Myotone Syndrome und die Differenzialdiagnose von Serienentladungen im EMG

Zusammenfassung

Myotone Serien im Elektromyogramm (EMG) gelten als charakteristischer Befund für myotone Erkrankungen. Elektromyographische Spontanaktivität, die mit myotonen Serien verwechselt werden kann, kommt aber auch bei einer Reihe anderer Erkrankungen vor, so bei der Neuromyotonie und dem Schwartz-Jampel-Syndrom, bei Myositiden, Glykogenosen, einzelnen selteneren Myopathien und bei chronisch neurogenen Erkrankungen. Myotone Serien fehlen nie bei den Chloridkanalmyotonien und werden häufig bei Patienten mit einer der myotonen Dystrophien gefunden. Bei Natriumkanalerkrankungen sind sie meistens unprovoziert nachweisbar, gelegentlich aber nur nach lokaler Muskelkühlung, Arbeits- oder Kaliumbelastung. Sie kommen bei periodischen Paralysen, die nicht auf einer Natriumkanalmutation beruhen, nicht vor. Auf dieser Basis werden Hinweise sowohl zur Differenzialdiagnose der myotonen Dystrophien und der Kanalerkrankungen als auch zur Differenzialdiagnose von Serienentladungen im EMG gegeben.

Abstract

Myotonic discharges in concentric needle electromyography are often considered to be diagnostic for myotonic disorders. However, electromyographic spontaneous activity that can be mistaken for myotonic discharges may occur in a variety of other disorders, such as neuromyotonia, Schwartz-Jampel syndrome, myosites, glycogenoses, a few rare myopathies, and in chronic neurogenic disorders. Myotonic discharges are always present in chloride channel myotonias and frequently in patients with one of the myotonic dystrophies. Myotonic discharges are a frequent finding in patients with sodium channelopathy, but in some patients they occur only by provoking their occurrence via local muscle cooling, work, or potassium load. So far, myotonic discharges have never occurred in patients with periodic paralyses not caused by altered sodium channels. Based on this fact we present pointers to differential diagnosis of myotonic dystrophies and muscle channelopathies as well as to differential diagnosis of myotonic discharges and similar EMG findings.

Key words

Electromyography - myotonia - myotonic discharges - spontaneous activity - channelopathy

