Homozygous TANGO2 Single Nucleotide Variants Presenting with Additional Manifestations Resembling Alternating Hemiplegia of Childhood-Expanding the Phenotype of a Recently Reported Condition.

CASE: We report a 15-year-old Indian girl born to a consanguineous couple, who presented with epilepsy, developmental delay, neuroregression, and episodes of alternating hemiparesis. In addition, she had one episode of rhabdomyolysis at the age of 7 years. Extensive genetic and metabolic work up through the years was unrevealing. Eventually a trio whole exome sequencing (WES) revealed homozygous single nucleotide variants in TANGO2 gene. DISCUSSION: TANGO2 related recurrent metabolic crises with encephalomyopathy and cardiac arrhythmias were described very recently and only 15 cases were reported in literature at the time of writing. Alternating hemiplegia of childhood which was seen in our patient, has not been described in previous patients with TANGO2 mutation, and thereby expands the emerging phenotypic spectrum of this novel entity. This report also reiterates the utility of WES in diagnosing newly recognized neurogenetic conditions.

Phase-amplitude coupling between interictal high-frequency activity and slow waves in epilepsy surgery.

OBJECTIVE: We hypothesized that the modulation index (MI), a summary measure of the strength of phase-amplitude coupling between high-frequency activity (>150 Hz) and the phase of slow waves (3-4 Hz), would serve as a useful interictal biomarker for epilepsy presurgical evaluation. METHODS: We investigated 123 patients who underwent focal cortical resection following extraoperative electrocorticography recording and had at least 1 year of postoperative follow-up. We examined whether consideration of MI would improve the prediction of postoperative seizure outcome. MI was measured at each intracranial electrode site during interictal slow-wave sleep. We compared the accuracy of prediction of patients achieving International League Against Epilepsy class 1 outcome between the full multivariate logistic regression model incorporating MI in addition to conventional clinical, seizure onset zone (SOZ), and neuroimaging variables, and the reduced logistic regression model incorporating all variables other than MI. RESULTS: Ninety patients had class 1 outcome at the time of most recent follow-up (mean follow-up = 5.7 years). The full model had a noteworthy outcome predictive ability, as reflected by regression model fit R2 of 0.409 and area under the curve (AUC) of receiver operating characteristic plot of 0.838. Incomplete resection of SOZ (P < 0.001), larger number of antiepileptic drugs at the time of surgery (P = 0.007), and larger MI in nonresected tissues relative to that in resected tissue (P = 0.020) were independently associated with a reduced probability of class 1 outcome. The reduced model had a lower predictive ability as reflected by R2 of 0.266 and AUC of 0.767. Anatomical variability in MI existed among nonepileptic electrode sites, defined as those unaffected by magnetic resonance imaging lesion, SOZ, or interictal spike discharges. With MI adjusted for anatomical variability, the full model yielded the outcome predictive ability of R2 of 0.422, AUC of 0.844, and sensitivity/specificity of 0.86/0.76. SIGNIFICANCE: MI during interictal recording may provide useful information for the prediction of postoperative seizure outcome.

Thalamic abnormalities in children with continuous spike-wave during slow-wave sleep: An F-18-fluorodeoxyglucose positron emission tomography perspective.

