The role of the anterior and midcingulate cortex in the neurobiology of functional neurologic disorder

Abstract

Functional neurological disorder (FND) / conversion disorder is a prevalent and disabling condition at the intersection of neurology and psychiatry. Clinicians often report feeling illequipped treating patients with FND, perpetuated by a historically limited understanding of neurobiological disease mechanisms. In this review, we summarize the neuroimaging literature across the spectrum of sensorimotor FND, including functional imaging studies during rest, sensorimotor, and emotional processing tasks as well as structural magnetic resonance imaging findings. Attention is given to studies implicating the anterior and middle cingulate cortex and related salience network structures (insula, amygdala, and periaqueductal gray) in the neurobiology of FND. Neuroimaging studies identify cingulo-insular functional alterations during rest, motor performance, and emotion processing in FND populations. The literature also supports that patients with FND exhibit heightened amygdalar and periaqueductal gray reactivity to affectively valenced stimuli, enhanced coupling between amygdalar and motor control areas, and increased amygdalar volumes. The early-phase structural neuroimaging literature implicates cingulo-insular areas in the pathophysiology of FND, though these findings require replication and clarification. While more research is needed to fully elucidate the pathophysiology of FND, salience network alterations appear present in some FND populations and can be contextualized using biopsychosocial models for FND.

Impaired effective functional connectivity of the sensorimotor network in interictal episodic migraineurs without aura

“…The current study also observed that, in resting state, there is decreased activity of the left MCC, a key region connected to circuits mediating cognitive control, nociceptive perception and multisensory integration [32,33]. Particularly, it is suggested that the consecutive hyperactivation of the MCC could alleviate the neuropathic pain, but the hypoactivity of the MCC may diminish the pain inhibitory abilities, corresponding to the present findings [32].…”

Impaired Effective Functional Connectivity of the Sensorimotor Network in Interictal Episodic Migraineurs Without Aura

“…The current study also observed that, in resting state, there is decreased activity of the left MCC, a key region connected to circuits mediating cognitive control, nociceptive perception and multisensory integration [32,33]. Particularly, it is suggested that the consecutive hyperactivation of the MCC could alleviate the neuropathic pain, but the hypoactivity of the MCC may diminish the pain inhibitory abilities, corresponding to the present ndings [32].…”

Altered Spontaneous Brain Activity in Somatic Symptom Disorder: A Resting-state fMRI Study

“…Compared with the controls, the SSD patients exhibited abnormal ReHo values and ALFF values in the MCG, ACC, medial frontal gyrus, inferior frontal gyrus, insula, precuneus, inferior/middle temporal gyri, parahippocampal gyrus and pons. These ndings are in line with previous neuroimaging studies [8,13,14]. A meta-analysis identi ed the middle frontal gyrus, the ACC, and the insula involved in SSD and consistently differed between patients and healthy controls, which seems to be of particular importance in SSD [15].…”

“…In our study, we found SSD exhibited spontaneous brain function alterations in frontal and subfrontal regions, including in the MCG, ACC, medial frontal gyrus, inferior frontal gyrus and insula. Previous structural and functional neuroimaging studies indicated alterations in the ACC and MCG play important roles in the neurobiology of functional neurologic disorder, and ACC dysfunction may be related to mood dysregulation and trauma symptoms, whereas MCG alterations may be related to impaired cognitive control, motor control, behavioural expression of mood states, nociception, and multimodal integration in patients with functional neurologic disorder [13]. The medial prefrontal cortex and ACC are involved in emotional disorders, such as anxiety and depression disorders [16,17].…”