There are many obstacles to a timely diagnosis. The diagnosis of exclusion can take weeks or even months. Insurance or a physician that is not knowledgeable in diagnosing an autoimmune encephalitis. It can be a challenge!
Some Obstacles You May Encounter
What are some of the primary obstacles to receiving a timely diagnosis?
Nonspecific findings in HE: Patients with HE can have standard imaging, EEG and lab results within normal range.
Gap between personal and statistical normal: Patients who start with an above-average level of cognitive functioning may not sound markedly abnormal in a short clinical session with a stranger, even after significant losses.
Gap between clinical and real world impairment: A patient can perform adequately on a standard mental state examination but suffer real-world impairments that lead to loss of jobs, relationships and homes.
Assessment for frontal lobe impairment: Many patients report symptoms consistent with frontal love impairment (e.g., inappropriate behavior, unusual apathy), but are not screened for frontal lobe issues.
Lack of standardized diagnostic criteria: There is no lab test that definitively confirms a patient has HE, and diagnostic criteria and clinical presentation described in the literature vary. Case studies often highlight unique or severe elements of HE rather than milder or more common aspects, and there is a shortage of large multi-case summaries.
Likelihood of heterogeneity of HE: Patients currently diagnosed with HE may turn out to have different antibodies causing their symptoms. They may have known brain-reactive antibodies for which they were not tested, or may have as-yet unidentified brain-reactive antibodies, not to mention other cerebrovascular or inflammatory issues.
Extensive "rule out" list: Exhaustive testing is rarely feasible to do all at once. In addition to ruling out a long list of potential "new" illnesses, doctors must validate that no "old" illnesses are responsible for a patient's symptoms.
Variance in treatment response: People respond differently to treatment. If an empirical course of immunotherapy is given and the response is not definitive, there are no firm criteria for when to attempt a higher dose, longer duration or alternate immunotherapy, or when to conclude the patient's condition is not autoimmune. Given the potential side effects of the immunomodulatory medications, this is an important consideration.
Overlap with psychiatric and emotional conditions: Patients' emotional state may impact their credibility with medical providers. They and their families may well be frustrated and frightened by the symptoms and loss of function. Patients may also display paranoia, altered personalities, and/or impaired emotional self-regulation due to the illness itself.
Complex health histories and symptom variability: As is often the case of those with autoimmune disease, patients with HE may have complex health histories and their symptoms may wax and wane, especially with illness, stress level and fatigue.
Confirmation bias: Confirmation bias is a psychological phenomenon in which people filter available information, giving more weight to data that supports what they already believe than to that which conflicts with their existing beliefs. This process can happen quite unintentionally, and in medical diagnosis can be influenced by the types of cases with which a practitioner is most familiar.
Insurance authorization: It can be difficult and sometimes impossible, to get insurance companies to authorize diagnostic services such as neuropsychological testing, SPECT or PET scans, testing to rule out other AE's, or an empirical course of plasmapheresis or IVIG to assess immunotherapy responsiveness when a patient does not respond to corticosteroids. Often insurance companies do not have HE or AE on their list of diagnostic criteria for a prescribed immunesupressant.
Specialist availability: There can be a long wait time for each of the specialists in the diagnostic journey and these wait times can be compounded when serial testing is used.
Coordination of care: The diagnostic journey in HE may involve neurologists, endocrinologists, immunologists, infectious disease specialists, rheumatologists, primary care doctors, neuropsychologists, psychiatrists and others- often without much communication or coordination across specialties.
Awareness of HE: Physicians may not even be aware of HE as a potential consideration or may have misconceptions about it.