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1.
J Hazard Mater ; 445: 130546, 2023 Mar 05.
Article in English | MEDLINE | ID: mdl-37055961

ABSTRACT

Radioactive technetium-99 (Tc) present in waste streams and subsurface plumes at legacy nuclear reprocessing sites worldwide poses potential risks to human health and environment. This research comparatively evaluated efficiency of zero-valent iron (ZVI) toward reductive removal of Tc(VII) in presence of Cr(VI) from NaCl and Na2SO4 electrolyte solutions under ambient atmospheric conditions. In both electrolytes, anticorrosive Cr(VI) suppressed oxidation of ZVI at elevated concentrations resulting in the delay of initiation of Tc(VII) reduction to Tc(IV). In the absence of Cr(VI), no delay was observed in the analogous systems. At low ionic strength (IS), retarded ZVI oxidation inhibited Tc(VII) reduction. Higher IS favored reduction of both Tc(VII) and Cr(VI), which followed second-order reaction rates in both electrolytes attributed to the more efficient iron oxidation as evident from solids characterization studies. Magnetite was the primary iron oxide phase, and its higher fraction in the SO42- solutions facilitated reductive removal of Tc(VII) and Cr(VI). In the Cl- matrix, Cr(VI) promoted further oxidation of magnetite as well as formation of chromite diminishing overall reductive capacity of this system and resulting in less effective removal of Tc(VII) compared to the SO42- solutions.

2.
Epilepsia Open ; 7(1): 36-45, 2022 03.
Article in English | MEDLINE | ID: mdl-34786887

ABSTRACT

OBJECTIVE: The question of whether a patient with presumed temporal lobe seizures should proceed directly to temporal lobectomy surgery versus undergo intracranial monitoring arises commonly. We evaluate the effect of intracranial monitoring on seizure outcome in a retrospective cohort of consecutive subjects who specifically underwent an anterior temporal lobectomy (ATL) for refractory temporal lobe epilepsy (TLE). METHODS: We performed a retrospective analysis of 85 patients with focal refractory TLE who underwent ATL following: (a) intracranial monitoring via craniotomy and subdural/depth electrodes (SDE/DE), (b) intracranial monitoring via stereotactic electroencephalography (sEEG), or (c) no intracranial monitoring (direct ATL-dATL). For each subject, the presurgical primary hypothesis for epileptogenic zone localization was characterized as unilateral TLE, unilateral TLE plus (TLE+), or TLE with bilateral/poor lateralization. RESULTS: At one-year and most recent follow-up, Engel Class I and combined I/II outcomes did not differ significantly between the groups. Outcomes were better in the dATL group compared to the intracranial monitoring groups for lesional cases but were similar in nonlesional cases. Those requiring intracranial monitoring for a hypothesis of TLE+had similar outcomes with either intracranial monitoring approach. sEEG was the only approach used in patients with bilateral or poorly lateralized TLE, resulting in 77.8% of patients seizure-free at last follow-up. Importantly, for 85% of patients undergoing SEEG, recommendation for ATL resulted from modifying the primary hypothesis based on iEEG data. SIGNIFICANCE: Our study highlights the value of intracranial monitoring in equalizing seizure outcomes in difficult-to-treat TLE patients undergoing ATL.


Subject(s)
Craniotomy , Seizures , Freedom , Humans , Retrospective Studies , Seizures/surgery , Treatment Outcome
3.
NMR Biomed ; 34(6): e4492, 2021 06.
Article in English | MEDLINE | ID: mdl-33751687

ABSTRACT

For the spectroscopic assessment of brain disorders that require large-volume coverage, the requirements of RF performance and field homogeneity are high. For epilepsy, this is also challenging given the inter-patient variation in location, severity and subtlety of anatomical identification and its tendency to involve the temporal region. We apply a targeted method to examine the utility of large-volume MR spectroscopic imaging (MRSI) in surgical epilepsy patients, implementing a two-step acquisition, comprised of a 3D acquisition to cover the fronto-parietal regions, and a contiguous parallel two-slice Hadamard-encoded acquisition to cover the temporal-occipital region, both with TR /TE = 2000/40 ms and matched acquisition times. With restricted (static, first/second-order) B0 shimming in their respective regions, the Cramér-Rao lower bounds for creatine from the temporal lobe two-slice Hadamard and frontal-parietal 3D acquisition are 8.1 ± 2.2% and 6.3 ± 1.9% respectively. The datasets are combined to provide a total 60 mm axial coverage over the frontal, parietal and superior temporal to middle temporal-occipital regions. We applied these acquisitions at a nominal 400 mm3 voxel resolution in n = 27 pre-surgical epilepsy patients and n = 20 controls. In controls, 86.6 ± 3.2% voxels with at least 50% tissue (white + gray matter, excluding CSF) survived spectral quality inclusion criteria. Since all patients were clinically followed for at least 1 year after surgery, seizure frequency outcome was available for all. The MRSI measurements of the total fractional metabolic dysfunction (characterized by the Cr/NAA metric) in FreeSurfer MRI gray matter segmented regions, in the patients compared with the controls, exhibited a significant Spearman correlation with post-surgical outcome. This finding suggests that a larger burden of metabolic dysfunction is seen in patients with poorer post-surgical seizure control.


