Implication of locus coeruleus dysfunction in Prader-Willi syndrome: Insights from a mouse model.

Prader-Willi syndrome (PWS) is a multisystemic disorder. Notably, many characteristic symptoms of PWS are correlated with locus coeruleus norepinephrine system (LC-NE) dysfunction, including impairment in arousal, learning, pain modulation, and stress-induced negative affective states. Although electrophysiological experiments in necdin-deficient mice, an established PWS animal model, have revealed decreased spontaneous neuronal firing activity in the LC and impaired excitability, the behavioral phenotypes related to LC-NE dysfunction remain unexplored. In this study, heterozygous necdin-deficient mice (B6.Cg-Ndntm1ky) were bred from wild-type (WT) females to generate WT (+m/+p) and heterozygous (+m/-p) animals. Compared to WT mice, Ndn + m/-p mice demonstrated impaired visual-spatial memory in the Y-maze test, reduced social interaction, impaired sexual recognition, and shorter falling latency on the Rotarod. Using the open field test (OFT) and elevated plus maze (EPM), we observed similar locomotion activity of Ndn + m/-p and WT mice, but Ndn + m/-p mice were less anxious. After acute restraint, Ndn + m/-p mice exhibited significant impairment in stress-induced anxiety. Additionally, the plasma norepinephrine surge following exposure to acute restraint stress was also impaired. Pretreatment with atomoxetine, a norepinephrine reuptake inhibitor aimed to enhance LC function, restored Ndn + m/-p mice to exhibit a normal response to acute restraint stress. Furthermore, by employing chemogenetic approaches to facilitate LC neuronal firing, post-stress anxious responses were also partially rescued in Ndn + m/-p mice. These data strongly suggest that LC dysfunction is implicated in the pathogenesis of stress-related neuropsychiatric symptoms in PWS. Manipulation of LC activity may hold therapeutic potential for patients with PWS.

Neuronal population activity in the olivocerebellum encodes the frequency of essential tremor in mice and patients.

Essential tremor (ET) is the most prevalent movement disorder, characterized primarily by action tremor, an involuntary rhythmic movement with a specific frequency. However, the neuronal mechanism underlying the coding of tremor frequency remains unexplored. Here, we used in vivo electrophysiology, optogenetics, and simultaneous motion tracking in the Grid2dupE3 mouse model to investigate whether and how neuronal activity in the olivocerebellum determines the frequency of essential tremor. We report that tremor frequency was encoded by the temporal coherence of population neuronal firing within the olivocerebellums of these mice, leading to frequency-dependent cerebellar oscillations and tremors. This mechanism was precise and generalizable, enabling us to use optogenetic stimulation of the deep cerebellar nuclei to induce frequency-specific tremors in wild-type mice or alter tremor frequencies in tremor mice. In patients with ET, we showed that deep brain stimulation of the thalamus suppressed tremor symptoms but did not eliminate cerebellar oscillations measured by electroencephalgraphy, indicating that tremor-related oscillations in the cerebellum do not require the reciprocal interactions with the thalamus. Frequency-disrupting transcranial alternating current stimulation of the cerebellum could suppress tremor amplitudes, confirming the frequency modulatory role of the cerebellum in patients with ET. These findings offer a neurodynamic basis for the frequency-dependent stimulation of the cerebellum to treat essential tremor.

Neurological manifestations of SARS-CoV-2 infection in children in Taiwan: A cross-section, multicenter study.

