Vigabatrin-associated Reversible MRI Abnormalities in an Infant with Tuberous Sclerosis

A Case of Vigabatrin Toxicity Mimicking Bilateral Thalamic Infarcts on MRI

A 20-month-old female with a past medical history of tuberous sclerosis, epilepsy, and infantile spasms treated with vigabatrin presented for surveillance MRI for multiple brain hamartomatous lesions and subependymal nodules. MRI showed new restricted diffusion to bilateral thalami and globi pallidi. This finding was concerning for bilateral thalamic strokes, with differential to include infection, metabolic etiologies, or toxic injuries. Without focal or diffuse neurologic symptoms or additional MRI lesions to suggest an acute or chronic pathology, it was determined the MRI signal changes were likely induced by vigabatrin. Vigabatrin therapy was continued, and a repeat MRI 17 months later showed a resolution of the diffusion restriction with no residual sequelae. Vigabatrin-induced MRI abnormalities are an uncommon adverse effect of therapy for infantile spasms, with adverse events being most common in young infants. It is crucial to consider this adverse drug effect in an asymptomatic patient presenting with these MRI lesions as the findings are otherwise suggestive of a serious disease process, such as an inborn error of metabolism, requiring expensive and invasive workup.

Brazilian experts' consensus on the treatment of infantile epileptic spasm syndrome in infants

BACKGROUND

Infantile epileptic spasms syndrome (IESS) is a rare but severe condition affecting children early and is usually secondary to an identifiable brain disorder. It is related to psychomotor deterioration in childhood and epilepsy in adult life. Treatment is challenging as infantile spasms may not respond to most antiseizure medication, and relapse is frequent.

OBJECTIVE

To evaluate the literature regarding treatment of IESS and provide a practical guidance to a healthcare system with limited resources.

METHODS

An expert committee from the Brazilian Society of Child Neurology reviewed and discussed relevant scientific evidence in the treatment of IESS regarding the drugs available in Brazil.

RESULTS

Oral prednisolone and vigabatrin are the most common drugs used as first-line therapy; they are efficient and affordable therapy as both are available in the Brazilian unified health system (SUS, in the Portuguese acronym). Intramuscular adrenocorticotropic hormone (ACTH) presents similar efficacy as oral prednisolone but has a higher cost and is not available in Brazil. Other antiseizure medications such as topiramate, levetiracetam, or benzodiazepines have limited response and are prescribed as adjuvant therapy. If the health service has nutritionists, a ketogenic diet should be implemented for those not responding to hormonal and vigabatrin treatment. Epilepsy surgery is mainly indicated for patients with focal lesions that do not respond to pharmacological therapy.

CONCLUSION

Early treatment of IESS with efficient drugs is feasible in our country. Using standard protocols increases the odds of achieving complete cessation in a shorter time and decreases relapse.