title: Progressive myoclonic epilepsies: definitive and still undetermined causes.
abstract: OBJECTIVE
  To define the clinical spectrum and etiology of progressive myoclonic epilepsies (PMEs) in Italy using a database developed by the Genetics Commission of the Italian League against Epilepsy.
  
  
  METHODS
  We collected clinical and laboratory data from patients referred to 25 Italian epilepsy centers regardless of whether a positive causative factor was identified. PMEs of undetermined origins were grouped using 2-step cluster analysis.
  
  
  RESULTS
  We collected clinical data from 204 patients, including 77 with a diagnosis of Unverricht-Lundborg disease and 37 with a diagnosis of Lafora body disease; 31 patients had PMEs due to rarer genetic causes, mainly neuronal ceroid lipofuscinoses. Two more patients had celiac disease. Despite extensive investigation, we found no definitive etiology for 57 patients. Cluster analysis indicated that these patients could be grouped into 2 clusters defined by age at disease onset, age at myoclonus onset, previous psychomotor delay, seizure characteristics, photosensitivity, associated signs other than those included in the cardinal definition of PME, and pathologic MRI findings.
  
  
  CONCLUSIONS
  Information concerning the distribution of different genetic causes of PMEs may provide a framework for an updated diagnostic workup. Phenotypes of the patients with PME of undetermined cause varied widely. The presence of separate clusters suggests that novel forms of PME are yet to be clinically and genetically characterized.
authors.affiliation: From the Department of Neurophysiopathology and Epilepsy Centre (S.F., L.C., E.V., F.P., G.A.), IRCCS Foundation C. Besta Neurological Institute, Milan; Unit of Neurology (R.M.), IRCCS Institute of Neurological Sciences, Bellaria Hospital, Bologna; Pediatric Neurology and Muscular Diseases Unit (P.S.), DINOGMI-Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, G. Gaslini Institute; Department of Medical and Surgical Sciences (A.G., E.F.), Magna Graecia University, Catanzaro; Institute of Neurological Sciences (A.G.), National Research Council, Mangone, Cosenza; Epilepsy Centre (A.M.), Department of Neuroscience, University of Messina; IRCCS Institute of Neurological Sciences and Department of Biomedical and Neuromotor Sciences (P.T.), University of Bologna; Epilepsy Centre (A.L.N.), Azienda Ospedaliero Universitaria Consorziale, Dipartimento di Scienze Mediche di Base, Neuroscienze ed Organi di Senso, Policlinico, Bari; Child Neurology Unit (G.G.), IRCCS delle Scienze Neurologiche, Bologna; Department of Neurology and Psychiatry (A.T.G.), Neurology Unit, La Sapienza University, Rome; Epilepsy Center (G.C.), Department of Child Neuropsychiatry, C. Poma Hospital, Mantua; University of Bologna (C.A.T.); Department of Neurology and Epilepsy Centre (A.B.), San Donato Hospital, Arezzo; and Istituto Gaslini (F.Z.), Laboratory of Neurogenetics, Genoa, Italy. Coinvestigators are listed on the Neurology® Web site at www.neurology.org.
authors.forename: Silvana
authors.initials: S
authors.lastname: Franceschetti
authors.forename: Roberto
authors.initials: R
authors.lastname: Michelucci
authors.forename: Laura
authors.initials: L
authors.lastname: Canafoglia
authors.forename: Pasquale
authors.initials: P
authors.lastname: Striano
authors.forename: Antonio
authors.initials: A
authors.lastname: Gambardella
authors.forename: Adriana
authors.initials: A
authors.lastname: Magaudda
authors.forename: Paolo
authors.initials: P
authors.lastname: Tinuper
authors.forename: Angela
authors.initials: A
authors.lastname: La Neve
authors.forename: Edoardo
authors.initials: E
authors.lastname: Ferlazzo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Gobbi
authors.forename: Anna Teresa
authors.initials: AT
authors.lastname: Giallonardo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Capovilla
authors.forename: Elisa
authors.initials: E
authors.lastname: Visani
authors.forename: Ferruccio
authors.initials: F
authors.lastname: Panzica
authors.forename: Giuliano
authors.initials: G
authors.lastname: Avanzini
authors.forename: Carlo Alberto
authors.initials: CA
authors.lastname: Tassinari
authors.forename: Amedeo
authors.initials: A
authors.lastname: Bianchi
authors.forename: Federico
authors.initials: F
authors.lastname: Zara
mesh_terms: D000293:Adolescent; D000328:Adult; D016000:Cluster Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007558:Italy / Q000453:epidemiology; D020192:Lafora Disease / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020191:Myoclonic Epilepsies, Progressive / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D020194:Unverricht-Lundborg Syndrome / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D055815:Young Adult