Rare and Seronegative Autoimmune Encephalitis

by Alanna | Oct 27, 2022 | Australian Autoimmune Encephalitis Consortium

October 28, 2022 | Written by Dr. Nabil Seery. Edited by Dr Mastura Monif, Ms Tiffany Rushen, Dr Loretta Piccenna, Ms Amanda Wells (consumer representative) and Ms Sasha Ermichina (consumer representative).

A message from IAES Blog Staff:

It is our honor and pleasure to present to all of you an overview of how autoimmune encephalitis can affect cognitive abilities. This overview is by the esteemed team at Monash University in Australia & lead by Dr. Mastura Monif, who is a member of IAES’ Medical Advisory Board.

We are proud to be in collaboration with Dr. Monif and her team in the Australian Autoimmune Encephalitis Consortium Project as we work closely with them to best support AE patients, caregivers and their families. This blog has been facilitated by IAES Support Services coordinator Mari Wagner Davis, with input from IAES volunteers Sasha Ermichina (impacted by GFAP AE) and Amanda Wells (caregiver for her daughter with AE). These IAES representatives provide input from their unique perspectives, helping to educate researchers in the difficulties that patients and families face.

You can find out more about the Australian Autoimmune Encephalitis Consortium and their efforts to help those with AE and their families via the following link:

https://www.monash.edu/medicine/autoimmune-encephalitis

—-

Rare and Seronegative Autoimmune Encephalitis

Source: Seery N, Butzkueven H, O’Brien TJ, Monif. M. Rare Antibody-Mediated and Seronegative Autoimmune Encephalitis: an Update. Autoimmunity Rev. 2022 May 18;21(7);103118. https://doi.org/10.1016/j.autrev.2022.103118

WHY WE DID THIS WORK

■ Autoimmune encephalitis (AE) is a form of autoimmune disease whereby immune cells in the body inappropriately target components of the nervous system. This causes dysfunction of nerve cells, and in some cases death of these cells, and further produces different clinical symptoms that are reversible. Such symptoms include (but are not limited to) cognitive symptoms, such as difficulties with memory and language, seizures, movement disorders, and psychiatric symptoms.

■ Antibodies are central to the diagnosis of many subtypes of autoimmune encephalitis. Generally, antibodies are proteins produced by the immune system to fight infections. In a proportion of patients with autoimmune encephalitis there can be an abnormal expression of antibodies, where, rather than targeting foreign molecules (e.g. viruses, bacteria), they mistakenly target self-proteins on nerve endings or self-proteins inside the nerve cell or neuron. In up to half of cases, an antibody is not detectable using current available tests or assays. This group of cases is called “seronegative” autoimmune encephalitis, i.e. denoting a lack of antibodies in the serum (a component of a patient’s blood) or cerebrospinal fluid (a clear fluid the surrounds the brain and spinal cord, obtained via a lumbar puncture, a procedure involving a fine needle being inserted in the lower back). ‘Seronegative’ autoimmune encephalitis most likely represents a broader collection of disorders.

■ Over the last two decades, antibody-mediated subtypes of autoimmune encephalitis continue to be discovered, with over ten such forms now recognised. Further, following the respective discovery of such new forms of autoimmune encephalitis, disease mechanisms and clinical features have been revealed. However, seronegative autoimmune encephalitis remains less well characterised, possibly in part to because of its heterogeneous nature – meaning that a variety of diseases forms may be included by the definition.

■ The purpose of our review was to explore advances regarding five rare antibody-mediated forms of autoimmune encephalitis, namely, anti-g-aminobutyric acid B (GABAB) receptor-, anti-a-amino-3hydroxy-5-methyl-4-isoxazolepropinoic receptor- (AMPAR), anti-GABAA receptor-and anti-dipeptidyl-peptidase-like protein-6 (DPPX) encephalitis and IgLON5 disease.

■ We also summarise current research and challenges in relation to ‘seronegative’ autoimmune encephalitis. For a detailed discussion of anti- NMDA autoimmune encephalitis, anti-LGI1 and anti-CASPR2 autoimmune encephalitis refer to (Contemporary advances in anti-NMDAR antibody (Ab)-mediated encephalitis -PubMed (nih.gov) (1) and Contemporary advances in antibody-mediated encephalitis: anti-LGI1 and anti-Caspr2 antibody (Ab)-mediated encephalitides -PubMed (nih.gov)) (2).

