Multifocal motor neuropathy without overt conduction block

Pakiam, Anthony S.-I.; Parry, Gareth

doi:10.1002/(sici)1097-4598(199802)21:2<243::aid-mus14>3.0.co;2-2

Cited by 95 publications

(63 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Der Nachweis von IgM-Antikörpern gegen GM1-Ganglioside und von persistierenden partiellen motorischen Leitungsblöcken in der Elektroneurographie wurden lange als unverzichtbar für die Diagnosestellung angesehen [17]. Diese Befunde lassen sich jedoch neueren Untersuchungen zufolge trotz des Vorliegens einer MMN nicht immer nachweisen [14,22]. Es ist daher mög-lich, daß Patienten mit MMN, welche die oben genannten strengen Diagnosekriterien nicht erfüllen, eine Therapie vorenthalten wird.…”

Section: Schlüsselwörterunclassified

“…Da die bei erworbenen entzündlichen Neuropathien häufig ebenso anzutreffende zeitliche Dispersion des MSAP (temporal dispersion) dessen Amplitude durch Phasenauslöschung deutlich reduzieren kann, kann die sichere Diagnosestellung eines LB schwierig sein. Ein partieller LB wird nur bei einer Amplitudenreduktion des MSAP von mehr als 20 % bei einer maximalen Verlängerung des MSAP um 15 % diagnostiziert [21].In neueren Studien konnten jedoch nur bei etwa 30 % der betroffenen Patienten mit MMN typische Leitungsblöcke beobachtet werden [14,22], weshalb der zuvor für die Diagnosestellung als essentiell betrachtete Nachweis von Leitungsblöcken derzeit kontrovers diskutiert wird. Wie an dem dargestellten Patienten deutlich wird, sollte die Diagnosestellung einer MMN und die mögliche Behandlung deshalb unseres Erachtens nicht zwingend von der Existenz von Leitungsblöcken abhängig gemacht werden.…”

Section: Elektrophysiologie Und Diagnosestellungunclassified

“…Wie an dem dargestellten Patienten deutlich wird, sollte die Diagnosestellung einer MMN und die mögliche Behandlung deshalb unseres Erachtens nicht zwingend von der Existenz von Leitungsblöcken abhängig gemacht werden. Entscheidend ist vielmehr der Nachweis anderer neurographischer Zeichen für eine Demyelinisierung an motorischen Nerven, die bei bis zu 94 % der Patienten mit MMN nachweisbar sind [14,22]. Zusätzlich zeigen sich jedoch auch bei etwa der Hälf-te der Patienten rein axonale und bei 80 % gemischt axonal-demyelinisierende Schädigungen an einzelnen Nerven [14].…”

Section: Elektrophysiologie Und Diagnosestellungunclassified

See 2 more Smart Citations

Die multifokale motorische Neuropathie

Fischer¹,

Reimann²,

Schröder³

et al. 2002

Der Nervenarzt

View full text Add to dashboard Cite

Multifocal motor neuropathy (MMN) is an acquired immune mediated motor neuropathy with characteristic clinical and neurographic features.Clinically, MMN is characterized by progressive, predominantly distal and asymmetrical limb weakness. Neurographic recordings demonstrate features of multifocal demyelination with or without conduction block. Sensory nerves are not affected. Due to strict diagnostic criteria,MMN may be underdiagnosed in patients with motor neuropathies. Since intravenous immunglobulins are an efficient therapy for MMN,clinical and electrophysiological differentiation from other neuromuscular disorders is mandatory to prevent progressive impairment of motor function. We present a patient with MMN and review the clinical, electrophysiological, and histological features. In addition,pathogenesis, differential diagnosis and treatment of MMN are discussed.

