Every disease has averages and guidelines but, as recent news that actress Christina Applegate was diagnosed with multiple sclerosis demonstrates, there are always exceptions.

MS, a disease of the central nervous system, typically starts in patients’ 20s and 30s. Applegate turns 50 in November. Dr. Brian Wong, head of the Hartford Healthcare Ayer Neuroscience Institute MS Center, said that while her age is slightly higher than the typical age of diagnosis, it is not unusual.

But patients diagnosed in their 50s and beyond have often had symptoms for years that are not initially attributed to the incurable disease.

“She is a little older than typical for a new MS diagnosis, but it is likely that the disease process started several years prior to her diagnosis,” Dr. Wong said, noting that many MS symptoms such as fatigue are “non-specific” to the disease and, therefore, could be attributed to other things, including occupational stress, or other medical conditions.

Applegate, an active actress with such television and movie credits as “Bad Moms” and “Dead to Me,” also battled breast cancer and had a double mastectomy in 2008.

Dr. Wong said people with MS can experience symptoms such as pain, fatigue, urinary troubles and gait instability, any of which could be explained by other environmental or medical conditions such as her cancer.

“Not every MS patient fits the mold, so it’s important to step back and assess the whole clinical picture when approaching a patient with a possible MS diagnosis” he said.

Now that she’s been diagnosed, he said Applegate and others with MS have far better treatments available, including several new medications approved in the last few years.

“There are many tools for the treatment of MS and we are better at significantly reducing the chance that patients experience more aggressive clinical outcomes,” Dr. Wong said. “It’s now more about minimizing symptoms and reducing the effects on daily life instead of just preventing relapses.”

Part of the care specialists like those at the MS Center, which was just designated a national Center for Comprehensive MS Care by the National MS Society for the breadth and depth of care offered there, is closely tracking symptoms to avoid disability.

“We work to prevent patients from experiencing as much disability as possible, and, in recent years, we have been more successful than ever,” Dr. Wong said.