WHAT WE FOUND

■ GABAB, AMPAR and GABAA autoimmune encephalitis have common and distinguishing clinical features. These three forms of autoimmune encephalitis are diagnosed by the presence of antibodies found in the blood or cerebrospinal fluid of suspected patients. All three are relatively rare, compared to some other antibody-mediated forms of autoimmune encephalitis such as anti-N-methyl-D-aspartate receptor (NMDAR) and anti-leucine-rich gliomainactivated 1 (LGI1) Ab-mediated encephalitis. GABAA encephalitis in particular is exceedingly rare, with approximately fifty cases reported overall as at a few years ago.

■In these diseases, antibodies target the GABAB, AMPAR and GABAA receptors (proteins present on nerve cell endings), causing neuronal dysfunction. GABAB and GABAA receptors both attract an inhibitory neurotransmitter called GABA. A neurotransmitter is a signalling molecule that helps with communication and transmission of impulses between neurons, and inhibitory neurotransmitters reduce the likelihood a given neuron will generate an electrical signal called an action potential.

■ Seizures in these diseases are a main feature, and may be particularly non-responsive to conventional anti-seizure treatment. Furthermore, cognitive and psychiatric symptoms are common in all three of these subtypes of autoimmune encephalitis. GABAB and AMPAR subtypes may have similar findings identified on MRI imaging of the brain, with inflammation and swelling seen in part of the brain called the mesial temporal lobe. The mesial temporal lobe is an area of the brain important for memory, emotion and behaviour.

■ The diagnosis of autoimmune encephalitis invariably necessitates that clinicians investigate for the possibility of a tumour (e.g. lung cancer, thyroid cancer, breast cancer) that may have triggered the disease. Treating the tumour or cancer where feasible and as promptly as possible has been linked to improvements in autoimmune encephalitis symptoms. Similarly, the presence of neurological symptoms, if preceding a cancer diagnosis, may allow for this to be facilitated more quickly than might have been the case otherwise, which may help afford a better chance of more effectively treating the underlying cancer.

■ In approximately half of patients diagnosed with GABAB encephalitis, an underlying tumour is found, most often small-cell lung cancer. In AMPAR encephalitis, almost two-thirds of patients have an underlying tumour, with thymus tumours and lung cancer most common. In GABAA encephalitis, approximately one third of patients have also been shown to have an underlying tumour.

■ DPPX encephalitis and IgLON5 disease are two rare and somewhat clinically unique forms of autoimmune encephalitis. In DPPX encephalitis, patients commonly present with profound weight loss or diarrhoea and have features of central-nervous system hyperexcitability. This is a state where the brain has increased responsiveness to a variety of external stimuli. In DPPX encephalitis, features attributed to CNS hyperexcitability include myoclonus, or rapid, involuntary muscle jerks, and tremor. IgLON5 disease on the other hand also has unique clinical features, such as a variety of sleep disturbances.

■ Seronegative autoimmune encephalitis overall requires further study and description to identify potential antibodies which may be the cause. Seronegative limbic encephalitis is a form of seronegative autoimmune encephalitis, where the limbic structures in the brain are affected. In this subset of the disease inflammation is observed in the mesial temporal lobes using Magnetic Resonance Imaging (MRI). Seronegative limbic encephalitis is typically seen in older patients, with conventional antibody testing not revealing an antibody. Patients typically have memory impairment, with or without psychiatric symptoms and seizures, and are treated with medications that lower effects of the immune system, as in other forms of autoimmune encephalitis.

HOW CAN WE USE THIS RESEARCH

■ These findings are intended to help researchers and clinicians better understand seronegative and rare forms of autoimmune encephalitis. By bringing this information together, it can assist with improving diagnosis and assisting with early treatment by clinicians.

