Persistent hypersensitivity after repeat concussion is associated with chronic cognitive dysfunction

Area of Science:

• Neuroscience
• Traumatic Brain Injury Research
• Sensory Processing

Background:

• Persistent sensory hypersensitivity is a common, under-recognized feature of post-concussion syndrome (PCS) after mild traumatic brain injury (mTBI).
• The link between long-term sensory dysregulation and cognitive dysfunction after repeat concussions is poorly understood.
• Understanding this relationship is crucial for developing effective treatments for PCS.

Purpose of the Study:

• To investigate whether chronic sensory processing abnormalities contribute to cognitive impairment under increased sensory load in a mouse model of repeated mild concussion.
• To determine the mechanistic relationship between sensory dysregulation and cognitive deficits in post-concussion syndrome.

Main Methods:

• A repeated closed-head injury (rCHI-5x) model was used in young adult mice.
• Sensory processing (tactile, auditory) and cognitive flexibility were assessed under baseline and increased sensory load conditions.
• Within-animal statistical analyses correlated sensory hypersensitivity with cognitive flexibility deficits.

Main Results:

• rCHI mice showed significant sensory dysfunction (tactile hypersensitivity, auditory habituation impairment) without gross brain damage.
• Cognitive flexibility deficits emerged only under increased auditory and tactile sensory load, not under baseline conditions.
• Severity of sensory hypersensitivity strongly correlated with cognitive flexibility deficits in rCHI mice.

Conclusions:

• Chronic sensory dysregulation is a primary contributor to cognitive impairment in post-concussion syndrome, particularly under sensory load.
• Persistent sensory processing and gating dysfunction are key drivers of PCS-related cognitive deficits.
• Targeting sensory circuitry may offer therapeutic benefits for cognitive dysfunction in PCS.