The diagnosis of MS is met when someone has symptoms suggesting lesions disseminated in space (multiple parts of the central nervous system or optic nerves) and time (either with two relapses separated by at least 30 days or slow progression for at least one year).

There should be evidence on the exam and/or MRI scans of lesions associated with the symptoms, and other causes should be ruled out. MRI scans of the brain (may also include orbits) and spine, typically with and without contrast when being diagnosed, should be performed. Spinal fluid examinations help establish dissemination in time. Typically, at least one clinical event must have occurred to confirm a diagnosis, so long as the MRIs and/or spinal fluid confirm dissemination in time.

The revised 2017 McDonald Criteria outlines specific guidelines, including MRI criteria distinguishing MS from other causes of white matter lesions in the brain and/or spine. The diagnostic criteria for MS changes on an irregular basis, and if MS is a consideration, it is best if the patient is referred to a neurologist.

There are two common errors in potentially diagnosing MS. The first is not thinking of MS in the differential diagnosis of MS, especially in younger individuals, resulting in delay of diagnosis. The second is that there are many causes of brain MRI abnormalities that may raise the concern for MS. In younger individuals, this is most commonly migraine, and in older persons this is most commonly vascular disease. This is confused further in that individuals may get a brain MRI for many reasons unrelated to MS (especially headache, or after a car accident or other trauma), and they may have findings highly suspicious for MS, despite having no overt symptoms typical of MS. This is referred to as “radiologically isolated syndrome” (RIS), a likely precursor to MS in at least some individuals.

It is important to remember that, at least in 2023, a formal diagnosis of MS is never made on MRI criteria alone.

Common MS Symptoms

After a relapse, or with slow progression, especially in older patients, ongoing or worsening symptoms may be very disabling and benefit from intervention.  Many of these are focal remnants from initial relapses, and others are less focal, more generalized symptoms.

Examples include:

