in survivors of moderate and severe traumatic brain injury

BACKGROUND

Transient paroxysmal alterations of consciousness or behavior are common sequelae of moderate and severe traumatic brain injury (TBI). Clinicians caring for patients with such episodes often diagnose them as epileptic seizures, a frequent and well-studied complication of TBI. As it is difficult to confirm this diagnosis, antiepileptic drugs are often used empirically. However, as such therapy is frequently ineffective, we studied the usefulness of prolonged video electroencephalogram (VEEG) monitoring in the clinical management of paroxysmal behaviors in TBI survivors.

METHODS

Records of patients referred evaluation in an epilepsy monitoring unit for management of medically intractable epilepsy were retrospectively reviewed. Patients with a documented history of moderate-to-severe brain injury preceding the onset of epilepsy were identified. These patients were studied by simultaneous videotape and scalp electroencephalographic recordings, and the majority also underwent magnetic resonance imaging and neuropsychologic studies.

RESULTS

Of the 1858 consecutive admissions over a 66-month period, 127 (7%) fulfilled enrollment criteria. VEEG monitoring was conducted for an average of 4.6 days. Monitoring was successful in establishing a diagnosis in 82% of the cases referred: 62% had focal seizures, 6% had generalized seizures, and 33% had psychogenic nonepileptic seizures. Of those with temporal lobe epilepsy, 53% had mesial temporal sclerosis, as shown by magnetic resonance imaging.

CONCLUSIONS

VEEG is a useful procedure in the evaluation of TBI survivors with spells. The yield of diagnoses that may alter treatment is substantial. Additionally, mesial temporal sclerosis is associated with TBI. Given the variety of seizure types found in survivors of moderate-to-severe TBI, obtaining specific diagnosis of seizure type by VEEG monitoring impacts treatment options.

Induction of prolonged electrographic seizures in vitro has a defined threshold and is all or none: implications for diagnosis of status epilepticus

PURPOSE

To study whether induction of prolonged (>30-min duration) in vitro electrographic seizure discharges resembling status epilepticus (SE) is graded or all-or-none, and to determine the critical factors mediating SE induction.

METHODS

Prolonged electrographic seizure discharges were induced in combined hippocampal-entorhinal cortical (HEC) brain slices by electrical stimulation of the Schaeffer collaterals. Discharges were recorded by using field-potential electrodes in the dentate gyrus, CA3, CA1, and entorhinal cortex. Slices were prepared from rats that were (a). 21- to 30-day-old naive, (b). 60- to 120-day old naive, (c). epileptic, and (d). status post a prior traumatic brain injury.

RESULTS

Induction of SE discharges was dependent on the duration, but not amplitude of the preceding stimulus train-induced afterdischarge in HEC slices from 21- to 30-day-old control, brain-injured, and epileptic animals, but not from 60- to 120-day-old animals. In slices from 21- to 30-day-old control animals, once afterdischarges exceeded 4 min in duration, SE was induced in 50% of slices, and after >or=6 min 37 s seizure activity; SE was induced in 95% of slices. A defined SE threshold also was evident in brain-damaged rats, including rats in which an epileptic condition was induced by pilocarpine injection 4-16 weeks before recording, and rats subjected to a fluid percussive head trauma 1-8 weeks before recording. However, in these brain-damaged animals, mean SE threshold was considerably lower (24 and 44 s, respectively). HEC slices from 60- to 120-day-old controls for the brain-injured and epileptic animals did not develop SE even after 20 stimulations, demonstrating the pronounced effect of brain injury and epilepsy on the development of SE in the HEC slice preparation compared with that in age-matched controls.

CONCLUSIONS

In vitro, SE discharges have a defined temporal threshold for initiation. Once a seizure exceeds 6-7 min in duration in control animals, and 30-55 s in brain-damaged animals, the probability of SE induction is greatly increased. This demonstrates that brain injury lowers the afterdischarge duration required to produce SE and suggests that brains injured from trauma or SE are more susceptible to develop status epilepticus.

