Risk factors for behavioral and psychotic dysregulation at the epilepsy monitoring unit in patients with intracranial electrodes.

OBJECTIVE: Aberrant behavior in patients with epilepsy (PWE) admitted to an epilepsy monitoring unit (EMU) can endanger their safety. We sought to identify predictive factors for post-ictal behavioral dysregulation and psychosis in patients with refractory epilepsy being monitored at an EMU. METHODS: Retrospective data were gathered from electronic patient files of all patients with refractory epilepsy who underwent intracranial registration at our EMU. We assessed behavioral and psychotic dysregulations by reviewing clinical notes, administered emergency medication, and reports of injuries or casualties in patients and nurses. In addition, we compared patient demographic characteristics, clinical characteristics, and antiepileptic drug (AED) profiles between patients with and without behavioral and/or psychotic dysregulation. RESULTS: Out of 73 admissions, 23 patients (32%) experienced behavioral dysregulation, and five patients experienced psychosis (7%). Behavioral dysregulation was only significantly associated with a previous history of interictal or postictal psychosis. Psychotic dysregulation is significantly associated with a psychiatric history, including a history of agitation or psychosis, whether or not epilepsy-related. For both types of dysregulations, there was no relation with a pre-admission frequency of seizures, clustering of seizures during monitoring, or a temporal focus of seizures. We could not report a relationship between AED use, tapering, and the occurrence of dysregulation. CONCLUSION: We conclude that a psychiatric history, including a history of agitation and psychosis, is related to an increased risk of behavioral and psychotic dysregulation in patients undergoing invasive seizure monitoring at the EMU.

Societal costs and quality of life analysis in patients undergoing resective epilepsy surgery: A one-year follow-up.

Although effectiveness of Resective Epilepsy Surgery (RES) for patients with drug-resistant epilepsy (DRE) is widely proven, research on the impact of societal costs (SC) is lacking. The aim of this study is to provide both clinical and economic outcomes of RES by offering an overview of treatment effectiveness as well as SC of RES in a cohort of 30 Dutch DRE patients. This project serves as a pilot project to offer an up-to-date model for larger cost-effectiveness studies. Medical consumption, productivity losses, disease-specific and generic health-related quality of life (QoL), and seizure frequency were assessed before and 3-, 6-, and 12-months post-surgery with validated questionnaires. Linear mixed models, ANOVAs, and logistic regressions were performed. SC for the first year after RES entailed €54,376 and decreased over time. Moreover, 50% of patients experienced a clinically important increase in disease-specific QoL and 53% of patients in generic health-related QoL. Lastly, 73% of patients reached seizure freedom 12 months postoperative. Seizure reduction was correlated with increase in disease-specific QoL. Within one year after surgery, RES leads to reduction in SC and improvements in QoL over time. Future research should encompass longer follow-up periods, larger sample size, and a cost-effectiveness analysis with a comparator.

Cognitive fMRI and soluble telencephalin assessment in patients with localization-related epilepsy.

Objectives - The use of telencephalin as a possible marker for altered cortical function as demonstrated by functional MRI was investigated in a pilot study with 16 patients with localization-related epilepsy and secondarily generalized seizures. Materials and methods - Functional MRI of verbal working memory performance (Sternberg paradigm) and self-regulatory control processes (Stroop paradigm) was used to examine cortical activation in 16 patients with localization-related epilepsy and secondarily generalized seizures. Additionally, blood serum concentrations of soluble telencephalin (marker for neuronal damage) were determined. Results - In three patients (one temporal and two frontal focus), telencephalin was detected. All three patients had lower functional MRI activation in the frontotemporal region (P = 0.04), but not in other regions (P > 0.35) compared with patients without detectable telencephalin. Additionally, an association of levetiracetam and frontotemporal activation was observed. Conclusions - These preliminary data in a heterogeneous group suggest an association between decreased frontotemporal activation on fMRI and both detectable telencephalin serum levels and levetiracetam use. Future longitudinal studies with larger patient groups are required to confirm these observations. It is hypothesized that altered local function of the frontotemporal cortex in localization-related epilepsy might be better predicted by the biochemical marker telencephalin than epilepsy characteristics such as seizure focus.

