Pa'nar syndrome

Pa'nar Syndrome is a Vulcan neural disease that results in the degradation of the synaptic pathways. It also affects the endocrine and immune systems.

It is caused by a disruption of neuro-electric impulses in the midbrain during mind melds performed by a Vulcan who has been improperly trained. It could be cured by a meld performed by an experienced melder.

The disease and its cure were known in Surak's time, but by the 22nd century the knowledge of the cure had been lost or suppressed.
By the 22nd century, melding was considered an "unnatural" practice. As a result, those afflicted with Pa'nar Syndrome were ostracized from Vulcan society. Consequently, medical research towards finding a cure was not a priority.

In 2152, Dr. Phlox was able to improve the course of treatment. The discovery of the Kir'Shara (an ancient Vulcan artifact) enabled others suffering from Pa'nar to come out and be cured. Phlox noted that Pa'nar "is no longer a stigma."