OBJECTIVE: Thalamic injury has been implicated in the development of continuous spike-wave during slow-wave sleep (CSWS) in children with epilepsy. We studied thalamic abnormalities in children with CSWS using F-18-fluorodeoxyglucose (FDG)-positron emission tomography (PET) imaging. METHODS: Twenty-three patients (12 male; mean age 9 years) with CSWS and normal thalami on brain magnetic resonance imaging (MRI) underwent FDG-PET. Thalamic glucose metabolism, represented by standardized uptake value normalized to whole brain (nSUV, RT for right thalamus and LT for left thalamus), and its asymmetry--absolute asymmetry index (AAI): ¦(RT-LT)¦*100/[(RT+LT)/2]--was calculated. These values were compared with those from 10 normal healthy controls (five female; mean age 11.1 years). RESULTS: Thalamic glucose metabolism was abnormal in 18 patients (78.3%). Thalamic nSUV was decreased (n = 6) or increased (n = 1) bilaterally in seven children without any asymmetry. Abnormal thalamic symmetry [AAI = 3.7-31.5% (0.8-3.3% in controls)] was seen in 11 children. Of these, six children had a unilateral thalamic metabolic abnormality (increased metabolism, n = 3 and decreased metabolism, n = 3), whereas 5 of 14 children had abnormal asymmetry index with bilaterally normal (n = 4) or increased (n = 1) thalamic metabolism. No clear association of thalamic metabolic abnormalities was seen with the stage of evolution of CSWS (prodromal, acute, or residual) or with the cortical FDG abnormalities. SIGNIFICANCE: Functional thalamic abnormalities, both unilateral and bilateral, are frequently seen in patients with CSWS. FDG-PET is a sensitive and quantifiable modality to detect these changes.

Ictal motor sequences: Lateralization and localization values.

OBJECTIVE: To determine the lateralization and localization values of ictal motor sequences in the setting of focal epilepsy ending with a secondarily generalized motor seizure. METHODS: Retrospectively, the ictal motor sequences were analyzed in patients with focal epilepsy ending with a secondarily generalized motor seizure by three readers blinded to all clinical and electrographic data. One representative seizure per patient was selected. Prevalence, positive predictive value (PPV), and Fleiss Kappa for the following motor signs were calculated: version, unilateral limb tonic posturing, unilateral limb clonic seizure, figure-of-4, M2e, hand dystonia, clonic asymmetric ending, and Todd's paralysis. Sequences of signs with a PPV ≥ 80% were then analyzed to determine their lateralization and localization values. RESULTS: A total of 47 seizures were studied. The "reliable" motor signs with a robust lateralizing value (PPV > 80%) were version, unilateral tonic posturing, M2e, unilateral clonic seizure, asymmetric clonic ending, and Todd's paralysis. Figure-of-4 and hand dystonia had a relatively low PPV, and therefore were not included in the following sequence analysis, which included only 38 patients with two or more motor signs of high PPV. Multiple combinations of temporal progression of motor signs were seen in these 38 patients, with version being the most common initial motor sign (29 of 38 patients) usually followed by M2e (15 of 29 patients), and/or a focal tonic seizure (7 of 29 patients). Accurate lateralization of the epileptogenic zone (EZ) with a PPV of 100% can be predicted when two or more reliable motor signs point to the same side. However, the various sequences of reliable motor signs did not differentiate between temporal and extratemporal epilepsy. SIGNIFICANCE: The presence of reliable ictal motor signs in focal epilepsy is extremely valuable in lateralizing the EZ, but not in determining the localization of the EZ. This is especially useful when epilepsy surgery is indicated.

Outcome of psychogenic nonepileptic seizures (PNES) in children: A 2-year follow-up study.

OBJECTIVE: The objective of this study was to determine the outcome of psychogenic nonepileptic seizures (PNES) in children seen at a level 4 epilepsy center. METHODS: We retrospectively analyzed patients under the age of 18 years who were diagnosed with PNES based on evaluation in the epilepsy monitoring unit and had a follow-up of at least 2 years postdiagnosis. Remission of events was noted at 6 months, 12 months, and 24 months of follow-up, and patient and disease variables affecting outcome were studied. RESULTS: Ninety patients met inclusion criteria (58 females; mean age: 14.03 ± 3.3 years). Thirty-two out of ninety (36%) patients had early (within 6 months) and sustained remission (until 2 years of follow-up) of their events ("favorable outcome"), while 30/90 patients (33%) never achieved remission during the study period ("unfavorable outcome"). The factors that were associated with "unfavorable outcome" included the presence of comorbid epilepsy [12/30 (40%) vs 0/32, p<0.0001] and prolonged duration of symptoms before establishment of the diagnosis (median 365 days vs 60 days, p<0.0001). Patient's age, gender, frequency of events, the presence of major psychosocial stressors, and comorbid psychiatric conditions had no significant impact on the disease outcome. CONCLUSIONS: About a third of children with PNES achieve early and sustained remission of symptoms, while another third continue to manifest seizure-like events until at least two years after the diagnosis. The presence of comorbid epilepsy and prolonged duration of PNES are associated with a poor two-year outcome. Early suspicion and diagnosis of PNES, especially in patients with epilepsy, is essential.