Subject(s)
Epilepsy/diagnostic imaging , Epilepsy/surgery , Magnetic Resonance Spectroscopy , Adult , Aspartic Acid/analogs & derivatives , Aspartic Acid/metabolism , Case-Control Studies , Female , Gray Matter/diagnostic imaging , Gray Matter/pathology , Humans , Male , Middle Aged , Young Adult
4.
Hum Brain Mapp ; 42(7): 2089-2098, 2021 05.
Article in English | MEDLINE | ID: mdl-33491831

ABSTRACT

Image labeling using convolutional neural networks (CNNs) are a template-free alternative to traditional morphometric techniques. We trained a 3D deep CNN to label the hippocampus and amygdala on whole brain 700 µm isotropic 3D MP2RAGE MRI acquired at 7T. Manual labels of the hippocampus and amygdala were used to (i) train the predictive model and (ii) evaluate performance of the model when applied to new scans. Healthy controls and individuals with epilepsy were included in our analyses. Twenty-one healthy controls and sixteen individuals with epilepsy were included in the study. We utilized the recently developed DeepMedic software to train a CNN to label the hippocampus and amygdala based on manual labels. Performance was evaluated by measuring the dice similarity coefficient (DSC) between CNN-based and manual labels. A leave-one-out cross validation scheme was used. CNN-based and manual volume estimates were compared for the left and right hippocampus and amygdala in healthy controls and epilepsy cases. The CNN-based technique successfully labeled the hippocampus and amygdala in all cases. Mean DSC = 0.88 ± 0.03 for the hippocampus and 0.8 ± 0.06 for the amygdala. CNN-based labeling was independent of epilepsy diagnosis in our sample (p = .91). CNN-based volume estimates were highly correlated with manual volume estimates in epilepsy cases and controls. CNNs can label the hippocampus and amygdala on native sub-mm resolution MP2RAGE 7T MRI. Our findings suggest deep learning techniques can advance development of morphometric analysis techniques for high field strength, high spatial resolution brain MRI.


Subject(s)
Amygdala/anatomy & histology , Brain/anatomy & histology , Deep Learning , Epilepsy/pathology , Hippocampus/anatomy & histology , Magnetic Resonance Imaging/methods , Neuroimaging/methods , Adult , Amygdala/diagnostic imaging , Brain/diagnostic imaging , Epilepsy/diagnostic imaging , Female , Hippocampus/diagnostic imaging , Humans , Image Processing, Computer-Assisted , Male , Middle Aged
5.
J Clin Neurophysiol ; 38(5): 439-447, 2021 Sep 01.
Article in English | MEDLINE | ID: mdl-32472781

ABSTRACT

PURPOSE: To compare the seizure detection performance of three expert humans and two computer algorithms in a large set of epilepsy monitoring unit EEG recordings. METHODS: One hundred twenty prolonged EEGs, 100 containing clinically reported EEG-evident seizures, were evaluated. Seizures were marked by the experts and algorithms. Pairwise sensitivity and false-positive rates were calculated for each human-human and algorithm-human pair. Differences in human pairwise performance were calculated and compared with the range of algorithm versus human performance differences as a type of statistical modified Turing test. RESULTS: A total of 411 individual seizure events were marked by the experts in 2,805 hours of EEG. Mean, pairwise human sensitivities and false-positive rates were 84.9%, 73.7%, and 72.5%, and 1.0, 0.4, and 1.0/day, respectively. Only the Persyst 14 algorithm was comparable with humans-78.2% and 1.0/day. Evaluation of pairwise differences in sensitivity and false-positive rate demonstrated that Persyst 14 met statistical noninferiority criteria compared with the expert humans. CONCLUSIONS: Evaluating typical prolonged EEG recordings, human experts had a modest level of agreement in seizure marking and low false-positive rates. The Persyst 14 algorithm was statistically noninferior to the humans. For the first time, a seizure detection algorithm and human experts performed similarly.