Posttraumatic epilepsy: neuroradiologic and neuropsychological assessment of long-term outcome

PURPOSE

We sought to detect the incidence and the risk factors of posttraumatic epilepsy (PTE) in rehabilitation patients; to define the influence of PTE for late clinical and functional outcome; and to assess the cognitive and behavioral features of the patients with PTE.

METHODS

Patients were examined with (a) cognitive and behavioral examinations, which included a clinical interview and psychometric tests performed by an expert clinical psychologist; (b) single-photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI); and (c) functional evaluation including the Glasgow Outcome Scale (GOS) and the Functional Independence Measure (FIM).

RESULTS

Of the 143 patients examined in this study, in 27 (19%), seizures developed after a mean time from trauma of 11.9 +/- 8.6 months. The occurrence of PTE was significantly correlated with the hypoperfusion in temporal lobes (p < 0.004), the degree of hydrocephalus (p < 0.04), the evidence of intracerebral hematoma (p < 0.01), and operative brain injury (p < 0.001). Patients with epilepsy showed a significantly higher incidence of personality disorders than did patients without epilepsy. The uninhibited behavior, irritability, and agitated and aggressive behavior were significantly more frequent and severe in PTE patients. The psychometric tests intended to explore memory, language, intelligence, attention, and spatial cognition did not show any significant difference between those with and without epilepsy. PTE also was significantly correlated with a worse functional outcome 1 year after the trauma.

CONCLUSIONS

The degrees of hydrocephalus and of hypoperfusion in the temporal lobes are significant risk factors for late PTE. Another main finding of our study is the absence of influence of epilepsy on cognitive disorders; its influence on neurobehavioral disorders and functional outcome is discussed.

Analyzing risk factors for late posttraumatic seizures: a prospective, multicenter investigation

OBJECTIVES

To ascertain the natural history and to stratify risks for the development of late posttraumatic seizures in individuals with moderate to severe traumatic brain injury (TBI).

DESIGN

Prospective, observational study of individuals with TBI admitted to 4 trauma centers within 24 hours of injury.

SETTING

Four tertiary care trauma centers in urban areas.

PARTICIPANTS

A total of 647 individuals (>/=16 y) with any of the following abnormal computed tomography (CT) scan findings: extent of midline shift and/or cisternal compression or presence of any focal pathology (eg, punctate, subarachnoid, or intraventricular hemorrhage; cortical or subcortical contusion; extra-axial lesions) during the first 7 days postinjury or best Glasgow Coma Scale (GCS) score of </=10 during the first 24 hours post-TBI. Subjects were enrolled from August 1993 through September 1997 and followed for up to 24 months, until death or their first late posttraumatic seizures.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Cumulative probability, relative risk, and survival analyses were used to stratify risks for development of late postttraumatic seizures on the basis of demographic factors, etiology of injury, initial GCS, early posttraumatic seizures, time post-TBI, types of intracerebral lesion by CT scan, and number and types of intracranial procedures.

RESULTS

Sixty-six individuals had a late posttraumatic seizures; 337 had no late posttraumatic seizures during full 24-month follow-up; 167 had no late posttraumatic seizures during time followed (<24 mo); and 54 were placed on anticonvulsants without a late posttraumatic seizures, whereas 23 died before their first late posttraumatic seizures. The highest cumulative probability for late posttraumatic seizures included biparietal contusions (66%), dural penetration with bone and metal fragments (62.5%), multiple intracranial operations (36.5%), multiple subcortical contusions (33.4%), subdural hematoma with evacuation (27.8%), midline shift greater than 5mm (25.8%), or multiple or bilateral cortical contusions (25%). Initial GCS score was associated with the following cumulative probabilities for development of late posttraumatic seizures at 24 months: GCS score of 3 to 8, 16.8%; GCS score of 9 to 12, 24.3%; and GCS score of 13 to 15, 8.0%.

CONCLUSIONS

Stratification by CT scan findings and neurosurgical procedures performed were the most useful findings in defining individuals at highest risk for late posttraumatic seizures.

Magnetization transfer MR imaging in patients with posttraumatic epilepsy

BACKGROUND AND PURPOSE

Intractable epilepsy is a well-recognized complication following head trauma, and many factors have been implicated in its pathogenesis. This study was performed to determine the severity of tissue damage after severe head injury as assessed with magnetization transfer (MT) MR imaging and the relationship of this damage with seizure intractability.

