Introduction: The inv dup (15) syndrome is a rare chromosomal characterized by developmental delay,
mental retardation, autistic features and epilepsy. Facial dysmorphic features are
absent or subtle. Clinical course of epilepsy and EEG findings are highly variable.
Up to date, our knowledge about the associated epilepsy types as well as the electrophysiological
features is limited.
Case-Report: We report the case of a mentally retarded 24-year-old woman without facial dysmorphic
features, diagnosed with catastrophic epilepsy, who was referred for the first time
to our centre to perform Video-EEG-recording. Manifestation of epilepsy in childhood
(9yrs of age, status epilepticus), in the course of time manifestation of various
seizure types, pharmacoresistent for VPA, TPM, OXC, LTG, PHT. Medication at time of
referral: CBZ, CLB, LTG; seizure frequency 50/day. During video-EEG-monitoring registration
of tonic, atonic seizures, atypical absences and secondarily generalized seizures.
Interictal EEG: during wakefulness: basal rhythm 8Hz, intermittent 2.5Hz slow spike
wave pattern, during sleep: increase of epileptic activity and bursts of generalized
ß-activity. We diagnosed Lennox-Gastaut syndrome and initiated add-on therapy with
RUF. 6 months later implantation of a vagal nerve stimulator with a profound reduction
of seizures (5–15/day). We performed MRI of the brain showing Arnold-Chiari-malformation
type 1 as well as standard cytogenetics associated with FISH analysis, detecting inv
dup (15) syndrome.
Discussion: About 50% of all patients with inv dup (15) who are published in literature develope
pharmacoresistent epilepsy with a wide variety of of seizure types. However, type
of epilepsy and EEG abnormalities are heterogeneous, up to now a common phenotype
could not be established. Chromosome analysis should be performed in all patients
with mental retardation and epilepsy even if dysmorphic features are absent.
