Background Angelman syndrome is a neurogenetic disorder characterised by severe learning difficulties and speech impairment, motor difficulties including jerky movements and ataxia, and seizures.
Epilepsy associated with Angelman syndrome consists of a variety of seizure types. Typically EEG shows a distinctive pattern which can aid diagnosis, but MRI scan shows no abnormality.
Although there is a known association between epilepsy and hippocampal sclerosis in the general population, the development of hippocampal sclerosis following a prolonged convulsion has not been described in a child with Angelman syndrome.
Methodology Literature search was carried out to review and compare similar reported cases. This elucidated that the association between hippocampal sclerosis and Angelman syndrome has rarely been cited.
Results The case presented here is a 3 year old girl with Angelman syndrome due to de novo micro deletion of chromosome 15, who suffered a prolonged convulsion and subsequently developed a persistent hemiplegia. Serial MRI scans demonstrate initially normal brain architecture and appearances, then the evolution from mild hippocampal swelling two days after the acute insult, to frank hippocampal sclerosis, as well as changes to the left cerebral hemisphere, several months later.
Conclusion This case evidences the development of hippocampal sclerosis following acute prolonged convulsion in a child with Angelman syndrome, and implicates this pathogenesis in the natural history of Angelman syndrome.