METHODS

Forty-four patients, 13 without seizures (disease controls) and 31 with seizures, underwent T1-weighted MT MR imaging 1-10 years after head trauma. Phase-corrected gradient-echo (GRE) imaging was also performed in all patients to look for the presence of hemosiderin. All patients were evaluated for the presence of an MT abnormality beyond an abnormality seen on T2-weighted images, an MT abnormality within a T2 abnormality, and hemosiderin deposition.

RESULTS

Patients with an MT abnormality beyond a T2 abnormality had a significantly higher intractability of seizures compared with those with an MT abnormality within a T2 abnormality (P <.05). In addition, the mere presence of hemosiderin deposit was not associated with seizure intractability; however, gliosis around the hemosiderin as seen on T1-weighted MT images was associated with seizure intractability.

CONCLUSIONS

T1-weighted MT imaging may be of value in predicting the intractability of the seizure in delayed posttraumatic epilepsy.

[Concussive convulsions in the differential diagnosis of post-traumatic epilepsy]

INTRODUCTION

Concussive convulsions are motor manifestations in acute head injury. This clinical phenomenon should be distinguished from epileptic seizures. We present two young men with motor and convulsive manifestations in acute head injury. Patient 1. A 18-year old basketball player fell on the parquet during a game. Initially he was struck on the right shoulder which caused brief and vigorous twitch of the head towards the ground and additional temporal impact. At the moment of impact he lost consciousness and developed tonic leg and arm posturing with both clenched fists. His legs were extended during next 20 seconds. Thereafter he was still and his loss of consciousness lasted 3 minutes. Patient 2. A 26-year old man fell on the wooden ground from a 4 m high ferry. He got head impact and lost consciousness. In a few seconds he had tonic/clonic convulsions for the next 10-15 seconds. Ten minutes later he awaked. Results of subsequent neurological examination, electroencephalography and cerebral magnetic resonance imaging studies were normal in both patients. They returned to their occupations after four weeks without problems for a further one year.

CONCLUSION

Described motor manifestations present concussive convulsions. These clinical features are due to transient functional decerebration and corticomedullary dissociation during cerebral concussion. Concussive convulsions are a non-epileptic phenomenon, they are not associated with structural brain injury and have good prognosis. Antiepileptic treatment is not indicated.

Suppression of cortical myoclonus by levetiracetam

A 16-year-old boy suffered severely disabling posthypoxic myoclonus. Neurophysiological investigation showed cortical but not reticular reflex myoclonus. Add-on therapy with levetiracetam significantly improved the patient's clinical condition, suppressed cortical myoclonus-associated spikes, and enabled further neurorehabilitation.

[Posttraumatic epilepsy: diagnosis and clinical variety]

125 patients with posttraumatic epilepsy (PTE) were examined using methods of neurovisualization (CT and MRI) and electroencephalography (EEG), including brain mapped EEG. The research resulted in the conclusion about heterogeneity of the disease. Differential diagnostic criteria were elaborated for three clinical variations of symptomatic epilepsy of the traumatic genesis. Besides, the second variation was a real PTE, with the most clear clinical signs. The knowledge about the ambiguous clinical pattern of the disease may improve therapy and prognosis, evaluate both physical and occupational abilities of the patients more objectively.

Symptomatic epilepsy with facial myoclonus triggered by language

We report on a patient with a left frontal lesion who, many years after an injury, developed non-fluent aphasia and facial myoclonic jerks triggered by speaking and listening to spoken language. At age 57, the patient first noted that he would begin to stutter when delivering lectures at conferences. The stuttering would worsen if he continued talking. The video-polygraphic EEG recording shows brief paroxysms of spikes and polyspikes, followed by a slow wave, more evident in the left fronto-temporal region. The myoclonic jerks originating from the submental area correlate with EEG abnormalities. Clinically, these jerks determined a form of stuttering. The triggering factors were reading, speaking and listening to spoken language. This case had several characteristic features: facial myoclonus was the only seizure type experienced by the patient; the seizures and language impairment had a very late onset--about 50 years after the traumatic event that produced a dramatic lesion in the left fronto-polar region. (Published with videosequences.)