BACKGROUND: The SARS-CoV-2 virus has been a global public health threat since December 2019. This study aims to investigate the neurological characteristics and risk factors of coronavirus disease 2019 (COVID-19) in Taiwanese children, using data from a collaborative registry. METHODS: A retrospective, cross-sectional, multi-center study was done using an online network of pediatric neurological COVID-19 cohort collaborative registry. RESULTS: A total of 11160 COVID-19-associated emergency department (ED) visits and 1079 hospitalizations were analyzed. Seizures were the most common specific neurological symptom, while encephalitis and acute disseminated encephalomyelitis (ADEM) was the most prevalent severe involvement. In ED patients with neurological manifestations, severe neurological diagnosis was associated with visual hallucination, seizure with/without fever, behavior change, decreased GCS, myoclonic jerk, decreased activity/fatigue, and lethargy. In hospitalized patients with neurological manifestations, severe neurological diagnosis was associated with behavior change, visual hallucination, decreased GCS, seizure with/without fever, myoclonic jerk, fatigue, and hypoglycemia at admission. Encephalitis/ADEM was the only risk factor for poor neurological outcomes at discharge in hospitalized patients. CONCLUSION: Neurological complications are common in pediatric COVID-19. Visual hallucination, seizure, behavior change, myoclonic jerk, decreased GCS, and hypoglycemia at admission are the most important warning signs of severe neurological involvement such as encephalitis/ADEM.

Application of bidirectional long short-term memory network for prediction of cognitive age.

Electroencephalography (EEG) measures changes in neuronal activity and can reveal significant changes from infancy to adulthood concomitant with brain maturation, making it a potential physiological marker of brain maturation and cognition. To investigate a promising deep learning tool for EEG classification, we applied the bidirectional long short-term memory (BLSTM) algorithm to analyze EEG data from the pediatric EEG laboratory of Taipei Tzu Chi Hospital. The trained BLSTM model was 86% accurate when identifying EEGs from young children (8 months-6 years) and adolescents (12-20 years). However, there was only a modest classification accuracy (69.3%) when categorizing EEG samples into three age groups (8 months-6 years, 6-12 years, and 12-20 years). For EEG samples from patients with intellectual disability, the prediction accuracy of the trained BLSTM model was 46.4%, which was significantly lower than its accuracy for EEGs from neurotypical patients, indicating that the individual's intelligence plays a major role in the age prediction. This study confirmed that scalp EEG can reflect brain maturation and the BLSTM algorithm is a feasible deep learning tool for the identification of cognitive age. The trained model can potentially be applied to clinical services as a supportive measurement of neurodevelopmental status.

Theta/beta ratio in EEG correlated with attentional capacity assessed by Conners Continuous Performance Test in children with ADHD.

Introduction: Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder affecting children worldwide; however, diagnosing ADHD remains a complex task. Theta/beta ratio (TBR) derived from electroencephalography (EEG) recordings has been proposed as a potential biomarker for ADHD, but its effectiveness in children with ADHD remains controversial. Behavioral assessments, such as the Conners Continuous Performance Test-3rd edition (CPT-3), have been utilized to assess attentional capacity in individuals with ADHD. This study aims to investigate the correlation between TBR and CPT-3 scores in children and adolescents with ADHD. Methods: In a retrospective analysis, we examined patients regularly monitored for ADHD at Taipei Tzu Chi Hospital, who underwent both EEG and CPT-3 assessments. Severity of ADHD was evaluated using parent- and teacher-completed Swanson, Nolan, and Pelham (SNAP)-IV rating scales. Results: The study encompassed 55 ADHD patients (41 with abnormal CPT-3 scores, 14 with normal CPT-3 scores) and 45 control subjects. TBR demonstrated elevation in ADHD patients with abnormal CPT-3 scores, indicating its potential to represent attentional capacity akin to behavioral assessments like CPT-3. However, significant correlations between TBR values and CPT-3 variables or SNAP-IV rating scales were not observed. Moreover, TBR values exhibited considerable overlap across the groups, leading to diminished sensitivity and negative predictive value as a potential neurophysiological ADHD biomarker. Discussion: While our study underscores the utility of both TBR and CPT-3 in assessing attentional capacity, their sensitivity in diagnosing ADHD is limited. A comprehensive evaluation, integrating clinical expertise, parental input, and detailed neuropsychometric tests, remains pivotal for a thorough and precise diagnosis of ADHD.

Peripheral Nervous System Adverse Events after the Administration of mRNA Vaccines: A Systematic Review and Meta-Analysis of Large-Scale Studies.

