Faculty Bibliography

Focal cortical dysplasia (FCD) is a malformation of cortical development that is associated with high rates of cognitive morbidity. However, the degree to which specific irregularities of dysplastic tissue directly impact cognition remains unknown. This study investigates the relationship between blurring of the cortical gray and white matter boundary on magnetic resonance imaging (MRI) and global cognitive abilities in FCD. Gray-white blurring (GWB) is quantified by sampling the non-normalized T1 image intensity contrast above and below the gray and white matter interface along the cortical mantle. Spherical averaging is used to compare resulting GWB for patients with histopathologically verified FCD with matched controls. Whole-brain correlational analyses are used to investigate the relationship between blurring and general cognitive abilities, controlling for epilepsy duration. Results show that cognitive performance is reduced in patients with FCD relative to controls. Patients show increased GWB in bilateral temporal, parietal, and frontal regions. Furthermore, increased GWB in these regions is linearly related to decreased cognition and mediates group differences in cognitive performance. These findings demonstrate that GWB is a marker of reduced cognitive efficiency in FCD that can potentially be used to probe general and domain-specific cognitive functions in other neurological disorders.

Postictal psychosis is characterized by a fluctuating combination of thought disorder, auditory and visual hallucinations, delusions, paranoia, affective change, and aggression including violent behavior. We present a case of homicide following a cluster of seizures. The patient's history and postictal behavior were his consistent with postictal psychosis. Contributing factors resulting in homicide may have included increased seizure frequency associated with a change in his AED regimen seizure frequency. The AED change to levetiracetam may also have increased impulsiveness with diminished mood regulation following discontinuation of carbamazepine. There is evidence that he had a cluster of seizures immediately prior to the murder which may have resulted in the postictal disinhibition of frontal lobe inhibitory systems. This homicide and other violent behaviors associated with postictal psychosis may be avoided with earlier recognition and treatment.

Magnetic resonance imaging (MRI) techniques have been used to quantitatively assess focal and network abnormalities. Idiopathic generalized epilepsy (IGE) is characterized by bilateral synchronous spike-wave discharges on electroencephalography (EEG) but normal clinical MRI. Dysfunctions involving the neocortex, particularly the prefrontal cortex, and thalamus likely contribute to seizure activity. To identify possible morphometric and functional differences in the brains of IGE patients and normal controls, we employed measures of thalamic volumes, cortical thickness, gray-white blurring, fractional anisotropy (FA) measures from diffusion tensor imaging (DTI) and fractional amplitude of low frequency fluctuations (fALFF) in thalamic subregions from resting state functional MRI. Data from 27 patients with IGE and 27 age- and sex-matched controls showed similar thalamic volumes, cortical thickness and gray-white contrast. There were no differences in FA values on DTI in tracts connecting the thalamus and prefrontal cortex. Functional analysis revealed decreased fALFF in the prefrontal cortex (PFC) subregion of the thalamus in patients with IGE. We provide minimum detectable effect sizes for each measure used in the study. Our analysis indicates that fMRI-based methods are more sensitive than quantitative structural techniques for characterizing brain abnormalities in IGE.

OBJECTIVE: Describe the characteristics of persons with epilepsy (PWEs) and caregivers that have or have not heard of sudden unexpected death in epilepsy (SUDEP) prior to completing a survey through the Internet or in the clinical setting. METHODS: An online survey for adult PWEs and caregivers was solicited by e-mail and newsletter to Epilepsy Therapy Project members. A similar survey was implemented in a clinic setting of a community hospital. The survey asked about seizure characteristics, epilepsy management, fear of death, and familiarity with the term SUDEP. Respondents that never heard of SUDEP read a definition and responded to questions about their initial reactions. RESULTS: Surveys from 1,392 PWEs and 611 caregivers recruited through an epilepsy Website and a clinic demonstrated that Internet respondents were much more likely to have heard about SUDEP than the clinic population (71.1% vs. 38.8%; p < 0.001), and caregivers of PWEs were more likely to have heard about SUDEP than PWEs (76.2% vs. 65.2%; p < 0.001). Prior awareness was related to an increased level of education, more severe and longer duration of epilepsy, and having an epileptologist as the primary care provider. Although most PWEs and caregivers reported feelings of fear, anxiety, and sadness after first hearing of SUDEP, they wanted to discuss it with their doctor. Persons with epilepsy, and especially their caregivers, often worry that the PWEs may die of epilepsy or seizures. This worry escalated with knowledge of SUDEP and increased epilepsy severity. Approximately half of PWEs and caregivers believed that knowledge about SUDEP would influence their epilepsy management. SIGNIFICANCE: Our results may help epilepsy care providers determine when to facilitate a discussion about epilepsy-related mortality and SUDEP among patients and caregivers, and to educate those at high risk about the importance of seizure control as well as reduce fears about death in patients with well-controlled and nonconvulsive epilepsies.

Integrated PET/MR with simultaneous acquisition may improve the identification of pathologic findings in patients. This pilot study evaluated metabolic activity differences between epilepsy patients and healthy controls and directly correlated FDG uptake with MR regional abnormality. Epilepsy patients (n=11) and controls (n=6) were imaged on a whole-body simultaneous PET/MR scanner. After FDG injection, simultaneous images were acquired for 60 minutes. Statistical analyses on SUV values (over 117 brain regions, including left and right, for 96 cortical and 21 subcortical regions) derived from three normalization methods, by individual subject's mean cortical, white matter or global brain, were compared between groups. The asymmetry was compared. T2, T1 and PET co-registered images were also used for lesion detection and correlation of PET and MR regional abnormality. Left and right postcentral gyri were found to be consistently hypermetabolic regions, while right temporal pole and planum polare were consistently hypometabolic regions by all three normalization methods. Using the asymmetry index (AI > 10% or SUV ratios > 1.2), more metabolic asymmetry regions were detected in patients than in controls, with 96.2% agreement. The presence of hippocampal abnormalities or cortical tubers detected via T2 FLAIR in patients correlated well with the hypometabolism detected via FDG-PET. Our results showed specific patterns of metabolic abnormality and asymmetry over 117 brain regions in epilepsy patients, as compared to controls, suggest that simultaneous PET/MR imaging provides a useful tool to help understand etiopathogenesis and localize seizure foci.

OBJECTIVE: Patients with tuberous sclerosis complex (TSC) commonly present with significant neurologic deficits, including seizures, autism, and intellectual disability. Previous evidence suggests that the TSC2 mutation genotype may be associated with a more severe disease phenotype. This study evaluates the association of the TSC1 and TSC2 genotype with patient and disease characteristics in a retrospective review of a large TSC Natural History Database consisting of 919 patients with TSC. METHODS: Univariate logistic regression was conducted to evaluate the association of the TSC1 and TSC2 gene mutations with patient and disease characteristics. RESULTS: As compared to patients with the TSC1 mutation, patients with the TSC2 mutation were younger (p = 0.02), more likely to have partial epilepsy (odds ratio (OR) 1.74, p = 0.0015), complex partial seizures (OR 2.03, p = 0.02), infantile spasms (IS) (OR 1.67, p = 0.01), subependymal giant-cell astrocytomas (SEGAs) (OR 1.64, p = 0.01), and intellectual disability (OR 2.90, p = 0.0002). SIGNIFICANCE: The clinical presentation of TSC is highly variable and not well understood. Our findings confirm and supplement existing literature that TSC2 mutation is likely to be associated with a more severe, earlier presenting TSC phenotype, including infantile spasms. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.