A form of stimulus sensitive MYOCLONIC EPILEPSY inherited as an autosomal recessive condition. The most common presenting feature is a single seizure in the second decade of life. This is followed by progressive myoclonus, myoclonic seizures, tonic-clonic seizures, focal occipital seizures, intellectual decline, and severe motor and coordination impairments. Most affected individuals do not live past the age of 25 years. Concentric amyloid (Lafora) bodies are found in neurons, liver, skin, bone, and muscle (From Menkes, Textbook of Childhood Neurology, 5th ed, pp111-110).

A rare, fatal autosomal recessive inherited disorder caused by mutations in the genes EPM2A and EPM2b. It is characterized by the presence of cytoplasmic inclusion bodies called Lafora bodies in many cells of the body including neurons, muscle cells, and liver cells. The Lafora bodies contain mucopolysaccharides. Signs and symptoms include seizures, myoclonus, ataxia, and dementia.

Progressive myoclonus epilepsy, Lafora type (also known as Lafora disease [LD]) is characterized by focal occipital seizures presenting as transient blindness or visual hallucinations and fragmentary, symmetric, or generalized myoclonus beginning in previously healthy individuals at age eight to 19 years (peak 14-16 years). Generalized tonic-clonic seizures, atypical absence seizures, atonic seizures, and focal seizures with impaired awareness may occur. The course of the disease is characterized by increasing frequency and intractability of seizures. Status epilepticus with any of the seizure types is common. Cognitive decline becomes apparent at or soon after the onset of seizures. Dysarthria and ataxia appear early while spasticity appears late. Emotional disturbance and confusion are common in the early stages of the disease and are followed by dementia. Most affected individuals die within ten years of onset, usually from status epilepticus or from complications related to nervous system degeneration.

Lafora disease is an inherited, severe form of progressive myoclonus epilepsy. The condition most commonly begins with epileptic seizures in late childhood or adolescence. Other signs and symptoms include difficulty walking, muscle spasms (myoclonus) and dementia. Affected people also experience rapid cognitive deterioration that begins...