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Epileptic and electroencephalographic manifestations of guanidinoacetate-methyltransferase deficiency.

Publication ,  Journal Article
Mikati, AG; Abu Gheida, I; Shamseddine, A; Mikati, MA; Karam, PE
Published in: Epileptic Disord
December 2013

AIM: Describe the seizure-related manifestations of guanidinoacetate methyltransferase (GAMT) deficiency in two new cases and compare these to the related literature. METHODS: We reviewed the clinical and electroencephalographic manifestations of two siblings with GAMT deficiency. We also performed a thorough literature review of all cases of GAMT deficiency, using the PubMed database, and compared our findings to those previously reported. RESULTS: One sibling presented with Lennox-Gastaut syndrome while the second had manifestations of late-onset West syndrome. Based on a literature search, we found that the clinical picture of GAMT deficiency has been described in a total of 58 cases, including our two patients, 45 of whom had at least some description of EEG and/or seizure manifestation. Epilepsy was present in 81%, with age at onset usually between 10 months and 3 years. Drug resistance was observed in approximately 45%. Initial seizures were febrile, tonic, or tonic-clonic. Drop attacks and generalised seizures were the most frequent seizure type. Absence and febrile seizures also occurred. Less frequently, focal seizures and late-onset infantile spasms (one prior case) were observed. Multifocal spikes and generalised <3-Hz-spike slow waves were common while only one prior single case report of hypsarrhythmia was described. Lennox-Gastaut syndrome was common, while progressive myoclonic epilepsy was also, less frequently, reported. CONCLUSIONS: To our knowledge, this is the second report of the occurrence of West syndrome in GAMT deficiency. The majority of patients with GAMT deficiency have seizures and approximately half are drug-resistant. Late-onset of hypsarrhythmia and/or epileptic spasms could potentially prove to be a distinctive, albeit infrequent, feature of this treatable metabolic disorder.

Duke Scholars

Published In

Epileptic Disord

DOI

ISSN

1294-9361

Publication Date

December 2013

Volume

15

Issue

4

Start / End Page

407 / 416

Location

United States

Related Subject Headings

  • Spasms, Infantile
  • Neurology & Neurosurgery
  • Movement Disorders
  • Male
  • Lennox Gastaut Syndrome
  • Language Development Disorders
  • Intellectual Disability
  • Infant
  • Humans
  • Guanidinoacetate N-Methyltransferase
 

Citation

APA
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ICMJE
MLA
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Mikati, A. G., Abu Gheida, I., Shamseddine, A., Mikati, M. A., & Karam, P. E. (2013). Epileptic and electroencephalographic manifestations of guanidinoacetate-methyltransferase deficiency. Epileptic Disord, 15(4), 407–416. https://doi.org/10.1684/epd.2013.0609
Mikati, Abdul G., Ibrahim Abu Gheida, Alhan Shamseddine, Mohamad A. Mikati, and Pascale E. Karam. “Epileptic and electroencephalographic manifestations of guanidinoacetate-methyltransferase deficiency.Epileptic Disord 15, no. 4 (December 2013): 407–16. https://doi.org/10.1684/epd.2013.0609.
Mikati AG, Abu Gheida I, Shamseddine A, Mikati MA, Karam PE. Epileptic and electroencephalographic manifestations of guanidinoacetate-methyltransferase deficiency. Epileptic Disord. 2013 Dec;15(4):407–16.
Mikati, Abdul G., et al. “Epileptic and electroencephalographic manifestations of guanidinoacetate-methyltransferase deficiency.Epileptic Disord, vol. 15, no. 4, Dec. 2013, pp. 407–16. Pubmed, doi:10.1684/epd.2013.0609.
Mikati AG, Abu Gheida I, Shamseddine A, Mikati MA, Karam PE. Epileptic and electroencephalographic manifestations of guanidinoacetate-methyltransferase deficiency. Epileptic Disord. 2013 Dec;15(4):407–416.

Published In

Epileptic Disord

DOI

ISSN

1294-9361

Publication Date

December 2013

Volume

15

Issue

4

Start / End Page

407 / 416

Location

United States

Related Subject Headings

  • Spasms, Infantile
  • Neurology & Neurosurgery
  • Movement Disorders
  • Male
  • Lennox Gastaut Syndrome
  • Language Development Disorders
  • Intellectual Disability
  • Infant
  • Humans
  • Guanidinoacetate N-Methyltransferase