Subject(s)
Algorithms , Seizures , Correlation of Data , Electroencephalography , Humans , Seizures/diagnosis , Sensitivity and Specificity
6.
Epilepsy Res ; 169: 106522, 2021 01.
Article in English | MEDLINE | ID: mdl-33296809

ABSTRACT

BACKGROUND: Ictal Single Photon Emission Computed Tomography (iSPECT) is one of the established tools utilized in the presurgical evaluation of patients with drug-resistant epilepsy (DRE). Timely isotope injection for an iSPECT is critical for optimal yield but poses logistical challenges when done manually. We aim to evaluate the added value of automatic iSPECT injectors (ASIs) in overcoming such challenges. METHODS: We retrospectively reviewed all cases admitted to the University of Pittsburgh Medical Center (UPMC) Epilepsy Monitoring Unit from Jan 1, 2010, through Dec 31, 2016, who underwent an iSPECT. We compared the manually injected iSPECTs with those performed with ASIs. RESULTS: A total of 123 iSPECTs were reviewed. The manually injected iSPECT group consisted of 35 patients (median age, 35 years; and 19 males). The automatically injected iSPECT group consisted of 88 patients (median age, 36 years; and 46 males). The two groups were comparable in age, gender, epilepsy treatment, focal features on neuropsychological testing (NPT), EEG, and MRI, and temporal origin of seizures (p > 0.05). Compared to manually injected iSPECTs, automatically injected ISPECTs' median injection latency (IL) was shorter (18.5 vs. 60 s, p < 0.001); the ratio of IL/total duration of seizure was lower (0.395 vs. 0.677, p < 0.001); postictal injections were less frequent (4 (4.5 %) vs. 7 (20 %), p = 0.007); the number of isotope spills was less (zero vs. 3, p = 0.022); and successfully localizing iSPECTs were more prevalent (81.8 % vs. 62.9 %, p = 0.025), even after adjusting for focal features on NPT, EEG, and MRI, the temporal origin of seizures, and seizure duration (OR of 5.539, 95 %CI = 1.653-18.563, p = 0.006). CONCLUSIONS: Utilization of ASIs leads to a significant shortening of iSPECT IL with less postictal injections, provides a safer injection option for the EMU staff, and leads to a significant improvement in the number of successfully localizing iSPECTs.


Subject(s)
Electroencephalography , Epilepsy , Seizures , Adult , Humans , Magnetic Resonance Imaging , Male , Retrospective Studies , Seizures/diagnostic imaging , Tomography, Emission-Computed, Single-Photon
7.
Front Neurol ; 11: 595454, 2020.
Article in English | MEDLINE | ID: mdl-33178129

ABSTRACT

Background: Laser interstitial thermal therapy (LiTT) has emerged as a minimally invasive option for surgical treatment of refractory epilepsy. However, LiTT of the mesial temporal (MT) structures is still inferior to anterior temporal lobectomy (ATL) in terms of postoperative outcome. In this pilot study, we identify intracranial EEG (iEEG) biomarkers that distinguish patients with favorable outcome from those with poor outcome after MT LiTT. Methods: We performed a retrospective review of 9 adult refractory epilepsy patients who underwent stereotactic electroencephalography (sEEG) followed by LiTT of MT structures. Their iEEG was retrospectively reviewed in both time and frequency domains. Results: In the time-domain, the presence of sustained 14-30 Hz in MT electrodes coupled with its absence from extra-MT electrodes at ictal onset was highly correlated with favorable outcomes, whereas the appearance of sustained 14-30 Hz or >30 Hz activity in extra-MT sites was negatively correlated to favorable outcomes. In the frequency domain, a declining spectral phase, beginning at the high frequency range (>14 Hz) at ictal onset and following a smooth progressive decline toward lower frequencies as the seizure further evolved, was positively correlated with improved outcomes. On the contrary, low frequency (<14 Hz) patterns and "crescendo-decrescendo" patterns with an early increasing frequency component at ictal onset that reaches the high-beta and low gamma bands before decreasing smoothly, were both correlated with poor surgical outcomes. Conclusions: This pilot study demonstrates the first evidence that iEEG analysis can provide neurophysiological markers for successful MT LiTT and therefore we strongly advocate for systematic sEEG investigations before offering MT LiTT to TLE and MTLE patients.