Although neurological complications after the administration of vaccines against coronavirus disease 2019 (COVID-19) are rare, they might result in long-term morbidity. This study was designed to determine the risk of peripheral nervous system (PNS) adverse events after the administration of mRNA vaccines against COVID-19. Large-scale randomized controlled trials (RCTs) and cohort studies were systematically searched in databases, and 15 cohort studies were included in the synthesis. Among all PNS adverse events, only Bell's palsy and Guillain-Barré syndrome (GBS) had sufficient data and were included for further analysis. Individuals who received mRNA vaccines had a higher risk of Bell's palsy than the unvaccinated group, and the risk of Bell's palsy after BNT162b2 was significantly higher than after mRNA-1273. Regarding GBS, no significant difference in the risk was observed between BNT162b2 and the unvaccinated group, but BNT126b2 introduced a higher risk of post-vaccinated GBS than mRNA-1273. In conclusion, PNS adverse events, especially Bell's palsy, should be carefully observed after mRNA vaccination against COVID-19. With the opportunity of vaccination campaigns on such a large scale, further investigation and surveillance of post-vaccination neurological adverse events should also be established.

Rhabdomyolysis in Pediatric Patients with SARS-CoV-2 Infection.

BACKGROUND: Rhabdomyolysis is a rare but severe complication in adult patients with Coronavirus disease 2019 (COVID-19), which can result in acute kidney injury and death; however, it is rarely reported in pediatric patients. METHODS: In this study, we retrospectively reviewed the clinical features and outcomes of rhabdomyolysis in pediatric patients aged 0-18 years with COVID-19 who were hospitalized at Taipei Tzu Chi Hospital, an epicenter of COVID-19 in northern Taiwan. RESULTS: We treated eight patients with rhabdomyolysis during the omicron variant-Severe acute respiratory syndrome coronavirus 2 (omicron variant-SARS-CoV-2) community outbreak and none during the alpha variant endemic. These eight patients shared stereotypical presentations, including the presence of bilateral calf pain after defervescence. The creatinine kinase (CK) levels were between 1346 and 6937 U/L on admission, and clinical course was uneventful after aggressive saline hydration. CONCLUSION: Rhabdomyolysis is not a rare complication in pediatric patients with the omicron-SARS-CoV-2 infection, and reassurance of a good prognosis is important to alleviate family anxiety.

Progression of Obstructive Sleep Apnea Syndrome in Pediatric Patients with Prader-Willi Syndrome.

Obstructive sleep apnea syndrome (OSAS) is one of the most common comorbidities in patients with Prader-Willi syndrome (PWS) and causes significant consequences. This observational study was conducted to investigate the progression of OSAS in pediatric patients with PWS, who had not undergone upper airway surgery, through a longitudinal follow-up of their annual polysomnography results. Annual body mass index (BMI), BMI z-score, sleep efficiency and stages, central apnea index (CAI), obstructive apnea-hypopnea index (OAHI), and oxygen saturation nadir values were longitudinally analyzed. At enrollment, of 22 patients (10 boys and 12 girls) aged 11.7 ± 3.9 years, 20 had OSAS. During the 4-year follow-up, only two patients had a spontaneous resolution of OSAS. The average BMI and BMI z-score increased gradually, but CAI and OAHI showed no significant differences. After statistical adjustment for sex, age, genotype, growth hormone use, and BMI z-score, OAHI was associated with the BMI z-score and deletion genotype. In conclusion, OSAS is common in patients with PWS, and rarely resolved spontaneously. Watchful waiting may not be the best OSAS management strategy. Weight maintenance and careful selection of surgical candidates are important for OSAS treatment in patients with PWS.

Dynamic Changes in the Quantitative Electroencephalographic Spectrum During Attention Tasks in Patients With Prader-Willi Syndrome.

