Cognitive Dysfunction in Fibromyalgia Patients is Not Associated with Alzheimer’s Disease

Cognitive Dysfunction in Fibromyalgia Patients is Not Associated with Alzheimer’s Disease

memoryResearchers at Rush Medical College in Chicago recently published in JCR: Journal of Clinical Rheumatology the conclusion that there is no link between the cognitive dysfunction seen in fibromyalgia patients and the development of Alzheimer’s disease. The study is entitled “Cross-sectional Neurocognitive Data Do Not Support a Transition From Fibrofog to Alzheimer Disease in Fibromyalgia Patients.

Fibromyalgia is a medical condition that can affect the ability of the individual to conduct simple daily tasks, compromising quality of life. It is characterized by widespread chronic musculoskeletal pain, stiffness and numbness in certain parts of the body, fatigue, headaches, sleep disorder and mood alterations. Women are more susceptible to this disorder than men.

Cognitive dysfunction can also occur in fibromyalgia patients, such as lapses in memory, confusion and word mix-ups, and it is usually referred to as “fibrofog.” The cause of fibromyalgia fog is not clear, but it has been suggested that it might be linked to sleep deprivation and/or depression. Many fibromyalgia patients that develop fibrofog in their middle years are concerned with the possibility that it might correspond to an early sign of Alzheimer’s disease.

To determine if the cognitive deficits found in fibromyalgia patients are related to the lapses in memory and progressive cognitive decline characteristic of Alzheimer’s disease, Dr. Frank Leavitt and Dr. Robert S. Katz conducted a cross-sectional study in two different cohorts of fibromyalgia patients based on the duration of the patients’ reported memory problems. The first cohort comprised 94 fibromyalgia patients reporting a short period of cognitive deficits (≤ 12 months), whereas the second one had 55 patients with a long period of cognitive problems (≥ 84 months).

Researchers provided patients with 12 neurocognitive tests concerning their cognition and function including the Controlled Oral Word Test (a verbal fluency test), Stroop Color and Word test (designed to discriminate between individuals who have brain damage from non-brain damaged), Trail-Making Tests A and B (neuropsychological tests of visual attention and task switching), Logical Memory and Paired Associates (to assess verbal memory), Beck Depression Inventory (to assess depression severity) and Paced Serial Arithmetic Test (to asses capacity and rate of information processing and attention). In addition, intelligence, vocabulary and education level were also evaluated.

Researchers found that the education, vocabulary and depression levels were similar between both groups. No differences were found in episodic cognitive memory and processing speed, which are considered to be markers of preclinical Alzheimer’s disease, in any of the neuropsychological parameters assessed. The only difference was found on the Trails A test, where the group with a longer period of cognitive problems performed worst.

The research team was unable to find a link between the development of Alzheimer’s disease and the fibromyalgia fibrofog as the cognitive pattern of the two disorders appears to be distinct. Fibrofog is not linked to episodic memory loss or progressive cognitive decline typical in Alzheimer’s disease. In addition, patients with fibrofog maintain their episodic memory (remember personally experienced events) while Alzheimer’s patients are unable to do so as the brain mechanisms responsible for storing these memories are irreversibly impaired. In fibromyalgia patients, it was found that the memory lapses are associated with the inability of the individual to filter out relevant distractions. The authors concluded that fibromyalgia patients should not be concerned with the possibility that the fibrofog they experience is a potential sign of the start of a dementing process.