General description

Infantile traumatic brain injury with a biphasic clinical course and late reduced diffusion (TBIRD) is a condition observed in infants after head trauma, including cases of abuse. It presents with clinical and imaging findings similar to Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD). However, unlike AESD, TBIRD is often associated with acute subdural hematoma in the early stages, which is a distinguishing feature.

TBIRD typically follows a biphasic course, with bright tree appearance (BTA) emerging around days three to six and severe brain atrophy developing in the chronic phase. The pathophysiology of TBIRD involves excitotoxicity mediated by glutamate, leading to rapid brain edema after late seizures, often resulting in a poor prognosis.

Differential diagnosis

While both TBIRD and AESD exhibit biphasic progression and BTA, TBIRD is linked to head trauma, necessitating careful differentiation between the two. AESD is caused by infections and usually presents with fever at onset, but fever can occasionally be seen in TBIRD cases as well, making diagnosis challenging. The presence of acute subdural hematoma and differences in BTA distribution—frontal predominance in AESD versus occipital involvement with asymmetry in TBIRD—are key factors in distinguishing between these conditions.