An estimated 15% of people with sarcoidosis, a rare condition which causes granulomas to form throughout the body, develop neurosarcoidosis. This form, which is characterized by central nervous system (CNS) inflammation, often affects the facial and cranial nerves, hypothalamus, and pituitary glands. The inflammation damages the protective nerve cell covering and leads to a variety of symptoms. Unfortunately, shares Steve Bryson, PhD in Sarcoidosis News, these symptoms may overlap with those of other conditions like multiple sclerosis (MS) or lupus.
Because of this, Bryson explains, neurosarcoidosis is significantly underdiagnosed. A study published in Nature Scientific Reports found that only one in every six people evaluated for suspected neurosarcoidosis received a definitive diagnosis.
The Challenges of Diagnosing Neurosarcoidosis
Symptoms of neurosarcoidosis may be non-specific and depend on the affected area of the body. For example, symptoms can range from the following:
- Confusion or disorientation
- Excessive thirst
- Fatigue
- Hearing loss
- Changes in menstrual periods
- Muscle weakness, numbness, and tingling
- Excessive urination
- Dementia
- Arm or leg paralysis
- Headache
- Facial palsy
- Seizures
- Changes in mood, behavior, or personality
This is not an exhaustive list of symptoms. These symptoms, as well as non-specific laboratory and MRI findings, can make it difficult to identify neurosarcoidosis over other conditions. While brain and spinal cord tissue biopsies can confirm diagnosis, these tests are often painful and invasive.
Risk factors for this condition include being between 20 and 40 years old, having certain immune disorders, certain infections, or being of Swedish or African descent.
The Need to Improve Diagnostic Efficacy
Within the study, researchers explored the prevalence of diagnosis in Sweden over a 30-year period. They identified 90 people with suspected neurosarcoidosis; their doctors had defined them as having probable or possible cases.
Symptoms experienced by participants included headaches, pituitary or hypothalamic dysfunction, movement difficulties, hallucinations, sexual dysfunction, fever, nausea and vomiting, and pain or tingling related to the cranial or optic nerves. Other findings show that:
- 55% of individuals also had sarcoidosis beyond the CNS.
- Brain and spinal cord MRIs noted that 17% of patients had pituitary gland and/or hypothalamic damage, which was much higher than previously thought or reported. Additionally, 22% of patients had optic nerve inflammation.
- High amounts of white blood cells were found in a majority of patients’ cerebrospinal fluid. This suggested some sort of neurological inflammatory response.
- Most people with systemic sarcoidosis did not undergo biopsies for neurosarcoidosis as their condition was considered probable. Those who underwent biopsies typically did so because their condition was named possible.
- 21% of patients had confirmed neurosarcoidosis diagnoses. The remaining 79% did not receive answers and could not have their conditions verified. This suggests that many individuals are remaining undiagnosed.
Despite advances in technology and medical research, the research team states that problems with meaningful biomarkers and difficulties in diagnostic methods are preventing patients from being reached.
