Convulsive status epilepticus in children with intractable epilepsy is frequently focal in origin

ACR Appropriateness Criteria® Seizures-Child

In children, seizures represent an extremely heterogeneous group of medical conditions ranging from benign cases, such as a simple febrile seizure, to life-threatening situations, such as status epilepticus. Underlying causes of seizures also represent a wide range of pathologies from idiopathic cases, usually genetic, to a variety of acute and chronic intracranial or systemic abnormalities. This document discusses appropriate utilization of neuroimaging tests in a child with seizures. The clinical scenarios in this document take into consideration different circumstances at the time of a child's presentation including the patient's age, precipitating event (if any), and clinical and electroencephalogram findings and include neonatal seizures, simple and complex febrile seizures, post-traumatic seizures, focal seizures, primary generalized seizures in a neurologically normal child, and generalized seizures in neurologically abnormal child. This practical approach aims to guide clinicians in clinical decision-making and to help identify efficient and appropriate imaging workup. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Indications for the performance of neuroimaging in children

Pediatric neurology relies on ultrasound, computed tomography (CT), and magnetic resonance (MR) imaging. CT prevails in acute neurologic presentations, including traumatic brain injury (TBI), nontraumatic coma, stroke, and status epilepticus, because of easy availability, with images of diagnostic quality, e.g., to exclude hemorrhage, usually completed quickly enough to avoid sedation. Concerns over the risks of ionizing radiation mean re-imaging and higher-dose procedures, e.g., arteriography and venography, require justification. T1/T2-weighted imaging (T1/T2-WI) MR with additional sequences (arteriography, venography, T2*, spectroscopy, diffusion tensor, perfusion, diffusion- (DWI) and susceptibility-weighted imaging (SWI)) often clarifies the diagnosis, which may alter management in acute settings, as well as chronic conditions, e.g., epilepsy. Clinical acumen remains essential to avoid imaging, e.g., in genetic epilepsies or migrainous headaches responding to treatment, or to target sequences to specific diagnosis, e.g., T1/T2-WI for shunt dysfunction (with SWI for TBI); DWI, arteriography including neck vessels, and venography for acute hemiplegia or coma; coronal temporal cuts for partial epilepsy; or muscle imaging for motor delay. The risk of general anesthesia is low; "head-only" scanners may allow rapid MRI without sedation. Timely and accurate reporting, with discrepancy discussion between expert neuroradiologists, is important for management of the child and the family's expectations.

Seizure Semiology: Value in Identifying Seizure Origin

The diagnosis of epilepsy depends upon a number of factors, particularly detailed and accurate seizure history, or semiology. Other diagnostic data, consisting of electroencephalography, video-monitoring of the seizures, and magnetic resonance imaging, are important in any comprehensive epilepsy program, particularly with respect to lateralizing and localizing the seizure focus, if such a focus exists, and with respect to determining the type of seizure or seizure syndrome. The aim of this review is to present a survey of important semiologic characteristics of various seizures that provide the historian with observations, which help to lateralize and localize epileptic zones. Clinical semiology is the starting point of understanding a seizure disorder and making the diagnosis of epilepsy. While it may not provide unequivocal evidence of localization of the epileptic focus, nevertheless it usually directs subsequent investigations, whose concordance is necessary for the ultimate localization.

Underlying neurologic disorders and recurrence rates of status epilepticus in childhood

BACKGROUND

The underlying neurologic disorders of status epilepticus (SE) in childhood remain poorly characterized.

METHODS

We reviewed 249 consecutive patients with SE, aged 1 month to 18 years, who were referred to Tottori University Hospital from 1984 to 2002. After exclusion of SE patients with acute symptomatic etiology and progressive encephalopathy, such as acute encephalitis/encephalopathy, meningitis, head trauma, or metabolic disorders, we analyzed 112 patients, aged 3 months to 14 years, and focused on the epilepsy classification and perinatal brain damage in these patients.

RESULTS

Major underlying neurologic disorders were non-symptomatic epilepsy (41 patients, 36.6%), perinatal brain damage (15 patients, 13.4%), non-syndromic mental retardation (17 patients, 15.2%), and congenital disorders including chromosomal abnormalities (13 patients, 11.6%). In non-symptomatic epilepsy, childhood epilepsy with occipital paroxysms (Panayiotopoulos syndrome, 11 patients) and severe myoclonic epilepsy in infancy (SMEI, 6 patients) were common and had high recurrence rates (81.8% and 66.7%, respectively). In patients with a history of perinatal brain damage, preterm birth, neonatal seizure, asphyxia, and neonatal hypoglycemia were frequent. Neonatal hypoglycemia and neonatal seizure were related to the recurrence of SE (100% and 87.5%, respectively). They were mostly diagnosed as symptomatic occipital lobe epilepsy. Parieto-occipital paroxysms were associated with a high recurrence rate of SE (80.6%).

CONCLUSIONS

Although the underlying neurologic disorders of SE are heterogeneous, three specific epileptic syndromes (Panayiotopoulos syndrome, SMEI, and symptomatic occipital lobe epilepsy secondary to neonatal hypoglycemia and neonatal seizure) were the most common causes of SE and were associated with higher recurrence rates.