Enhanced Epilepsy Surveillance and Awareness in the Age of Zika

Evaluation of Seizure Etiology From Routine Testing to Genetic Evaluation

PURPOSE OF REVIEW

Recognizing the cause of a first seizure and identifying the etiology of epilepsy are essential for management. A systematic approach to patients who present with a first seizure helps distinguish between an acute symptomatic seizure, a provoked or unprovoked seizure, and potential mimickers. Routine testing with EEG and MRI may reveal a predisposition for further seizures and help to establish the underlying epilepsy syndrome. An acquired etiology can be identified in 30% of patients with established epilepsy. The remaining 70% of patients have a presumably genetic etiology. Particularly in patients with specific epilepsy syndromes or suspicion for an autosomal dominant inheritance, genetic testing and counseling should be considered.

RECENT FINDINGS

Neuroimaging, autoimmune antibodies, and genetic testing have revolutionized our ability to investigate the etiology of many epilepsies. The new epilepsy classification distinguishes structural, metabolic, genetic, infectious, and immune-mediated etiologies, which often help determine prognosis and treatment.

SUMMARY

There is growing acceptance and demystification of the term epilepsy as the most common cause for recurrent seizures. The new classification of epilepsy does not stop with the recognition of particular epilepsy syndromes but aims to determine the underlying etiology. This can lead to earlier recognition of surgical candidates, a better understanding of many of the genetic epilepsies, and medical treatments aimed at the underlying mechanism causing the disease.

Motor Abnormalities and Epilepsy in Infants and Children With Evidence of Congenital Zika Virus Infection

Initial reports of congenital Zika virus (ZIKV) infection focused on microcephaly at birth with severe brain anomalies; the phenotype has broadened to include microcephaly that develops after birth and neurodevelopmental sequelae. In this narrative review, we summarize medical literature describing motor abnormalities and epilepsy in infants with evidence of congenital ZIKV infection and provide information on the impact of these conditions. Specific scenarios are used to illustrate the complex clinical course in infants with abnormalities that are consistent with congenital Zika syndrome. A search of the English-language medical literature was done to identify motor abnormalities and epilepsy in infants with evidence of congenital ZIKV infection by using Medline and PubMed, Embase, Scientific Electronic Library Online, Scopus, the OpenGrey Repository, and the Grey Literature Report in Public Health. Search terms included "Zika" only and "Zika" in combination with any of the following terms: "epilepsy," "seizure," "motor," and "cerebral palsy." Clinical features of motor abnormalities and epilepsy in these children were reviewed. Thirty-six publications were identified; 8 were selected for further review. Among infants with clinical findings that are consistent with congenital Zika syndrome, 54% had epilepsy and 100% had motor abnormalities. In these infants, impairments that are consistent with diagnoses of cerebral palsy and epilepsy occur frequently. Pyramidal and extrapyramidal motor abnormalities were notable for their early development and co-occurrence. Prompt identification of potential disabilities enables early intervention to improve the quality of life for affected children. Long-term studies of developmental outcomes and interventions in children with congenital ZIKV infection are needed.

Hydrocephalus associated to congenital Zika syndrome: does shunting improve clinical features?

PURPOSE

Congenital Zika syndrome (CZS) is a new entity with little information about its course and natural history. It is known that prenatal infection by Zika virus is associated to disrupted nervous system development, leading to typical neurological disabilities and deformities. Some children present progressive ventriculomegaly and hydrocephalus associated to aggravation of seizures and neurological impairment. The aim of this study is to evaluate the development of hydrocephalus and the impact of ventriculoperitoneal shunt insertion in the clinical condition of these children.

METHODS

Data was obtained from chart review, direct interviews with patients' parents, direct neurological examination, and analysis of pre- and postoperative neuroimages.

RESULTS

A group of 115 patients had CZS diagnosis from November 2015 to July 2017. Among them, 21 (18.3%) patients had ventricular enlargement noted on follow-up CT scans. Six children (28.6%) underwent a ventriculoperitoneal shunt and all had some improvement after surgery concerning either waking time during the day and better interaction. Overall improvement was also noted in seizures. Spasticity decrease and more cervical control were also achieved. In two out of six cases, a slight increase in parenchymal length could be noted on the CT scans.

CONCLUSION

This series points out the possibility of hypertensive hydrocephalus development in CZS patients. Affected children may benefit from VP shunt insertion. These findings suggest a dual pathology association: fetal brain disruption and primary cortical malformation by the virus itself and hypertensive hydrocephalus. This is already seen in some cases of congenital rubella, toxoplasmosis, or cytomegalovirus-associated hydrocephalus.