CPT® Code 95958

The Wada activation test, identified by CPT® Code 95958, is a specialized procedure designed to assess hemispheric function in the brain, particularly in relation to language and memory. This test is crucial for patients who are candidates for surgical interventions, such as those undergoing treatment for epilepsy or other neurological conditions. The primary objective of the Wada test is to ascertain which hemisphere of the brain—right or left—dominates language function and to evaluate the contributions of each hemisphere to memory processes. Typically, the left hemisphere is associated with language control, while both hemispheres play roles in memory, albeit with one side often being more dominant. However, individual variations exist, making this assessment vital for personalized treatment planning. During the procedure, electroencephalographic (EEG) monitoring is employed to observe brain activity. This involves placing electrodes on the patient's scalp, which are connected to a recording device to capture electrical activity in the brain. The physician administers an anesthetic into one of the internal carotid arteries, effectively 'putting to sleep' the corresponding hemisphere of the brain. This allows for a clear evaluation of the awake hemisphere's ability to perform language and memory tasks. The physician tests the patient's speech capabilities and recognition of visual stimuli, such as cards with pictures and words, to determine the functional dominance of the active hemisphere. After the anesthetic effect wears off, the process is repeated for the opposite hemisphere, allowing for a comprehensive comparison of both sides. The findings from the Wada test are documented in a written report, providing essential insights for surgical decision-making and patient management.