Introduction: Attention problems are frequently observed in patients with Prader-Willi syndrome (PWS); however, only few studies have investigated the severity and mechanisms of attention problems in them. In this study, we aim to evaluate dynamic changes in the quantitative electroencephalographic (EEG) spectrum during attention tasks in patients with PWS. Method: From January to June 2019, 10 patients with PWS and 10 age-matched neurotypical control participants were recruited at Taipei Tzu Chi Hospital. Each participant completed Conners' continuous performance test, third edition (CPT-3), tasks with simultaneous EEG monitoring. The dynamic changes in the quantitative EEG spectrum between the resting state and during CPT-3 tasks were compared. Results: Behaviorally, patients with PWS experienced significant attention problems, indicated by the high scores for several CPT-3 variables. The theta/beta ratio of the resting-state EEG spectrum revealed no significant differences between the control participants and patients with PWS. During CPT-3 tasks, a significant decrease in the alpha power was noted in controls compared with that in patients with PWS. The attention-to-resting alpha power ratio was positively correlated with many CPT-3 variables. After adjusting for genotype, age, intelligence, and body mass index, the attention-to-resting alpha power ratio was still significantly correlated with participants' commission errors. Conclusion: This study provides evidence that attention problems are frequently observed in patients with PWS, while attention impairment can be demonstrated by dynamic changes in the quantitative EEG spectrum.

Cerebellar Oscillations in Familial and Sporadic Essential Tremor.

Enhanced cerebellar oscillations have recently been identified in essential tremor (ET) patients as a key pathophysiological change. Since ET is considered a heterogeneous group of diseases, we investigated whether cerebellar oscillations differ in ET subtypes (familial vs. sporadic). This study aims to determine cerebellar physiology in familial and sporadic ET. Using surface electroencephalogram, we studied cerebellar physiology in 40 ET cases (n = 22 familial and n = 18 sporadic) and 20 age-matched controls. Both familial and sporadic ET cases had an increase in the intensity of cerebellar oscillations when compared to controls. Interestingly, cerebellar oscillations correlated with tremor severity in familial ET but not in sporadic ET. Our study demonstrated that ET cases have enhanced cerebellar oscillations, and the different relationships between cerebellar oscillations and tremor severity in familial and sporadic ET suggest diverse cerebellar pathophysiology.

Parenting stress in families of children with Prader-Willi syndrome.

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder characterized by multiple endocrine, metabolic, respiratory, cognitive, and behavioral/psychiatric symptoms that may lead to severe emotional strain in their caregivers. In this study, we evaluated parenting stress by the Parenting Stress Index-short form (PSI/SF) and parent-reported behavioral symptoms by the Child Behavior Checklist (CBCL/6-18) in families of children with PWS. Sixty-seven home-resident PWS patients and their families were recruited in this study. The patients' mean age was 14.9 ± 8.3 years, and 33 (50.8%) were male. High parenting stress was reported by 41.5% families, as determined by high total stress scores of PSI/SF. The patients in high stress families were significantly older than those in low stress families (18.2 ± 8.0 vs. 12.6 ± 7.8 years, p = .007). CBCL/6-18 was used to evaluate the somatic and neuropsychiatric symptoms of PWS patients aged between 6 and 18 in the subgroup of the 35 families. In this subgroup, 37.1% of families reported high parenting stress. High stress families reported a higher T-score in anxiety/depression, withdrawn behavior, somatic complaints, thought problems, attention problems, and delinquent and aggressive behavior of their children with PWS. After multivariate stepwise logistic regression analysis, the T-score of somatic complaints was the only factor related to high parenting stress, with an odds ratio of 1.279. Our data demonstrated the high care burden of families with PWS and highlighted the importance of having dedicated medical care for both somatic and neuropsychiatric symptoms.

Firing activity of locus coeruleus noradrenergic neurons decreases in necdin-deficient mice, an animal model of Prader-Willi syndrome.

