Test Catalog

Test ID: MDS1    
Movement Disorder Evaluation, Serum

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 is performed at an additional charge.

 

If IFA pattern suggest AMPA-R antibody, then AMPA-R AbCBA 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 are 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 ANN1S, ANN2S, ANN3S, PCABP, PCAB2, PCATR or AGN1S, then paraneoplastic autoantibody Western blot is performed at an additional charge.

 

See Movement Disorder Evaluation Algorithm, Serum 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 65kDa 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

GANG

AChR Ganglionic Neuronal Ab, S

<0.02

AMPHS

Amphiphysin Ab, S

<1:240

AGN1S

Anti-Glial Nuclear Ab, Type 1

<1:240

ANN1S

Anti-Neuronal Nuclear Ab, Type 1

<1:240

ANN2S

Anti-Neuronal Nuclear Ab, Type 2

<1:240

ANN3S

Anti-Neuronal Nuclear Ab, Type 3

<1:240

CS2CS

CASPR2-IgG CBA, S

Negative

CRMS

CRMP-5-IgG, S

<1:240

CRMWS

CRMP-5-IgG Western Blot, S

Negative

DPPIS

DPPX Ab IFA, S

Negative

GD65S

GAD65 Ab Assay, S

<0.02

LG1CS

LGI1-IgG CBA, S

Negative

GL1IS

mGluR1 Ab IFA, S

Negative

VGKC

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

<0.02

NMDCS

NMDA-R Ab CBA, S

Negative

CCN

N-Type Calcium Channel Ab

<0.03

CCPQ

P/Q-Type Calcium Channel Ab

<0.02

PCABP

Purkinje Cell Cytoplasmic Ab Type 1

<1:240

PCAB2

Purkinje Cell Cytoplasmic Ab Type 2

<1:240

PCATR

Purkinje Cell Cytoplasmic Ab Type Tr

<1:240

 -

 

 

 

Reflex Information:

Test ID

Reporting Name

Reference Value

ABLOT

Amphiphysin Western Blot, S

Negative

AMPIS

AMPA-R Ab IF Titer Assay, S

<1:120

AMPCS

AMPA-R Ab CBA, S

Negative

DPPCS

DPPX Ab CBA, S

Negative

DPPTS

DPPX Ab IFA Titer, S

<1:240

GABCS

GABA-B-R Ab CBA, S

Negative

GABIS

GABA-B-R Ab IF Titer Assay, S

<1:120

GL1CS

mGluR1 Ab CBA, S

Negative

GL1TS

mGluR1 Ab IFA Titer, S

<1:240

NMDIS

NMDA-R Ab IF Titer Assay, S

<1:120

NMOFS

NMO/AQP4 FACS, S

Negative

NMOTS

NMO/AQP4 FACS Titer, S

<1:5

WBN

Paraneoplastic Autoantibody WBlot,S

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 serum draw may cause a false negative result.

 

Intravenous immunoglobulin (IVIg) treatment prior to the serum 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