Safety, Awareness, and Familiarity regarding Epilepsy in Teenage Years (SAFETY): understanding the adolescents' perspective about their disease.

OBJECTIVE: The objective of this study was to evaluate the understanding of adolescent patients regarding epilepsy. METHODS: The SAFETY (Safety, Awareness, and Familiarity regarding Epilepsy in Teenage Years) questionnaire (content validity index: 0.96, Flesch readability score: 66.6) was administered to 165 cognitively normal adolescents with epilepsy (85 females, mean age: 15.2 ± 1.6 years, range: 13-18 years). The first part of the questionnaire was devised to evaluate knowledge about epilepsy and antiepileptic medications (SAFETY-K: 7 questions). The second part queried lifestyle modifications and safety (SAFETY-S: 10 questions). Female participants answered 5 additional questions related to reproductive health (RH questionnaire). RESULTS: The correct response rate for the composite SAFETY questionnaire was 51.5%. The average rates of correct responses for the SAFETY-K and SAFETY-S questions were 47.9% and 53.9%, respectively. On univariate logistic regression analysis, factors which were significant predictors of correct responses included age (odds ratio: 1.8, C.I. = 1.3-2.4), race (Caucasian vs. African-American; odds ratio: 3.9, C.I. = 1.4-10.4), and employment of at least one parent in a professional occupation (odds ratio: 3.3, C.I. = 1.1-10.3). The correct response rate did not correlate with the duration of epilepsy, extent of seizure control, number of antiepileptic medications, parental educational, or (un)employment status. The mean rate of correct responses for the RH questions amongst teenage girls was 17.4%. CONCLUSIONS: There is lack of awareness about epilepsy and its associated lifestyle modifications in adolescents with epilepsy seen at our institution. This is especially true in young adolescents, African-American patients, and those whose parents are not employed in professional occupations. Teenage girls with epilepsy appear to have limited knowledge with respect to contraception and childbearing.

Psychogenic non-epileptic seizures in children.

Psychogenic Non-Epileptic Seizures (PNES) are a relatively common condition in children. While their clinical presentation resembles epileptic seizures, the underlying cause for PNES involves a multitude of bio-psychosocial factors. Patients may be misdiagnosed with epilepsy and subjected to unnecessary treatments, often delaying the diagnosis for years. A strong understanding of its symptomatology is essential for diagnosis of PNES. Successful management depends on effective teamwork that involves the neurologist as well as mental health professionals. This paper reviews the various aspects of PNES in children with emphasis on the clinical presentation, diagnosis as well as the underlying psychological basis and treatment.

Measuring the Barriers to Adherence With Neurology Clinic Appointments for Children With Epilepsy: A Pilot Study.