BACKGROUND: Prader-Willi syndrome (PWS) is a neurodevelopmental disorder characterized by multiple respiratory, cognitive, endocrine, and behavioral symptoms, such as central apnea, intellectual disabilities, exaggerated stress responses, and temper tantrums. The locus coeruleus noradrenergic system (LC-NE) modulates a diverse range of behaviors, including arousal, learning, pain modulation, and stress-induced negative affective states, which are possibly correlated with the pathogenesis of PWS phenotypes. Therefore, we evaluated the LC-NE neuronal activity of necdin-deficient mice, an animal model of PWS. METHODS: Heterozygous necdin-deficient mice (B6.Cg-Ndntm1ky) were bred from wild-type (WT) females to generate WT (+m/+p) and heterozygotes (+m/-p) animals, which were examined of LC-NE neuronal activity, developmental reflexes, and plethysmography. RESULTS: On slice electrophysiology, LC-NE neurons of Ndntm1ky mice with necdin deficiency showed significantly decreased spontaneous activities and impaired excitability, which was mediated by enhanced A-type voltage-dependent potassium currents. Ndntm1ky mice also exhibited the neonatal phenotypes of PWS, such as hypotonia and blunt respiratory responses to hypercapnia. CONCLUSIONS: LC-NE neuronal firing activity decreased in necdin-deficient mice, suggesting that LC, the primary source of norepinephrine in the central nervous system, is possibly involved in PWS pathogenesis.

Clinical characteristics and epilepsy in genomic imprinting disorders: Angelman syndrome and Prader-Willi syndrome.

Angelman syndrome (AS) and Prader-Willi syndrome (PWS) are considered sister imprinting disorders. Although both AS and PWS congenital neurodevelopmental disorders have chromosome 15q11.3-q13 dysfunction, their molecular mechanisms differ owing to genomic imprinting, which results in different parent-of-the-origin gene expressions. Recently, several randomized controlled trials have been proceeded to treat specific symptoms of AS and PWS. Due to the advance of clinical management, early diagnosis for patients with AS and PWS is important. PWS is induced by multiple paternal gene dysfunctions, including those in MKRN3, MAGEL2, NDN, SNURF-SNPRPN, NPAP1, and a cluster of small nucleolar RNA genes. PWS patients exhibit characteristic facial features, endocrinological, and behavioral phenotypes, including short and obese figures, hyperphagia, growth hormone deficiency, hypogonadism, autism, or obsessive- compulsive-like behaviors. In addition, hypotonia, poor feeding, failure to thrive, and typical facial features are major factors for early diagnosis of PWS. For PWS patients, epilepsy is not common and easy to treat. Conversely, AS is a single-gene disorder induced by ubiquitin-protein ligase E3A dysfunction, which only expresses from a maternal allele. AS patients develop epilepsy in their early lives and their seizures are difficult to control. The distinctive gait pattern, excessive laughter, and characteristic electroencephalography features, which contain anterior-dominated, high-voltage triphasic delta waves intermixed with epileptic spikes, result in early suspicion of AS. Often, polytherapy, including the combination of valproate, levetiracetam, lamotrigine, and benzodiazepines, is required for controlling seizures of AS patients. Notably, carbamazepine, oxcarbazepine, and vigabatrin should be avoided, since these may induce nonconvulsive status epilepticus. AS and PWS presented with distinct clinical manifestations according to specific molecular defects due to genomic imprinting. Early diagnosis and teamwork intervention, including geneticists, neurologists, rehabilitation physicians, and pulmonologists, are important. Epilepsy is common in patients with AS, and after proper treatment, seizures could be effectively controlled in late childhood or early adulthood for both AS and PWS patients.

GABAB receptor-mediated tonic inhibition of locus coeruleus neurons plays a role in deep anesthesia induced by isoflurane.

Noradrenergic neurons in the locus coeruleus referred to as locus coeruleus neurons, provide the major supply of norepinephrine to the forebrain and play important roles in behavior through regulation of wakefulness and arousal. In a previous study using brain slice preparations, we reported that locus coeruleus neurons are subject to tonic inhibition mediated by γ-aminobutyric acid B receptors (GABABRs) and that the extent of tonic inhibition varies with ambient GABA levels. Since ambient GABA in the locus coeruleus was reported to fluctuate during the sleep-wakefulness cycle, here we tested whether GABABR-mediated tonic inhibition of locus coeruleus neurons could be a mechanism underlying changes in brain arousal. We first demonstrated that GABABR-mediated tonic inhibition of locus coeruleus neurons also exists in vivo by showing that local infusion of CGP35348, a GABABR antagonist, into the locus coeruleus increased the firing rate of locus coeruleus neurons in anesthetized rats. We then showed that this manipulation accelerated the behavioral emergence of rats from deep anesthesia induced by isoflurane. Together, these observations show that GABABR-mediated tonic inhibition of locus coeruleus neurons occurs in vivo and support the idea that this effect may be important in regulating the functional state of the brain.

