Fibromyalgia patients have reduced hippocampal volume compared with healthy controls

Abstract

ObjectiveFibromyalgia patients frequently report cognitive abnormalities. As the hippocampus plays an important role in learning and memory, we determined whether individuals with fibromyalgia had smaller hippocampal volume compared with healthy control participants.MethodsT1-weighted structural magnetic resonance imaging (MRI) scans were acquired from 40 female participants with fibromyalgia and 22 female healthy controls. The volume of the hippocampus was estimated using the software FreeSurfer. An analysis of covariance model controlling for potentially confounding factors of age, whole brain size, MRI signal quality, and Beck Depression Inventory scores were used to determine significant group differences.ResultsFibromyalgia participants had significantly smaller hippocampi in both left (F[1,56]=4.55, P=0.037, η2p=0.08) and right hemispheres (F[1,56]=5.89, P=0.019, η2p=0.10). No significant effect of depression was observed in either left or right hemisphere hippocampal volume (P=0.813 and P=0.811, respectively).DiscussionPotential mechanisms for reduced hippocampal volume in fibromyalgia include abnormal glutamate excitatory neurotransmission and glucocorticoid dysfunction; these factors can lead to neuronal atrophy, through excitotoxicity, and disrupt neurogenesis in the hippocampus. Hippocampal atrophy may play a role in memory and cognitive complaints among fibromyalgia patients.

Painful After-Sensations in Fibromyalgia are Linked to Catastrophizing and Differences in Brain Response in the Medial Temporal Lobe

“…Anatomofunctional changes have also been reported in patients with chronic pain in the amygdala, 22,42,51 including decreases in gray matter volume, 15,53 increases in fractional anisotropy, 53 and alterations of power spectral density of low frequency. 42 Finally, studies have also reported FM-related changes in the hippocampus, including hippocampal atrophy, 55 reduced activation during a cognitive performance task, 54 reduced levels of N-acetyl aspartate, a measure of neuronal integrity, 4 as well as reduced binding potential for m-opioid receptor ligands. 36 Our study further uncovers a link between altered functional response in the MTL in FM patients and their experience of PAS.…”

Towards a neurophysiological signature for fibromyalgia

“…Of note, neuroimaging studies have shown augmented responses to a variety of painful stimuli in FM[15; 25; 56], and altered brain structure, metabolic activity and resting state functional connectivity in regions that are consistently involved in processing pain, e.g. [23; 28; 34; 36; 38; 44; 50; 57; 58; 60; 61]. …”

Low-to-Moderate Alcohol Consumption is Associated With Hippocampal Volume in Fibromyalgia and Insomnia

“…As noted above, an additional analysis including these participants was recently published by our group (McCrae et al, 2015). None of the analyses included here overlap with those in the previous report.…”

“…Previous work has shown hippocampal volume reductions in fibromyalgia patients (Lutz et al, 2008) and chronic insomnia patients (Riemann et al, 2007) separately. In addition, we recently reported results of a structural analysis indicating lower hippocampal volume bilaterally in a mixed cohort of patients with fibromyalgia and fibromyalgia with comorbid insomnia (McCrae et al, 2015). However, not all authors have replicated these results in insomnia (Winkelman et al, 2010) or other pain-related conditions such as frequent migraines (Maleki et al, 2013) and osteoarthritis (Mutso et al, 2012).…”