Cryptogenic late-onset epileptic spasms

Cryptogenic late-onset epileptic spasms is a rare epileptic condition characterized by the occurrence of epileptic spasms (brief, sudden flexion or extension movements of the trunk and limbs) with onset after the typical age window associated with infantile spasms (West syndrome). In this condition, spasms begin after one year of age, often in later childhood. The term 'cryptogenic' indicates that no identifiable underlying cause (such as a structural brain abnormality, genetic syndrome, or metabolic disorder) can be found despite thorough investigation, distinguishing it from symptomatic forms where a clear etiology is present. The condition primarily affects the central nervous system. Epileptic spasms may occur in clusters, often upon awakening, and can be associated with an electroencephalographic (EEG) pattern of hypsarrhythmia or modified hypsarrhythmia, though EEG findings may be atypical given the later onset. Affected individuals may experience developmental regression or cognitive difficulties, although the neurodevelopmental prognosis in cryptogenic cases is generally considered more favorable than in symptomatic cases. Some patients may also develop other seizure types over time. Treatment approaches are largely extrapolated from the management of infantile spasms and may include hormonal therapies such as adrenocorticotropic hormone (ACTH) or oral corticosteroids, as well as vigabatrin. Other antiseizure medications may be used depending on individual response. Early and effective treatment of spasms is considered important for optimizing developmental outcomes. The overall prognosis varies, and long-term follow-up is essential to monitor for seizure recurrence and neurodevelopmental progress.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

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