Cerebellar oscillations driven by synaptic pruning deficits of cerebellar climbing fibers contribute to tremor pathophysiology.

Essential tremor (ET) is one of the most common movement disorders and the prototypical disorder for abnormal rhythmic movements. However, the pathophysiology of tremor generation in ET remains unclear. Here, we used autoptic cerebral tissue from patients with ET, clinical data, and mouse models to report that synaptic pruning deficits of climbing fiber (CF)-to-Purkinje cell (PC) synapses, which are related to glutamate receptor delta 2 (GluRδ2) protein insufficiency, cause excessive cerebellar oscillations and might be responsible for tremor. The CF-PC synaptic pruning deficits were correlated with the reduction in GluRδ2 expression in the postmortem ET cerebellum. Mice with GluRδ2 insufficiency and CF-PC synaptic pruning deficits develop ET-like tremor that can be suppressed with viral rescue of GluRδ2 protein. Step-by-step optogenetic or pharmacological inhibition of neuronal firing, axonal activity, or synaptic vesicle release confirmed that the activity of the excessive CF-to-PC synapses is required for tremor generation. In vivo electrophysiology in mice showed that excessive cerebellar oscillatory activity is CF dependent and necessary for tremor and optogenetic-driven PC synchronization was sufficient to generate tremor in wild-type animals. Human validation by cerebellar electroencephalography confirmed that excessive cerebellar oscillations also exist in patients with ET. Our findings identify a pathophysiologic contribution to tremor at molecular (GluRδ2), structural (CF-to-PC synapses), physiological (cerebellar oscillations), and behavioral levels (kinetic tremor) that might have clinical applications for treating ET.

Is prone sleeping dangerous for neonates? Polysomnographic characteristics and NDN gene analysis.

OBJECTIVE: Prone sleep is an identified risk factor for sudden infant death syndrome, possibly due to reduced blood pressure, cerebral oxygenation, and impaired cerebral vascular control. Cardiac and respiratory responses in neonates during supine and prone sleep have not been reported. MATERIALS AND METHODS: In this study, daytime polysomnography (PSG) data from 17 neonates aged 2-3 days during supine and prone sleep were reported and the NDN gene, an important gene for neonatal respiratory control, was sequenced for correlation with neonatal respiratory parameters. Heart rate (HR), oxygen saturation, carbon dioxide concentration, sleep stages, central apnea index (CAI), obstructive apnea/hypopnea index (OAHI), and oxygen nadir were compared between supine and prone sleep and between participants with different single-nucleotide polymorphisms (SNPs) in the NDN gene. RESULTS: During prone sleep, neonates had a faster HR, decreased oxygen saturation, and a longer duration of oxygen saturation <90% than during supine sleep, suggesting that cardiopulmonary responsiveness was impaired. Sleep efficiency, sleep stages, oxygen nadir, and carbon dioxide tension were not different during supine and prone sleep. Central apnea occurred more significantly than obstructive apnea. During supine and prone sleep, the CAI was 3.3 ± 2.9/h and 2.3 ± 2.6/h and the OAHI was 0.6 ± 0.7/h and 0.6 ± 0.8/h, respectively. We found one SNP rs3743340 in the NDN gene that had no effect on the sleep and respiratory parameters of PSG. CONCLUSION: Tachycardia and respiratory instability were recorded in neonates during prone sleep, suggesting that neonates are vulnerable to cardiopulmonary events during prone sleep. Therefore, young neonates should be kept in the supine sleep position unless there are contraindications.

The Role of Gastrodin on Hippocampal Neurons after N-Methyl-D-Aspartate Excitotoxicity and Experimental Temporal Lobe Seizures.