[The forensic determination of post-traumatic epilepsy in 21 patients]

To evaluate the forensic determination of post cerebral traumatic epilepsy.

METHODS

In 21 patients, traumatic history and previous history were analysied combined with the demonstrations of electroencephalogram(EEG), X-ray, CT and MRI.

RESULTS

Post-traumatic epilepsy, manily in late stage, usually occurred following serious cerebral trauma. The type of traumatic epilepsy was determined by the traumatic location and extent. Abnormal epileptic wave in scalp EEG and 24 h dynamic EEG and medical image examinations were helpful for qualitative analysis.

CONCLUSION

The forensic determination of post traumatic epilepsy must be on the basis of traumatic and previous history combined with EEG, CT and MRI analysis.

Prognostic factors in the occurrence of posttraumatic epilepsy after penetrating head injury suffered during military service

In this retrospective study, the authors evaluated confounding risk factors, which are allegedly influential in causing unprovoked posttraumatic epilepsy, in 489 patients from the frontlines of the Iran–Iraq War.

Four hundred eighty-nine patients were followed for 6 to154 months (mean 39.4 months, median 23 months), and important factors precipitating posttraumatic epilepsy were evaluated using uni- and multivariate regression analysis.

One hundred fifty-seven (32%) of 489 patients became epileptic during the study period. The results of univariate analysis indicated a significant relationship between epilepsy and Glasgow Outcome Scale (GOS) score (X2 = 76.49, p < 0.0001, df = 2), Glasgow Coma Scale score at admission (X2 = 19.48, p < 0.0001, df = 3), motor deficit (X2 = 11.79, p < 0.001, df = 1), mode of injury (X2 = 10.731, p < 0.05), transventricular injury (X2 = 6.9, p < 0.008, df = 1), dysphasia (X2 = 5.3, p < 0.02), central nervous system infections (X2 = 5.3, p < 0.02), and early-onset seizures (X2 = 4.1, p < 0.04, df = 1). The results of multivariate analysis, on the other hand, indicated that the GOS score and motor deficit were of greater statistical importance (X2 = 35.24, p < 0.0001; and X2 = 7.1, p < 0.07, respectively). Factors that did have much statistically significant bearing on posttraumatic epilepsy were the projectile type, site of injury on the skull, patient age, number of affected lobes, related hemorrhagic complications, and retained metallic or bone fragments.

Glasgow Outcome Scale score and focal motor neurological deficit are of particular importance in predicting posttraumatic epilepsy after missile head injury.

[The forensic psychiatric expertise of patients with epilepsy of traumatic origin and moderately pronounced mental disorders]

A total of 17 patients were examined with epilepsy of traumatic genesis presenting with moderately severe mental disorder and unfavourable course of the illness. Criteria were defined more exactly of forensic psychiatric assessment of chronic mental disorders in this most challenging "borderline" (in the expert respect) group of patients. Established in these cases were conditions of use of juristical (psychological) criterion of the diminished responsibility formula: the presence of manifest changes in the personality with moderately severe ("borderline") deterioration of intellect, social and occupational disadaptation, predominance of psychopathological mechanisms in behaviour of patients including those during their committing illegal actions, rapidly progredient type of epilepsy course, and chronic alcoholism going in with the underlying condition.

Posttraumatic epilepsy risk factors: one-year prospective study after head injury

PURPOSE

Prospective evaluation of risk factors for posttraumatic epilepsy (PTE) by using clinical, EEG, and brain computed tomography (CT) data in four assessments from the head injury (HI) acute phase to 1 year later; and evaluation of the possible epileptogenic role of hemosiderin as shown by brain magnetic resonance imaging (MRI).

METHODS

Risk factors for PTE were evaluated by using Kaplan-Meier curves, log-rank test, and the Cox model in 137 consecutively enrolled adult inpatients. Percentage differences of patients with brain hyperintense and/or hemosiderin areas shown by MRI 1 year after HI were statistically evaluated by univariate tests considering two subgroups [e.g., patients with (PTE) and without (WLS) late seizures].

