Dealing With Brain Fog When You Have Progressive MS

Multiple sclerosis (MS) is best known for the physical symptoms it can cause, such as numbness, weakness, spasticity, and difficulty walking. But this autoimmune disease of the central nervous system can also affect thinking and memory.

Many people describe these cognitive symptoms as brain fog, cognitive fog, or cog fog. Cognitive symptoms can appear at any point in MS, but they tend to be especially common and noticeable in people with progressive forms of the disease.

Here’s what to know about MS brain fog, why it happens, and what you and your healthcare team can do about it.

Lisa Stropp, MD, clinical assistant professor and neurologist at the University of Michigan in Ann Arbor, says that many people describe a sense of being mentally slower or less sharp.

“I have patients say things like, ‘I’m thinking slow,’ or ‘I’m not as sharp as I used to be,’” says Dr. Stropp.

Other common complaints that may signal brain fog are issues with focus and attention, misplacing items more often, and difficulty finding words, she says.

“A sense of difficulty finding words or putting their thoughts into words and communicating effectively is something I hear from people with MS,” says Stropp.

MS-Related Changes in the Brain

Fatigue and Cognitive Energy

Fatigue is a common symptom that can make many aspects of MS more difficult, including brain fog, says Stropp.

Mood and Stress

“Mood disorders can impact concentration, attention, and memory in people with MS,” Stropp says.

Sleep Problems

“If someone with MS brings up a cognitive concern, sleep is something we focus on very early on. Sometimes we will be able to see classic signs of sleep apnea, like loud snoring, but sometimes we have to dig more. Sleep apnea can be quiet and not have those typical symptoms,” says Stropp.

Medications

Some medications used to treat MS symptoms can contribute to fogginess, including drugs for neuropathic pain, migraine, spasticity, and bladder symptoms.

“It’s a good idea to go through your medication list with your neurologist to see if any of your cognitive issues could be a side effect of a drug you’re taking,” says Stropp.

Migraine

MS doesn’t cause migraine, but it is more common in people with MS, says Stropp. “If someone has severe migraines that aren’t well controlled, that can create its own version of cognitive cloudiness,” she says.

Menopause

“It can be almost impossible to distinguish menopause-related symptoms from MS ones based on how they feel,” says Stropp.

Stropp recommends mentioning brain fog early, even if symptoms seem mild. “There may be contributing factors we can address,” she says.

Consider talking with your doctor in these situations:

• Brain fog disrupts your daily life or work.
• Symptoms are worsening or happening more often.
• You notice new or unusual memory or thinking problems.
• Family, friends, or coworkers mention changes.
• You suspect contributing factors like menopause, migraine, medication effects, sleep issues, or mood symptoms.
• You recently started or changed medications.
• You have persistent fatigue that doesn’t improve with rest.

Your neurologist can collaborate with primary care, sleep medicine, mental health, or gynecology providers to explore all possible contributors.

There is no single test that diagnoses MS brain fog.

Many MS centers use the Symbol Digit Modalities Test as a measure of processing speed and cognitive efficiency, but the test doesn’t measure other domains such as memory and learning.

No single treatment reliably reverses MS-related cognitive changes, and no medications are specifically approved to treat MS brain fog. Treatment focuses on identifying contributing factors and supporting the brain’s ability to function as well as possible.

Adjusting Medications If a medication is contributing to fogginess, your doctor may adjust the dose, change the timing, or switch to another option that still manages other MS symptoms effectively, says Stropp.

Treating Depression and Anxiety Addressing depression or anxiety with therapy, medication, or both may improve cognitive clarity, says Stropp.

Treating Sleep Disorders A sleep evaluation, including testing for sleep apnea when appropriate, can uncover treatable causes of persistent fatigue and slowed thinking. Treating any underlying sleep issues, along with lifestyle changes such as improved sleep hygiene, may also improve sleep quantity and quality.

Alongside medical treatment, practical and manageable strategies can help you function more easily day-to-day.

• Create consistent routines. Using planners, calendars, reminders, and checklists can reduce the mental load of remembering tasks. Keeping frequently used items in the same place can help prevent misplacing them.
• Break tasks into smaller steps. This can make complex tasks feel more manageable, especially on days when thinking feels slower.
• Monitor changes over time. Brain fog can fluctuate with fatigue, infections, stress, medication changes, and hormonal symptoms. Staying connected with your care team ensures that new or worsening issues are evaluated promptly.

• Brain fog is common in progressive MS and often reflects a mix of MS-related brain changes, fatigue, mood, sleep issues, and medication effects.
• Bringing up thinking or memory concerns early can help your care team identify treatable contributors such as sleep problems, menopause symptoms, mood changes, and medication side effects.
• While no medication reverses MS-related cognitive changes, options like cognitive rehabilitation, better sleep, mood treatment, and medication adjustments can meaningfully improve day-to-day clarity.
• Strategies such as creating routines, using reminders, and breaking tasks into smaller steps can make daily life more manageable when brain fog flares.