What Are the Mechanisms of Injury Involved in Pedestrian–Vehicle Collisions?

Pedestrian–vehicle collisions are a leading cause of traumatic brain injury (TBI) in both urban and suburban environments. While external injuries may be immediately visible following impact, the neurological consequences often occur at a microscopic or functional level—making them more difficult to detect in the acute setting.

Understanding the mechanism of injury involved in these incidents is essential not only for clinical management but also for evaluating causation and long-term functional impairment in litigation.

When a pedestrian is struck by a motor vehicle, the forces transmitted to the body frequently result in both linear and rotational acceleration of the brain within the skull. Unlike static injuries, these dynamic forces can disrupt normal neuronal function through:

• Shearing of axonal fibers

• Disruption of functional neural networks

• Impaired neuronal signaling

• Metabolic dysfunction at the cellular level

This pattern of injury is commonly associated with diffuse axonal injury (DAI), a form of traumatic brain injury that may not be visible on standard CT or MRI imaging.

In many pedestrian injury cases, patients may present with persistent cognitive, behavioral, or emotional symptoms despite “normal” imaging findings. These may include:

• Memory impairment

• Slowed processing speed

• Reduced attention and executive functioning

• Fatigue

• Emotional regulation difficulties

Because these impairments often develop gradually following the initial trauma, the connection between the mechanism of injury and symptom manifestation may not be immediately recognized.

From a medical-legal perspective, this presents a critical challenge when evaluating causation, injury severity, and long-term disability.

Neurological expert witness evaluation plays an important role in determining whether the reported mechanism of injury is consistent with the patient’s clinical presentation. This includes assessing the biomechanical plausibility of the trauma, identifying delayed neurocognitive decline, and differentiating trauma-related deficits from pre-existing conditions.

Establishing Clinical Correlation

A comprehensive neurological review can help establish:

• Clinical correlation between trauma dynamics and symptom progression

• Functional limitations affecting employability and daily living

• Prognosis and anticipated long-term care needs

Understanding how acceleration–deceleration and rotational forces affect brain function is essential when assessing damages, loss of earning capacity, and future care requirements in pedestrian-related TBI litigation.

As many of these injuries occur at a cellular level, neurological expertise is often necessary to translate complex clinical findings into objective medical opinions that support accurate case evaluation.

📩 For inquiries or medical expert witness consultations, please contact me in the form below or directly at doctor.claudia@gmail.com; info@drclaudiamunoz.com

Dr. Claudia

Neurologist | Medical Expert Witness

Traumatic Brain Injury & Neurological Cases