RESUMEN
To report a typical case of Morvan syndrome with positive anti-leucine rich glioma-inactivated 1(LGI1) and contactin-associated protein 2 (CASPR2) antibodies in serum and cerebrospinal fluid. A 39-years-old female initially presented weakness of extremeties. The main symptoms included paroxysmal limb pain, wheezing, itching, muscle twitching, epilepsy, hypomnesia, dysphoria, apathy, intractable insomnia, salivation and sweating. Tests of electrolytes found hypokalemia (2.7-3.1 mmol/L) and hyponatremia (130-136 mmol/L). Arterial blood gas analysis showed hypoxemia (oxygen saturation 50%-70%). Total thyroxine (TT4) was elevated to 207 nmol/L with positive thyroid peroxidase antibody (TPO-Ab) and thyroglobulin antibody (TG-Ab). LGI1and CASPR2 antibodies (CBA method) were positive in both serum and cerebrospinal fluid, and the remaining antibodies related to autoimmune encephalitis and paraneoplastic syndrome were negative. Head MRI was almost normal, while mild abnormalities were found in electroencephalogram. Electromyography showed slightly increased voltage of left quadriceps motor unit potential. After treated with corticosteroids, IVIG and mycophenolate mofetil, the patient completely improved. Cognitive function scores recovered from MoCA/MMSE (16/24) to MoCA/MMSE (26/29). Positivity of LGI1/CASPR2 antibodies both in serum/cerebrospinal fluid are rarely seen in patients with Morvan syndrome. Steroids and immunosuppressants are suggested for treatment as early as possible.
RESUMEN
The autoimmune encephalopathies are a group of conditions that are associated with autoantibodies against surface neuronal proteins, which are likely to mediate the disease. They are established as a frequent cause of encephalitis. Characteristic clinical features in individual patients often allow the specificity of the underlying antibody to be confidently predicted. Antibodies against the VGKC-complex, mainly LGI1(leucine-rich glioma-inactivated 1), CASPR2 (contactin-associated protein 2), and contactin-2, and NMDA (N-methyl, D-aspartate) -receptor are the most frequently established serological associations. In the minority of cases, an underlying tumour can be responsible. Early administration of immunotherapies, and tumour removal, where it is relevant, offer the greatest chance of improvement. Prolonged courses of immunotherapies may be required, and clinical improvements often correlate well with the antibody levels. In the present article, we have summarised recent developments in the clinical and laboratory findings within this rapidly expanding field.
As encefalopatias autoimunes constituem um grupo de condições associadas à presença, no soro, de anticorpos contra proteínas de superfície neuronais. Acredita-se que esses anticorpos sejam mediadores da ocorrência da doença, sendo reconhecidos atualmente como causas frequentes de encefalite. Apresentações clínicas características permitem, muitas vezes, predizer o grupo específico de anticorpos subjacentes. Anticorpos contra o complexo VGKF, especialmente LGI1 (leucine-rich glioma-inactivated1), CASPR2 (contactin-associated protein 2) e contactina-2, e contra o receptor NMDA(N-methyl, D-aspartate) são as associações sorológicas mais frequentemente estabelecidas. Na minoria dos casos, pode ser detectado um tumor subjacente. As maiores chances de melhora estão relacionadas à administração precoce de imunoterapia e à remoção do tumor, quando presente. A duração da imunoterapia pode se prolongada e a melhora se correlaciona, muitas vezes, com os níveis séricos de anticorpos. Neste artigo, estão resumidos os avanços recentes nos achados clínicos e laboratoriais neste campo que está em tão rápida expansão.