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Featured researches published by Ryan Hays.


Current Neurology and Neuroscience Reports | 2010

Sudden Unexpected Death in Epilepsy

Maromi Nei; Ryan Hays

Sudden unexpected death in epilepsy (SUDEP) is a significant cause of death for people with epilepsy. Recent research suggests that multiple factors may contribute and that both cardiac and respiratory mechanisms are involved. Both human and animal data suggest that specific genetic factors might play a role in some cases. Recent animal data suggest that serotonin might affect respiratory mechanisms and may be involved. Both cardiac and respiratory abnormalities are more likely with generalized tonic–clonic seizures. Uncontrolled epilepsy, particularly with generalized tonic–clonic seizures, appears to be the most highly associated modifiable risk factor for SUDEP.


JAMA Neurology | 2017

Neurological Autoantibody Prevalence in Epilepsy of Unknown Etiology

Divyanshu Dubey; Abdulradha Alqallaf; Ryan Hays; Matthew Freeman; Kevin Chen; Kan Ding; Mark Agostini; Steven Vernino

Importance Autoimmune epilepsy is an underrecognized condition, and its true incidence is unknown. Identifying patients with an underlying autoimmune origin is critical because these patients’ condition may remain refractory to conventional antiseizure medications but may respond to immunotherapy. Objective To determine the prevalence of neurological autoantibodies (Abs) among adult patients with epilepsy of unknown etiology. Design, Setting, and Participants Consecutive patients presenting to neurology services with new-onset epilepsy or established epilepsy of unknown etiology were identified. Serum samples were tested for autoimmune encephalitis Abs as well as thyroperoxidase (TPO) and glutamic acid decarboxylase 65 (GAD65) Abs. An antibody prevalence in epilepsy (APE) score based on clinical characteristics was assigned prospectively. Data were collected from June 1, 2015, to June 1, 2016. Main Outcomes and Measures Presence of neurological Abs. A score based on clinical characteristics was assigned to estimate the probability of seropositivity prior to antibody test results. Good seizure outcome was estimated on the basis of significant reduction of seizure frequency at the first follow-up or seizure freedom. Results Of the 127 patients (68 males and 59 females) enrolled in the study, 15 were subsequently excluded after identification of an alternative diagnosis. Serum Abs suggesting a potential autoimmune etiology were detected in 39 (34.8%) cases. More than 1 Ab was detected in 7 patients (6.3%): 3 (2.7%) had TPO-Ab and voltage-gated potassium channel complex (VGKCc) Ab, 2 (1.8%) had GAD65-Ab and VGKCc-Ab, 1 had TPO-Ab and GAD65-Ab, and 1 had anti-Hu Ab and GAD65-Ab. Thirty-two patients (28.6%) had a single Ab marker. Among 112 patients included in the study, 15 (13.4%) had TPO-Ab, 14 (12.5%) had GAD65-Ab, 12 (10.7%) had VGKCc (4 of whom were positive for leucine-rich glioma-inactivated protein 1 [LGI1] Ab), and 4 (3.6%) had N-methyl-D-aspartate receptor (NMDAR) Ab. Even after excluding TPO-Ab and low-titer GAD65-Ab, Abs strongly suggesting an autoimmune cause of epilepsy were seen in 23 patients (20.5%). Certain clinical features, such as autonomic dysfunction, neuropsychiatric changes, viral prodrome, faciobrachial dystonic spells or facial dyskinesias, and mesial temporal sclerosis abnormality on magnetic resonance imaging, correlated with seropositivity. The APE score was a useful tool in predicting positive serologic findings. Patients who were Ab positive were more likely to have good seizure outcome than were patients with epilepsy of unknown etiology (15 of 23 [65.2%] vs 24 of 89 [27.0%]; odds ratio, 4.8; 95% CI, 1.8-12.9; P = .002). In patients who were seropositive, reduction in seizure frequency was associated with use of immunomodulatory therapy. Conclusions and Relevance Among adult patients with epilepsy of unknown etiology, a significant minority had detectable serum Abs suggesting an autoimmune etiology. Certain clinical features (encoded in the APE score) could be used to identify patients with the highest probability of harboring neurological Abs.


