AT: "xx" A neurologist is a professional specializing in the brain and the synapses of a human and other sentient species.
In 2364, Doctor Beverly Crusher suggested that Lieutenant Geordi La Forge consider exploratory surgery by a neurologist to desensitize certain areas of his brain after he reported his VISOR implants were causing him pain. La Forge rejected the idea as it would hinder his ability to get full use out of the device. (TNG: "Encounter at Farpoint")
In 2371, The Doctor began to experience a series of illusions in which Reginald Barclay attempted to convince him he was in fact Doctor Lewis Zimmerman and was isolated in a holographic simulation at Jupiter Station. In the illusory Barclay's attempt to get The Doctor to turn off his holoprogram, he claimed to have consulted with neurologist Dr. Kaplan, who said that if he couldn't get out of the holodeck within the next hour, that radiation would completely oxidize his neuro-cellular structures thereby killing him. (VOY: "Projections")
After being transported to an alternate timeline during the year 2372, Ensign Harry Kim attempted to explain to his fiance Libby that he did not belong in her reality. Libby, believing him to be ill or confused, suggested he speak to a counsellor or a neurologist. Kim said he would but not before he met up with Tom Paris. (VOY: "Non Sequitur")