SUDEP in the Netherlands: a retrospective study in a tertiary referral center.

OBJECTIVE: To evaluate risk factors for sudden and unexpected death in epilepsy (SUDEP) in a high-risk population, i.e. patients treated in a Dutch tertiary referral center for epilepsy. METHODS: All patients who died between January 1999 and April 2004 while under treatment of the epilepsy center were identified. Based on clinical data, deaths were classified as definite, probable, possible or non-SUDEP. Potential risk factors were compared in SUDEP cases and non-SUDEP cases. RESULTS: SUDEP incidence was 1.24 per 1000 patient years. SUDEP patients died at a younger age than patients from the control group of non-SUDEP deaths with epilepsy and had an earlier onset of epilepsy. However, the frequently mentioned factors in previous studies, i.e. male sex, generalized tonic-clonic seizures, high seizure frequency, specific AEDs, polytherapy with several AEDs, mental retardation, psychiatric illness and psychotropic comedication, were not found to be correlated with SUDEP. CONCLUSIONS: Even in this high-risk population of patients with refractory epilepsy, treated in a tertiary referral center, SUDEP is not a frequently occurring phenomenon. Specific risk factors could not be identified within an already high-risk population.

Loss of network efficiency associated with cognitive decline in chronic epilepsy.

OBJECTIVE: To study the relation between possibly altered whole brain topology and intellectual decline in chronic epilepsy, a combined study of neurocognitive assessment and graph theoretical network analysis of fMRI was performed. METHODS: Forty-one adult patients with cryptogenic localization-related epilepsy and 23 healthy controls underwent an intelligence test and fMRI with a silent-word generation paradigm. A set of undirected graphs was constructed by cross-correlating the signal time series of 893 cortical and subcortical regions. Possible changes in cerebral network efficiency were assessed by performing graph theoretical network analysis. RESULTS: Healthy subjects displayed efficient small world properties, characterized by high clustering and short path lengths. On the contrary, in patients with epilepsy a disruption of both local segregation and global integration was found. An association of more pronounced intellectual decline with more disturbed local segregation was observed in the patient group. The effect of antiepileptic drug use on cognitive decline was mediated by decreased clustering. CONCLUSIONS: These findings support the hypothesis that chronic localization-related epilepsy causes cognitive deficits by inducing global cerebral network changes instead of a localized disruption only. Whether this is the result of epilepsy per se or the use of antiepileptic drugs remains to be elucidated. For application in clinical practice, future studies should address the relevance of altered cerebral network topology in prediction of cognitive deficits and monitoring of therapeutic interventions.

Functional connectivity and language impairment in cryptogenic localization-related epilepsy.

BACKGROUND: An often underestimated cognitive morbidity in patients with epilepsy is language dysfunction. To investigate the neuronal mechanisms underlying neuropsychological language impairment, activation maps and functional connectivity networks were studied by fMRI of language. METHOD: Fifty-two patients with cryptogenic localization-related epilepsy and 27 healthy controls underwent neuropsychological assessment of IQ, word fluency, and text reading. fMRI was performed with a standard covert word-generation and text-reading paradigm. Functional connectivity analysis comprised cross-correlation of signal time series of the characteristic and most strongly activated regions involved in the language tasks. RESULTS: After careful selection, 34 patients and 20 healthy controls were found eligible for analysis. Patients displayed lower IQ, lower fluency word count, and lower number of words correctly read compared to controls. fMRI activation maps did not differ significantly between patients and controls. For the word-generation paradigm, patients with epilepsy had significantly lower functional connectivity than controls in the prefrontal network. Patients performing worse on the word-fluency test demonstrated a significantly lower mean functional connectivity than controls. Text reading demonstrated lower functional connectivity in patients with epilepsy in the frontotemporal network. Similarly, lower mean functional connectivity was observed in patients with lowest reading performance compared to controls. A relation between reduced functional connectivity and performance on word-fluency and text-reading tests was demonstrated in epilepsy patients. CONCLUSION: Impaired performance on language assessment in epilepsy patients is associated with loss of functional connectivity in the cognitive language networks.