10 Unpacking the Link Between Neurosarcoidosis and Memory

Neurosarcoidosis (NS) is a rare sarcoidosis variant affecting the nervous system. NS is inflammation that develops in the nervous system caused by a buildup of inflammation cells. It is caused directly by the lymphatic system, as well as the inhalation of foreign substances. NS can be diagnosed through magnetic resonance imaging (MRI) and a combination of nerve conduction, spinal fluid, and blood tests. With MRI, the appearance of NS will vary depending on the location and how inflamed the affected area is. However, diagnostics is challenging depending on if there are no other symptoms present, and this happens in approximately 3% of cases (Fels et al., 2004). Subsequently, MRI findings of neurosarcoidosis can include a range of brain abnormalities such as periventricular high-signal lesions on T2-weight images, multiple supratentorial and infratentorial brain lesions, solitarily intra-axial mass, and leptomeningeal enhancement (Pictuth et al. 2000)

Two different forms of NS can be found in the nervous system. The first is pachymeningitis, a build-up of cells on the outer layer of the meninges, and it is often thought of as a tumor. NS comes from a direct spread from the sinuses and the tissues behind the ear. The second form, leptomeningitis, is much more severe as it is directly associated with the brain. This can be very destructive if treated incorrectly and can develop into hydrocephalus. Subsequently, NS may also affect the peripheral nervous system. Hydrocephalus is a less common form of NS; although it can cause numbness and muscle weakness, it is often misdiagnosed as a motor neuron disease. NS is not a common health disorder, so it is important to be able to identify symptoms. Symptoms of NS include headache, seizure, blurred vision, and decreased motor skills, which often worsen over time if they are not treated correctly. Treatment can range from life management to an intense medication regimen. Proper occupational therapy and physiotherapy are essential to build on the individual’s foundation and keep their overall ability from declining. Simple walks and mind-activation activities, such as doing a puzzle or having a meaningful conversation, will benefit patients.

Memory deficits in NS patients are caused by lesions in the brain involving areas including the left temporal lobe, left globus pallidus, and hypothalamus (Fortes et al., 2013). Patients in the study by Fortes and colleagues had lesions in areas throughout the brain. However, the hypothalamus was mainly affected (Fortes et al., 2013).  Two case studies revealed lesions in these brain areas discovered through multiple MRIs over a six-month period. This study was able to identify regions of the brain that were responsible for both diagnoses of NS. Therefore, with the evidence found in Fortes et al., study, we can presume that lesions in the brain involving the hypothalamus, suprasellar, chiasmatic, and optic regions are common for individuals with NS. Lesions in these areas allow for a connection of memory with NS. The brain regions previously listed have been linked to basic physiological functions, although they play a key role in memory consolidation and retrieval. As the hypothalamus forms a part of the limbic system that involves various emotional and memory processes.

Different tests are used to test memory, and one used to test individuals with NS is the Cognitive Failure Questionnaire (CFQ). In this study, the CFQ was developed to assess a group of 131 individuals who have already been diagnosed with NS. The CFQ consisted of 25 items assessing cognitive abilities and everyday tasks. The total score was calculated out of 100, with a score greater than 43 indicating that the individual is subject to cognitive failure (Voortman et al., 2019). NS can affect any part of the nervous system and vary from person to person. In the study by Voortman et al., 55.7% of patients had a score higher than 43, indicating a cognitive decline. Ninety-two percent of patients reported fatigue, and 53.4% reported extreme fatigue while completing the CFQ. Therefore, mental fatigue while completing everyday tasks is a strong indicator of why cognitive failure is common for individuals with NS.

Throughout my experience with individuals with NS, there is a significant impact on the individual’s memory. Working with patients with NS from a therapy perspective has allowed for hands-on experience with NS. With this opportunity, many physical tests and neurological tests were used to help better understand NS deeper, as this was the first case for any of the therapy staff. Although NS may be uncommon in rural areas, it is still essential to have the correct information about it so patients can be treated when needed. Short-term memory and essential motor functions such as walking and getting out of bed have indicated that NS affects primary memory function. The primary memory function allows individuals to do foundational things that they have done every day of their life, (e.g., walking). Experience with NS patients has shown a rapid decline in basic life skills and a rapid decline in memory. The patient would often have difficulty remembering different healthcare professionals and family members. An example of a tactic to help the patient remember where they were, and what was going around with them, was to post notes to enhance their memory and make them comfortable in the hospital setting. Symptoms are often rapidly changing, making it necessary to adapt and get proper treatment. Cognitive decline is a symptom of NS that affects individuals daily; an example of memory loss is not remembering if they had a meal or the name of the individual they just met (Fortes et al.). A decline in short-term memory will begin first. Then over time, there are possibilities of a decline in long-term memory and the ability to complete everyday tasks that the patient could do without thinking, or subconsciously (Fortes et al. 2013). The symptoms of NS need to be adequately treated to ensure that the patient does not severely suffer from the symptoms, as NS does not have a cure. NS does not have a cure, although it is not fatal. Like most other neurological symptoms, death is a possibility, although it often is the result of other complications while living with NS. The mortality rate for NS is less than 10% (Wells. 2017), which means that being able to live with NS is important and that individuals who have NS need to work with their doctors, neurologists, and therapeutical professionals to develop adaptation skills that allow them to live with NS.