■ It should be noted that antibody-related forms of autoimmune encephalitis are usually diagnosed as “possible autoimmune encephalitis” prior to the availability of antibody results, which can take up to a period of weeks. A diagnosis of autoimmune encephalitis is based on broad criteria involving consideration of a patient’s symptoms and test results, including MRI, electroencephalogram (EEG – a measure of the electrical activity of the brain) and cerebrospinal fluid biopsy results, combined with the exclusion other diseases, for example, viruses that could mimic the observed symptoms.

■ Prompt diagnosis of autoimmune encephalitis, and prompt exclusion of other causes such as viral encephalitis is very important, as there is a growing body of evidence indicating that earlier initiation of immune-lowering treatment for autoimmune encephalitis may be able to facilitate better recovery.

■ The seronegative form of autoimmune encephalitis can represent a large proportion of autoimmune encephalitis patients overall so its understanding is crucial for improvements in clinical care.

■ Regarding very rare subtypes of autoimmune encephalitis, an understanding of the characteristic features of these rare entities is crucial in forming a diagnostic workup plan. Further, awareness of the features of some of these rarer subtypes can ensure prompt and accurate investigation of underlying tumours. Knowledge of rarer subtypes may also be able to inform clinicians and patients about the possible outcomes of these conditions to inform day to day discussions with patients and their caregivers.

—-

For more information and resources from Dr. Monif and her group at the Australian Autoimmune Encephalitis Consortium Project, visit this link here. To download a plain language PDF of the paper summarized in this blog, click the button below:

Download Plain Language Summary

Click here or the image below to subscribe to our mailing list:

Your generous Donations allow IAES to continue our important work and save lives!

On June 16 th, 2022, Tabitha Orth, President and Founder of International Autoimmune Encephalitis Society officially became the 7,315 th “point of light”. Recognized for the volunteer work she and IAES has done to spark change and improve the world for those touched by Autoimmune Encephalitis. The award was founded by President George H.W. Bush in 1990.

Become an Advocate by sharing your story. It may result in accurate diagnosis for someone suffering right now who is yet to be correctly identified. Submit your story with two photos to IAES@autoimmune-encephalitis.org

International Autoimmune Encephalitis Society (IAES), home of the AEWarrior®, is the only Family/Patient-centered organization that assists members from getting a diagnosis through to recovery and the many challenges experienced in their journey. Your donations are greatly appreciated and are the direct result of IAES’ ability to develop the first product in the world to address the needs of patients, Autoimmune Encephalitis Trivia Playing Cards. Every dollar raised allows us to raise awareness and personally help Patients, Families, and Caregivers through their Journey with AE to ensure that the best outcomes can be reached. Your contribution to our mission will help save lives and improve the quality of life for those impacted by AE. For this interested in face masks, clothing, mugs, and other merchandise, check out our AE Warrior Store! This online shop was born out of the desire for the AE patient to express their personal pride in fighting such a traumatic disease and the natural desire to spread awareness. Join our AE family and help us continue our mission to support patients, families and caregivers while they walk this difficult journey.

Be a part of the solution by supporting IAES with a donation today.

why zebra - Aphasia as a Symptom of Autoimmune Encephalitis

The Darkness of a Brain on Fire

by Alanna | Apr 26, 2022 | AE Warrior Personal Stories

April 27, 2022 | By Chelsea Wagner

Numbers, numbers, numbers – we all have them. It’s how we organize and make sense of what’s happened to us. It is how we put our experiences into boxes so that they don’t spill over into every aspect of our lives.

For me it was 1,000 mg of steroids, 7 Plasmapheresis infusions, 6 EEG’s, 5 MRIs, 4 CT scans, 1 PET scan, 1 botched lumbar puncture, 1 traumatizing bedside central line insertion, and countless fascinated residents, fellows, and physicians who had no idea what was happening to me right in front of them. All those numbers were packed into a 31-day hospital stay split between 2 hospitals in the largest medical center in the world. And those numbers lead me here, to you, to the Autoimmune Encephalitis community.

During February 2019, I began to experience subtle signs and had an overwhelming feeling that something was “off” with myself. I had trouble spelling words, remembering passwords and even had trouble speaking with patients I saw as a genetic counselor. I began experiencing extreme anxiety, panic attacks, and other neurological symptoms. I would eventually go to the ER after my doctor discovered a right sided facial droop, fearing that I was having a stroke, I was admitted to the first of 2 hospitals.

