Continuum of Irreversible and Potentially Reversible Traumatic Brain Injury Sequelae: Axonal Injury and Hydrocephalus

Area of Science:

• Neuroscience
• Neurology
• Traumatic Brain Injury Research

Background:

• Chronic traumatic encephalopathy (CTE) is a tauopathy linked to repetitive head trauma, with traumatic encephalopathy syndrome (TES) as its clinical correlate.
• Diffuse axonal injury (DAI) and post-traumatic hydrocephalus (PTH) are interacting mechanisms contributing to neurocognitive decline after traumatic brain injury (TBI).
• DAI is largely irreversible axonal damage, while PTH involves potentially reversible cerebrospinal fluid (CSF) dynamic disturbances, often underrecognized.

Purpose of the Study:

• To review the pathophysiology, neuroimaging, and management of CTE/TES, DAI, and PTH.
• To highlight the importance of understanding the continuum of these post-TBI conditions.
• To emphasize the potential for improved outcomes through recognition and treatment of reversible PTH.

Main Methods:

• A narrative review of PubMed-indexed literature from 1980-2025.
• Prioritization of case series, clinical trials, and review articles on post-traumatic CSF disturbances.
• Inclusion of 62 articles after screening 100 records for relevance to pathophysiology, diagnosis, or management.

Main Results:

• Persistent ventriculomegaly post-TBI is often misdiagnosed as cerebral atrophy, overlooking treatable PTH.
• Advanced neuroimaging aids in differentiating DAI-related atrophy from PTH.
• Patients with PTH show functional recovery after CSF diversion procedures like shunts and endoscopic third ventriculostomy.

Conclusions:

• The continuum of DAI and PTH underscores the significance of identifying reversible components of post-TBI injury.
• Early diagnosis and management of PTH can substantially enhance functional outcomes in chronic TBI patients.
• Recognizing PTH as distinct from cerebral atrophy is crucial for timely surgical intervention.