‘Brain Fog’ Reported Frequently by Patients with Fibromyalgia, Systemic Lupus Erythematous

Confusion, fatigue common symptoms of immune system diseases

lung xray

Repeated moments of confusion combined with difficulty concentrating are symptoms experienced frequently by patients with fibromyalgia (FM) and systemic lupus erythematosus (SLE) and other autoimmune diseases.

Diagnosing the condition, also described as ‘brain fog’ by patients and physicians, can be relatively straightforward. But answering patients’ questions and developing effective therapies present distinctive challenges.

Robert T. Keenan, MD, MPH, MBA, vice chief for clinical affairs for the Duke Division of Rheumatology, says the condition is common among patients with FM and is encountered often in patients with SLE.

“In patients with fibromyalgia, brain fog is almost a given,” Keenan says. “Well over 70% to 80% of those patients will experience the phenomenon. Among patients with lupus, it’s not uncommon to see rates of 30% to 40%, depending on the kind of disease and the acuity of the disease process in each individual patient.”

Several characteristics are common among patients who experience the condition:

  • Lack of focus
  • Lack of mental clarity
  • Increased forgetfulness
  • Increased fatigue and irritability
  • Poor concentration
  • Low energy
  • Slower learning and processing time

Important to treat underlying disease

Specialists should treat the underlying disease rather than focus on the symptoms of brain fog, Keenan says. He encourages patients to get adequate sleep and assess potential disruptions to sleep such as apnea. “In some situations, we recommend a sleep study to identify potential complications,” Keenan says. Overmedicating can also cause fatigue and a reduction in mental focus, he adds.

Opinions vary among rheumatologists about the origin of brain fog. “The causes are more unclear in fibromyalgia patients than in some other autoimmune diseases such as lupus because we believe the condition is associated with long-term potentiation, synaptic plasticity, and neurogenesis,” he says. “It’s clear that the plasticity of the immune system is involved as well as the so-called ‘cleaning process’ that occurs within our nervous system.”

Some patients report more debilitating effects than others, and those reports vary significantly. The symptoms may improve with better control of FM or SLE, but Keenan says fatigue and brain fog can persist for long periods and may be debilitating to some patients.

In addition to sheer fatigue and significant sleep cycle disruption, which may be a contributor to mental confusion in patients with FM, other physical processes may be involved. “It’s hard to say how much of this is related to the neuro-endocrine pathways that may be impacted by inflammatory or immune system disease,” Keenan says.