RESULTS

The PTE subgroup included 18 patients with at least two seizures between the second and twelfth months. Kaplan-Meier curves demonstrated that Glasgow Coma Scale low score, early seizures, and single brain CT lesions are PTE risk factors, as is the development of an EEG focus 1 month after HI. No significant percentage difference was found between PTE and WLS patients with hemosiderin spots shown by MRI 1 year after HI.

CONCLUSIONS

the Cox model indicates that, for HI patients with early seizures and brain CT single temporal or frontal lesions in the acute phase, the PTE risk is 8.58 and 3.43 times higher, respectively, than for those without. An EEG focus 1 month after HI is a risk factor 3.49 times higher than for patients without such EEG changes. One year after HI, a higher percentage of PTE than WLS patients had cortical MRI hyper-intense areas including hemosiderin.

Early and late posttraumatic seizures in traumatic brain injury rehabilitation patients: brain injury factors causing late seizures and influence of seizures on long-term outcome

PURPOSE

To demonstrate risk factors involved in the origin of late posttraumatic seizures (LPTSs) in civilian traumatic brain injury (TBI) rehabilitation patients and the occurrence of LPTSs in this population, as well as the time of the first late seizures, and influence of these seizures on functional and occupational long-term outcome.

METHODS

A consecutive sample of 490 patients (age range, 0.8-71 years) with TBI, and with postinjury problems in their education and employment, were followed up for > or =5 years from the time of injury in a rehabilitation and reemployment program. The study was carried out at the outpatient neurologic clinic of the Kauniala Hospital, which specializes in brain injuries in Finland and works in close cooperation with the Department of Clinical Neurosciences at the Helsinki University Central Hospital. Main outcome measures were functional outcome, as measured on the Glasgow Outcome Scale (GOS), and the capacity for employment at the end of follow-up. Outcomes were studied separately among patients with late seizures and for the nonseizure group.

RESULTS

Children age 7 years or younger at time of injury more often had early posttraumatic seizures (EPTSs), than did adolescents or adults. The time elapsed between brain injury and the first late seizure also was longer in older age groups. EPTSs and depressed skull fracture had a statistically significant relation to the origin of LPTSs. Permanent posttraumatic neurologic deficit, linear skull fracture, and permanent local brain lesion documented on a computed tomography (CT) scan appeared clinically important as risk factors. Late seizures did worsen the functional outcome but had no significant influence on reemployment at the end of follow-up.

CONCLUSIONS

Young children are more prone to early seizures, and adolescents and adults, to late seizures. The main risk factors for LPTSs are early seizures and depressed skull fracture. Severity of brain injury, as measured by a low GCS score, prolonged unconsciousness, and posttraumatic amnesia (PTA) without local brain lesion, should not be considered risk factor for LPTSs. Thorough follow-up of patients with TBI with seizures and adequate antiepileptic therapy may help attain rehabilitation goals and reemployment.

[Structural-functional interrelations in patients with an epileptic syndrome in posttraumatic hydrocephalus]

Overall forty two patients presenting with epileptic syndrome in posttraumatic hydrocephalus in the remote period of light closed craniocerebral injury, who ranged from 16 to 60 years old, were examined. Degree of severity and variety of posttraumatic hydrocephalus were assessed by findings from axial computerized tomography, pneumoecephalography, magnetoresonance tomography. All patients underwent electroencephalography. The examinees were predominantly those persons presenting with light and internal symmetrical hydrocephalus. 57.2% of patients developed cerebral seizures within the first 5 years of sustaining the injury. Normal EEG was recordable in those patients with epileptic syndrome presenting with light and internal symmetrical hydrocephalus. Apparent diffusive disturbances in the bioelectrical activity of the brain were more common in moderately severe hydrocephalus and in mixed hydrocephalus. The presence of paroxysmal activity is a particular characteristic of patients with epileptic syndrome in outer hydrocephalus. A distinguishing feature of internal asymmetrical hydrocephalus is an observation of a decrease in the general level of biopotentials.

