Derrick Wei Shih Chan

Quantifying Limb Movements in Epileptic Seizures Through Color-Based Video Analysis

This paper proposes a color-based video analytic system for quantifying limb movements in epileptic seizure monitoring. The system utilizes colored pyjamas to facilitate limb segmentation and tracking. Thus, it is unobtrusive and requires no sensor/marker attached to patients body. We employ Gaussian mixture models in background/foreground modeling and detect limbs through a coarse-to-fine paradigm with graph-cut-based segmentation. Next, we estimate limb parameters with domain knowledge guidance and extract displacement and oscillation features from movement trajectories for seizure detection/analysis. We report studies on sequences captured in an epilepsy monitoring unit. Experimental evaluations show that the proposed system has achieved comparable performance to EEG-based systems in detecting motor seizures.

Topographic movie of intracranial ictal high‐frequency oscillations with seizure semiology: Epileptic network in Jacksonian seizures

Purpose:  We developed a technique to produce images of dynamic changes in ictal high‐frequency oscillations (HFOs) >40 Hz recorded on subdural electroencephalography (EEG) that are time‐locked to the ictal EEG and ictal semiology video. We applied this technique to Jacksonian seizures to demonstrate ictal HFO propagation along the homunculus in the primary sensory‐motor cortex to visualize the underlying epileptic network.

Pediatric epilepsy and first afebrile seizure in Singapore: epidemiology and investigation yield at presentation.

The authors studied pediatric epilepsy and first afebrile seizure at presentation in Singapore. A total of 211 participants aged 1 month to 15 years with first presentation for afebrile seizures were recruited from November 2002 to May 2004; 108 with ≥2 prior afebrile seizures (newly diagnosed epilepsy) and 103 with first afebrile seizures. A χ2 analysis of demographics, risk factors, examination, and investigation findings showed significant differences in development (normal in 87% [newly diagnosed epilepsy] and 93% [first afebrile seizure], P = .046), neurological examination (normal in 92% [newly diagnosed epilepsy] and 98% [first afebrile seizure], P = .016), and electroencephalogram findings (abnormal in 75% [newly diagnosed epilepsy] and 36.9% [first afebrile seizure], P < .005). Pediatric epilepsy incidence at our institution is 24 per 100 000 person-years and is highest in early childhood. Focal epilepsy is more common than generalized epilepsy. Patients with first afebrile seizure and abnormal development, neurological examination, and electroencephalogram findings should be monitored for future development of epilepsy. Population-based studies are recommended.

Hemophagocytic Lymphohistiocytosis With Isolated Central Nervous System Reactivation and Optic Nerve Involvement

Hemophagocytic lymphohistiocytosis is a rare childhood disorder characterized by uncontrolled proliferation of benign lymphocytes and histiocytes in multiple organs. Neurological presentations of central nervous system involvement are highly variable. The authors present a case of familial hemophagocytic lymphohistiocytosis in an 8-month-old girl with isolated central nervous system reactivation and optic nerve involvement. She presented with fever and hepatosplenomegaly at 2 months of age. Genetic studies confirmed familial hemophagocytic lymphohistiocytosis. There were no clinical features of central nervous system involvement at presentation. While on maintenance chemotherapy awaiting bone marrow transplant, she presented with new-onset seizures. Magnetic resonance imaging of the brain revealed extensive areas of abnormal signal and a thickened and enhancing left optic nerve. Ocular manifestations of hemophagocytic lymphohistiocytosis have rarely been described. To the authors’ knowledge, this is the first case report of magnetic resonance imaging findings of optic nerve involvement in a child with hemophagocytic lymphohistiocytosis.

Markerless video analysis for movement quantification in pediatric epilepsy monitoring

This paper proposes a markerless video analytic system for quantifying body part movements in pediatric epilepsy monitoring. The system utilizes colored pajamas worn by a patient in bed to extract body part movement trajectories, from which various features can be obtained for seizure detection and analysis. Hence, it is non-intrusive and it requires no sensor/marker to be attached to the patients body. It takes raw video sequences as input and a simple user-initialization indicates the body parts to be examined. In background/foreground modeling, Gaussian mixture models are employed in conjunction with HSV-based modeling. Body part detection follows a coarse-to-fine paradigm with graph-cut-based segmentation. Finally, body part parameters are estimated with domain knowledge guidance. Experimental studies are reported on sequences captured in an Epilepsy Monitoring Unit at a local hospital. The results demonstrate the feasibility of the proposed system in pediatric epilepsy monitoring and seizure detection.

