This article explores the specific concepts in the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides) that apply to assessing impairments of the brain. The AMA Guides emphasizes deficits that can be identified during a standard neurological evaluation and using standard clinical techniques. Complex and integrative cerebral functions are evaluated according to five criteria: disturbances of consciousness and awareness; aphasia or other communication disturbances; mental status and integrative functioning abnormalities; emotional and behavioral disturbances; and special types of preoccupation or obsession. The AMA Guides recommends that clinicians should first evaluate patients for aphasia. Tables show how other cerebral functions are evaluated, and the discussion includes major motor and sensory abnormalities; movement disorders; episodic neurological disorders; and sleep and arousal disorders. An example case is presented and evaluated according to the five criteria: the patient shows impairments in mental status functioning and behavioral status; mental status impairment is evaluated using a table to assign a percentage impairment, and a similar approach based on examination and tables is used to evaluate the patient's behavioral impairment and episodic seizures; finally, the clinician chooses the greater between mental and behavioral status and combines with the value regarding episodic behaviors, giving a total impairment rating.