Encefalitis autoinmune mediada por anticuerpos contra el receptor N-Metil-N-Aspartato: reporte de cuatro casos en Perú / Autoimmune encephalitis mediated by antibodies against the N-Nethyl-N-Aspartate receptor: report of four cases in Peru

RESUMEN La encefalitis autoinmune por anticuerpos contra el receptor N-metil-D-aspartato (anti-NMDAR) es un desorden mediado por anticuerpos contra antígenos de superficie neuronal, cuyo diagnóstico temprano y tratamiento oportuno mejoran el pronóstico de la enfermedad. Se presentan cuatro casos con el diagnóstico definitivo de encefalitis autoinmune por anti-NMDAR, tratados en el Instituto Nacional de Ciencias Neurológicas en Lima-Perú. Todos los pacientes presentaron crisis epilépticas y tres casos desarrollaron un estado epiléptico refractario. Asimismo, tres pacientes presentaron alteraciones neuropsiquiátricas, discinesias y disautonomías. Dos casos requirieron soporte ventilatorio. Todos presentaron un electroencefalograma anormal, dos casos tuvieron pleocitosis en líquido cefalorraquídeo, y sólo uno mostró anormalidades cerebrales en la resonancia magnética. Respecto al tratamiento, todos los pacientes recibieron inmunoterapia con metilprednisolona y sólo dos de ellos requirieron plasmaféresis por respuesta ineficaz al tratamiento con corticoides. A los 12 meses del alta hospitalaria, tres pacientes quedaron libre de crisis epilépticas y sólo un caso no logró la independencia funcional. Estos casos muestran que la encefalitis anti-NMDAR es una condición tratable y su reconocimiento temprano junto con un tratamiento adecuado (inmunoterapia/plasmaféresis) son esenciales para una evolución favorable.

ABSTRACT Autoimmune encephalitis with antibodies against the N-methyl-D-aspartate receptor (anti-NMDAR) is a disorder mediated by antibodies against neural surface antigens, whose early diagnosis and timely treatment improve the prognosis of the disease. Four cases with the definitive diagnosis of autoimmune encephalitis by anti-NMDAR are presented, treated at the National Institute of Neurological Sciences in Lima-Peru. All patients had epileptic seizures and three cases developed a refractory epileptic state. In addition, three patients presented neuropsychiatric alterations, dyskinesias, and dysautonomia. Two cases required ventilatory support. All presented an abnormal electroencephalogram; two cases had pleocytosis in cerebrospinal fluid, and only one showed brain abnormalities on MRI. Regarding treatment, all patients received methylprednisolone immunotherapy and only two of them required plasma exchange for an ineffective response to corticosteroid treatment. After 12 months of hospital discharge, three patients were free of epileptic seizures and only one case did not achieve functional independence. These cases show that anti-NMDAR encephalitis is a treatable condition and its early recognition together with appropriate treatment (immunotherapy/plasmapheresis) are essential for a favorable evolution.

Encefalitis autoinmunitaria asociada a anticuerpos contra el receptor N-metil-D-aspartato: presentación de dos casos / Autoimmune encephalitis associated to antibodies against the N-methyl-D-aspartate receptor: Report of two cases

Resumen La encefalitis asociada a anticuerpos contra receptores N-metil-D-aspartato es un síndrome neurológico que se presenta más comúnmente en mujeres jóvenes y frecuentemente se asocia al teratoma de ovario. Se caracteriza por un cuadro clínico agudo con síntomas generales inespecíficos que evoluciona hacia deterioro neurológico, psicosis y convulsiones; en su etapa más avanzada, se asocia con movimientos anormales y disautonomía. Se reportan dos casos en mujeres de 23 y 12 años. Dada su baja incidencia, se explica el proceso clínico que llevó a su diagnóstico y las opciones de tratamiento empleadas.

Abstract Anti-N-methyl-D-aspartate receptor encephalitis is a neurological syndrome that is more common in young women and is often associated with ovarian teratoma. It is characterized by acute general unspecific symptoms that evolve to neurological deterioration, psychosis and seizures. In its more advanced stage it is associated with abnormal movements and dysautonomia. We report two cases in women of 23 and 12 years of age. Given its low incidence, we present the clinical exercise that led to their diagnoses and the treatment options employed.

Encefalitis aguda mediada por anticuerpos contra el receptor ionotrópico de glutamato activado por N-metil-D-aspartato (NMDAR): análisis de once casos pediátricos en Argentina (Premio Benito Yelín) / [Acute encephalitis anti-ionotropic glutamate receptor activated N-methyl-D-aspartate (NMDAR): analysis of eleven pediatric cases in Argentina (Benito Yelín Award)].

Encephalitis are an inflammatory processes of various origin, among which include autoimmune origin. The identification of antibodies against the N-methyl-D- aspartate, allowed clinical immunological characterization of an entity susceptible to immunomodulatory therapy. Originally described in young women associated with ovarian teratoma, is now a recognized entity in children even in the absence of detectable tumors. The aim of the study was conducted through review of medical records, was to describe the clinical, developmental and findings in further studies of eleven children with confirmed diagnosis of this entity through identification of specific antibodies. All debuted with psychiatric symptoms in nine associating seizures, and two extrapyramidal movements. In the evolution of language all had commitment nine severe autonomic symptoms, one with hypoventilation and requirements of ARM. Brain MRI was abnormal in three. Eight had voltage EEG asymmetry and / or amplitude, three of them had spikes. Six had CSF pleocytosis and three of seven positive oligoclonal bands. Five IgM serology for mycoplasma were positive. CPK increase occurred in conjunction with antisychotics in five. With immunomodulatory treatment, five had complete recovery three behavioral disorders / cognitive deficits and one severe. A patient’s clinical picture resolved without treatment. In any associated tumor was detected. We conclude that in front of a child with acute encephalopathy and clinical support this entity after infectious cause were ruled out, immunomodulatory therapy should be started early, avoid the use of antipsychotic drugs and search for possible hidden tumors.

Encefalitis autoinmune reversible y anticuerpos anti-receptores de N-metil-D-aspartato: Report of one case / Limbic encephalitis with positive anti-N-methyl-D-aspartate antibodies

Background: Limbic encephalitis is a subacute syndrome characterized by memory impairment, confusion, seizures, hypothalamic dysfunction and psychiatric symptoms. It has been associated to tumors located outside of the central nervous system. In 2007, anti-N-methyl-D-aspartate receptors (NMDAr) antibodies were found in serum and CSF of patients with this particular type of encephalitis. We report a 25-year-old female who, following upper respiratory tract symptoms, developed serious behavioral and consciousness impairment that progressed to coma. Cerebrospinal fluid (CSF) analysis showed a lymphocyte pleocytosis, the electroencephalogram was altered with a slow encephalopathic rhythm and a brain magnetic resonance imaging was normal. Infectious etiologies were ruled out. CSF and serum anti NMDA receptors antibodies were positive.

The expanding spectrum of clinically-distinctive, immunotherapy-responsive autoimmune encephalopathies / O espectro em expansão das encefalopatias autoimunes clinicamente distintas e que respondem à imunoterapia

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.