Myoclonic occipital photosensitive epilepsy with dystonia (MOPED): A familial epilepsy syndrome.
PURPOSE
To describe clinical and EEG phenotypes of a family with an unusual familial epilepsy syndrome characterized by myoclonus and dystonia.


METHODS
Family members underwent electroclinical phenotyping including review of EEGs and MRI. DNA from family members was genotyped using Illumina OmniExpress genotyping arrays. Parametric and nonparametric linkage analyses were performed using MERLIN.


RESULTS
The disorder followed autosomal dominant (AD) inheritance and affected seven individuals over two generations. Seizures began at a mean of 14.5 years. Six individuals had spontaneous myoclonic seizures, of which five also had photic-induced myoclonus and four had photic-induced occipital seizures. Six individuals had convulsive seizures; generalized in two and focal in four. Photosensitivity was prominent with generalized spike wave and polyspike wave in four individuals of which two also had occipital spikes. MRI scans were normal in the four individuals tested. Extensive metabolic investigation was normal. Juvenile myoclonic epilepsy (JME) occurred in two; and JME overlapping with idiopathic photosensitive epilepsy (IPOE) in four individuals. All three affected males had a more severe disorder than the four affected females. Two males had a progressive neurological disorder with progressive myoclonus epilepsy and deterioration in their early 30s. They developed episodes of paroxysmal cervical dystonia with cognitive decline during periods of poor seizure control. One plateaued after years of poor seizure control but remained intractable with periods of deterioration. The other deteriorated with episodes of status dystonicus and status epilepticus, ataxia and a progressive ophthalmoplegia before succumbing at 38 years. Parametric linkage analysis identified three peaks achieving a maximum LOD score of 1.21. Nonparametric analysis identified eight peaks achieving LOD scores above 0.80. These were not statistically significant.


CONCLUSIONS
This is a novel autosomal dominant familial epilepsy syndrome. "Myoclonic occipital photosensitive epilepsy with dystonia" (MOPED) involves a spectrum of phenotypes from JME, sometimes with an IPOE overlap, to progressive myoclonus epilepsy with paroxysmal dystonia.
['Sadleir|Lynette G|LG|', 'Paterson|Sarah|S|', 'Smith|Katherine R|KR|', 'Redshaw|Natalie|N|', 'Ranta|Annemarei|A|', 'Kalnins|Renate|R|', 'Berkovic|Samuel F|SF|', 'Bahlo|Melanie|M|', 'Hildebrand|Michael S|MS|', 'Scheffer|Ingrid E|IE|']
D000328:Adult D000927:Anticonvulsants D002648:Child D003072:Cognition Disorders D004247:DNA D020821:Dystonic Disorders D004831:Epilepsies, Myoclonic D005190:Family D005260:Female D008040:Genetic Linkage D006801:Humans D007178:Inbreeding D008279:Magnetic Resonance Imaging D008297:Male D008875:Middle Aged D020190:Myoclonic Epilepsy, Juvenile D010375:Pedigree D010641:Phenotype D010787:Photosensitivity Disorders D012640:Seizures D013577:Syndrome D055815:Young Adult
Juvenile myoclonic epilepsy Progressive myoclonus epilepsy Genetic Idiopathic photosensitive occipital epilepsy