Literatur

• 1 Dengler R. Spontanaktivität. In: Bischoff C, Dengler R, Hopf H (Hrsg) Elektromyographie-Nervenleitungsuntersuchungen. Stuttgart; Thieme 2003: 44-53
• 2 Lehmann-Horn F, Engel A G, Ricker K, Rüdel R. The Periodic Paralyses and Paramyotonia Congenita. In: Engel A, Franzini-Armstrong C (eds) Myology. 2^nd ed. New York; McGraw-Hill 1994: 1303-1334
• 3 Schulte-Mattler W. Myotonien, Myositis, nichtentzündliche Myopathien. In: Bischoff C, Dengler R, Hopf H (Hrsg) Elektromyographie-Nervenleitungsuntersuchungen. Stuttgart; Thieme 2003: 132-134
• 4 Caruso G, Eisen A, Stalberg E, Kimura J, Mamoli B, Dengler R, Santoro L, Hopf H C. Clinical EMG and glossary of terms most commonly used by clinical electromyographers.  Electroenceph clin Neurophysiol. 1999;  Suppl 52 189-198
• 5 Bischoff C, Schulte-Mattler W, Conrad B. Das EMG-Buch. Stuttgart; Thieme 2005
• 6 Gatchel J R, Zoghbi H Y. Diseases of unstable repeat expansion: mechanisms and common principles.  Nat Rev Genet. 2005;  6 743-755
• 7 Mankodi A, Takahashi M P, Jiang H, Beck C L, Bowers W J, Moxley R T, Cannon S C, Thornton C A. Expanded CUG repeats trigger aberrant splicing of ClC-1 chloride channel pre-mRNA and hyperexcitability of skeletal muscle in myotonic dystrophy.  Mol Cell. 2002;  10 35-44
• 8 Charlet B N, Savkur R S, Singh G, Philips A V, Grice E A, Cooper T A. Loss of the muscle-specific chloride channel in type 1 myotonic dystrophy due to misregulated alternative splicing.  Mol Cell. 2002;  10 45-53
• 9 Ranum L P, Rasmussen P F, Benzow K A, Koob M D, Day J W. Genetic mapping of a second myotonic dystrophy locus.  Nat Genet. 1998;  19 196-198
• 10 Liquori C L, Ricker K, Moseley M L, Jacobsen J F, Kress W, Naylor S L, Day J W, Ranum L P. Myotonic dystrophy type 2 caused by a CCTG expansion in intron 1 of ZNF9.  Science. 2001;  293 864-867
• 11 Bachinski L L, Udd B, Meola G, Sansone V, Bassez G, Eymard B, Thornton C A, Moxley R T, Harper P S, Rogers M T, Jurkat-Rott K, Lehmann-Horn F, Wieser T, Gamez J, Navarro C, Bottani A, Kohler A, Shriver M D, Sallinen R, Wessman M, Zhang S, Wright F A, Krahe R. Confirmation of the type 2 myotonic dystrophy (CCTG)n expansion mutation in patients with proximal myotonic myopathy/proximal myotonic dystrophy of different European origins: a single shared haplotype indicates an ancestral founder effect.  Am J Hum Genet. 2003;  73 835-848
• 12 Finsterer J. Myotonic dystrophy type 2.  Eur J Neurol. 2002;  9 441-447
• 13 Day J W, Ricker K, Jacobsen J F, Rasmussen L J, Dick K A, Kress W, Schneider C, Koch M C, Beilman G J, Harrison A R, Dalton J C, Ranum L P. Myotonic dystrophy type 2: molecular, diagnostic and clinical spectrum.  Neurology. 2003;  60 657-664
• 14 Thornton C, Griggs R, Moxley R. PROMM Syndrome (Ricker's Disease).  Ann Neurol. 1995;  38 273
• 15 Ricker K, Koch M C, Lehmann-Horn F, Pongratz D, Otto M, Heine R, Moxley 3rd  R T. Proximal myotonic myopathy: a new dominant disorder with myotonia, muscle weakness, and cataracts.  Neurology. 1994;  44 1448-1452
• 16 Ricker K, Koch M C, Lehmann-Horn F, Pongratz D, Speich N, Reiners K, Schneider C, Moxley 3rd  R T. Proximal myotonic myopathy. Clinical features of a multisystem disorder similar to myotonic dystrophy.  Arch Neurol. 1995;  52 25-31
• 17 Schulte-Mattler W, Zierz S. Myotonien und Ionenkanalerkrankungen. In: Berlit P (Hrsg) Klinische Neurologie. Berlin, Heidelberg, New York; Springer 1999: 250-259
• 18 Venance S L, Cannon S C, Fialho D, Fontaine B, Hanna M G, Ptacek L J, Tristani-Firouzi M, Tawil R, Griggs R C. CINCH investigators . The primary periodic paralyses: diagnosis, pathogenesis and treatment.  Brain. 2006;  129 8-17
• 19 Jurkat-Rott K, Lerche H, Lehmann-Horn F. Skeletal muscle channelopathies.  J Neurol. 2002;  249 1493-1502
• 20 Jurkat-Rott K, Lehmann-Horn F. Muscle channelopathies and critical points in functional and genetic studies.  J Clin Invest. 2005;  115 2000-2009
• 21 Colding-Jorgensen E. Phenotypic variability in myotonia congenita.  Muscle Nerve. 2005;  32 19-34
• 22 Pusch M. Myotonia caused by mutations in the muscle chloride channel gene CLCN1.  Hum Mutat. 2002;  19 423-434
• 23 Rüdel R, Lehmann-Horn F, Ricker K. The nondystrophic myotonias. In: Engel A, Franzini-Armstrong C (eds) Myology. 2^nd ed. New York; McGraw-Hill 1994: 1291-1302
• 24 Fournier E, Arzel M, Sternberg D, Vicart S, Laforet P, Eymard B, Willer J C, Tabti N, Fontaine B. Electromyography guides toward subgroups of mutations in muscle channelopathies.  Ann Neurol. 2004;  56 650-661
• 25 Ricker K, Hertel G, Langscheid K, Stodieck G. Myotonia not aggravated by cooling. Force and relaxation of the adductor pollicis in normal subjects and in myotonia as compared to paramyotonia.  J Neurol. 1977;  216 9-20
