Konjenital miyastenik sendromlarda elektrofizyolojik özellikler

Giris: Konjenital miyastenik sendromlar genellikle infantil yada çocukluk çağında baslayan, presinaptik, sinaptik veya postsinaptik alandaki defekt sonucu ortaya çıkan bir grup herediter nöromuskuler bileske hastalıklarıdır. Bu çalısmada, konjenital miyastenik sendromlarda elektrofizyolojik özelliklerin değerlendirilmesi ve konjenital miyasyenik sendromların alt gruplarını ayırt etmede rollerinin ortaya konması amaçlandı. Gereç ve Yöntem: Çalısmaya Ege Üniversitesi Tıp Fakültesi (EÜTF) Nöroloji kliniği çocuk nörolojisi ünitesine basvurmus 12 olgu alındı. Olgular klinik ve elektrofizyolojik özellikler yönünden değerlendirildi. Olgulara supramaksimal tek elektrik uyarımı, 1-3 Hz frekansında ardısık uyarım ve tek lif elektromiyogramı(EMG) yöntemleri uygulandı. Bulgular: Olguların hepsinde tek supramaksimal uyarım ile elde edilen motor yanıtın faz sayısında ve genliğinde artıs saptandı. Bütün olgulara 1-3 Hz frekansında ardısık uyarım uygulandı, 8 olguda dekremental yanıt saptandı. Dokuz olguya istemli tek lif EMG uygulandı, hepsinde jitter artısı ve/veya blok saptandı. Olguların hepsinde ardısık uyarım ve/veya tek lif EMG ile anormallik belirlendi. Đki olguda tek supramaksimal uyarım ile motor yanıtta instabilite saptandı, bu olguların klinik ve elektrofizyolojik özellikleri değerlendirildiğinde yavas kanal hastalığı tanısı düsünüldü. Sonuç: Uygulaması kolay, basit elektrofizyolojik yöntemlerin konjenital miyastenik sendromların alt gruplarının tanısında yardımcı olabileceği düsünüldü.

Electrophysiological properties of congenital myasthenic syndromes

Introduction: Congenital myasthenic syndromes are a group of hereditary neuromuscular junction diseases, usually present in infancy or childhood period, caused by defects of presynaptic, synaptic or postsynaptic area. In this trial, evaluating electrophysiologic properties of congenital myasthenic syndromes and determining the role of electrophysiologic characteristics for distinction of subgroups of congenital myasthenic syndromes are aimed. Material and Method: Twelve cases which applied to Ege University Department of Neurology, child neurology unit were received to trial. Cases were evaluated according to clinical and electrophysiologic properties. Supramaximal single stimulation, 1-3 Hz repetative stimulation and single fiber electromyography (EMG) methods were carried out. Results: In all of cases, phase number and wideness of motor responses increased after single supramaximal stimulation. 1-3 Hz repetetive stimulation was applied to all of cases, in 8 of cases, decremental responses were established. Single fiber EMG was carried out for 9 of cases, in all of them increased jitter and/or block was determined. In all of cases, abnormalities were determined by repetative stimulation and/or single fiber EMG. Two cases presented motor response instability with single supramaximal stimulation, by evaluation of clinical and electrophysiologic properties of this cases, diagnosis of slow channel disease considered. Conclusion: Easily applied, simple electrophysiologic methods are considered as assistant to diagnosis of subgroups of congenital myasthenic syndromes.

PDF

___

1. Engel AG, Ohno K. Congenital myasthenic syndromes. Adv Neurol 2002;88:203-15
2. Ohno K, Engel AG. Congenital myasthenic syndromes: genetic defects of the neuromuscular junction. Curr Neurol Neurosci Rep 2002;2:78-88.
3. Engel AG, Ohno K, Sine SM. Congenital myasthenic syndromes:recent advances. Arch Neurol 1999;56:163-7.
4. Engel AG. Congenital myasthenic syndromes. J Child Neurol 1999;14:38-41.
5. Deymeer F, Serdaroğlu P, Özdemir C. Familial infantile myasthenia:confusion in terminology. Neuromus Disord 1999;9:129-30.
6. Beeson D, Palace J, Vincent A. Congenital myasthenic syndromes. Curr Opin Neurol 1997;10:402-7.
7. Beeson D,Newland C, Croxen R, et al. Congenital myasthenic syndromes. Studies of the AChR and other candidate genes. Ann N Y Acad Sci 1998;841:181-183.
8. Ertekin, C: Sentral ve periferik EMG. Đzmir: Meta Basım Matbaası, 2006:257-258.
9. Engel AG, Ohno K, Sine SM. Congenital myasthenic syndromes: progress over the past decade. Muscle & Nevre 2003;27:4-25.
10. Conomy JP, Levisohn M, Fanaroff A. Familial infantile myasthenia gravis: a cause of sudden death in young children . J Pediatr 197;87:428-429.
11. Engel AG, Lambert EH. Congenital myasthenic syndromes. Electroencephalogr Clin Neurophysiol Suppl 1987;39:91-102.
12. Mora M, Lambert EH, Engel AG. Synaptic vesicle abnormality in familial infantile myasthenia. Neurology 1987;37:206-214.
13. Engel AG, Ohno K, sine SM. Congenital myasthenic syndromes. In: Engel AG, editor. Myasthenia gravis and myasthenic disorders. New York:Oxford University Pres;1999. p251-297.
14. Harper CM. Electrodiagnosis of endplate disease. In: Engel AG, editor. Myasthenia gravis and myasthenic disorders. Newyork:Oxford University Pres; 2002. p 65-84.
15. Robertson WC, Chun RWM, Kornguth SE. Familial infantile myasthenia. Arch Neurol 1980;37:117-119.
16. Donger C, Krejci E, Serradell P et al. Mutation inthe human acetylcholinesterase-associated gene, COLQ is responsible for congenital myasthenic syndrome with end-plate acetylcholinesterase deficiency. Am J Hum Genet 1998;63:967-75.
17. Shapira YA, Sadeh ME, Bergtraum MP et al. The novel COLQ mutations and variation of phenotypic expressivity due to G240X. Neurology 2002;58:603-9.