As used in this section and NRS 427A.850 and 427A.860, ‘traumatic brain injury’ means a sudden shock or damage to the brain or its coverings which is not of a degenerative nature and produces an altered state of consciousness or temporarily or permanently impairs the mental, cognitive, behavioral or physical functioning of the brain. The term does not include:

1.  A cerebral vascular accident;

2.  An aneurism; or

3.  A congenital defect.