自身免疫性腦炎
2025年09月22日
陳灌豪教授
香港大學醫學院
臨床醫學學院內科學系梁顯利基金教授 (腦神經科)
自身免疫性腦炎是一種罕見的疾病。患者因免疫系統失調，導致免疫系統攻擊中樞神經系統，從而引發腦炎。大部分病人的血液和/或腦脊液中帶有異常的自身免疫抗體，這些抗體可分為兩種類型，分別針對腦神經細胞表面抗原及細胞內抗原。
自身免疫性腦炎的症狀多樣，患者大多數會在數天至數星期內出現精神錯亂、行為異常、癲癇(例如複雜部分性癲癇)、不自主活動，以及精神病症狀如焦慮、沮喪及思覺失調。若未能及早診斷和治療，病情可能惡化至昏迷及呼吸不足。此外，不自主神經系統的失調可導致心跳和血壓不穩定，增加患者的死亡風險。
檢測自身免疫抗體對診斷自身免疫性腦炎有很大的幫助。在臨床診斷過程中，醫生會盡快為疑似患者安排一系列檢查，包括抽血及腦脊液化驗、腦部磁力共振掃描及腦電圖。這些檢查旨在檢測自身免疫抗體，並排除由病毒引起的腦炎或其他類似的中樞神經系統感染。
如病人確診或有很大機會患上自身免疫性腦炎，醫生會安排進一步檢查，利用正電子電腦掃描以確定病人體內是否有腫瘤。以較常見的抗NMDA受體腦炎(anti-NMDAR encephalitis)為例，部分患者經檢查後發現同時患有卵巢畸胎瘤(ovarian teratoma)。
在治療方面，及早診斷並接受免疫治療有助於加速病人康復，避免腦神經的永久損害和殘障。脈衝類固醇、免疫球蛋白、血漿置換術及生物製劑(如針對B型淋巴細胞的單克隆抗體)都是常用的一線和二線治療。
As the BBC reported on the work on NMDAR in 2016, this blog post was from Sep 1, 2013 and it was an answer to my case of Teratoma induced coma/psychosis.
In medicine, truly new discoveries are uncommon and with the emergence of guidelines and protocols it has become even more difficult to make new discoveries. It has taken over 30 years before I could understand what happened to my Teratoma patient. Luckily for her, the treatment she received would have been in line with what we know now of the condition.
Hospital Medicine indeed has its important place and most important of all in the discovery of new conditions and establishing diagnostic and treatment programmes.
It is perhaps timely to remind the next generation of Bright Young Things that become doctors to remember that psychiatric symptoms presented by a patient may indeed be the presentation of a neurological condition.
This is more so for bizarre combinations of psychiatric and other symptoms. It was in the last five years or so that much progress has been made on what is now called Anti-NMDA Receptor Encephalitis.
Who knows, one day medical scientists might be able to decipher the most difficult of psychiatric conditions: Schizophrenia. Bright Young Psychiatrist might have noticed that Clozapine, one of the most effective drugs for schizophrenia has a marked effect on the immune system.
In the meantime Pennsylvania
Hospital Medicine indeed has its important place and most important of all in the discovery of new conditions and establishing diagnostic and treatment programmes.
It is perhaps timely to remind the next generation of Bright Young Things that become doctors to remember that psychiatric symptoms presented by a patient may indeed be the presentation of a neurological condition.
This is more so for bizarre combinations of psychiatric and other symptoms. It was in the last five years or so that much progress has been made on what is now called Anti-NMDA Receptor Encephalitis.
Who knows, one day medical scientists might be able to decipher the most difficult of psychiatric conditions: Schizophrenia. Bright Young Psychiatrist might have noticed that Clozapine, one of the most effective drugs for schizophrenia has a marked effect on the immune system.
In the meantime Pennsylvania
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Anti-NMDA Receptor Encephalitis
NEW ORLEANS — A mysterious, difficult-to-diagnose, and potentially deadly disease that was only recently discovered can be controlled most effectively if treatment is started within the first month that symptoms occur, according to a new report by researchers from the Perelman School of Medicine at the University of Pennsylvania. The researchers analyzed 565 cases of this recently discovered paraneoplastic condition, called Anti-NMDA Receptor Encephalitis, and determined that if initial treatments fail, second-line therapy significantly improves outcomes compared with repeating treatments or no additional treatments (76 percent versus 55 percent). The research is being presented at the American Academy of Neurology's 64th Annual Meeting in New Orleans
565 cases! Not so rare!
The condition occurs most frequently in women (81 percent of cases), and predominately in younger people (36 percent of cases occurring in people under 18 years of age, the average age is 19). Symptoms range from psychiatric symptoms, memory issues, speech disorders, seizures, involuntary movements, to decreased levels of consciousness and breathing. Within the first month, movement disorders were more frequent in children, while memory problems and decreased breathing predominated in adults.
My patient was under 18 and presented with catatonia symptoms. She later lose consciousness and was ventilated.