8.
Seizure ; 83: 234-241, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33121875

ABSTRACT

OBJECTIVE: We performed a systematic review of the literature to synthesize the data on EEG findings in COVID-19. Frontal EEG patterns are reported to be a characteristic finding in COVID-19 encephalopathy. Although several reports of EEG abnormalities are available, there is lack of clarity about typical findings. METHODS: Research databases were queried with the terms "COVID" OR "coronavirus" OR "SARS" AND "EEG". Available data was analyzed from 617 patients with EEG findings reported in 84 studies. RESULTS: The median age was 61.3 years (IQR 45-69, 33.3 % female). Common EEG indications were altered mental status (61.7 %), seizure-like events (31.2 %), and cardiac arrest (3.5 %). Abnormal EEG findings (n = 543, 88.0 %) were sub-classified into three groups: (1) Background abnormalities: diffuse slowing (n = 423, 68.6 %), focal slowing (n = 105, 17.0 %), and absent posterior dominant rhythm (n = 63, 10.2 %). (2) Periodic and rhythmic EEG patterns: generalized periodic discharges (n = 35, 5.7 %), lateralized/multifocal periodic discharges (n = 24, 3.9 %), generalized rhythmic activity (n = 32, 5.2 %). (3) Epileptiform changes: focal (n = 35, 5.7 %), generalized (n = 27, 4.4 %), seizures/status epilepticus (n = 34, 5.5 %). Frontal EEG patterns comprised of approximately a third of all findings. In studies that utilized continuous EEG, 96.8 % (n = 243) of the 251 patients were reported to have abnormalities compared to 85.0 % (n = 311) patients who did not undergo continuous EEG monitoring (χ2 = 22.8, p =< 0.001). SIGNIFICANCE: EEG abnormalities are common in COVID-19 related encephalopathy and correlates with disease severity, preexisting neurological conditions including epilepsy and prolonged EEG monitoring. Frontal findings are frequent and have been proposed as a biomarker for COVID-19 encephalopathy.


Subject(s)
COVID-19/physiopathology , Electroencephalography , Epilepsy/physiopathology , COVID-19/virology , Electroencephalography/methods , Epilepsy/diagnosis , Humans , Monitoring, Physiologic/methods , SARS-CoV-2/pathogenicity , Seizures/diagnosis , Seizures/physiopathology
9.
Clin Neurophysiol ; 130(9): 1570-1580, 2019 09.
Article in English | MEDLINE | ID: mdl-31302567

ABSTRACT

OBJECTIVE: To investigate the intracranial correlate of the 14&6/sec positive spikes normal variant of scalp EEG. METHODS: Out of 35 adult refractory focal epilepsy patients who underwent intracranial electrode implantation with simultaneous scalp EEG electrodes, the 14&6/sec positive spikes variant was found in 4. We used three methods to identify and quantify intracranial correlates to the variant: visual inspection, time-referenced waveform averaging and 3D brain volume spectrum-based statistical parametric mapping (SPM). RESULTS: We discovered a novel and robust relationship between the scalp variant and an atypical hippocampal discharge. This intracranial correlate is an ipsilateral hippocampal burst of highly synchronized high-amplitude paroxysmal-like spikes of negative polarity, with a ramping up amplitude profile, which often ramps down and is accompanied by an underlying sequence of low-amplitude negative slow waves. The 14/sec positive spikes of the variant are time-locked to the negative peak of the hippocampal spikes, while the 6/sec positive spikes are time-locked to the negative spikes overlying the low-amplitude slow waves. CONCLUSIONS: The 14&6/sec positive spikes variant correlates with bursts of negative polarity spikes in the ipsilateral hippocampus. SIGNIFICANCE: The identification of the hippocampal correlate of the 14&6/sec positive spikes variant fills a gap in our knowledge of normal intracranial variants. In clinical practice, this knowledge should reduce the chance that this electrophysiological signature is misinterpreted as epileptiform activity, which could inappropriately influence the interpretation of the intracranial study and subsequent surgical recommendation.


