Stiff-Person Spectrum Disorders, including Progressive Encephalomyelitis with Rigidity and Myoclonus, Interpretation, Serum
Use
Stiff-person spectrum disorders, including classical or focal forms such as stiff-limb or stiff-trunk, and progressive encephalomyelitis with rigidity and myoclonus (PERM), are linked to central nervous system hyperexcitability with symptoms of stiffness, spasms, heightened startle responses, and falls. The test aids in identifying paraneoplastic and idiopathic autoimmune causes through the presence of specific neuronal IgG antibodies such as GAD65 and others. It is important in differentiating between these conditions and guiding appropriate treatment options as patients may respond to immune therapy. GlyR-IgG, for example, may predict immune therapy responses even in patients co-existing with GAD65 antibodies.
Special Instructions
This test is not orderable alone but must be part of a larger profile. Additional test setup details and interfacing support between labs can be accessed through setup resources provided.
Limitations
Negative results do not exclude stiff-person spectrum disorders or progressive encephalomyelitis with rigidity and myoclonus (PERM). Caution is advised when interpreting GAD65 antibody-positive values below 20 nmol/L as they can occur in 8% of the general population. Nevertheless, GAD65 autoimmunity is associated with neurological symptoms in other autoimmune diseases. The test should be used in conjunction with clinical findings for a comprehensive assessment.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 69048-7
- 69048-7
- 48767-8
Result Turnaround Time
8-12 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
Not provided
Minimum Volume
Not provided
Storage Instructions
Refrigerated (preferred) for up to 28 days, ambient stability up to 72 hours, and frozen stability up to 28 days.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 28 days |
| Frozen | 28 days |