Multiple sclerosis, or MS, is characterized by the inflammation and destruction of myelin sheaths, the fatty coverings that protect nerve cells. This loss of insulation causes nerve function in many areas of the body to deteriorate. The majority of people with MS are diagnosed between the ages of 20 and 40; late-onset MS occurs in people over the age of 50. Because the symptoms of late-onset MS are similar to other medical problems typically found in older people, MS may be misdiagnosed in this population.
Motor Symptoms
Problems walking or moving the arms and legs, muscle spasms, clumsiness, weakness and tremor are the most predominant symptoms of late-onset MS. According to the United Spinal Association, most people have only one symptom in the beginning. In a study published in the May 2008 issue of the "Journal of Neurology," German researchers found that motor symptoms were characteristic in 90 percent of late-onset MS cases. The disease follows a primary-progressive course in the majority of subjects, which is associated with a gradual but steady accumulation of neurological symptoms and a poorer response to medications than relapse-remitting types seen more often in young-onset MS. Visual disturbances typically accompany the relapsing-remitting type of disease in which symptoms may come and go.
Cognitive Disorder
The German researchers also found no difference in the prevalence of cognitive disorder among late-onset or young-onset MS. Affects on nervous tissue in the brain impair memory and learning ability in both types. Rosalind Kalb, Ph.D., states in her book, "Multiple Sclerosis: The Questions You Have, The Answers You Need", that it is not uncommon for those with MS to have difficulty with selective attention, or the ability to tune out background noise and focus on what others are saying. A quiet environment may be needed for MS patients to participate in conversation. Short term memory deficits may make it hard to remember information, or to become overwhelmed by input that is too rapid or too much at once. Digital devices, sticky notes, dry-erase boards and large calendars can help families replace memory with organization.
Depression
An Israeli study of multiple sclerosis patients found that the frequency of late-onset MS was not rare, occurring in 30 of 640 subjects. Depression was found to be a common symptom, with 20 percent of late-onset patients having had a major depressive episode in the two years prior to being diagnosed with MS, and 7 out of the 30 patients experienced major depression within four years following diagnosis. Depression was assessed in the study with an interview tool and defined by using criteria found in the "DSM-IV," a manual of mental disorders provided by the American Psychiatric Association. The research findings were published in the February 2001 issue of the "Journal of the American Geriatric Society."
References
- United Spinal Association: Late-Onset MS
- "Journal of Neurology"; Clinical Characteristics of Patients with Late-Onset Multiple Sclerosis; Kis B; May 2008
- "Multiple Sclerosis: The Questions You Have, The Answers You Need"; Rosalind C. Kalb, Ph.D.; 2008
- "Journal of the American Geriatric Society"; Late Onset Multiple Sclerosis, Polliack ML; February 2001