Subject(s)
Electrodes, Implanted , Electroencephalography/methods , Epilepsies, Partial/physiopathology , Hippocampus/physiology , Adult , Female , Humans , Male , Middle Aged , Scalp
11.
Seizure ; 64: 8-15, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30502684

ABSTRACT

PURPOSE: To determine if simultaneous bilateral scalp EEG (scEEG) can accurately detect a contralateral seizure onset in patients with unilateral intracranial EEG (IEEG) implantation. METHODS: We evaluated 39 seizures from 9 patients with bitemporal epilepsy who underwent simultaneous scEEG and IEEG (SSIEEG). To simulate conditions of unilateral IEEG implantation with a missed contralateral seizure onset, we analyzed the IEEG recording contralateral to the seizure onset (CL- IEEG), in conjunction with simultaneous scEEG. The following criteria were evaluated between scEEG and CL- IEEG (1) latency: the time to onset of EEG seizure (2) location: concordance of ictal onset zones and (3) pattern: congruence of EEG morphology and frequency. RESULTS: SSIEEG correctly lateralized 36/39 (92.3%) seizures compared to 13/39 (33.3%) seizures using CL- IEEG alone (OR = 24.0, p < 0.01), 33 (84.6%) seizures using scEEG alone (OR = 2.2, p = 0.29) and 26 (66.9%) seizures using time of clinical onset alone (OR = 6.0, p = 0.01). For the three criteria evaluated, (1) 22/39 (56.4%) seizures had an earlier onset on the scEEG, compared to CL- IEEG; (2) lack of congruence of location of seizure onset was noted in 33/39 (84.6%) of the seizures; and (3) 22/39 (56.4%) seizures did not have a congruent ictal pattern. CONCLUSIONS: The chronological, topographic and morphologic features of SSIEEG can accurately detect the hemisphere of seizure onset in most cases with unilateral IEEG implantation. SSIEEG is significantly better than, IEEG, scEEG or clinical onset alone in this scenario. We propose that SSIEEG should be considered in all cases of intractable focal epilepsy undergoing unilateral IEEG evaluation.


Subject(s)
Electroencephalography/methods , Epilepsy, Temporal Lobe/diagnosis , Adult , Electrocorticography/methods , Epilepsy, Temporal Lobe/physiopathology , Female , Humans , Male , Middle Aged , Scalp , Young Adult
12.
Mikrochim Acta ; 185(7): 358, 2018 07 04.
Article in English | MEDLINE | ID: mdl-29974265

ABSTRACT

This review (with (318) refs) describes progress made in the design and synthesis of morphologically different metal oxide nanoparticles made from iron, manganese, titanium, copper, zinc, zirconium, cobalt, nickel, tungsten, silver, and vanadium. It also covers respective composites and their function and application in the field of electrochemical and photoelectrochemical sensing of chemical and biochemical species. The proper incorporation of chemical functionalities into these nanomaterials warrants effective detection of target molecules including DNA hybridization and sensing of DNA or the formation of antigen/antibody complexes. Significant data are summarized in tables. The review concludes with a discussion or current challenge and future perspectives. Graphical abstract ᅟ.


Subject(s)
Biosensing Techniques/methods , Electrochemistry/methods , Metals/chemistry , Oxides/chemistry , Electrodes , Nanoparticles/chemistry
13.
Neurocrit Care ; 28(3): 353-361, 2018 06.
Article in English | MEDLINE | ID: mdl-29327152

ABSTRACT

BACKGROUND: Status epilepticus (SE) has been identified as a predictor of morbidity and mortality in many acute brain injury patient populations. We aimed to assess the prevalence and impact of SE after intracerebral hemorrhage (ICH) in a large patient sample to overcome limitations in previous small patient sample studies. METHODS: We queried the Nationwide Inpatient Sample for patients admitted for ICH from 1999 to 2011, excluding patients with other acute brain injuries. Patients were stratified into SE diagnosis and no SE diagnosis cohorts. We identified independent risk factors for SE and assessed the impact of SE on morbidity and mortality with multivariable logistic regression models. Logistic regression was used to evaluate the trend in SE diagnoses over time as well. RESULTS: SE was associated with significantly increased odds of both mortality and morbidity (odds ratios (OR) 1.18 [confidence intervals (CI) 1.01-1.39], and OR 1.53 [CI 1.22-1.91], respectively). Risk factors for SE included female sex (OR 1.17 [CI 1.01-1.35]), categorical van Walraven score (vWr 5-14: OR 1.68 [CI 1.41-2.01]; vWr > 14: OR 3.77 [CI 2.98-4.76]), sepsis (OR 2.06 [CI 1.58-2.68]), and encephalopathy (OR 3.14 [CI 2.49-3.96]). Age was found to be associated with reduced odds of SE (OR 0.97 [CI 0.97-0.97]). From 1999 to 2011, prevalence of SE diagnosis increased from 0.25 to 0.61% (p < 0.001). Factors associated with SE were female sex, medium and high risk vWr score, sepsis, and encephalopathy. Independent predictors associated with increased mortality from SE were increased age, pneumonia, myocardial infarction, cardiac arrest, and sepsis. CONCLUSIONS: SE is a significant, likely underdiagnosed, predictor of morbidity and mortality after ICH. Future studies are necessary to better identify which patients are at highest risk of SE to guide resource utilization.


