Test Catalog

Test ID: MDC1    
Movement Disorder Evaluation, Spinal Fluid

Useful For Suggests clinical disorders or settings where the test may be helpful

Evaluating patients with suspected paraneoplastic or other autoimmune movement disorders including patients with ataxia, chorea, dyskinesias, myoclonus, parkinsonism, and stiff-person spectrum.

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

If IFA suggests Amphiphysin antibody, then Amphiphysin Western blot are performed at an additional charge.

 

If IFA pattern suggest AMPA-R antibody, then AMPA-R Ab CBA and AMPA-R titer are performed at an additional charge.

 

If IFA pattern suggests DPPX antibody, then DPPX Ab CBA and DPPX titer are performed at an additional charge.

 

If IFA pattern suggests GABA-B-R antibody, then GABA-B-R Ab CBA and GABA-B-R titer are performed at an additional charge.

 

If IFA pattern suggests mGluR1 antibody, then mGluR1 Ab CBA and mGluR1 titer are performed at an additional charge.

 

If IFA pattern suggests NMDA-R antibody and NMDA-R Ab CBA is positive, then NMDA-R titer is performed at an additional charge.

 

If IFA pattern suggests NMO/AQP4-IgG, then NMO/AQP4-IgG FACS is performed at an additional charge.

 

If NMO/AQP4-IgG FACS screen assay requires further investigation, then NMO/AQP4-IgG FACS titration assay is performed at an additional charge.

 

If indirect immunofluorescence assay (IFA) suggests ANN1C, ANN2C, ANN3C, PCA1C, PCA2C, PCTRC or AGN1C, then paraneoplastic autoantibody Western blot is performed at an additional charge.

 

See Movement Disorder Evaluation Algorithm, Spinal Fluid in Special Instructions.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Autoimmune movement disorders encapsulate a large and diverse group of neurologic disorders occurring either in isolation or accompanying more diffuse autoimmune encephalitic illnesses.

 

The full range of movement phenomena has been described and, as they often occur in adults, many of the presentations can mimic neurodegenerative disorders, such as autoimmune chorea mimicking Huntington disease. Disorders may be ataxic, hypokinetic (parkinsonism), or hyperkinetic (myoclonus, chorea other dyskinetic disorders).

 

The autoantibody targets are diverse and include neuronal surface proteins such as leucine-rich, glioma-inactivated 1 (LGI1), as well as antibodies reactive with intracellular antigens (such as PCA-1) that are markers of a central nervous system process mediated by CD8+ cytotoxic T cells.

 

In some instances (such as Purkinje cell cytoplasmic antibody-1 (PCA-1) autoimmunity), antibodies detected in serum and cerebrospinal fluid can be indicative of a paraneoplastic cause, and may direct the cancer search. In other instances (such as 65 kDa isoform of glutamic acid decarboxylase [GAD65] autoimmunity), a paraneoplastic cause is very unlikely, and early treatment with immunotherapy may promote improvement or recovery.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Test ID

Reporting Name

Reference Value

AMPHC

Amphiphysin Ab, CSF

<1:2

AGN1C

Anti-Glial Nuclear Ab, Type 1

<1:2

ANN1C

Anti-Neuronal Nuclear Ab, Type 1

<1:2

ANN2C

Anti-Neuronal Nuclear Ab, Type 2

<1:2

ANN3C

Anti-Neuronal Nuclear Ab, Type 3

<1:2

CS2CC

CASPR2-IgG CBA, CSF

Negative

CRMWC

CRMP-5-IgG Western Blot, CSF

Negative

CRMC

CRMP-5-IgG, CSF

<1:2

DPPIC

DPPX Ab IFA, CSF

Negative

GD65C

GAD65 Ab Assay, CSF

<0.02

LG1CC

LGI1-IgG CBA, CSF

Negative

GL1IC

mGluR1 Ab IFA, CSF

Negative

NMDCC

NMDA-R Ab CBA, CSF

Negative

PCTRC

Purkinje Cell Cytoplasmic Ab Type Tr

<1:2

PCA1C

Purkinje Cell Cytoplasmic Ab Type 1

<1:2

PCA2C

Purkinje Cell Cytoplasmic Ab Type 2

<1:2

VGKCC

Neuronal (V-G) K+ Channel Ab, CSF

<0.02

 

Reflex Information:

Test ID

Reporting Name

Reference Value

ABLTC

Amphiphysin Western Blot, CSF

Negative

AMPIC

AMPA-R Ab IF Titer Assay, CSF

<1:2

AMPCC

AMPA-R Ab CBA, CSF

Negative

DPPTC

DPPX Ab IFA Titer, CSF

<1:2

DPPCC

DPPX Ab CBA, CSF

Negative

GABIC

GABA-B-R Ab IF Titer Assay, CSF

<1:2

GABCC

GABA-B-R Ab CBA, CSF

Negative

GL1TC

mGluR1 Ab IFA Titer, CSF

<1:2

GL1CC

mGluR1 Ab CBA, CSF

Negative

NMDIC

NMDA-R Ab IF Titer Assay, CSF

<1:2

NMOFC

NMO/AQP4 FACS, CSF

Negative

NMOTC

NMO/AQP4 FACS Titer, CSF

<1:2

WBNC

Paraneoplastic Autoantibody WBlot, CSF

Negative

Interpretation Provides information to assist in interpretation of the test results

A positive antibody result is consistent with a diagnosis of an autoimmune movement disorder. A search for cancer may be indicated, depending on the antibody profile. A trial of immune therapy may bring about improvement in neurological symptoms.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

A negative antibody test result does not exclude an autoimmune movement disorder.

 

Corticosteroid treatment prior to the cerebrospinal fluid (CSF) draw may cause a false negative result.

 

Intravenous immunoglobulin (IVIg) treatment prior to the CSF draw may cause a false positive result.

Clinical Reference Recommendations for in-depth reading of a clinical nature

Honorat JA, McKeon A: Autoimmune Movement Disorders: a Clinical and Laboratory Approach. Curr Neurol Neurosci Rep 2017 Jan;17(1):4 doi: 10.1007/s11910-017-0709-2

Special Instructions Library of PDFs including pertinent information and forms related to the test