Neuropediatrics 2017; 48(S 01): S1-S45
DOI: 10.1055/s-0037-1602987
P – Poster
Georg Thieme Verlag KG Stuttgart · New York

Northern Epilepsy: Not So Northern Anymore

B. Henzi
1   Division of Neuropediatrics, University of Bern, University Children’s Hospital, Bern, Switzerland
,
D. Bartholdi
2   Division of Human Genetics, University of Bern, University Children’s Hospital, Bern, Switzerland
,
M. Wildbolz
3   Division of Pediatric Cardiology, University of Bern, University Children’s Hospital, Bern, Switzerland
,
B. Kohler
1   Division of Neuropediatrics, University of Bern, University Children’s Hospital, Bern, Switzerland
,
S. Bürki
1   Division of Neuropediatrics, University of Bern, University Children’s Hospital, Bern, Switzerland
,
E. Perret
1   Division of Neuropediatrics, University of Bern, University Children’s Hospital, Bern, Switzerland
,
S. Strozzi
1   Division of Neuropediatrics, University of Bern, University Children’s Hospital, Bern, Switzerland
,
K. Schindler
4   Department of Neurology, Bern University Hospital, University of Bern, Bern, Switzerland
,
S. Gallati
2   Division of Human Genetics, University of Bern, University Children’s Hospital, Bern, Switzerland
,
S. Bigi
1   Division of Neuropediatrics, University of Bern, University Children’s Hospital, Bern, Switzerland
› Author Affiliations
Further Information

Publication History

Publication Date:
26 April 2017 (online)

 

Background/Purpose: Neuronal ceroid-lipofuscinoses (NCL) are a group of neurodegenerative disorders of variable clinical phenotype. We present a case of Northern Epilepsy caused by a newly described homozygous mutation in the CLN8 gene.

Case Presentation: A 13-year-old girl of Turkish descent was diagnosed with focal epilepsy at the age of 6 years. Neurocognitive testing and brain MRI were unremarkable. Treatment with valproic acid was initiated. Regular follow up revealed normal EEGs and seizure freedom. A marked decline in school performance at the age of 12 years prompted a diagnostic follow-up. Neurocognitive decline of 20 IQ points and progressive cerebellar atrophy were noted. Genetic analysis by epilepsy panel testing detected a homozygous missense mutation in the CLN8 gene (exon 3, c.677T>C p.(Leu226Pro)), first published in 11/16 in members of a Turkish family with similar clinical presentation. Subsequent ophthalmological examination revealed a beginning retinopathy.

Discussion: Mutations in the CLN8 gene lead to different phenotypes, depending on the functional effect of the underlying mutations. The clinical presentation of our patient corresponds to the phenotype of Northern Epilepsy—an entity until recently known to be restricted to a Finnish cohort only.

Conclusion: Regular neuropsychological testing is important in patients with epilepsy to detect early neurocognitive decline being symptomatic for possible underlying neurodegenerative disease. The identification of the underlying cause for the neurocognitive decline (hidden nocturnal epileptic activity versus underlying neurodegenerative disease) is important for the clinical management. Genetic epilepsy panel testing is a crucial diagnostic tool in widening the spectrum of neurometabolic disorders.