However, the outcome is better compared to patients with Lennox-Gastaut syndrome. Myoclonic seizures appear by the second or third year and are often photosensitive. Atypical absence seizures may be seen without an electrographic correlate. Most patients have fluctuating ataxia and erratic myoclonus. The myoclonic seizures may resolve after a few years, but other seizures tend to be persistent.
Nonconvulsive status is common.
The EEG is normal initially, despite frequent seizures. Multifocal spikes may also be seen and may be unilateral. Most patients are photosensitive and this feature may be diagnostic, if present in children younger than 1 year. MRI and CT scans are usually normal and do not show focal lesions or atrophy. Generally, the outlook is poor, with most children markedly dependent for care or institutionalized.