Functional magnetic resonance imaging response was utilized to test motor, somatosensory association cortex, perception, and sensory integration processing in a recent study.
Functional magnetic resonance imaging (fMRI) utilized in a recent study found a correlation between psychological stress and exacerbated brain activity in female patient with atopic dermatitis (AD). Affected areas of brain activity included motor, somatosensory association cortex, perception, and sensory integration processing.1
Researchers Jonsson et al noted that in addition to already understood relationships between psychological stress and aggravated AD, a 2020 study explored T1-weighted voxel brain morphometry in a small patient cohort. The study, published in Acta Dermato-Venereologica, revealed a significant link between hypothalamic volume and perceived stress among patients with AD.2
With previous understandings and recent research of AD and psychological stress in mind, researchers sought to explore the potential of brain processing dysfunction among individuals facing acute psychological stress.
A total of 29 adult female patients with AD were enrolled in the single-center study, each presenting with a Scoring Atopic Dermatitis scale (SCORAD) score of 30 or more. Researchers opted to age-match 23 otherwise healthy adult control patients.
Clinical examinations were conducted following fMRI sessions in all patients. Clinical measures of AD and neuropsychological traits included SCORAD, level of itch, sleep disturbance, salivary cortisol, exhaustion symptoms of chronic stress, stress susceptibility, somatic trait anxiety, physical trait anxiety, lack of assertiveness, transient irritability, and impulsivity.
Researchers used a 3T MRI scanner for whole-body measurements and conducted an fMRI session with a task involving arithmetic problems. They induced stress during the fMRI session using a numerical subtraction task. Participants had to respond within a specific time using a response button pad. Immediate feedback was given on whether the answer was right or wrong. Throughout the process, pulse rate was monitored to assess stress levels.
T1-weighted MPRAGE data were processed using CAT12 Toolbox in SPM12. Researchers also created grey matter, white matter, and cerebrospinal fluid probability maps. Data were smoothed and analyzed using statistical tests, considering age and total intracranial volume as covariates. They also performed a region of interest-based analysis for a specific brain region.
fMRI data underwent preprocessing using AFNI. This involved motion correction, spatial registration, bandpass filtering, and detrending. Individual brain activation maps were generated using a block-designed paradigm.
The only significant difference clinical or neuropsychological measurement observed by researchers was the salivary cortisol level between patients with AD and healthy control subjects, with patients with AD exhibiting significantly higher average values than healthy controls.
Additionally, significant correlations were noted among patients with AD in objective SCORAD and sleep disturbance, SCORAD and exhaustion symptoms of chronic stress. Impulsivity was also correlated with somatic trait anxiety, physical trait anxiety, and transient irritability.
The voxel-wise two-sample t-test revealed no significantly large clusters with statistically significant difference in blood oxygen level dependent response among both patients with AD and without. However, notable deactivation variations were observed in the right angular gyrus, bilateral temporal poles, and temporal lobes.
Higher mathematical anxiety was linked to reduced default mode network deactivation in response to numerical tasks. Although stress and anxiety levels showed no significant differences, blood oxygen level dependent responses to mental stress exhibited contrasting patterns. For patients blood oxygen level dependent responses in specific brain regions and objective scores or itch severity. The primary somatosensory cortex and posterior insular cortex played a role in itch perception.
"Findings from this study support the notion that psychological stress exacerbates brain activities for the AD subjects in the motor, somatosensory association cortex, perception and sensory integration processing," according to study authors.