"Our study establishes the first treatment guidelines for NMDA-receptor encephalitis, based on data from a large group of patients, experience using different types of treatment, and extensive long-term follow-up," said lead author Maarten Titulaer , MD , PhD, clinical research fellow in Neuro-oncology and Immunology in the Perelman School of Medicine at the University of Pennsylvania
The disease was first characterized by Penn's Josep Dalmau, MD, PhD, adjunct professor of Neurology, and David R. Lynch, MD, PhD, associate professor of Neurology and Pediatrics, in Annals of Neurology in 2007. One year later, the same investigators in collaboration with Rita Balice-Gordon, PhD, professor of Neuroscience, characterized the main syndrome and provided preliminary evidence that the antibodies have a pathogenic effect on the NR1 subunit of the NMDA receptor in the Lancet Neurology in December 2008. The disease can be diagnosed using a test developed at the University of Pennsylvania
Teratoma: finally!
In earlier reports, 59 percent of patients had tumors, most commonly ovarian teratoma, but in the latest update, 54 percent of women over 12 years had tumors, and only six percent of girls under 12 years old had ovarian teratomas. In addition, relapses were noted in 13 percent of patients, 78 percent of the relapses occurred in patients without teratomas.
Anti-NMDA-receptor encephalitis: case series and analysis of the effects of antibodies
Of 100 patients with anti-NMDA-receptor encephalitis, a disorder that associates with antibodies against the NR1 subunit of the receptor, many were initially seen by psychiatrists or admitted to psychiatric centres but subsequently developed seizures, decline of consciousness, and complex symptoms requiring multidisciplinary care. While poorly responsive or in a catatonic-like state, 93 patients developed hypoventilation, autonomic imbalance, or abnormal movements, all overlapping in 52 patients. 59% of patients had a tumour, most commonly ovarian teratoma. Despite the severity of the disorder, 75 patients recovered and 25 had severe deficits or died.
Related paper:
.jpg)
Anti-NMDA Receptor Encephalitis
NEW ORLEANS — A mysterious, difficult-to-diagnose, and potentially deadly disease that was only recently discovered can be controlled most effectively if treatment is started within the first month that symptoms occur, according to a new report by researchers from the Perelman School of Medicine at the University of Pennsylvania. The researchers analyzed 565 cases of this recently discovered paraneoplastic condition, called Anti-NMDA Receptor Encephalitis, and determined that if initial treatments fail, second-line therapy significantly improves outcomes compared with repeating treatments or no additional treatments (76 percent versus 55 percent). The research is being presented at the American Academy of Neurology's 64th Annual Meeting in New Orleans
565 cases! Not so rare!
The condition occurs most frequently in women (81 percent of cases), and predominately in younger people (36 percent of cases occurring in people under 18 years of age, the average age is 19). Symptoms range from psychiatric symptoms, memory issues, speech disorders, seizures, involuntary movements, to decreased levels of consciousness and breathing. Within the first month, movement disorders were more frequent in children, while memory problems and decreased breathing predominated in adults.
My patient was under 18 and presented with catatonia symptoms. She later lose consciousness and was ventilated.
"Our study establishes the first treatment guidelines for NMDA-receptor encephalitis, based on data from a large group of patients, experience using different types of treatment, and extensive long-term follow-up," said lead author Maarten Titulaer , MD , PhD, clinical research fellow in Neuro-oncology and Immunology in the Perelman School of Medicine at the University of Pennsylvania
The disease was first characterized by Penn's Josep Dalmau, MD, PhD, adjunct professor of Neurology, and David R. Lynch, MD, PhD, associate professor of Neurology and Pediatrics, in Annals of Neurology in 2007. One year later, the same investigators in collaboration with Rita Balice-Gordon, PhD, professor of Neuroscience, characterized the main syndrome and provided preliminary evidence that the antibodies have a pathogenic effect on the NR1 subunit of the NMDA receptor in the Lancet Neurology in December 2008. The disease can be diagnosed using a test developed at the University of Pennsylvania
Teratoma: finally!
In earlier reports, 59 percent of patients had tumors, most commonly ovarian teratoma, but in the latest update, 54 percent of women over 12 years had tumors, and only six percent of girls under 12 years old had ovarian teratomas. In addition, relapses were noted in 13 percent of patients, 78 percent of the relapses occurred in patients without teratomas.
As Anti-NMDA Receptor Encephalitis, the most common and best characterized antibody-mediated encephalitis, becomes better understood, quicker diagnosis and early treatment can improve outcomes for this severe disease.
The study was presented in a plenary session on Wednesday, April 25, 2012 ET at 9:35 AM at the American Academy of Neurology's annual meeting.
[PL01.001] Clinical Features, Treatment, and Outcome of 500 Patients with Anti-NMDA Receptor Encephalitis
Anti-NMDA-receptor encephalitis: case series and analysis of the effects of antibodies
Of 100 patients with anti-NMDA-receptor encephalitis, a disorder that associates with antibodies against the NR1 subunit of the receptor, many were initially seen by psychiatrists or admitted to psychiatric centres but subsequently developed seizures, decline of consciousness, and complex symptoms requiring multidisciplinary care. While poorly responsive or in a catatonic-like state, 93 patients developed hypoventilation, autonomic imbalance, or abnormal movements, all overlapping in 52 patients. 59% of patients had a tumour, most commonly ovarian teratoma. Despite the severity of the disorder, 75 patients recovered and 25 had severe deficits or died.
Related paper:
