Clinical exome sequencing in neuromuscular diseases: an experience from Turkey.

Neuromuscular diseases (NMDs) encompass a variety of ailments from muscular dystrophies to ataxias, in the course of which the functioning of the muscles is eventually either directly or indirectly impaired. The clinical diagnosis of a particular NMD is not always straightforward due to the clinical and genetic heterogeneity of the disorders under investigation. Traditional diagnostic tools such as electrophysiological tests and muscle biopsies are both invasive and painful methods, causing the patients to be reluctant. Next-generation sequencing, on the other hand, emerged as an alternative method for the diagnosis of NMDs, both with its minimally invasive nature and fast processing period. In this study, clinical exome sequencing (CES) was applied to a cohort of 70 probands in Turkey, 44 of whom received a final diagnosis, representing a diagnostic rate of 62.9%. Out of the 50 mutations identified to be causal, 26 were novel in the known 27 NMD genes. Two probands had complex/blended phenotypes. Molecular confirmation of clinical diagnosis of NMDs has a major prognostic impact and is crucial for the management and the possibility of alternative reproductive options. CES, which has been increasingly adopted to diagnose single-gene disorders, is also a powerful tool for revealing the etiopathogenesis in complex/blended phenotypes, as observed in two probands of the cohort.

Follow-up of patients with epilepsy harboring antiglycine receptor antibodies.

OBJECTIVE: The long-term follow-up of patients with epilepsy harboring autoantibodies against the glycine receptor (also glycine receptor antibodies or GlyR-Ab) is not well-known. Our aim was to investigate the 5-year prognosis and treatment response of patients with epilepsy who were seropositive for GlyR-Ab. METHODS: Clinical features; electroencephalogram (EEG), neuroradiological, and neuropathological findings; and treatment responses of patients with epilepsy with GlyR-Ab seropositivity were investigated. RESULTS: Thirteen (5.46%) of 238 patients with epilepsy were GlyR-Ab positive: focal epilepsy of unknown cause (FEoUC) was diagnosed in four (7.27%) out of 55 patients, mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) in five (4.5%) out of 111 patients, epileptic encephalopathy (EE) in two (4%) out of 50 patients, and status epilepticus (SE) in two (9.09%) out of 22 patients. None of the patients developed any other neurological symptoms or cancer during the 5-year follow-up. Seven of them had seizures that were resistant to antiepileptic drug (AED). Immunotherapy was used in two patients (with FEoUC and EE) improving seizure control. Three patients with MTLE-HS benefited from epilepsy surgery, and another patient with EE showed spontaneous remission. CONCLUSION: Glycine receptor antibodies are detected in a wide spectrum of epileptic disorders with unclear pathogenic significance. Two GlyR-Ab seropositive patients with AED-resistant epilepsy treated with intravenous immunoglobulin (IVIg) showed clear benefit from immunotherapy. Future studies will be valuable in determining the role of screening patients with drug-resistant epilepsy for GlyR-Ab in order to identify patients who may benefit or respond to immunotherapy.

Neuronal autoantibodies in mesial temporal lobe epilepsy with hippocampal sclerosis.

OBJECTIVE: Our aim was to investigate the prevalence of neuronal autoantibodies (NAbs) in a large consecutive series with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) and to elucidate the clinical and laboratory clues for detection of NAbs in this prototype of frequent, drug-resistant epilepsy syndrome. METHODS: Consecutive patients diagnosed with MTLE fulfilling the MRI criteria for HS were enrolled. The sera of patients and various control groups (80 subjects) were tested for eight NAbs after ethical approval and signed consents. Brain tissues obtained from surgical specimens were also investigated by immunohistochemical analysis for the presence of inflammatory infiltrates. The features of seropositive versus seronegative groups were compared and binary logistic regression analysis was performed to explore the differentiating variables. RESULTS: We found antibodies against antigens, contactin-associated protein-like 2 in 11 patients, uncharacterised voltage-gated potassium channel (VGKC)-complex antigens in four patients, glycine receptor (GLY-R) in 5 patients, N-methyl-d-aspartate receptor in 4 patients and γ-aminobutyric acid receptor A in 1 patient of 111 patients with MTLE-HS and none of the control subjects. The history of status epilepticus, diagnosis of psychosis and positron emission tomography or single-photon emission CT findings in temporal plus extratemporal regions were found significantly more frequently in the seropositive group. Binary logistic regression analysis disclosed that status epilepticus, psychosis and cognitive dysfunction were statistically significant variables to differentiate between the VGKC-complex subgroup versus seronegative group. CONCLUSIONS: This first systematic screening study of various NAbs showed 22.5% seropositivity belonging mostly to VGKC-complex antibodies in a large consecutive series of patients with MTLE-HS. Our results indicated a VGKC-complex autoimmunity-related subgroup in the syndrome of MTLE-HS.

Idiopathic intracranial hypertension: Do we diagnose and manage it appropriately in the light of current data?