An aggressive seizure and behavioural disorder following trivial head injury

We report on a normal 6-year-old boy in whom a trivial head injury triggered a severe seizure, behavioural and cognitive disorder. Complete recovery occurred within 6 months. An aetiology such as trivial head injury is significant for prognosis as the outcome is invariably excellent.

Frontal lobe epilepsy with secondarily generalized 3 Hz spike-waves: a case report

We report a case of frontal lobe epilepsy with bursts of 3 Hz spike-wave, often dominant in the left frontal lobe, that sometimes developed into a secondary bilateral generalization. This patient was a 69-year-old male with a history of epileptic seizures that began 3 months following a head injury at the age of 17. His seizures occurred two or three times a day, but after medication the frequency was halved. The seizures began with a feeling of heaviness of the head, accompanied by myoclonus at both angles of the mouth. Consciousness was clear for most of the seizures, which ranged from several seconds to many minutes. When seizures lasted for longer than 10 minutes, a temporary generalization accompanied by a loss of consciousness was sometimes observed. Neurological tests and cranial MRI yielded no abnormal local findings. The secondary generalized seizure seen in this case is the so called "secondary bilateral synchrony (SBS)." We succeeded in making an EEG recording of the bilateral generalization of a seizure discharge originating in the left frontal lobe, which until now has not been done. This case is direct proof that a primary frontal focus can give rise to SBS.

Predictors and dynamics of posttraumatic epilepsy

OBJECTIVES

The goal of our study was to identify clinical, neurophysiological and neuroradiological variables in severe head trauma (SHT) with predictive value for posttraumatic epilepsy (PTE) and to evaluate the influence of each risk factor for the dynamics of epilepsy.

MATERIALS AND METHODS

We systematically compared 57 PTE patients with 50 age and sex-matched control patients with SHT and no PTE. Mean follow-up was 8 years.

RESULTS

Of all PTE-patients 68.5% had their first seizure within 2 years after the trauma. Significant risk factors for PTE were focal signs in the first examination (P < 0.01), missile injuries (P < 0.01), frontal lesions (P < 0.01), intracerebral hemorrhage (P < 0.01), diffuse contusion (P < 0.01), prolonged posttraumatic amnesia (P < 0.001), depression fracture (P < 0.01) and cortical-subcortical lesions (P < 0.001). The combination of the last 3 variables conferred a particularly high risk for PTE (logistic regression analysis). Combined seizure pattern, high seizure frequency, AED-noncompliance and alcohol abuse predicted poor seizure control.

CONCLUSION

The risk for PTE is clearly determined by those variables which correlate with the severity, the extent of tissue loss and the penetrating nature of the brain trauma.

The impact of posttraumatic seizures on 1-year neuropsychological and psychosocial outcome of head injury

This study examined the relationship of posttraumatic seizures and head injury severity to neuropsychological performance and psychosocial functioning in 210 adults who were prospectively followed and assessed 1 year after moderate to severe traumatic head injury. Eighteen percent (n = 38) of the patients experienced 1 or more late seizures (i.e., seizures occurring 8 or more days posttrauma) by the time of the 1-year followup. As expected, the head injured patients who experienced late posttraumatic seizures were those with the most severe head injuries, and they were significantly more impaired on the neuropsychological and psychosocial measures compared to those who remained seizure free. However, after the effects of head injury severity were controlled, there were no significant differences in neuropsychological and psychosocial outcome at 1 year as a function of having seizures. These findings suggest that worse outcomes in patients who develop posttraumatic seizures up to 1 year posttrauma largely reflect the effects of the brain injuries that cause seizures, rather than the effect of seizures.

Relative risk of deterioration after mild closed head injury

In this prospective study, a series of 1812 consecutive mild head injured adult patients who visited the hospital emergency department were assessed. Twenty-eight patients (1.5%) deteriorated after head injury; 23 of these (1.3% of the series) required surgical intervention. Five patients (0.3%) deteriorated due to non-surgical causes [post-traumatic seizure 2, syndrome of inappropriate secretion of antidiuretic hormone (SIADH) 3]. Most of the deterioration occurred within the first 24 hours (57%). Post-traumatic headache was found in 280 patients (15.5%) and 84 patients (4.6%) suffered post-traumatic vomiting. The relative risk is calculated. Age over 60, presence of drowsiness, focal motor weakness, post-traumatic headache and vomiting has increased risk of deterioration (p < 0.001). This study suggests that post-traumatic headache and vomiting deserve more clinical attention rather than being considered as post-traumatic syndrome only.

