WEDNESDAY, April 14, 2010 (HealthDay News) -- Involuntary crying or laughing can be a common symptom in patients with certain neurological disorders, such as Alzheimer's, multiple sclerosis or amyotrophic lateral sclerosis (ALS).
However, a combination of drugs could be the first effective long-term treatment for the problem, researchers say.
The new treatment for curbing these unwanted crying/laughing episodes -- known to doctors as "pseudobulbar affect" or PBA -- uses two drugs, dextromethorphan and low-dose quinidine.
Early indications are that the two drugs do reduce the incidence and severity of PBA episodes and improve quality of life.
"There's no FDA-approved therapy for pseudobulbar affect," noted study lead author Dr. Erik P. Pioro, director of the section for ALS and related disorders at the Cleveland Clinic in Ohio, and a member of the American Academy of Neurology (AAN). "The off-label medications that are being used have their own set of side effects and problems. So from a medical and patient care point of view, it would be very worthwhile to have an approved medication that is both safe and effective," he said.
Pioro presented the findings at a press conference held earlier this week at the AAN's annual meeting in Toronto.
The study authors note that PBA typically manifests in patients with an underlying neurological illness, including those with multiple sclerosis (MS), ALS (also known as Lou Gehrig's disease) or Alzheimer's, as well as patients suffering from other dementias and/or brain infections and injuries.
Pioro said that conservative estimates put the number of Americans with PBA at close to 2 million, although he said the figure might actually be as high as 6 million to 7 million.
Dextromethorphan is a common medication and a principle ingredient of standard cough syrup, according to Dr. Lily K. Jung, medical director of the neurology clinic and chief of neurology at the Swedish Medical Center in Seattle. The drug has previously been shown to have a "significant" effect upon parts of the brain responsible for behavioral control, she said at the press briefing.
Jung, who did not take part in the study, noted that quinidine is sometimes used to treat heart rhythm abnormalities. When combined at very low doses with dextromethorphan, it appears to help prolong that drug's usefulness.
In the study, Pioro and his colleagues enlisted 283 patients with PBA in an initial drug trial, during which some patients received one of two dosage levels of the two medications, while others received placebos.
After a two-week break, this was followed by a second phase involving 253 of the original study participants.
During the study's second part, patients were exposed to daily doses of the two-drug regimen for 12 weeks.
Pioro and his colleagues observed "significant improvement" among all the patients -- particularly among those who had not been exposed to the drug combo until the second part of the study.
Overall, Pioro noted that "there was an improvement of probably about 30 to 40 percent of symptoms" on average.
"Hopefully, we will soon have a very effective approved therapy to help these patients, which is important because this problem is probably much wider and more prevalent than we realize," he said.
"Very often patients who have this can be mistaken for having depression," Pioro explained. "But they're not depressed. Pseudobulbar affect is actually incongruent usually to the inner mood that the person has. So it can generate a lot of misconceptions. And patients will often be stigmatized, if you will, as a result."
Jung agreed. "This is exciting," she said, "because pseudobulbar affect can be so significantly socially disabling."
Still, further investigation into the drug combo's potential is warranted, since Pioro's study was relatively small. "Obviously more studies need to be done in larger groups of patients," Jung cautioned. "And testing for benefit should be done with other validated measures."
There's more on motor neuron diseases (including pseudobulbar affect), at the U.S. National Institute of Neurological Disorders and Stroke.