• 26 Nielsen V, Friis M, Johnsen T. Electromyographic distinction between paramyotonia congenita and myotonia congenita: effect of cold.  Neurology. 1982;  32 827-832
• 27 Ricker K, Lehmann-Horn F, Moxley 3rd  R T. Myotonia fluctuans.  Arch Neurol. 1990;  47 268-272
• 28 Ricker K, Moxley 3rd  R T, Heine R, Lehmann-Horn F. Myotonia fluctuans. A third type of muscle sodium channel disease.  Arch Neurol. 1994;  51 1095-1102
• 29 Lennox G, Purves A, Marsden D. Myotonia fluctuans.  Arch Neurol. 1992;  49 1010-1011
• 30 Trudell R, Kaiser K, Griggs R. Acetazolamide repsonsive myotonia congenita.  Neurology. 1987;  37 488-491
• 31 Ptacek L J, Tawil R, Griggs R C, Storvick D, Leppert M. Linkage of atypical myotonia congenita to sodium channel locus.  Neurology. 1992;  42 431-433
• 32 Ptacek L J, George Jr A L, Griggs R C, Tawil R, Kallen R G, Barchi R L, Robertson M, Leppert M F. Identification of a mutation in the gene causing hyperkalemic periodic paralysis.  Cell. 1991;  67 1021-1027
• 33 Rojas C, Wang J, Schwartz L, Hoffman E P, Powell B, Brown R J. A Met-to-Val mutation in the skeletal muscle Na+ channel alpha-subunit in hyperkalaemic periodic paralysis.  Nature. 1991;  354 387-389
• 34 McClatchey A I, McKenna-Yasek D, Cros D, Worthen H G, Kuncl R W, DeSilva S M, Cornblath D R, Gusella J F, Brown Jr R H. Novel mutations in families with unusual and variable disorders of the skeletal muscle sodium channel.  Nat Genet. 1992;  2 148-152
• 35 Miller T M, Dias da Silva M R, Miller H A, Kwiecinski H, Mendell J R, Tawil R, McManis P, Griggs R C, Angelini C, Servidei S, Petajan J, Dalakas M C, Ranum L P, Fu Y H, Ptacek L J. Correlating phenotype and genotype in the periodic paralyses.  Neurology. 2004;  63 1647-1655
• 36 Ptacek L J, Tawil R, Griggs R C, Engel A G, Layzer R B, Kwiecinski H, McManis P G, Santiago L, Moore M, Fouad G, Bradley P, Leppert M F. Dihydropyridine receptor mutations cause hypokalemic periodic paralysis.  Cell. 1994;  77 863-868
• 37 Bulman D, Scoggan K, Oene M van, Nicolle M, Hahn A, Trollar L, Ebers G C. A novel sodium channel mutation in a family with hypokalemic periodic paralysis.  Neurology. 1999;  53 1932-1936
• 38 Jurkat-Rott K, Mitrovic N, Hang C, Kouzmekine A, Iaizzo P, Herzog J, Lerche H, Nicole S, Vale-Santos J, Chauveau D, Fontaine B, Lehmann-Horn F. Voltage-sensor sodium channel mutations cause hypokalemic periodic paralysis type 2 by enhanced inactivation and reduced current.  Proc Natl Acad Sci. 2000;  97 9549-9554
• 39 Struyk A, Scoggan K, Bulman D, Cannon S C. The human skeletal muscle Na channel mutation R669H associated with hypokalemic periodic paralysis enhances slow inactivation.  J Neurosci. 2000;  20 8610-8617
• 40 Bendahhou S, Cummins T, Hahn A, Langlois S, Waxman S, Ptacek L J. Sodium channel inactivation defects are associated with azetazolamid-exacerbated hypokalemic paralysis.  Ann Neurol. 2001;  50 417-420
• 41 Sternberg D, Maisonobe T, Jurkat-Rott K, Nicole S, Launay E, Chauveau D, Tabti N, Lehmann-Horn F, Hainque B, Fontaine B. Hypokalaemic periodic paralysis type 2 caused by mutations at codon 672 in the muscle sodium channel gene SCN4A.  Brain. 2001;  124 1091-1099
• 42 Davies N P, Eunoson L, Samuel M, Hanna M G. Sodium channel gene mutations in a hypokalemic periodic paralysis: an uncommon cause in the UK.  Neurology. 2001;  57 1323-1325
• 43 Plaster N M, Tawil R, Tristani-Firouzi M, Canun S, Bendahhou S, Tsunoda A, Donaldson M R, Iannaccone S T, Brunt E, Barohn R, Clark J, Deymeer F, George Jr A L, Fish F A, Hahn A, Nitu A, Ozdemir C, Serdaroglu P, Subramony S H, Wolfe G, Fu Y H, Ptacek L J. Mutations in Kir2.1 cause the developmental and episodic electrical phenotypes of Andersen's syndrome.  Cell. 2001;  105 511-519
• 44 Tristani-Firouzi M, Jensen J L, Donaldson M R, Sansone V, Meola G, Hahn A, Bendahhou S, Kwiecinski H, Fidzianska A, Plaster N, Fu Y H, Ptacek L J, Tawil R. Functional and clinical characterization of KCNJ2 mutations associated with LQT7 (Andersen syndrome).  J Clin Invest. 2002;  110 381-388
• 45 Tawil R, Ptacek L J, Pavlakis S G, DeVivo D C, Penn A S, Ozdemir C, Griggs R C. Andersen's syndrome: potassium-sensitive periodic paralysis, ventricular ectopy, and dysmorphic features.  Ann Neurol. 1994;  35 326-330
• 46 Bendahhou S, Fournier E, Sternberg D, Bassez G, Furby A, Sereni C, Donaldson M R, Larroque M M, Fontaine B, Barhanin J. In vivo and in vitro functional characterization of Andersen's syndrome mutations.  J Physiol. 2005;  565 731-741
• 47 Mertens H G, Zschocke S. Neuromyotonie.  Klin Wochenschr. 1965;  43 917-925
• 48 Isaacs H. Continuous muscle fibre activity in an Indian male with additional evidence of terminal motor fibre abnormality.  J Neurol Neurosurg Psychiatry. 1967;  30 126-133
• 49 Ricker K, Rohkamm R, Moxley 3rd  R T. Hypertrophy of the calf with S-1 radiculopathy.  Arch Neurol. 1988;  45 660-664