Subject(s)
Cerebral Hemorrhage/epidemiology , Status Epilepticus/epidemiology , Age Factors , Aged , Cerebral Hemorrhage/complications , Cerebral Hemorrhage/mortality , Cohort Studies , Female , Humans , Male , Middle Aged , Prevalence , Risk Factors , Severity of Illness Index , Sex Factors , Status Epilepticus/etiology , Status Epilepticus/mortality , United States/epidemiology
14.
World Neurosurg ; 112: e385-e392, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29355799

ABSTRACT

OBJECTIVE: Spontaneous intracerebral hemorrhage (ICH) is one of the most frequent causes of epilepsy in the United States. However, reported risk factors for seizure after are inconsistent, and their impact on inpatient morbidity and mortality is unclear. We aimed to study the incidence, risk factors, and impact of seizures after ICH in a nationwide patient sample. METHODS: We queried the Nationwide Inpatient Sample for patients admitted to the hospital with a primary diagnosis of ICH between the years 1999 and 2011. Patients were subsequently dichotomized into groups of those with a diagnosis consistent with seizure and those without. Multivariate logistic regression was used to assess risk factors for seizure in this patient sample, and the association between seizures and mortality and morbidity. Logistic regression was then used for trend analysis of incidence of seizure diagnoses over time. RESULTS: We identified 220,075 patients admitted with a primary diagnosis of ICH. Of these, 11.87% had a diagnosis consistent with seizure. Factors associated with increased risk of seizure after ICH included higher categorical van Walraven score, encephalopathy, alcohol abuse, solid tumor, and prior stroke. Seizure was independently associated with decreased odds of morbidity (odds ratio [OR], 0.89; 95% confidence interval [CI], 0.86-0.92) and mortality (OR, 0.75; 95% CI, 0.72-0.77) in multivariate models controlling for existing comorbidities. CONCLUSIONS: Seizures after were associated with decreased mortality and morbidity despite attempts to correct for existing comorbidities. Continuous monitoring of these patients for seizures may not be necessary in all circumstances, despite their frequency.


Subject(s)
Cerebral Hemorrhage/complications , Seizures/epidemiology , Seizures/etiology , Aged , Female , Humans , Incidence , Male , Middle Aged , Prognosis , Registries , Risk Factors , Seizures/mortality , Survival Rate , United States/epidemiology
15.
Clin EEG Neurosci ; 49(3): 206-212, 2018 May.
Article in English | MEDLINE | ID: mdl-29067832

ABSTRACT

OBJECTIVE: To assess the utility of simultaneous scalp EEG in patients with focal epilepsy undergoing intracranial EEG evaluation after a detailed presurgical testing, including an inpatient scalp video EEG evaluation. METHODS: Patients who underwent simultaneous scalp and intracranial EEG (SSIEEG) monitoring were classified into group 1 or 2 depending on whether the seizure onset zone was delineated or not. Seizures were analyzed using the following 3 EEG features at the onset of seizures latency, location, and pattern. RESULTS: The criteria showed at least one of the following features when comparing SSIEEG: prolonged latency, absence of anatomical congruence, lack of concordance of EEG pattern in 11.11% (1/9) of the patients in group 1 and 75 % (3/4) of the patients in group 2. These 3 features were not present in any of the 5 patients who had Engel class I outcome compared with 1 of the 2 patients (50%) who had seizure recurrence after resective surgery. The mean latency of seizure onset in scalp EEG compared with intracranial EEG of patients in group 1 was 17.48 seconds (SD = 16.07) compared with 4.33 seconds (SD = 11.24) in group 2 ( P = .03). None of the seizures recorded in patients in group 1 had a discordant EEG pattern in SSIEEG. CONCLUSION: Concordance in EEG features like latency, location, and EEG pattern, at the onset of seizures in SSIEEG is associated with a favorable outcome after epilepsy surgery in patients with intractable focal epilepsy. SIGNIFICANCE: Simultaneous scalp EEG complements intracranial EEG evaluation even after a detailed inpatient scalp video EEG evaluation and could be part of standard intracranial EEG studies in patients with intractable focal epilepsy.


