Tests for Neurological Disorders

September 2010

Autoantibody tests performed on serum and spinal fluid aid in the diagnosis of autoimmune disorders of the brain, nerve, and muscle that are often a reflection of immune responses initiated by unsuspected cancer. These disorders are commonly mistaken for multiple sclerosis, stroke, and untreatable degenerative disorders.

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Dysautonomias

• Autoimmune Dysautonomia Evaluation, Serum
  The most commonly encountered autoantibody marker of autoimmune dysautonomia is the neuronal ganglionic alpha-3-AChR autoantibody (Ab). Importantly, cancer is detected in 30% of patients with alpha-3-AChR Ab. MORE >
• Autoimmune Gastrointestinal Dysmotility Evaluation, Serum
  Autoimmune gastrointestinal dysmotility (AGID) is a limited form of dysautonomia that is sometimes a paraneoplastic disorder. Neoplasms found most commonly are lung cancer, thymoma and miscellaneous adenocarcinomas. MORE >
• Familial Dysautonomia, Mutation Analysis
  Mutations in the gene encoding IkappaB kinase complex-associated proteins (IKBKAP) cause the clinical findings of familial dysautonomia. The carrier rate in the Ashkenazi Jewish population is 1/31. MORE >

Lambert-Eaton Syndrome (LES)

• Myasthenia Gravis (MG)/Lambert-Eaton Syndrome (LES) Evaluation
  A patient's autoantibody profile is more informative than the result of any single test for supporting a diagnosis of Myasthenia Gravis (MG) or Lambert-Eaton syndrome (LES), and for predicting the likelihood of lung carcinoma. MORE >

Myasthenia Gravis (MG)

• Acetylcholine Receptor (Muscle AChR) Binding Antibody, Serum
  The assay for muscle AChR binding antibodies is considered a first-order test for the laboratory diagnosis of MG, and for detecting "subclinical MG" in recipients of D-penicillamine, in patients with thymoma without clinical evidence of MG, and in patients with graft-versus-host disease. MORE >
• Myasthenia Gravis (MG) Evaluation, Adult
  The patient's autoantibody profile is more informative than the result of any single test for supporting a diagnosis of MG, and for predicting the likelihood of thymoma. MORE >
• Myasthenia Gravis (MG) Evaluation, Pediatric
  Seronegativity is more frequent in children with prepubertal onset of acquired MG (33%-50%) than in adults (<10%). Thymoma is rare under age 20, and striational antibodies... also are rare, except in the context of MG related to neoplasia (usually thymoma or neuroblastoma), graft-versus-host disease, autoimmune liver disease, or D-penicillamine therapy. MORE >
• Myasthenia Gravis (MG) Evaluation, Thymoma
  It is estimated that approximately 20% of adult patients have a paraneoplastic basis for MG. Thymoma is the most common neoplasm, often occult at the onset of MG, its diagnosis may precede MG onset. MORE >
• Myasthenia Gravis (MG)/Lambert-Eaton Syndrome (LES) Evaluation
  A patient's autoantibody profile is more informative than the result of any single test for supporting a diagnosis of Myasthenia Gravis (MG) or Lambert-Eaton syndrome (LES), and for predicting the likelihood of lung carcinoma. MORE >
• Striational (Striated Muscle) Antibodies, Serum
  Autoantibodies directed against the contractile elements of striatedmuscle are found in 30% of adult patients with myasthenia gravis (MG) and in 80% of those with thymoma. MORE >

Neuromuscular Hyperexcitability

• Autoimmune Dysautonomia Evaluation, Serum
  The most commonly encountered autoantibody marker of autoimmune dysautonomia is the neuronal ganglionic alpha-3-AChR autoantibody (Ab).... Importantly, cancer is detected in 30% of patients with alpha-3-AChR Ab.MORE >
• Glutamic Acid Decarboxylase (GAD65), Serum
  Antibodies directed against the 65-kd isoform of GAD(GAD65) are seen in a variety of autoimmune neurologic disorders including stiff-man (Moersch-Woltman) syndrome, autoimmunecerebellitis, brain stem encephalitis, seizure disorders, neuromyelitisoptica and other myelopathies, myasthenia gravis, Lambert-Eaton syndrome, and dysautonomia. MORE >
• Paraneoplastic Autoantibody Evaluation, Serum
  Paraneoplastic autoimmune neurological disorders reflect a patient's humoral and cellular immune responses to cancer. The cancer may be new or recurrent, is usually limited in metastatic volume, and is often occult by standard imaging procedures. MORE >

Neuromyelitis Optica (NMO) Spectrum Disorders

• Neuromyelitis Optica (NMO) Autoantibody, IgG - Serum
  Seropositivity for NMO autoantibody IgG (NMO-IgG) allows early diagnostic distinction between NMO (73% positive; 91% specific) and multiple sclerosis (0% positive). NMO-IgG is uniformly negative in patients with classical multiple sclerosis, for which no biomarker is currently recognized. MORE >
• Neuromyelitis Optica (NMO) Autoantibody, IgG - Spinal Fluid
  Serum is the preferred specimen for detection of NMO-IgG; cerebrospinal fluid is usually less informative. MORE >

Peripheral Nerve Disorders

• Peripheral Nerve Path Consult
  Neuropathic abnormalities include decreased density of myelinated fibers, segmental demyelination, and axonal degeneration. Some possible interstitial abnormalities that affect nerves include necrotizing vasculitis and amyloidosis. MORE >

Thymoma

• Myasthenia Gravis (MG) Evaluation, Thymoma
  It is estimated that approximately 20% of adult patients have a paraneoplastic basis for MG. Thymoma is the most common neoplasm, often occult at the onset of MG, its diagnosis may precede MG onset. MORE >