Review of clinical studies of perampanel in adolescent patients

To assess the clinical trial and real‐world data for adjunctive perampanel in adolescents and develop consensus recommendations to guide the use of perampanel in this population in clinical practice.

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome may have a hypothalamus-periaqueductal gray localization.

BACKGROUND Anatomical localization of the rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome has proved elusive. Most patients had neuroimaging after cardiorespiratory collapse, revealing a range of ischemic lesions. PATIENT DESCRIPTION A 15-year-old obese boy with an acute febrile encephalopathy had hypoventilation, autonomic dysfunction, visual hallucinations, hyperekplexia, and disordered body temperature, and saltwater regulation. These features describe the ROHHAD syndrome. Cerebrospinal fluid analysis showed pleocytosis, elevated neopterins, and oligoclonal bands, and serology for systemic and antineuronal antibodies was negative. He improved after receiving intravenous steroids, immunoglobulins, and long-term mycophenolate. Screening for neural crest tumors was negative. CONCLUSION Magnetic resonance imaging of the brain early in his illness showed focal inflammation in the periaqueductal gray matter and hypothalamus. This unique localization explains almost all symptoms of this rare autoimmune encephalitis.

Use of Magnesium Sulfate Infusion for the Management of Febrile Illness-Related Epilepsy Syndrome A Case Series

Febrile illness-related epilepsy syndrome is a catastrophic epileptic encephalopathy that is highly refractory to most antiepileptic drugs leading to high morbidity and mortality. The authors report the use of a pediatric infusion protocol of continuous intravenous magnesium sulfate for the control of seizures in 2 children with febrile illness-related epilepsy syndrome refractory to multiple antiepileptic drugs in a pediatric intensive care unit of a tertiary care children’s hospital. Both patients, 2 and 16 years of age, respectively, were treated with continuous magnesium sulfate infusion. Serum magnesium concentrations ranging from 2.1 to 5 mmol/L were achieved. Seizure reduction and cessation were noted in 1 patient with magnesium more than 3.0 mmol/L. No significant adverse effects were observed. Magnesium sulfate infusions can be safely used in pediatric refractory status epilepticus. Magnesium sulfate can be considered in the management of children with febrile illness-related epilepsy syndrome.

Neonatal Seizures: When to Consider and How to Investigate for an Inborn Error of Metabolism:

Seizures occur more frequently in the neonatal period than in the remainder of childhood. Neonatal seizures can have different aetiologies. Inborn errors of metabolism are rare causes of seizures in the newborn. However, they are an important cause of intractable neonatal seizures, accounting for 30% of cases. Diagnosis is necessary for timely institution of appropriate treatment and is important in determining clinical outcome. As these are genetic conditions, it allows for appropriate genetic counselling. We describe the clinical presentation of neonatal seizures and the investigation findings in symptomatic neonatal seizures and epilepsy syndromes that arise in the neonatal period. The approach in diagnosis and investigation of an underlying inborn error of metabolism is described and inborn errors of metabolism that are important causes of neonatal seizures are reviewed.

Guiding follow-up of paediatric idiopathic intracranial hypertension with optical coherence tomography

Idiopathic intracranial hypertension (IIH) is uncommon in the paediatric population. Papilloedema is the hallmark sign and patients can suffer permanent vision loss as a consequence. We describe the role of optical coherence tomography (OCT) in the follow-up of two paediatric patients with newly diagnosed IIH. Patient A presented with vomiting and examination showed ophthalmoplaegia and papilloedema. She was treated with acetazolamide, furosemide and therapeutic lumbar punctures. Patient B presented with incidental papilloedema and was treated with acetazolamide and she reported intermittent headache during follow-up. Fundoscopic examinations for both patients showed persistent blurred disc margins but OCT examinations documented improvement of average retinal nerve fibre layers. OCT may be of value in monitoring for recurrence in paediatric IIH.