Seizure-european Journal of Epilepsy | 2015

Retrospective case series of the clinical features, management and outcomes of patients with autoimmune epilepsy

Divyanshu Dubey; Puneet Gupta; Mark Agostini; Kan Ding; Paul C. Van Ness; Steven Vernino; Ryan Hays

PURPOSE Analyze clinical and electrographic characteristics of patients with autoimmune epilepsy, and evaluate the effect of early diagnosis and treatment on reduction of seizure frequency. METHODS Observational retrospective case series, conducted using electronic medical data from two teaching hospitals. Clinical data was collected from 2008 to 2013. Cases of new onset seizures were selected based on the presence of laboratory evidence of autoimmunity. RESULTS 34 hospitalized patients who presented predominantly due to seizures with concern for autoimmune etiology were identified. Mean age of patients was 44.94 years and 64.7% were males. Autoimmune antibodies were detected in 76.5% (26) of patients as follows: VGKc (8); NMDA-R (7); anti-thyroid (5); GAD (4); GABAB (2). 22 patients had unilateral temporal lobe onset and 4 had bilateral temporal lobe onset, while 8 had extra-temporal onset/multiple ictal foci. Median number of seizures during initial prolonged vEEG monitoring was 8 (range 0-48); median number of anti-seizure medications used was 2 (range 1-5). 9 patients had an underlying malignancy. 94.1% (32) patients received immunomodulation, as follows: high dose corticosteroids (96.8%), plasmapheresis (62.5%), IVIG (34.4%), rituximab (21.8%), mycophenolate (15.6%), cyclophosphamide (12.5%). 63.3% (19) participants achieved ≥ 50% seizure reduction (Responder Rate) at first clinic visit. Patients without malignancy had better seizure control (p < 0.05). Time from symptom onset to diagnosis (p < 0.005) and symptom onset to immunomodulation (p < 0.005) was significantly lower among patients who achieved responder rate (RR). CONCLUSION This study highlights certain important clinical and electrographic aspects of autoimmune epilepsy, and the significance of early diagnosis and initiation of immunomodulatory therapy.


Therapeutic Advances in Neurological Disorders | 2016

Evaluation of positive and negative predictors of seizure outcomes among patients with immune-mediated epilepsy: a meta-analysis

Divyanshu Dubey; Zehra Farzal; Ryan Hays; L. Steven Brown; Steven Vernino

Background: The objective of this study was to analyze published literature on autoimmune epilepsy and assess predictors of seizure outcome. Methods: From PubMed and EMBASE databases, two reviewers independently identified publications reporting clinical presentations, management and outcomes of patients with autoimmune epilepsy. A meta-analysis of 46 selected studies was performed. Demographic/clinical variables (sex, age, clinical presentation, epilepsy focus, magnetic resonance imaging [MRI] characteristics, time to diagnosis and initiation of immunomodulatory therapy, and type of immunomodulatory therapy) were compared between two outcome groups (responders and nonresponders). Clinical response was defined as >50% reduction in seizure frequency. Unstandardized effect sizes were collected for the studies for responder and nonresponder groups. Sample size was used as the weight in the meta-analysis. The random effects model was used to account for heterogeneity in the studies. Results: The 46 reports included 186 and 96 patients in responder and nonresponder groups respectively. Mean age of the responders and nonresponders was 43 and 31 years (p < 0.01). Responders were more likely to have cell-surface antibodies (68% versus 39%, p < 0.05), particularly voltage-gated potassium channel complex antibodies (p < 0.01). Mean duration from symptom onset to diagnosis, and symptom onset to initiation of immunomodulation was significantly lower among the responders (75 versus 431 days, p < 0.05, and 80 versus 554, p < 0.01, respectively). There was no outcome difference based on gender, MRI characteristics, seizure type, type of acute immunomodulatory therapy, or use of chronic immunomodulation. Conclusions: Among published cases to date, older age, presence of cell-surface antibodies, early diagnosis and immunomodulatory treatment are associated with better seizure outcomes among patients with autoimmune epilepsy.


Epilepsy Research and Treatment | 2016

Predictors of Postoperative Seizure Recurrence: A Longitudinal Study of Temporal and Extratemporal Resections

Hai Chen; Pradeep N. Modur; Niravkumar Barot; Paul C. Van Ness; Mark Agostini; Kan Ding; Puneet Gupta; Ryan Hays; Bruce Mickey