Subject(s)
Electroencephalography , Epilepsies, Partial/surgery , Scalp/physiopathology , Seizures/surgery , Adolescent , Adult , Electroencephalography/methods , Epilepsies, Partial/physiopathology , Epilepsy/physiopathology , Epilepsy/surgery , Female , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Seizures/physiopathology , Treatment Outcome , Young Adult
16.
Epilepsy Behav ; 78: 73-77, 2018 01.
Article in English | MEDLINE | ID: mdl-29175694

ABSTRACT

Our goal was to evaluate how accurate neurologists are at differentiating between different paroxysmal events based on clinical history versus observation of the spell in question. Forty-seven neurologists reviewed 12 clinical histories and videos of recorded events of patients admitted in the Epilepsy Monitoring Unit (EMU). They were asked to diagnose events as epileptic seizures, non-epileptic behavioral spells (NEBS), or other physiologic events as well as rate their confidence in their diagnosis. The median diagnostic accuracy for all paroxysmal events was 67% for clinical history and 75% for observation (p=.001). This was largely due to the difference in accuracy within the subgroup of patients with NEBS (67% history vs. 83% observation, p<.001). There were trends for higher diagnostic accuracy and increased inter-rater agreement with higher levels of training. Physicians with higher levels of training were more confident with diagnosis based on observation. In summary, reviewing videos of paroxysmal spells may improve diagnostic accuracy and enhance the evaluation of patients. Neurologists at all levels of training should encourage the recording and review of videos of recurrent spells to aid in medical decision-making especially when there is high concern that the spells in question are NEBS.


Subject(s)
Clinical Competence , Electroencephalography/methods , Epilepsy/diagnosis , Movement Disorders/diagnosis , Neurologists , Seizures/diagnosis , Telemetry , Videotape Recording/methods , Clinical Decision-Making , Diagnosis, Differential , Female , Hospital Units , Humans , Male , Mental Processes , Monitoring, Physiologic/methods , Seizures/etiology , Seizures/psychology
17.
Exp Neurol ; 294: 68-77, 2017 08.
Article in English | MEDLINE | ID: mdl-28495218

ABSTRACT

Individuals with pharmacoresistant epilepsy remain a large and under-treated patient population. Continued technologic advancements in implantable neurostimulators have spurred considerable research efforts directed towards the development of novel antiepileptic stimulation therapies. However, the lack of adequate preclinical experimental platforms has precluded a detailed understanding of the differential effects of stimulation parameters on neuronal activity within seizure networks. In order to chronically monitor seizures and the effects of stimulation in a freely-behaving non-human primate with idiopathic epilepsy, we employed a novel simultaneous video-intracranial EEG recording platform using a state-of-the-art sensing-enabled, rechargeable clinical neurostimulator with real-time seizure detection and wireless data streaming capabilities. Using this platform, we were able to characterize the electrographic and semiologic features of the focal-onset, secondarily generalizing tonic-clonic seizures stably expressed in this animal. A series of acute experiments exploring low-frequency (2Hz) hippocampal stimulation identified a pulse width (150µs) and current amplitude (4mA) combination which maximally suppressed local hippocampal activity. These optimized stimulation parameters were then delivered to the seizure onset-side hippocampus in a series of chronic experiments. This long-term testing revealed that the suppressive effects of low-frequency hippocampal stimulation 1) diminish when delivered continuously but are maintained when stimulation is cycled on and off, 2) are dependent on circadian rhythms, and 3) do not necessarily confer seizure protective effects.


Subject(s)
Deep Brain Stimulation , Epilepsy/therapy , Hippocampus/physiology , Online Systems , Analysis of Variance , Animals , Biophysical Phenomena/physiology , Disease Models, Animal , Electrodes, Implanted , Electroencephalography , Epilepsy/diagnostic imaging , Evoked Potentials/physiology , Fourier Analysis , Functional Laterality , Hippocampus/diagnostic imaging , Hippocampus/pathology , Imaging, Three-Dimensional , Macaca mulatta , Magnetic Resonance Imaging , Male , Neurons/physiology , Video Recording , Wakefulness
18.
Neurol India ; 65(Supplement): S6-S11, 2017.
Article in English | MEDLINE | ID: mdl-28281490

ABSTRACT

Approximately 50 million people live with epilepsy worldwide. The aim of this review is to present an overview of the current evidence and management recommendations for evaluation and treatment of patients with epilepsy. Systematic literature reviews were undertaken. A review of contemporary published evidence-based guidelines (American Academy of Neurology, American Epilepsy Society, and the Indian Epilepsy Society) and published peer reviewed scientific publications was done. The guideline is addressed to all clinicians who manage epilepsy patients. Evidence-based recommendations are provided for the evaluation and treatment of the first seizure, use of antiepileptic medications, treatment of status epilepticus, use of epilepsy surgery, and the management of epilepsy in specific populations as well as in unique clinical situations such as neurocysticercosis infestation, brain tumor and human immunodeficiency virus infection. It also addresses the special considerations in women with epilepsy.