Seizures and 'disappearing' brain lesions

BACKGROUND--Patients with seizures may have abnormal brain imaging. Lesions demonstrated on computerized tomography or magnetic resonance imaging often suggest the underlying cause of the seizures, and may prompt an invasive investigation for diagnosis and treatment. In an increasingly recognized subset of patients however, the imaged lesions spontaneously resolve. While poorly understood, these 'disappearing' lesions may in fact be the consequence of seizures, rather than the cause. Two patients with 'disappearing' lesions are presented: the first patient had a proven cause, the second a probable one. Case 1. A patient with new onset seizures had an abnormal MRI. An angiogram confirmed thrombosis of the straight sinus. On follow-up, she was doing well; repeat imaging was normal with resolution of the lesion. Case 2. A patient with a long seizure history had been well controlled on medications, and had no change in frequency of her seizures. She was found to have a left homonymous hemianopsia. MRI revealed a right parieto-occipital lesion. The patient refused further work-up and was lost to follow-up. She returned almost a year later; repeat imaging was normal. CONCLUSION--Patients with seizures and abnormal imaging suggestive of structural lesions may occasionally have lesions that resolve spontaneously. While some diagnoses remain elusive, an important consideration to exclude in these patients is venous thrombosis.

Posttraumatic seizures

Posttraumatic epilepsy is one of the most clinically disturbing and, to date, difficult predictive factors associated with head trauma. The risk of developing seizures after head trauma depends on several factors. This article explores the mechanisms and biochemical effects of brain injury, their relationship to developing seizures, antiepileptic prophylaxis, and neuroprotective pharmacologic therapy.

Family history of seizures in posttraumatic and alcohol-associated seizure disorders

The potential role of genetic factors in the etiology of posttraumatic and alcohol-associated seizures was studied in 289 male patients with recurrent seizures and in 174 individuals who had never experienced a seizure. The incidence of seizures in first-degree relatives of probands was compared with that in relatives of unaffected individuals. Relatives of patients with alcohol-associated seizures had a rate ratio of 2.45 [95% confidence interval (CI) 1.41-4.25], whereas no excess incidence was noted among relatives of posttraumatic epilepsy patients (rate ratio 1.20, 0.64-2.25 CI). Relatives of probands with both antecedents showed an intermediate rate ratio of 1.72 (0.92-3.20 CI). Among probands with alcohol-associated seizures, the rate ratio of 2.05 for patients with alcohol-related seizures (i.e., spontaneously occurring seizures in association with chronic alcohol abuse) was slightly higher than that of 1.85 for probands with alcohol withdrawal seizures. Trauma severity had a slight impact on the incidence of affected relatives; patients with severe head injuries had a rate ratio of 0.73 and probands with milder trauma had a rate ratio of 0.99. The results indicate a limited, if any, role of genetic predisposition in development of posttraumatic seizures. Alcohol-related seizures, however, showed familial aggregation of unprovoked seizures, suggesting an involvement of genetic factors in the origin of such seizures.

Psychiatric presentations of epilepsy

The abnormal neuronal excitability underlying seizure disorders may alter behavior. Behavioral alterations associated with epilepsy can occur during the ictal period, especially in patients who suffer partial seizures of temporal or frontal lobe origin, or during the interictal period in the setting of chronic temporolimbic seizure discharges. We use case descriptions to illustrate behavioral presentations of epilepsy that resemble primary psychiatric illnesses, including schizophrenic psychoses, mood disorders, panic disorder, and dissociative disorders. The varied secondary psychiatric syndromes produced by epilepsy are elucidated by a consideration of normal functions of temporal and frontolimbic structures. The clinical pictures provide clues to the causes of primary psychiatric disorders.