ICD-11 classes
08 Diseases of the nervous system
Other disorders of the nervous system
8E4A — Paraneoplastic or autoimmune disorders of the nervous system
8E4A.2 — Paraneoplastic or autoimmune neuromuscular transmission...

ICD-11 8E4A.2 — Paraneoplastic or autoimmune neuromuscular transmission disorders

NMT disorders are defined by a variable disturbance of the function of the neuromuscular transmission, resulting in fluctuating muscle weakness and fatigue. These are usually classified into pre- and postsynaptic disorders.Presynaptic disorders, mainly the Lambert Eaton Myasthenic Syndrome (LEMS) is associated with antibodies targeting the voltage gated calcium channels (PQ and N type). LEMS is associated with malignancy (pulmonary or extra-pulmonary small cell carcinoma) in about 50 % of cases. In the context of LEMS the detection of SOX 1 (anti glial nuclear) antibodies is highly predictive of cancer.Postsynaptically, myasthenia gravis is mostly (>90%) associated with antibodies targeting the muscle acetylcholine receptor (AChR) or rarely other proteins (including muscle -specific kinase -MUSK). Myasthenia is usually not considered a paraneoplastic disease, with the exception of thymoma in about 10% cases.

The diagnosis includes nothing.

The diagnosis excludes nothing.

Diagnosis with code 8E4A.2 contains 2 clarifying diagnoses:

1. 8C62 — Lambert-Eaton syndrome
2. 8C60 — Myasthenia gravis
   It contains 4 clarifying diagnoses.