Epilepsy in ring chromosome 20 syndrome.
Ring chromosome 20 syndrome is characterized by severe, drug resistant childhood onset epilepsy, often accompanied by cognitive impairment. We characterized the electro-clinical phenotype and the long-term course of epilepsy in a large series.



We reviewed the electro-clinical phenotype of 25 patients (aged 8-59 years), and assessed the relationship between epilepsy severity and clinical and/or genetic variables. We also searched for reports of patients diagnosed with r(20) syndrome in the literature, included those whose clinical information was sufficiently accurate, and compared their clinical features with the ones of our patients.



Epilepsy exhibited an age dependent course. When seizure onset occurred in childhood (21 patients), terrifying hallucinations associated with focal motor seizures, often sleep-related (8 patients), or dyscognitive seizures (13 patients), were prominent features, often evolving into epileptic encephalopathy associated with non-convulsive status epilepticus (11 patients). In the long-term, progressive stabilization of drug resistant epilepsy associated with non-convulsive status epilepticus, focal seizures with motor and autonomic features, and eyelid myoclonia were noticed. Epilepsy onset in adolescence (3 patients) was accompanied by a milder developmental course, dyscognitive seizures and non-convulsive status epilepticus, and no cognitive decline. Only three older patients became seizure free (>5 years) We found statistically significant correlations between age at epilepsy onset and cognitive level. Although in the study cohort the relationship between r(20) ratio, age at epilepsy onset and cognitive level was non-statistically significant, it reached significance evaluating the larger cohort of patients previously published.



In ring(20) syndrome, epilepsy has an age dependent course and a worse outcome when age at seizure onset is earlier. The r(20) ratio and severity of cognitive impairment appear to be directly related to each other and inversely correlated with the age at epilepsy onset.
Epilepsy Center, San Paolo Hospital, Milano, Italy; Department of Health Sciences, University of Milan, Milano, Italy. Electronic address: aglaia.vignoli@ao-sanpaolo.it.
Aglaia
A
Vignoli
IRCCS Istituto delle Scienze Neurologiche di Bologna and Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
Francesca
F
Bisulli
Department of Life and Reproduction Sciences, University of Verona, Verona, Italy.
Francesca
F
Darra
Pediatric Neurology, V. Buzzi Hospital, ICP, Milan, Italy.
Massimo
M
Mastrangelo
Pediatric Neurology, A. Meyer Children's Hospital, University of Florence, Florence, Italy.
Carmen
C
Barba
Child Neuropsychiatric Division, Spedali Civili, Brescia, Italy.
Lucio
L
Giordano
Epilepsy Center, San Paolo Hospital, Milano, Italy.
Katherine
K
Turner
Epilepsy Center, San Paolo Hospital, Milano, Italy.
Elena
E
Zambrelli
Epilepsy Center, San Paolo Hospital, Milano, Italy.
Valentina
V
Chiesa
Pediatric Neurology, V. Buzzi Hospital, ICP, Milan, Italy.
Stefania
S
Bova
Pediatric Neurology, V. Buzzi Hospital, ICP, Milan, Italy.
Isabella
I
Fiocchi
Epilepsy Center, San Paolo Hospital, Milano, Italy; Department of Health Sciences, University of Milan, Milano, Italy.
Angela
A
Peron
IRCCS Istituto delle Scienze Neurologiche di Bologna and Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
Ilaria
I
Naldi
Child Neuropsychiatric Division, Spedali Civili, Brescia, Italy.
Giuseppe
G
Milito
IRCCS Istituto delle Scienze Neurologiche di Bologna and Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
Laura
L
Licchetta
IRCCS Istituto delle Scienze Neurologiche di Bologna and Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
Paolo
P
Tinuper
Pediatric Neurology, A. Meyer Children's Hospital, University of Florence, Florence, Italy.
Renzo
R
Guerrini
Department of Life and Reproduction Sciences, University of Verona, Verona, Italy.
Bernardo
B
Dalla Bernardina
Epilepsy Center, San Paolo Hospital, Milano, Italy; Department of Health Sciences, University of Milan, Milano, Italy.
Maria Paola
MP
Canevini
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000927:Anticonvulsants / Q000627:therapeutic use; D001921:Brain / Q000503:physiopathology; D002648:Child; D018450:Disease Progression; D004569:Electroencephalography; D004827:Epilepsy / Q000150:complications* / Q000235:genetics / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D056726:Genetic Association Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012189:Retrospective Studies; D012303:Ring Chromosomes; D012720:Severity of Illness Index; D055815:Young Adult
D000927:Anticonvulsants
Age-dependent course; Epileptic encephalopathy; Ring chromosome 20 syndrome; Seizure semiology