Brain fog describes the inability to think or concentrate when we are sick. We don’t notice it as much when we have a bad cold or the flu, because we don’t even try to go to work or school for the few days that it lasts, and then it goes away. But in chronic illness, lasting weeks, months, or years, it begins to interfere with our ability to do our job, pay our bills, pass our courses or maintain our relationships. Brain fog is result of the activation of the immune system, and it is a symptom of chronic infectious, inflammatory and autoimmune illnesses, such as Lyme disease, multiple sclerosis, rheumatoid arthritis, lupus, fibromyalgia and chronic fatigue syndrome. Similarly, people undergoing chemotherapy often suffer from “chemo-brain.”
Brain fog usually varies in severity, often along with other symptoms. It is caused by some aspect of immune system that we don’t yet fully understand, perhaps involving cytokines, the chemicals that instruct white blood cells to attack invading bacteria. (A more technical term for brain fog is immune-mediated cognitive dysfunction.) I think of it as “the brain on power saver.” In the same way that we lose our energy, and our appetite, the immune system may be conserving energy by shutting down non-essential functions, in order to better fight infection. Unfortunately, although higher-level brain function may be considered non-essential by the immune system, focusing, remembering and getting things done seem pretty important to us.
We all have times when we are thinking less clearly or forgetting something we should remember, and these usually are times of stress or fatigue. We get foggy-headed when we have a cold, for example, and even if we drag ourselves to work or school, not much gets accomplished. We try to read something late at night, and our eyes get to the bottom of the page, but we have no idea what we’ve read. Just as the higher level processes of thinking and attention only work when we are safe and our basic needs are met (Affective System), they don’t work well when we are sick or fatigued, or when we are worried or upset about something. Because we have all had these brief experiences of brain malfunction, we tend to become concerned only when they persist over time. Here is a new article about brain fog.
The symptoms of Lyme disease area usually flu-like aches and pains, joint and muscle aches, and fatigue. However just about any symptom can be caused by Lyme, including headache, stomach or digestive problems, heart palpitations, vision changes, and so on. Sleep disturbance – problems falling asleep or staying asleep, are very common, as is mood disturbance – irritability, depression or anxiety. In Lyme disease, a frequent complaint is “brain fog”, or cognitive dysfunction, that interferes with school or job performance. (See my article on Educational Accommodations for Children with Lyme Disease)