BACKGROUND AND OBJECTIVE: Idiopathic intracranial hypertension (IIH) is an increase of intracranial pressure without a known cause, which usually presented with headache. This study aimed to evaluate the changing diagnosis and management approaches of neurologists for IIH in light of recent data. METHODS: An online questionnaire about IIH was developed covering 28 questions, and five sections: demographic data, diagnosis, examination, treatment, and follow-up. We compared the approach of neurologists with 1-9 years of experience (group-A) with that of neurologists with more than 10 years' experience (group-B). RESULTS: A total of 517 neurologists (group A: n = 252, group B: n = 265) participated in the study. Responder rate of questionarre is 18.3%. The approach to IIH in diagnosis, examination, treatment, and follow-up processes was similar in both groups. The younger group (group A) recognized all neuro-radiologic findings, especially flattening of the posterior aspect of the globe (p = 0.001) and tortuosity of the optic nerve (p < 0.001) at higher rates compared with group B. The most commonly used medical treatment was acetazolamide (99%); corticosteroids were used more frequently by group B (p < 0.001). Optic nerve sheath fenestration (88.3%) was the first-line and ventriculo-peritoneal shunt (70.5%) was the second preferred surgical approach. It was observed that serial lumbar puncture applications (57.0%) were preferred more frequently than venous sinus stenting (19.0%) and bariatric surgery (10.0%). CONCLUSIONS: The changing information in the last decade about IIH was more closely followed by younger neurologists despite their lesser experience, but classic methods were preferred in surgical approaches in both groups. Our findings indicated that post-graduate education and guidelines should be disseminated for IIH.

Long-term follow-up of a large cohort with focal epilepsy of unknown cause: deciphering their clinical and prognostic characteristics.

BACKGROUND AND PURPOSE: Focal epilepsy of unknown cause (FEUC) is an under-investigated topic despite its remarkable frequency. We aimed to report the long-term follow-up findings along with the drug-response, 5 year remission rates and diagnostic changes to give an insight about the heterogeneous characteristics of FEUC. METHODS: Demographic, clinical, neurophysiological and imaging data of 196 patients diagnosed as FEUC according to ILAE criteria, with a minimum 5-year follow-up were evaluated in a tertiary epilepsy center. The drug resistance, 5 years of remission and relapse rates were investigated and the subgroups were compared statistically. RESULTS: The rate of drug resistance was 21.8% and status epilepticus (p < 0.001), abnormal neurological examination (p = 0.020), seizure onset before 10 years (p = 0.004) and a high initial seizure frequency (p = 0.006) were significant predictors of drug resistance. The rates of terminal 5-year remission, 5-year remission ever and relapse were 39.9%, 44.26% and 24.04%, respectively. There were 13 patients (6.6%) with a changed final diagnosis. Drug resistance (p = 0.004), pathological EEG (p = 0.034) and status epilepticus (p = 0.021) were negative variables for achieving remission. The lobar localization of seizures was not a predictor of remission or relapse. Onset after 10 years of age had a higher probability of achieving a 5-year remission according to Kaplan-Meier curves (p < 0.001). CONCLUSIONS: Focal epilepsy of unknown cause has a benign electroclinical subgroup with favorable long-term course, lower drug resistance and higher 5 years of terminal remission and remission ever rates, when appropriately treated. Our findings might be valuable in terms of counseling and management of patients with FEUC at the first referral to epilepsy clinics.

Correction to: Long-term follow-up of a large cohort with focal epilepsy of unknown cause: deciphering their clinical and prognostic characteristics.

The original version of this article unfortunately contained a mistake.

Reflex epileptic features in patients with focal epilepsy of unknown cause.

OBJECTIVES: There is a gap of knowledge regarding reflex seizures in patients with focal epilepsy of unknown cause (FEUC). We aimed to evaluate the prevalence, demographic and clinical characteristics of reflex seizures in patients with FEUC to provide an insight to the underlying ictogenic mechanisms and to draw attention to this important but under-investigated topic. PATIENTS AND METHODS: After carefully questioning for reflex triggers, 186 patients diagnosed according to ILAE criteria and followed-up for a minimum of 5 years were included. The demographic and clinical properties as well as electrophysiological and neuroimaging data of these patients were reevaluated and compared to the patients without reflex seizures. RESULTS: The reflex seizure rate was 6.5 % in patients with FEUC. Patients with reflex features had lower monotherapy rates (p = 0.005) and higher major depression rates (p = 0.001) than patients without reflex features. The distribution of the patients according to their reflex triggers were as follows: hot-water induced (n = 3, 25 %), photosensitive (n = 2, 16.7 %), eating- induced (n = 2, 16.7 %), musicogenic (n = 2, 16.7 %), startle induced (n = 2, 16.7 %) and both musicogenic and startle type (n = 1, 8.3 %) respectively. The drug resistance rate of patients with reflex seizures was 25 % (n = 3). One patient with drug resistant reflex seizures showed benefit from epilepsy surgery and became seizure-free during last 3 years of follow-up. CONCLUSION: A careful and thoroughly history taking specifically questioning and focusing on seizure inducing factors in patients with FEUC is needed to confirm the presence of reflex seizures in patients with FEUC, who had higher rates of polytherapy and major depression. Elaborative evaluation of reflex features in FEUC might contribute to effective seizure control, ensure new therapeutic approaches, enlighten the obscurity and the resulting anxiety of having a diagnosis of FEUC in epilepsy patients.

