Mild Traumatic Brain Injury and Postconcussive Syndrome
Mild TBI constitutes 80% to 90% of TBI cases in the United States

~ 2.3 million cases in the United States

Multiple terms, definitions, and diagnostic criteria available for mild or minor traumatic brain injury

The American Congress of Rehabilitation (1995) has defined mild TBI as a traumatically induced physiologic disruption of brain function with at least one of four manifestations:

Any loss of consciousness (LOC)

Any loss of memory for events immediately before or after the injury

Any alteration in mental status at the time of the accident

Focal neurological deficits that may or may not be transient

Usually, mild TBI has negative radiological findings (CT/MRI)

The injury cannot exceed the following severity criteria:

LOC greater than 30 minutes

Posttraumatic amnesia (PTA) > 24 hours

Initial GCS ≤ 12 (13 to 15)

Signs and symptoms after mild TBI include:

Headache (most common)

Dizziness

Tinnitus

Hearing loss

Blurred vision

Altered taste and smell

Sleep disturbances/insomnia

Fatigue

Sensory impairments

Attention and concentration deficits

Slowed mental processing (slowed reaction and information processing time)

Memory impairment (mostly recent memory)

Lability

Irritability

Depression

Anxiety

Most mild TBI patients have a good recovery with symptoms clearing within the first few weeks or months postinjury (usually within 1 to 3 months)

In some patients the symptoms (previously mentioned) persist and are associated with social and vocational difficulties that appear to be out of proportion to the severity of the neurologic insult. This condition has been termed postconcussive syndrome (PCS)

In a recent study, 14 mild TBI patients with unusually persistent deficits evaluated with single photon emission computed tomography (SPECT) showed significant anterior mesial temporal (lobe) hypoperfusion and less striking dominant (left) orbitofrontal abnormalities

Memory and learning deficits have been associated with lesions at the hippocampus and related structures in the medial temporal lobes or with injuries to structures that control attention, concentration, and information processing in the frontal and temporal lobe

Pharmacologic intervention may be used including antidepressants and psychostimulants

Concussion/Sports Related Head Injuries

Classification of concussion is controversial

The most widely used grading systems for concussion/mild head injury are the Colorado and the Cantu guidelines

Table 2-14

Cantu and Colorado Head Injury Grading Systems.
Return to Play Guidelines

Return to play criteria have been similarly controversial

Colorado Medical Society and Cantu Guidelines are among the most widely used.

Table 2-15

Cantu's Guidelines for Return to Play after Concussion.
The American Academy of Neurology endorsed the Colorado Medical Society Guidelines for classification and management of concussion in sports in its Report of the Quality Standards Subcommittee Practice Parameter published in Neurology, 1997.

Table 2-16

When to Return to Play—Colorado Medical Society Guidelines.
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Copyright © 2004, Demos Medical Publishing, Inc.

http://www.ncbi.nlm.nih.gov/books/NBK27185/