show abstract

Section: Schlüsselwörterunclassified

Section: Elektrophysiologie Und Diagnosestellungunclassified

See 1 more Smart Citation

Die multifokale motorische Neuropathie

Fischer¹,

Reimann²,

Schröder³

et al. 2002

Der Nervenarzt

View full text Add to dashboard Cite

show abstract

“…[2][3][4] Although, the pathophysiology underlying CB and other nerve dysfunction in MMN is not exactly clear, the node of Ranvier and its surrounding structures likely play an important role in MMN. [5][6][7] In addition, clinical response to immune modulation therapy and elevated titers of anti-ganglioside antibodies, such as immunoglobulin M (IgM) anti-GM1 antibodies in 30-88% of patients with MMN, support an immune-mediated etiology.…”

mentioning

confidence: 99%

“…[8][9][10] The absence of CB in some patients may represent limitations of electrodiagnostic testing for identification of CB at very proximal or distal nerve segments. 3,4 It may also represent activity-dependent CB (ADCB), which is not detectable by routine electrodiagnostic studies. The pathophysiology of ADCB has been attributed to Na + -K + pump-induced axonal hyperpolarization.…”

mentioning

confidence: 99%

Delayed Appearance of Conduction Block in Multifocal Motor Neuropathy—A Case Report

Darki¹,

Beydoun²

2017

US Endocrinology

View full text Add to dashboard Cite

I ntroduction: Multifocal motor neuropathy (MMN) is a rare, treatable, immune-mediated neuropathy often associated with multifocal conduction block (CB). The hallmark electrodiagnostic feature is the presence of CB occurring at non-entrapment sites. However, MMN without CB has also been described and can be diagnosed, even in the absence of CB. Therefore, it is crucial to diagnose and identify MMN cases without CB, as it is a treatable disorder. Case presentation: We present a case with progressive symptoms of asymmetric distal upper and lower extremity weakness with no sensory deficits. Intravenous immunoglobulin (IVIG) therapy was initiated, as the patient fulfilled the criteria for probable MMN, despite the absence of CB. The patient's symptoms demonstrated a relative plateau phase in response to IVIG. Although the patient lost follow-up visits, repeated electrodiagnostic study, conducted 11 years after initial presentation, revealed new CB in nerve segments that previously did not show any evidence of CB. Conclusion: This case emphasizes the importance of early diagnosis and respectively initiating early IVIG treatment in MMN, in order to maintain the clinical function. Underdiagnosis of clinically suspected MMN, based on absence of CB, will result in denial of treatment to potential IVIG responders. Keywords Multifocal motor neuropathy, conduction block, intravenous immunoglobulinDisclosure: Said R Beydoun has received grant research support from Alexion, Argenx, Daiichi Pharma, and Pfizer. He has served as an advisory board member for Grifols, MT Pharma and Sarepta, and is a speaker for Grifols. Leila Darki has nothing to disclose in relation to this article.Compliance with Ethics: All procedures were followed in accordance with the responsible committee on human experimentation and with the Helsinki Declaration of 1975 and subsequent revisions. Written informed consent was not obtained from the patient for publication of this case report due to loss of follow-up; no identifying information or images were used in the publication of this paper.Open Access: This article is published under the Creative Commons Attribution Noncommercial License, which permits any non-commercial use, distribution, adaptation and reproduction provided the original author(s) and source are given appropriate credit. 1,2 Presence of multifocal motor conduction block (CB) at locations other than common entrapment sites, with normal sensory nerve conduction in the corresponding segments, is the hallmark of MMN, but some patients with typical MMN have no detectable CB. 2-4Although, the pathophysiology underlying CB and other nerve dysfunction in MMN is not exactly clear, the node of Ranvier and its surrounding structures likely play an important role in MMN. [5][6][7] In addition, clinical response to immune modulation therapy and elevated titers of anti-ganglioside antibodies, such as immunoglobulin M (IgM) anti-GM1 antibodies in 30-88% of patients with MMN, support an immune-mediated etiology. [8][9][10] The absence of CB in some pa...

show abstract