Peripheral blood expression levels of inflammasome complex components in two different focal epilepsy syndromes.

BACKGROUND: Although the role of inflammation in epilepsy pathogenesis has been extensively investigated, the inflammasome complex, a key component of neuroinflammation, has been understudied in epilepsy patients. METHODS: To better understand the involvement of this system in epilepsy, levels of inflammasome complex components (NLRP1, NLRP3, CASP1, ASC), end-products of inflammasome complex activity [IL-1ß, IL-18, nitric oxide synthase (NOS) isoforms] and other inflammatory factors (NFκB, IL-6, TNF-α) were measured in peripheral blood of patients with focal epilepsy of unknown cause (FEoUC) (n = 47), mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) (n = 35) and healthy controls using real time qPCR and/or ELISA. RESULTS: Inflammasome complex associated factors were either downregulated or unchanged in epilepsy patients. Likewise, flow cytometry studies failed to show an increase in ratios of NLRP3-expressing CD3+ and CD14+ peripheral blood mononuclear cells (PBMC) in epileptic patients. Anti-neuronal antibody positive epilepsy patients showed increased NLRP1 and neuronal NOS mRNA expression levels, whereas patients under poly-therapy showed reduced serum inflammasome levels. FEoUC patients demonstrated increased PBMC NFκB mRNA expression levels and serum IL-1ß and IL-6 levels. Both MTLE-HS and FEoUC patients displayed higher ratios of NFκB-expressing CD14+ PBMC than healthy controls. CONCLUSIONS: Although previous clinical studies have implicated increased inflammasome complex expression levels in epilepsy, our results indicate suppressed inflammasome complex activity in the peripheral blood of focal epilepsy patients. Alternatively, the IL-6-NFκB signaling pathway, appears to be activated in focal epilepsy, suggesting that factors of this pathway might be targeted for future theranostic applications.

Investigation of Generalized EEG Paroxysms Accompanying Focal Epilepsies.

Interictal focal EEG features were frequently observed in generalized, epilepsies, but there is limited information about interictal, epileptiform/nonepileptiform generalized paroxysms in focal epilepsies. We aimed to report the frequency and associated factors of generalized EEG discharges in focal epilepsy with unknown cause (FEUC) and mesial, temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). A total of 200 patients (FEUC in 90 patients; MTLE-HS in 110 patients) were included. Generalized epileptiform (spike/sharp waves simultaneously in all regions) and nonspecific generalized discharges (paroxysmal slow waves) were investigated. All clinical and laboratory findings of 2 groups were compared with each other and with remaining control group, without generalized paroxysms, statistically. Generalized EEG features were present in 22 (11%; 4 males) patients; 9 in the FEUC group (10%; 2) and 13 in the MTLE-HS group (11.8%). Female gender (P < .021), febrile seizure (P < .034), precipitant factors (P < .025), and parental consanguinity (P < .033) were significantly higher in the group with generalized EEG findings. Monotherapy rates were lower in the MTLE-HS group (P < .05). The relationship of generalized EEG features with female gender and parental consanguinity may point out to a genetic property among focal epilepsies, while the relationship with febrile seizures and precipitant factors may be a clue about mechanisms with more extensive involvement of the neuronal networks.

Delta Brush Pattern Is Not Unique to NMDAR Encephalitis: Evaluation of Two Independent Long-Term EEG Cohorts.

PURPOSE: Although its specificity has not previously been investigated in other cohorts, delta brush pattern (DBP) is increasingly reported in the EEGs of patients with anti- N-methyl-d-aspartate receptor (NMDAR) encephalitis. METHODS: We aimed to investigate the DBP in the EEGs of 2 cohorts; patients with change in consciousness for various causes monitored in the intensive care unit (ICU) (n = 106) and patients with mesial temporal lobe epilepsy (MTLE) with or without antineuronal antibodies (n = 76). RESULTS: These patients were investigated for the presence of DBP, defined as an EEG pattern characterized by delta activity at 1 to 3 Hz with superimposed bursts of rhythmic 12- to 30-Hz activity. Two investigators blindfolded for the clinical and immunological data independently analyzed the EEGs for recognition of this pattern. An EEG picture compatible with DBP was observed in 4 patients; only 1 of them (1.3%) belonged to the MTLE group. She did not bear any of the investigated autoantibodies and was seizure-free after epilepsy surgery. In the ICU group, there were 3 additional patients showing DBP with various diagnoses such as hypoxic encephalopathy, brain tumor, stroke, and metabolic derangements. All of them had died in 1-month period. CONCLUSIONS: Our results underlined that DBP is not unique to NMDAR encephalitis; it may very rarely occur in MTLE with good prognosis after surgery and second, in ICU patients who have high mortality rate. Therefore, the presence of this pattern should alert the clinician for NMDAR encephalitis but other possible etiologies should not be ignored.