Diffuse axonal injury is characterized by lesions at
**Core Concept**
Diffuse axonal injury (DAI) is a type of traumatic brain injury characterized by widespread damage to axons in the brain, resulting from shearing forces caused by rapid acceleration or deceleration of the head. This type of injury is often seen in cases of high-speed motor vehicle accidents or falls from height.
**Why the Correct Answer is Right**
DAI is typically associated with lesions in the corpus callosum, brainstem, and subcortical white matter. The damage occurs due to the disruption of axonal integrity, leading to the release of intracellular contents, including excitatory neurotransmitters, which can cause further neuronal injury. The corpus callosum is particularly susceptible to DAI due to its high water content and the presence of myelinated axons.
**Why Each Wrong Option is Incorrect**
* **Option A:** Grey matter is more commonly associated with contusion injuries, which are focal injuries to the brain caused by direct impact.
* **Option B:** The cerebellum is involved in motor coordination and balance, but it is not a typical site for diffuse axonal injury.
* **Option C:** The basal ganglia are involved in movement control and cognition, but they are not specifically associated with DAI.
**Clinical Pearl / High-Yield Fact**
DAI is often referred to as a "shearing injury" because it is caused by the shearing forces that occur when the brain is rapidly accelerated or decelerated. This type of injury can be difficult to diagnose on imaging studies, but it is often associated with a poor prognosis.
**Correct Answer:** C.