By A. G. Moore 7/22/2013
I’ve written about CNS lupus in previous posts. Recently I learned that someone in my family developed a serious CNS issue. During the early weeks of the illness, when doctors ran batteries of tests and yet arrived at no clear diagnosis, I wondered if an important clue might be discovered in the patient’s family history, where a host of autoimmune diseases can be found. It turns out, this is indeed the case. Doctors are now treating my family member for autoimmune (limbic) encephalitis; supporting this course of action is the fact that treatment with immune suppressive therapy is showing good results.
As I read research papers on limbic encephalitis I cross referenced my searches with material on lupus encephalitis. I found at least one case in the literature where there was an association between the two conditions. The scientist who noted this association hypothesized that in this particular case there might be an “autoimmunity shared” between systemic lupus and the encephalitis (Encephalitis and Status Epilepticus in a Patient With Systemic Lupus Erythematosus)
One clear fact emerged from my reading: any kind of autoimmune encephalitis is difficult to diagnose–which is unfortunate, because early diagnosis is key to a good outcome. And a good outcome is possible, in most cases, with proper treatment. In fact, one of the ways doctors may be confident in the diagnosis of autoimmune encephalitis is in the response they see to treatment with immune suppressive drugs.
Anyone who is familiar with lupus knows how difficult diagnosis of that disease can be. The difficulty is magnified when encephalitis is the first symptom of lupus. Although encephalitis is rarely the first symptom, in a small number of cases this appears months before any other sign. One research article (CNS Lupus Presenting as Encephalitis: a Case Report) describes just how hard it is to distinguish lupus encephalitis from other kinds of brain inflammation: “The clinical distinction is always vague because of overlapping clinical features”. Another research article suggests that one of the reasons diagnosing CNS lupus may be so difficult is that this symptom may occur when there are no other signs of active lupus. The authors state: “…up to 81% of the cases of CNS lupus may occur without systemic SLE activity, often leading to a delayed diagnosis“.
When a patient presents with encephalitis, doctors begin eliminating the most likely causes: generally these are bacterial or viral in nature. Once infectious pathogens have been taken out of the picture, doctors move on to other possibilities, including autoimmune factors. In the case of autoimmune encephalitis, laboratory confirmation of diagnosis is often not possible because antibodies may not be detectable. The day may come when tests will be sensitive enough to detect these specific auto-antibodies in serum and spinal fluid, but that is not always true in current clinical practice. Even in the absence of confirmatory lab results, however, doctors entertain the possibility of an autoimmune trigger. Symptoms and response to specific treatment are the major clues in this situation.
If the doctor is considering an autoimmune trigger in encephalitis, the possibility of a discrete cancer has to also be considered. An undiagnosed cancer may prompt the production of auto-antibodies. This phenomenon is call paraneoplastic syndrome. If there is not a cancer and the body is producing auto-antibodies (in a classic auto-immune syndrome) that are causing encephalitis, the phenomenon is called a non-paraneoplastic syndrome.
The important thing to remember here is that non-paraneoplastic syndromes (no cancer present) respond well to immune suppressive therapy. That’s one of the ways a doctor might be guided in coming to a diagnosis; if there is a good response to immune suppressive therapy, there’s a good chance that the autoimmune encephalitis did not originate from a cancer.
While all of this information might be confusing, there are a few important points to keep in mind:
*The recent illness of my family member reinforces for me a guiding principle of medical care: never go to a doctor unless the doctor is brilliant. Or to a hospital unless the hospital is a first-rate research hospital. Do your own research before a crisis strikes– because things can get out of hand pretty quickly and if that happens, you should be in the very best medical facility, getting the very best medical care.
*Encephalitis is really difficult to figure out; if lupus is present, perhaps that’s what’s causing the inflammation. Or, maybe it’s not. A doctor should have a complete picture of your medical history–and the family’s medical history–in order to help trace the problem’s causes.
*Early, prompt treatment of encephalitis–any kind of encephalitis–is essential to increase the chance of recovery and help to prevent permanent damage.
*I’m going to repeat my first point here: go to only the brightest, most attentive physicians. Even a seemingly benign symptom can become serious. We can’t control a lot of what happens to us, but we often can control the quality of the treatment we receive.
Some readings that might be helpful on autoimmune encephalitis: (Please note: we, the patients, may only be able to understand a portion of this material. But understanding even a portion allows us to participate in a conversation about our care)