Altered brain functional connectivity in patients with resistance to thyroid hormone ß

Area of Science:

• Neuroscience
• Endocrinology
• Psychiatry

Background:

• Resistance to thyroid hormone beta (RTHβ) is a rare genetic disorder affecting thyroid hormone action.
• Neurobehavioral similarities between RTHβ and attention-deficit hyperactivity disorder (ADHD) warrant investigation.
• Understanding these similarities may offer insights into ADHD pathophysiology.

Purpose of the Study:

• To investigate alterations in brain network organization in RTHβ patients.
• To explore potential neurobehavioral similarities between RTHβ and ADHD.
• To compare resting-state functional connectivity (rs-fMRI) and cognitive domains between RTHβ patients and healthy controls.

Main Methods:

• A prospective case-control study involving 21 genetically confirmed RTHβ patients and 21 matched healthy controls.
• Assessment of ADHD symptoms using the Adult ADHD Self-Report Scale (ASRS-v1.1) and ADHD Rating Scale-IV.
• Analysis of rs-fMRI data using voxel-wise and atlas-based approaches to identify brain network changes.

Main Results:

• RTHβ patients reported behavioral symptoms consistent with ADHD.
• Weaker network integration was observed in the lingual and fusiform gyri in RTHβ patients, linked to reduced connectivity with the insula and supplementary motor cortex.
• Increased functional connectivity between the default mode network and cognitive control network regions was found in RTHβ patients compared to controls.

Conclusions:

• RTHβ is associated with distinct brain network alterations, including weaker connectivity in visual processing areas and altered default mode/cognitive control network interactions.
• These findings support the notion of significant neuropsychological similarities between RTHβ and ADHD.
• The observed brain connectivity patterns in RTHβ may underlie ADHD-like symptoms such as distractibility and attention deficits.