A little girl in England seemed perfectly fine except for one thing: her eyes welled up with tears every time she peed.
In fact, a rare situation in which the eyes produce tears when a person passes urine may be more common that thought — because it's painless, and perhaps more of an inconvenience than anything else, people may be unlikely to seek medical help for it, researchers in England who dealt with the little girl's case reported today (Feb. 13).
The cause of the condition may lie in the brain or in the facial nerves, according to the report. Both the production of tears and the passing of urine are under the control of a brain region called the pons.
The report is published online in the journal Pediatrics.
An unusual case
The 3-year-old girl was brought to doctors in November 2009, because of "watering of her eyes every time she passed urine," according to the report. When it happened, her jaw would drop and her expression would become vacant, although she remained conscious and was not in any pain, wrote the researchers from University College London Hospital, and Conquest Hospital in Hastings.
The problem began when the girl was just weeks old. An ultrasound of her kidneys revealed nothing abnormal, and there were no signs dry eyes or of any other medical problem.
The researchers searched the medical literature, and found only one other formal report of a similar case, from 1932. In that case, a young man who was a medical student reported a "copious flow of dears during defecation and urination."
The man kept track of his symptoms for 94 days, according to that report by a researcher at the University of Louisville in Kentucky, and the problem was fixed by a dose of atropine, a drug that lowers the activity of certain nerves, and can also be used to dilate the pupils of the eyes.
Looking for more information, the researchers in England turned to health websites, and found more cases. A search of online discussion groups revealed 35 people who described having the problem of tear production during painless urination. Slightly more than half were female, and three described having a close relative with similar symptoms.
None of the people had sought medical advice, saying that the tears, while inconvenient and embarrassing, weren't a significant medical problem, according to the report.
A clue from crocodile tears?
In their search for an explanation, the researchers looked at what happens when someone cries "crocodile tears." Though the term has more recently been applied to insincere or fake crying, the original description of crocodile tear syndrome was based on people who would cry while eating or drinking, due to either a facial injury or a condition called Bell's palsy.
In those cases, nerves that regrow after an injury or disease may be misdirected toward the lacrimal gland, which produces tears, according to the report. There are also cases of crocodile tear syndrome occurring from birth, and these cases may be due to the nerves crossing over during embryonic development, the researchers wrote.
If such an abnormal nerve connection could cause a person to have produce tears while eating or drinking, a similar process could cause a person to produce tears when they urinate, according to the report.
However, this would not explain the little girl's vacant expression, or her jaw dropping when the crying happens, according to the report. For now, those symptoms remain a mystery.