Question: What diagnoses can we use to support medical necessity for a blink test? Arizona Subscriber Answer: The reason for ordering the test should support its necessity. For example, a blink reflex test (95933, Orbicularis oculi (blink) reflex, by electrodiagnostic testing) evaluates brainstem function and nerve activity in the head and neck. Blink tests can detect conditions affecting the fifth and seventh cranial nerves and brainstem lesions or tumors pressing on the nerves. Possible diagnoses leading to a blink test could include acoustic neuroma (225.1. Benign neoplasm of brain and other parts of nervous system; cranial nerves), hereditary sensory neuropathy (356.2), facial nerve palsy (351.1 Bell's palsy), or others.