Objective. We investigated the longitudinal outcome of resective epilepsy surgery to identify the predictors of seizure recurrence. Materials and Methods. We retrospectively analyzed patients who underwent resections for intractable epilepsy over a period of 7 years. Multiple variables were investigated as potential predictors of seizure recurrence. The time to first postoperative seizure was evaluated using survival analysis and univariate analysis at annual intervals. Results. Among 70 patients, 54 (77%) had temporal and 16 (23%) had extratemporal resections. At last follow-up (mean 48 months; range 24–87 months), the outcome was Engel class I in 84% (n = 59) of patients. Seizure recurrence followed two patterns: recurrence was “early” (within 2 years) in 82% of patients, of whom 83% continued to have seizures despite optimum medical therapy; recurrence was “late” (after 2 years) in 18%, of whom 25% continued to have seizures subsequently. Among the variables of interest, only resection site and ictal EEG remained as independent predictors of seizure recurrence over the long term (p < 0.05). Extratemporal resection and discordance between ictal EEG and resection area were associated with 4.2-fold and 5.6-fold higher risk of seizure recurrence, respectively. Conclusions. Extratemporal epilepsy and uncertainty in ictal EEG localization are independent predictors of unfavorable outcome. Seizure recurrence within two years of surgery indicates poor long-term outcome.


Journal of Molecular Catalysis A-chemical | 1998

Cyclodextrins in reactions of alcohols with aqueous hypochlorite: catalysts or reactants?

Ryan Hays; G.Paul Hobbs; Massaran Kourouma; Jennifer J. Ries; Timothy M Ste. Marie; Susan K.M Sherwood; Robert G. Landolt

β-Cyclodextrin, a cyclic oligosaccharide/poly alcohol, reacts with aqueous sodium hypochlorite at elevated temperatures, resulting in a drop in the pH of the medium. Hypochlorite-induced oxidations of 1-phenyl-1-propanol or benzyl alcohol in the presence of the cyclic oligosaccharide are enhanced by lowering of pH rather than by inverse phase transfer catalysis. The secondary alcohol is inert in aqueous hypochlorite maintained at high pH, even in presence of the cyclodextrin. More rapid and efficient oxidations may be effected by pH control than by heating and/or addition of β-cyclodextrin.


Clinical Therapeutics | 2016

Effect of Gabapentin Enacarbil on Individual Items of the International Restless Legs Study Group Rating Scale and Post-sleep Questionnaire in Adults with Moderate-to-Severe Primary Restless Legs Syndrome: Pooled Analysis of 3 Randomized Trials

Mansoor Ahmed; Ryan Hays; J. Steven Poceta; Mark J. Jaros; Richard Kim; Gwendoline Shang

PURPOSE Few studies have investigated restless legs syndrome (RLS) treatment effects on individual International RLS Study Group Rating Scale (IRLS) items. We assessed the effects of gabapentin enacarbil (GEn) on individual IRLS items and their correlation with sleep disturbances in adults with moderate-to-severe primary RLS. METHODS Data were pooled from the randomized, double-blind, placebo-controlled, 12-week studies of XP052, XP053, and XP081 for adults who received GEn (600 or 1200 mg) or placebo once daily. Adults had primary RLS, IRLS total score ≥15, and RLS symptoms >15 days during the month before screening and for ≥4 of the 7 consecutive evenings at baseline. End points included mean change from baseline to week 12 in individual IRLS and post-sleep questionnaire (PSQ) items. For IRLS items, least squares mean treatment differences were calculated from a mixed model for repeated measures. For PSQ items, Cochran-Mantel-Haenszel row mean scores tests with integer scoring were used. Correlations between IRLS and PSQ items were assessed by Spearmans rank coefficients. Safety profile outcomes included treatment-emergent adverse events (TEAEs) and serious TEAEs. FINDINGS The modified intent-to-treat population included 671 patients (GEn 600 mg = 161; GEn 1200 mg = 266; placebo = 244). GEn significantly improved mean [SE] differences versus placebo for all IRLS items at week 12, including severity of sleep disturbance (GEn 600 mg, -0.4 [0.10]; GEn 1200 mg, -0.4 [0.09]), daytime tiredness (-0.4 [0.09]; -0.4 [0.08]), RLS severity (-0.4 [0.10]; -0.3 [0.08]), impact on daily affairs (-0.3 [0.07]; -0.3 [0.07]), and mood disturbance (-0.2 [0.07]; -0.3 [0.06]); all P<0.001). For PSQ items, significant (P<0.01) improvements occurred with both GEn doses versus placebo at week 12. The correlations between IRLS and PSQ items for change from baseline to week 12 were moderate to strong, and all correlations were significant (P<0.001). The most frequent TEAEs were somnolence (GEn 600 mg, 20%; GEn 1200 mg, 23%; placebo, 5%) and dizziness (GEn 600 mg, 14%; GEn 1200 mg, 22%; placebo, 5%). IMPLICATIONS GEn significantly improved individual IRLS items and sleep disturbance versus placebo. Correlations between IRLS and PSQ items were moderate to strong. This was not a formal meta-analysis and was not powered to compare the GEn doses. Nevertheless, our study finds that the benefits of GEn extend to individual IRLS items and supports the importance of sleep quality in RLS treatment. ClinicalTrials.gov identifiers: NCT00298623, NCT00365352, and NCT01332305.


