"Mr. Weller
communicated this secret with great glee, and winked so
indefatigably after doing so, that Sam began to think he must have
got the TIC DOLOUREUX in his right eyelid."

From the Internet:
TRIGEMINAL NEURALGIA

As you probably know, trigeminal neuralgia commonly is called "tic douloureux" or just "tic". When severe, it is the most excruciating pain known to man. This pain most frequently involves the lower lip and lower teeth or the upper lip and cheek, but it also may involve the nose and the area above the eye.

This is a truly dreadful affliction. The slightest touch to the trigger area can cause very severe pain. It is nothing like Mr. Weller's winking or whatever Dickens meant.

Well, I know what he meant, the eyelid or a spot on the cheekbone quivers uncontrollably. I get it occasionally if I'm very tired. It's annoying rather than painful. I've always called it a tic. If that's not the right word for it, what is?

Bingley

Dear Bingley: an involuntary facial muscle contraction is commonly called a tic. But they are not exquisitely painful.

Here's another kind of tic that is not laughable:
From the Internet:
What's Tourette Syndrome?

Tourette Syndrome (TS) is essentially a movement disorder. It is also a disorder of inhibition. It is classified as a neurological condition. E.M. Bouteille first separated movement disorders in 1810 in his medical literature on the choreas. Although Bouteille did not include symptoms of TS in his journals, in 1825, Dr. J.M.G. Itard described involuntary functions of movement of the locomotor apparatus of grasp and voice, or motor and vocal tics.

In 1884, George Gilles de la Tourette became the intern of the famous neurologist Jean M. Charot. Tourette became interested in movement disorders by reading medical reports of the "jumping Frenchmen of Maine", by George Beard in 1878 and 1880. The "jumping Frenchmen" were lumberjacks of French-Canadian decent living in the Moosehead Lake region of Maine. These men, when startled would jump excessively, and if given a command, would carry it out immediately while repeating the instruction over and over. (As there was little entertainment in a lumber camp, they would often be provoked deliberately by co-workers.)

Gilles de la Tourette made the deduction that if there were jumping Frenchmen in Maine, there ought to be jumping Frenchmen in France. He searched the wards of hospitals but failed to find them. He did however find six patients with tics and abnormal vocalizations. To these six, he added three patients of other doctors, and Tourette Syndrome was born.

Tourette found that the occurrence of tics was familial. He recognized echolalia and coprolalia. He also recognized that the onset of the symptoms was in childhood with a male prepondence. He found that the symptoms were progressive only to a certain point, and that different symptoms would replace each other. Most important, he found that the patients did not deteriorate psychologically or intellectually.

After Tourette died in 1902, very little was done on the subject of TS. Some patients were referred to hypnotists with no avail. Little was learned about TS until the 1960's when advances were made in the understanding of brain chemistry and have put tic disorders in a different perspective. Perhaps, with even more advances in medicine and public awareness, the young TS patients of today will be the last generation to yearn for the light at the end of the tunnel.