INTRODUCTION: Epilepsy is one of the most common neurological disorders in children. Missed appointments reflect missed opportunity to provide care for children with epilepsy. The objective of this study was to identify social determinants of health (SDH) and other factors associated with missed appointments in children with epilepsy and measure the relation between missed appointments and frequency of emergency room (ER) visits and inpatient admissions. METHODS: This was a prospective study conducted in the neurology division at a level 4 epilepsy center. Children (0 to < 18 years of age) with a diagnosis of epilepsy were included and a semi-structured questionnaire was provided to the families. Patients with 2 or more missed neurology clinic appointments in the previous year ("study group", n = 36) were compared to those with 1 or zero missed appointments ("control group", n = 49). A comparison of the clinical characteristics, emergency room visits and hospitalizations in the past year as well as SDH was performed. Statistical analysis was performed using SPSS and p < 0.05 was considered significant. RESULTS: The mean age, gender distribution and presence of medical refractoriness were comparable between the 2 groups. Families in the study group reported a higher likelihood of having to make special work arrangements for clinic appointments. Children in the study group were noted to have a significantly higher frequency of single mother households, presence of public insurance, father not graduating from high school and household income less than 50,000 dollars. Within the preceding year, children in the study group were noted to have a higher frequency of visits to the emergency department as well as 6 times higher likelihood of inpatient hospitalization for seizures. CONCLUSIONS: Social determinants of health play an important role in determining adherence with neurology clinic visits in children with epilepsy. Children with more missed appointments are likely to have a higher frequency of visits to the emergency department as well as a higher incidence of hospitalization for seizures. Identification of high-risk families and implementation of early interventions may improve adherence to office visits and decrease emergency room visits and hospitalization for seizures.

Differential DNA Methylation Patterns in Patients with Epilepsy due to Malformations of Cortical Development: A Pilot Study.

OBJECTIVE: To study the DNA methylation profiles in brain tissue of patients with refractory epilepsy due to malformations of cortical development (MCDs). MATERIALS AND METHODS: Clinical, neuroimaging, and pathology characteristics were defined for 13 patients who underwent resective surgery for epilepsy. Methylation analysis was performed using Illumina® 450k Methylation Microarray. Data analysis was completed, and pathway identification was done using the R/Bioconductor package. RESULTS: Genes associated with Ephrin-Reelin pathway, potassium channels, and glutathione metabolism were differentially methylated in the MCD group when compared with patients who had no evidence of MCD. CONCLUSIONS: Our preliminary data reveal that epigenetic pathways may have a role in the pathobiogenesis of MCDs.

Functional Neurologic Symptom Disorder in Children: Clinical Features, Diagnostic Investigations, and Outcomes at a Tertiary Care Children's Hospital.

OBJECTIVE: To describe the presenting symptoms and short-term outcomes of children diagnosed with functional neurologic symptom disorder and to compare the demographic and clinical characteristics of children who received neurodiagnostic testing to those who did not. STUDY DESIGN: Single center, retrospective review of 222 children who presented to the emergency department of a children's hospital, and diagnosed with functional neurologic symptom disorder, between 2010 and 2015. RESULTS: Out of 222 visits (females = 156, African Americans = 130, mean age = 13.9 years), neurodiagnostic tests were performed in 102/222 (46%) visits. The most commonly performed investigations were magnetic resonance imaging (MRI) of brain (n = 37) and electroencephalogram (EEG) (n = 56) and were noted to be unremarkable in all instances. Neurodiagnostic tests were more likely to be performed in patients who (1) were non-African American (54% vs 40%; P = .03), (2) presented with new-onset symptoms (55% vs 31%; P < .01), (3) underwent hospitalization (61% vs 17%; P < .01), and (4) were evaluated by a neurologist (59% vs 9%; P < .01) or a psychiatrist (58% vs 28%; P < .01). Common clinical presentations included seizurelike or strokelike symptoms. Short-term follow-up was possible in 20%, with an alternate diagnosis of syncope, noted in only 1 child. CONCLUSIONS: Most children who presented with a functional neurologic symptom disorder in our study were noted to have seizurelike or strokelike presentations and were adolescent females. Caucasians were more likely to undergo neurodiagnostic investigations. Radiologic and neurophysiological tests were more commonly performed when neurology and psychiatry consultations were sought. Such investigations had low diagnostic utility.

More than meets the eye: infant presenting with hypoxic ischaemic encephalopathy.

We report a newborn infant who presented with poor Apgar scores and umbilical artery acidosis leading to the diagnosis of hypoxic ischaemic encephalopathy. During the course of the infant's hospitalisation, subsequent workup revealed an underlying genetic cause that masqueraded as hypoxic ischaemic encephalopathy.