Case: Worsening memory
Mrs. K, age 46, is being treated by a neurologist for stable relapsing-remitting multiple sclerosis (MS) and migraine headaches when she complains of worsening memory over the past 5 years. She reports having difficulty recalling details of recent events and conversations. She describes occasional word-finding difficulties and problems maintaining her train of thought. She forgets where she places things and has gotten lost while driving, even on familiar routes. Her husband reports she takes more time to process things in general.
Mrs. K’s cognitive decline has affected her daily life and ability to work. For 4 years, she has been an office assistant at a campground, where she takes phone reservations and keeps a site schedule. Formerly simple tasks—such as taking a phone number—have become increasingly difficult, and she cannot recall a list of 3 things to buy at the supermarket without writing them down.
As a teenager, Mrs. K suffered migraines but did not seek treatment, and her headaches remitted for about 10 years. At age 29, she started to experience tunnel vision. Three years later she reported bilateral foot numbness and was diagnosed with MS. She responded well to interferon beta-1b but her migraines returned, occurring several times a week. Her migraines are successfully treated with topiramate, 75 mg/d, for prophylactic therapy and rizatriptan, 10 mg, as needed for abortive therapy. Her medication regimen also includes:
- eszopiclone, 2 mg/d, and amitriptyline, 10 mg/d, for insomnia
- butalbital/aspirin/caffeine, 50/325/40 mg, as needed for tension headaches
- fexofenadine, 12 mg/d, and budesonide, 32 mcg, 4 sprays/d, for allergy symptoms
- esomeprazole, 80 mg/d, and famotidine, 20 mg/d, as needed for dyspepsia
- propranolol, 120 mg/d, for hypertension
- levothyroxine, 75 mcg/d, for hypothyroidism
- conjugatedestrogens, 0.45 mg/d, for hypoestrogenemia
- alprazolam, 0.25 mg/d, aspirin, 81 mg/d, vitamin E, 800 IU/d, and a multivitamin.
The neurologist orders neuropsychological testing. Mrs. K demonstrates some depressive symptoms but is within normal limits across all aspects of neurocognition, including basic and complex attention, memory, bilateral motor functioning, expressive and receptive language, visuospatial/constructional function, and self-regulatory/executive functioning. The neurologist refers Mrs. K for psychiatric evaluation of her depressive symptoms.
The author’s observations
Although the cause of cognitive impairment in patients with MS is unclear, its extent and profound impact on functioning has become widely recognized over the past 20 years.2
- information processing speed
- working memory
- verbal memory
- visuospatial function
- executive functions.4
- reduced social interactions
- increased sexual dysfunction
- greater difficulty with household tasks.6
Long-term interferon beta-1b treatment prevents MS relapses, but a recent study found that interferon beta-1b had a negative impact on patients’ mental health composite score and in most quality-of-life subscales over 2 years.8 Nevertheless, Mrs. K received interferon beta-1b therapy for at least 9 years without noticing cognitive decline.