Subject(s)
Anticonvulsants/therapeutic use , Epilepsy/drug therapy , Practice Guidelines as Topic , Seizures/drug therapy , Anticonvulsants/adverse effects , Epilepsy/diagnosis , Female , Humans , Pregnancy , Pregnancy Complications , Status Epilepticus/drug therapy
19.
J Clin Neurophysiol ; 34(2): 179-186, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27749505

ABSTRACT

PURPOSE: Fellowship training in Clinical Neurophysiology (CNP) is often sought following Neurology residency. However, data documenting the reasons for choosing CNP fellowship, and experiences therein, are sparse. METHODS: Current Neurophysiology fellows across the United States participated in a 17-item, Internet-based survey. Data regarding demographics, reasons for choosing fellowship, adequacy of training, and future plans were collected. RESULTS: Among respondents (n = 49), 84% graduated from a US medical school. Personal interest in CNP was the most common reason for choosing the fellowship. Program choice was guided by location and clinical strength of the program. Choosing a program based on clinical strength was likely to result in higher satisfaction scores. Overall, most (87%) were satisfied with their current program giving a satisfaction score of 4 or 5 on a 1-5 Likert scale. Lesser time spent in the epilepsy monitoring unit and EEG was also associated with higher satisfaction scores-these were also the areas that seemed to be most stressed during training. No differences emerged between male and female respondents in their answers to the various survey questions. CONCLUSIONS: The authors encountered a group of academically minded CNP trainees who are satisfied with their choice of fellowship, the current application process, and training received. Most intend to have a future in academic medicine. The CNP areas that seem to need further development in providing a well-rounded fellowship include training in sleep, evoked potentials, and intraoperative monitoring. The findings would be informative to future fellowship trainees and to program officers.


Subject(s)
Career Choice , Fellowships and Scholarships , Neurophysiology/education , Education, Medical, Graduate , Female , Humans , Male , Personal Satisfaction , Surveys and Questionnaires , United States
20.
Epilepsy Behav ; 62: 140-6, 2016 09.
Article in English | MEDLINE | ID: mdl-27474963

ABSTRACT

Changes in cognitive function are a well established risk of anterior temporal lobectomy (ATL). Deficits in verbal memory are a common postoperative finding, though a small proportion of patients may improve. Postoperative evaluation typically occurs after six to 12months. Patients may benefit from earlier evaluation to identify potential needs; however, the results of a formal neuropsychological assessment at an early postoperative stage are not described in the literature. We compared pre- and postoperative cognitive function for 28 right ATL and 23 left ATL patients using repeated measures ANOVA. Changes in cognitive function were compared to ILAE seizure outcome. The mean time to postoperative neuropsychological testing was 11.1weeks (SD=6.7weeks). There was a side×surgery interaction for the verbal tasks: immediate memory recall (F(1,33)=20.68, p<0.001), short delay recall (F(1,29)=4.99, p=0.03), long delay recall (F(1,33)=10.36, p=0.003), recognition (F(1,33)=5.69, p=0.02), and naming (F(1,37)=15.86, p<0.001). This indicated that the left ATL group had a significant decrement in verbal memory following surgery, while the right ATL group experienced a small but significant improvement. For the right ATL group, there was a positive correlation between ILAE outcome and improvement in immediate recall (r=-0.62, p=0.02) and long delay recall (r=-0.57, p=0.03). There was no similar finding for the left ATL group. This study demonstrates that short-interval follow-up is effective in elucidating postoperative cognitive changes. Right ATL was associated with improvement in verbal memory, while left ATL resulted in a decrement in performance. Improvement in the right ATL group was related to improved seizure outcome. Short-interval follow-up may lend itself to the identification of patients who could benefit from early intervention.


Subject(s)
Anterior Temporal Lobectomy/adverse effects , Cognitive Dysfunction/etiology , Epilepsy, Temporal Lobe/surgery , Memory Disorders/etiology , Adult , Cognition/physiology , Cognitive Dysfunction/psychology , Female , Functional Laterality/physiology , Humans , Male , Memory Disorders/psychology , Mental Recall , Middle Aged , Neuropsychological Tests , Postoperative Complications/psychology , Postoperative Period , Treatment Outcome
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