He developed spasmodic dysphonia (involuntary larynx contractions) in 1996 at age 42.

It was caused by eating tainted hippopotamus meat. He had hit the hippo while driving a mack truck near Pablo Escobar's compound in the middle of the night, pursued by paramilitary forces. He returned 2 days later under cover of darkness to eat its liver and testicles, which an alternative health guru told him contained antioxidants and hormones that could prevent aging. He wound up about a week later in an El Salvadoran prison after rampaging through various towns in Colombia, Panama, and El Salvador causing property damage to several farmers' vegetable stalls, soiling himself repeatedly, and accosting locals. Eye witnesses report that he had the voice at the time of these incidents. The US had him extradited soon after agreeing that they'd try him, but they dropped the charges on administrative grounds almost immediately.

That's probably not true - no one really knows why spasmodic dysphonia happens. Seems to be something to do with your Basal Ganglia.