People suffering from multiple sclerosis often experience sleep-related problems. The researchers of a new study said that these sleep problems might be the root cause of a common symptom of MS- fatigue.

The study was conducted by researchers at the University of California, Davis. Data for the study came from more than 2000 members of the Northern California Chapter of the National MS Society.

Multiple sclerosis is a chronic medical condition characterized by double vision, confusion, fatigue, poor coordination, memory loss and numbness. It is an autoimmune disease and affects the brain and spinal cord. The disease affects more women than men. There is no cure for MS.

The latest study shows that people with MS also suffer from sleep loss, which increases fatigue.

"A large percentage of MS subjects in our study are sleep deprived and screened positive for one or more sleep disorders," said Steven Brass, associate clinical professor and director of the Neurology Sleep Clinical Program and co-medical director of the UC Davis Sleep Medicine Laboratory.

"The vast majority of these sleep disorders are potentially undiagnosed and untreated," he added in a news release. "This work suggests that patients with MS may have sleep disorders requiring independent diagnosis and management."

For the study, the researchers assessed the quality of sleep of 2375 participants enrolled in the Northern California Chapter of the National MS Society. Consistent with previous findings, a majority of MS patients were females (over 80 percent).

The researchers found that around 52 percent of the respondents said that it took them more than 30 minutes to fall asleep, with 11 percent saying that they used medications to sleep at night. Around 38 percent of the participants had obstructive sleep apnea - a conditon that leads to severe snoring and frequent awakenings. About 32 percent of the people had moderate to severe insomnia and 37 percent had restless leg syndrome.

What's disturbing is that just four percent of the participants with OSA were actually diagnosed by a physician, meaning that common sleep problems go unnoticed and untreated in people suffering from MS.

The study is published in the Journal of Clinical Sleep Medicine.