Tian ma (Gastrodia elata, GE) is an ancient Chinese herbal medicine that has been suggested to be effective as an anticonvulsant and analgesic, and to have sedative effects against vertigo, general paralysis, epilepsy and tetanus. The primary active ingredient isolated from GE is termed gastrodin, which is the glucoside of 4-hydroxybenzyl alcohol (4-HBA). Gastrodin can abolish hypoxia-, glutamate- and N-methyl-D-aspartate (NMDA) receptor-induced toxicity in primary culture of rat cortical neurons, and reduces seizure severity in seizure-sensitive gerbils. We evaluated the effect of gastrodin on NMDA excitotoxicity in hippocampal slice cultures (HSCs) with propidium iodide (PI) fluorescence measurement. We also evaluated the effects of gastrodin for treating active in vivo temporal lobe seizures induced by lithium/pilocarpine. Seizure severity, time span to seizure onset, mortality rate and hippocampal histology for survivors were compared. The effect of gastrodin was evaluated for treating in vitro seizures induced by Mg²âº-free medium in hippocampal slices. Frequencies and amplitudes of epileptiform discharges were compared. The effect of gastrodin on synaptic transmission was evaluated on hippocampal CA1 Schaffer collaterals. Application of 25 µM gastrodin significantly suppressed NMDA excitotoxicity in CA3 but not in CA1 hippocampus and dentate gyrus. Intraventricular gastrodin accelerated seizure onset for 12 min after intraperitoneal pilocarpine injection (P = 0.051). Three of five rats (60%) in the gastrodin group, and three of four (75%) in the dimethyl sulfoxide (DMSO) group died within 3 days after status epilepticus (SE). Gastrodin also failed to inhibit epileptiform discharges in hippocampal slices induced by Mg²âº-free medium, believed to be NMDA receptor-mediated spontaneous activity. The frequencies of the spontaneous epileptiform discharges were similar under treatments with 25 µM gastrodin, 200 µM gastrodin and DMSO. For the evaluation of gastrodin on synaptic transmission, application of DMSO, 25 µM or 200 µM gastrodin had no significant effect on excitatory postsynaptic potential (EPSP) slopes. Gastrodin at 200 µM decreased paired-pulse facilitation (PPF) from 1.23 ± 0.04 to 1.12 ± 0.04 (P = 0.002). In conclusion, gastrodin failed to suppress in vivo and in vitro seizures in our study. Gastrodin showed no effect on hippocampal Schaffer collateral EPSP. These findings suggest that gastrodin does not interact with ionotropic glutamate receptors to inhibit NMDA receptor-facilitated seizures. However, gastrodin showed protective effects against NMDA toxicity on cultured hippocampal slices. Nevertheless, gastrodin is still a potential neuroprotective agent against NMDA excitotoxicity, with potential benefits for stroke and patients with epilepsy.

Drug-induced sleep endoscopy in children with Prader-Willi syndrome.

PURPOSE: Review drug-induced sleep endoscopy (DISE) findings in children with Prader-Willi syndrome (PWS) and correlate the patterns of airway collapse with apnea-hypopnea index (AHI) and body mass index (BMI). METHODS: A total of nine children with PWS underwent DISE. DISE findings were recorded using the VOTE classification system. The relationship between different patterns of airway collapse with AHI and BMI was analyzed. RESULTS: The majority of children with PWS were found to have multilevel obstruction (six out of nine children, 66.6 %). The velum was the most common site of obstruction (nine out of nine children, 100 %). All of the patients had positional obstructive sleep apnea (OSA). Patients with partial or complete anterior-posterior tongue base collapse were associated with a significantly higher AHI (P = 0.016) compared to patients with no anterior-posterior tongue base collapse. Apart from tongue base collapse, no other patterns of airway collapse showed a consistent association with AHI in our results. No patterns of airway collapse showed a significant association with BMI in our study. CONCLUSIONS: In our study, partial or complete anterior-posterior tongue base collapse was associated with higher AHI values in children with PWS. Therefore, careful attention should be addressed to the management of tongue base collapse. Positional therapy could be a potential treatment for patients with PWS since it may alleviate the severity of tongue base collapse.