Clinical Analysis For Six Cases Of Anti-NMDA Receptor Encephalitis

BackgroundAnti-NMDA receptor encephalitis is a relatively rare autoimmune disease of the central nervous system which mainly invades the limbic system. Foreign scholars found that a majority of patients underwent at least four of the following eight kinds of symptoms within a month:abnormal behavior, seizures, cognitive impairment, speech impairment, movement disorders, decreased level of consciousness, autonomic symptoms and central low ventilation. It is often misdiagnosed as viral encephalitis. Now there is no unified standard of diagnosis and treatment for it is found and researched in recent years. The clinical research at home and abroad is still at the stage of accumulated experience. The key evidence of definitive diagnosis is the foundation of anti-NMDA receptors in the cerebrospinal fluid (CSF). The first line of treatment is venous application of methylprednisolone and human immunoglobulin, or plasma exchange. If the above methods are invalid, the second line drugs (immunosuppressive drus) such as cyclophosphamide or rituximab and etc. should be used.ObjectiveTo summarize the clinical features and treatments of the adult patients in our hospital, and to provided a practical base for the clinical diagnosis and treatment of anti-NMDA receptor encephalitis.Materials and MethodsThe clinical materials of 6 adult patients who suffered from of anti-NMDA receptor encephalitis from Jan.1,2014 to Feb.30,2016 in our hospital were retrospectively analyzed. The clinical materials include the basis information, symptoms and signs, the results of assistant examination, and the treatments. To summarize the clinical features and management approach.Results1. Population characteristics:Four of the six adult patients were male youth (66.67%). The average age is 33.67. None of them has history of tumors.2. Clinical symptoms:Four patients of the six patients (66.7%) had premonitory headache before the onset of anti-NMDA receptor encephalitis. Four patients of the six patients (66.7%) were accompanied with the following symptoms such as mental and behavior disorder, cognitive decline, ataxia and autonomic symptoms. The initial symptoms include mental and behavior disorder (3/6) and epileptic seizure (3/6). No patient got a fever at the onset. In the first week of the early stage (l-15d), cognitive decline proceeded rapidly in 66.67%(4/6),50%(3/6) developed autonomic dysfunction. Ataxia appeared in the second week in 50%of the patients.66.67%(4/6) got abnormal electrocardiogram. At the late stage of the disease(15-30d), two of the six patients (33.33%) developed other symptoms of autonomic nervous. Only one case (16.67%) developed central hypoventilation when recurrence in this study.3. Signs:All patients were admitted to hospital within half a month after the onset. The main signs at admission were described as follows. One patient of the six patients (16.7%) was found unconscious. One patient (1/6) has mixed aphasia, apraxia, agnosia and logagraphia. One patient of the six patients (16.7%) showed slightly decreased muscle power (IV level). One patient of the six patients (16.7%) had lead pipe rigidity. Three patients of the six patients (33.33%) showed positive Babinski sign. As for meningeal irritation sign,50%(3/6) has mild neck rigidity.33.33%(2/6) showed positive Kerning sign and all patients showed negative Bruzinski sign.4. Laboratory examination:(1) peripheral blood examination:50%(3/6) showed etiological detection (+).83.33%(5/6) had no obvious abnormity in thyroid function, rheumatism and tumor detection. Only one case has elevated Ferr, NSE and SA level. (2) CSF examination:Only one patient (16.67%) has mild increased intracranial pressure and all the other cases were in the normal range. 83.33%(5/6) had mild increased white blood cell count while 16.67%(1/6) showed moderate increased level.50%(3/6) showed weakly positive in protein qualitative test.33.33%(2/6) had abnormal Single-core and multinucleated cells proportion.83.33%(5/6) had normal cerebrospinal fluid biochemical test while only one case had mild increase protein level.83.33%(5/6) showed mixed cell reaction mainly with lymphocyte. Mild-to-moderate increased IgG level was detected in 50%(3/6) patients. Mild increased IgA level was found in 50%(3/6) patients.16.67%(1/6) CSF OB ±,16.67% (1/6) EBV+,16.67%(l/6) TrpT+. Positive rate of ANMDAR-Ab in CSF was 100%, while it is 66.7% in the serum test. Paraneoplastic syndrome associated antibodies were all negative.5. Auxiliary examination:No tumor was found.16.67%(1/6) showed characteristic of paraneoplastic limbic encephalitis in MRI.83.33%(5/6) had electroencephalogram abnormality. 66.67%(4/6) had abnormal ECG in the early stage.6. Diagnosis and condition of recovery:All patients were diagnosed as viral encephalitis in the first place. The mean confirmed diagnosis time was 17.5 days and the immunotherapy was used afterwards. First-line immune drugs has poor curative effect on patients who developed four kinds of symptoms in the first week. Switching to the second-line drug was a good choice. First-line treatment was effective for these patients with single symptom and no recurrence had been observed.Conclusion1. Young patients characterized with premonitory headache, mental and behavior disorder or epilepsy without fever should be considered for anti-NMDA receptor encephalitis. CSF NMDAR-Ab test can help to make a definite diagnosis at the early date.2. For patients with a variety of symptoms at the early stage, second-line drugs should be considered when first-line treatment has poor effect.3. Less symptoms at the onset and early treatment were the key to a good prognosis.