Epilepsy Research | 2016

Temporal lobe volume predicts Wada memory test performance in patients with mesial temporal sclerosis

Kan Ding; Yunhua Gong; Pradeep N. Modur; Ramon Diaz-Arrastia; Mark Agostini; Puneet Gupta; Roderick McColl; Ryan Hays; Paul C. Van Ness

The Wada test is widely used in the presurgical evaluation of potential temporal lobectomy patients to predict postoperative memory function. Expected asymmetry (EA), defined as Wada memory lateralized to the nonsurgical hemisphere, or a higher score after injection of the surgical hemisphere would be considered favorable in terms of postoperative memory outcome. However, in some cases, nonlateralized memory (NM) results, with no appreciable asymmetry, may occur because of impaired scores after both injections, often leading to denial of surgery. The reason for such nonlateralized Wada memory in patients with intractable temporal lobe epilepsy (TLE) remains unclear. Given that quantitative morphometric magnetic resonance imaging studies in TLE patients have shown bilateral regional atrophy in temporal and extratemporal structures, we hypothesized that the volume loss in contralateral temporal structures could contribute to nonlateralized Wada memory performance. To investigate this, we examined the relationship between the volume changes of temporal structures and Wada memory scores in patients with intractable TLE with mesial temporal sclerosis (MTS) using an age- and gender-matched control group. Memory was considered nonlateralized if the absolute difference in the total correct recall scores between ipsilateral and contralateral injections was <11%. Among 21 patients, Wada memory was lateralized in 15 and nonlateralized in 6 patients, with all the nonlateralized scores being observed in left TLE. The recall scores after ipsilateral injection were significantly lower in patients with an NM profile than an EA profile (23 ± 14% vs. 59 ± 18% correct recall, p ≤ 0.001). However, the recall scores after contralateral injection were low but similar between the two groups (25 ± 17% vs. 25 ± 15% correct recall, p=0.97). Compared to controls, all the patients showed greater volume loss in the temporal regions. However, patients with a NM profile showed significantly more volume loss than those with a lateralized memory profile in both contralateral and ipsilateral temporal regions (p<0.05). Left hemispheric Wada memory performance correlated positively with the size of the left mesial and neocortical temporal structures (r=0.49-0.63, p=0.005-0.04). Our study suggests that volume loss in the nonsurgical temporal structures is associated with nonlateralized Wada memory results in patients with intractable TLE.


Epilepsy & Behavior | 2011

Mimetic automatisms expressing a negative affect in two patients with temporal lobe epilepsy

Ryan Hays; Neeta Lal; Joshua M. Rosenow; Michael P. Macken; Stephan U. Schuele

Ictal automatisms of fear or sadness, of which the patient is unaware and which are not preceded by a corresponding emotion, have not been well characterized. Of 557 patients admitted for video/EEG monitoring, 2 (0.36%) were identified who had automatisms of fear and sadness. One patient was found to have a sudden ictal expression of sadness of which he was not aware. The second patient showed a sudden fearful expression, followed by oral automatisms, staring, and amnesia for the event. Both patients had left mesial temporal lobe epilepsy. The patient with ictal fear underwent further invasive monitoring and became seizure free after a limited mesial temporal resection. The mesial temporal structures not only mediate emotional experiences, but can also activate stereotyped expressions of fear or sadness without the patients awareness, arguing for an efferent pathway for expressing negative affects within the mesial temporal lobe.


Sleep Medicine | 2016

Efficacy of gabapentin enacarbil in adult patients with severe primary restless legs syndrome

Daniel O. Lee; Mark J. Buchfuhrer; Diego Garcia-Borreguero; Alon Y. Avidan; Mansoor Ahmed; Ryan Hays; William G. Ondo; Mark J. Jaros; Richard Kim; Gwendoline Shang

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Mark Agostini

University of Texas Southwestern Medical Center

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Kan Ding

University of Texas Southwestern Medical Center

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Paul C. Van Ness

University of Texas Southwestern Medical Center

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Puneet Gupta

University of Texas Southwestern Medical Center

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Steven Vernino

University of Texas Southwestern Medical Center

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Pradeep N. Modur

University of Texas Southwestern Medical Center

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Abdulradha Alqallaf

University of Texas Southwestern Medical Center

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Barbara Voth

Parkland Memorial Hospital

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Bruce Mickey

University of Texas Southwestern Medical Center

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