Stiff person syndrome with negative anti-gad 65 antibodies. Case report

Abstract

We present a case of 42-year-old woman without significant medical history, admitted in our clinic for painful neck stiffness, aggravated by emotions and stress relieved during sleep, accompanied by sweating, predominantly lower limbs weakness. The symptoms insidiously appeared one month prior presentation. On neurological examination we found painful paravertebral and laterocervical muscle contracture and spastic paraparesis. Laboratory tests included the analysis of anti-glutamic acid decarboxylase (anti-GAD65) and anti-Borrelia antibodies, carcinoma antigens (CA 125, CA 15-3) which were found negative. Cerebrospinal fluid analysis found positive oligoclonal bands with a slight increase of IgG component. Other tests including thyroid function were found normal. Brain and spinal MRI examinations showed no changes. Methylprednisolone, baclofen and carbamazepine were administered without a significant improvement. After 4 months from the first admission, the patient returns with increased symptoms for which plasma exchange achieved a slight improvement of motor deficit and rigidity. Stiff person syndrome is thought to be triggered by anti-GAD antibodies that limit the GABA receptor activity, although about 10 to 40% of the patients do not shows these antibodies in the serum.

Síndrome de la persona rígida Caso clínico y revisión de la literatura

“…La determinación de los anticuerpos antiglutamato descarboxilasa (específicamente las isoformas GAD65 o GAD67) en sangre o líquido cefalorraquídeo es complementaria para el diagnóstico. Si bien los anticuerpos anti-GAD están presentes en el SPS, pueden ser negativos 18,19 . En los casos de SPS con anti-GAD positivos, la proteinorraquia y la pleiocitosis constituyen los hallazgos más frecuentes y en algunos casos pueden encontrarse bandas oligoclonales y anticuerpos anti-GAD 20 .…”