During my lengthy stay on the stroke recovery unit (the youngest person by several decades), the doctors would be puzzled by my progressing symptoms and my eventual catatonic state. I lost the ability to speak, read, and write. After being placed on high-dose steroids, I became violent and turned into what the nurses and my family would call the “she-hulk” and throw objects, kick walls, and wrestle with hospital staff as they put restraints on my ankles and wrists and bound me to my hospital bed for days at a time. During this time, I would become a prisoner of my own mind. I endured auditory and visual hallucinations of my worst nightmares and lived in multiple alternate realities, many of which included me dying. I would return to reality for only brief periods of lucid time – although I could not speak or recognize my family, the terror and confusion were respite to what was happening inside of my mind.

Eventually, the first facility would diagnose me with seronegative autoimmune encephalitis – but did not implement the well established treatment for AE – and I was sent home from the first hospital on a steroid taper with no attempt at plasmapheresis exchange or IVIG. The doctors were frustrated with me and with what little I was able to comprehend. They had given up on me regaining any semblance of normal cognitive function. They told my husband and family that I’d go home and I’d either “get better, or I wouldn’t.”

I didn’t. In fact, I was actively hallucinating as they discharged me from my first hospital and then spent an interim week drifting in and out of reality – barely able to communicate, having dystonic movements and absence seizures. I was clearly getting worse. I was fortunate enough to have personal connections to another hospital due to my job as a genetic counselor in the medical center. I was rushed in for a same day appointment with a leading neurologist in Autoimmune Encephalitis and admitted directly from her clinic to my second hospital.

After receiving the first of seven plasmapheresis exchange treatments, it was like a fog was lifted. Blobs of strange people began to take the shape of my husband, my mom, my friends and family. I found my voice, although Broca’s aphasia made it hard to communicate, I started making progress in speech and occupational therapy. Everyday it felt like fireworks were going off in my brain – the zing of new neural connections being made – I would tell my therapists “I can feel it in my brain” – every sense heightened, every new word remembered became a cause for celebration, every step around the ward was a sign of my physical strength returning. Who would have guessed the exhilaration of holding a crayon in my hand could bring, or the relief of hearing my name and knowing it was mine? The doctors were impressed and optimistic about my recovery, but no one could predict how much cognitive function I would regain. I was told I would likely never be the same person I was before. And in so many ways that is true.

Even after my second discharge, I had months of speech therapy, occupational therapy, and cognitive rehabilitation. I lost most of my independence – depending on everyone around me to drive me everywhere, make follow-up appointments, pay my bills because reading words on a screen was akin to reading hieroglyphics. I felt, at my worst, like a burden to those around me, weighed down by guilt and shame of the upheaval I had caused in our lives. I felt lost in my professional life, unsure of who I was or what I contributed to a society where my 19 years of education did not triumph over my brain trauma. I felt alone, because no one had been inside my mind and could understand exactly what I had been through: how harrowing, how terrifying, how humbling, it is to stand on the brink of insanity and be brought back from the darkness of a brain on fire.

No one except this community – reading your experiences, your struggles, your triumphs – they connect me in a way I never thought I would be able to connect and helped me understand my singular experience is part of a larger community experience. Almost three years later, I have returned to my full-time job as a genetic counselor and help patients navigate an overly-complicated and often frustrating healthcare system that I am all too familiar with. My compassion and empathy for those struggling with a diagnosis, finding resources, and advocating for themselves abounds. And I am grateful to be here, to be able to return to my career, to recognize my husband’s face, to be alive, to be typing these words. I know that when I lay awake at night (because, hello, insomnia!) thinking of how everything has changed for me since AE – there is light, there is hope, there is resilience, there is grit, there is strength in me. All it takes is a brain on fire to illuminate it.

Click here or the image below to subscribe to our mailing list :

Your generous Donations allow IAES to continue our important work and save lives!

For those interested in face masks, clothing, mugs, and other merchandise, check out our AE Warrior Store! This online shop was born out of the desire for the AE patient to express their personal pride in fighting such a traumatic disease and the natural desire to spread awareness. Join our AE family and help us continue our mission to support patients, families and caregivers while they walk this difficult journey.