  • Fatigue: Fatigue is the most common symptom of MS, occurring in 80+% of patients. Fatigue in MS patients may be aggravated by heat, come on easily and suddenly, worsen as the day progresses, and is more likely to interfere with daily activities. It is difficult to diagnose the exact cause of fatigue, and it can be helpful to rule out other possible attributions to a patient’s fatigue. People with MS often report that their fatigue is minimal in the morning, most evident by early afternoon and often subsides in the evening. The presence and severity of fatigue does not appear to be related to sex, disease duration, or age, and may occur at any time in the patient’s course with MS.  Several studies report a strong connection between disease severity and fatigue. However, people with what might appear to be “mild” MS can have severe fatigue and some people with progressive MS may have no fatigue at all. As a first step when seeing a patient with MS, it is important to rule out other causes of fatigue, which can include primary or secondary sleep disturbances, anemia, thyroid dysfunction, polypharmacy, depression, and the other co-morbidities, eg diabetes, obesity, and other medical conditions. While medications can be prescribed, behavioral interventions such as sleep improvement, energy conservation strategies, cognitive behavioral therapy, exercising, yoga, Pilates, massage, and other interventions may significantly lessen the effects of MS fatigue. The 4 P’s of energy conservation can also be a helpful tool for helping people manage their MS fatigue. For more information about the types of fatigue people living with MS may experience, please read our InforMS Fall 2019 Issue, Focusing on Fatigue.
  • Cognition Studies estimate that 25-35% of people living with MS have no cognitive deficits; 40-50% of the MS population is believed to have problems in one cognitive domain; and about 20% may have multiple affected cognitive domains. With MS, cognitive difficulties can be “non-specific”, such as feeling cloudy or fuzzy, or just slowed down. The most common more specific issues, as can be identified with cognitive testing, are in the areas of information processing speed, memory, difficulty with problem solving, and difficulty with visual-spatial skills. While some of the disease modifying therapies (DMTs, see below) have been shown to slow cognitive decline over time, there are no documented medications or devices that are proven to aid cognition deficits in MS. Ampyra, a drug that speeds nerve condition and is used primarily to improve walking, is sometimes helpful for cognitive problems. Enhanced sleep and physical, as well as mental exercise (reading, crossword puzzles, word games, etc) are likely the most important factors in maintaining maximal cognitive function over time in MS. It is also important to define that depression is not a contributing factor of cognitive decline, as it may be associated with a pseudodementia that responds to treatment. Many Speech Pathologists are also adept at cognitive retraining skills as well.
  • Dizziness and Vertigo: Vertigo can be a disabling feature of MS in a minority of patients. Vertigo can occur during an exacerbation or on an ongoing basis, and can last for days, weeks, or months. Vertigo due to MS needs to be distinguished from other common causes of vertigo, especially Benign Paroxysmal Positional Vertigo, the latter of which is treated by the Epley or half somersault maneuvers. Dizziness is a term that requires further explanation as it may mean varied things to different people.  Most commonly dizziness relates to lightheadedness upon standing (unlikely to be directly related to MS) or general imbalance (which may or may not be part of MS).
  • Mood Disorders and Depression: Depression and anxiety are more common in MS than in the general population and may be seen in 50% or more of people with MS. Depression and anxiety in MS patients have proven receptive towards standard treatments, such as talk therapy, prescription medication, mindfulness & meditation, exercise or cognitive behavioral therapy. A careful review of medications is also critical when symptoms of depression occur — steroids, which are widely used to treat MS exacerbations, can affect mood, especially in the short run. Other symptomatic medications that are often used in MS can also cause depression, such as baclofen, dantrolene and tizanidine, as may some disease modifying therapies such as interferons and Tysabri (natalizumab). Mood disruptions may be a short-term symptom as a patient adjusts to a new diagnosis or may develop to be a long-term symptom. In both cases, patients should be encouraged to take their symptoms seriously and seek resolution through talk-therapy, medication, or a combination.
  • Heat Sensitivity: It’s estimated that 60% to 80% of people living with MS are sensitive to increased temperatures.  When a person’s body temperature rises, it impairs the ability of the demyelinated nerve to conduct electrical impulses properly, which increases the severity of a person’s symptoms. We recommend people who experience overheating to take cool showers, wear light clothing, avoid going out during the warmest parts of the day, and conserve energy. Exercise should be continued, but with breaks as needed, and with cooling available via air conditioning, cool drinks and/or cooling devices. The Multiple Sclerosis Association of America (MSAA) provides free cooling vests and necklaces for people diagnosed with MS, more information can be found here.
  • Pain: Many people living with MS will experience pain throughout their disease course. It can be helpful to define the cause of pain as either primary (due to the MS lesions and affecting mostly sensory pathways, or muscular pain with spasticity), or secondary (eg as with mechanical back, knee or hip problems due to walking asymmetrically). Neuropathic pain may be searing, stinging, “electrical” or shooting, and may be very disruptive to sleep and activities of daily living. Heat, overuse, and periods of exacerbation can increase these symptoms, which in some patients are constantly present. Neuropathic MS pain is not mitigated by anti-inflammatory medications such as ibuprofen but is commonly treated with any of a variety of medications that target neurotransmitters such as gabapentin, pregabalin, carbamazepine, duloxetine, amitriptyline and others. Topical lidocaine and capsaicin may be useful for isolated, focal pain.  For more information, please visit our InforMS Spring 2020 Issue: Pain: Exploring One of the Most Common ­and Often Misunderstood Symptoms of MS.
  • Spasticity: Approximately 40-80% of people with MS experience trouble moving due to spasticity. Signs of spasticity include pain, stiffness, tightness, or involuntary muscle spasms, and can make mobility and sleep difficult. It may be absent, mild or severe. Untreated, severe spasticity can cause the restriction of movement in the joints or pain and skin breakdown which may lead to pressure ulcers and infection. It may be helpful to explore possible triggers for each patient. Common events that have been known to cause spasticity in MS patients include an increase in body temperature, an infection, constipation causing a full bowel, tight clothing, or a lack of sleep. Occasionally, even just touching or stroking a limb, especially the leg, may induce a painful spasm. Mild cases are treated with stretching, physical therapy or drug therapies such as baclofen and tizanidine. When spasticity is relatively focal, botulinum toxin injections can be helpful. For severe, disabling spasticity unresponsive to stretching, or oral or injectable medication, a baclofen pump may be used. This is implanted under the abdominal skin, with a catheter connected in the upper lumbar region. This delivers very small quantities of baclofen directly to the spinal cord. Tonic spasms are brief, stereotyped, painful involuntary movements of the limbs that may be seen in MS.  They are felt to be different from typical MS spasticity, somewhat equivalent to spinal cord seizures, and may be treated with carbamazepine or other anticonvulsants.
  • Numbness or Tingling: Numbness or tingling, or paresthesia, are often the most common early symptoms of MS. Most experiences of numbness tend to come and go. Patients usually experience numbness or tingling in their extremities, though this can also be experienced on the face. If an individual experiences a new onset of severe numbness that is associated with a MS relapse, corticosteroids may be prescribed. While gabapentin and other medications for neuropathic pain may be used, the utility is lower, and many would view the side effects (mainly sedation) not worth the benefit achieved.
  • Vision Problems: When individuals have severe optic neuritis, they may have ongoing poor vision that may benefit from visiting a low vision clinic. Other common visual disturbances with MS are diplopia, double vision due to a misalignment of the eyes, or jumpy vision as may be seen with nystagmus. The anatomical causes here are many, but diplopia may be treated with prisms inserted into glasses, and some causes of nystagmus me be responsive to medications such as gabapentin or clonazepam.
  • Walking and Mobility: Spasticity, weakness, poor balance, and sensory disturbances can contribute to walking problems. Toe drags or foot drop are common in MS patients, and can be treated by physical therapy, assistive devices (ankle foot orthotics and sometimes functional electrical stimulators), or energy conservation. Physical therapy is a mainstay for all weakness and imbalance problems in MS, as fall risk avoidance is paramount. Fear of falling is also prevalent and may limit patients’ participation in activities and may be responsive to a variety of exercise approaches.
  • Bladder Problems: Urinary dysfunction manifested by urinary urgency, frequency, incontinence, and infections are very common in MS and correlated primarily with spinal cord lesions. A spastic, or hyperdynamic, bladder is very common in younger patients. These individuals may have a small post-void residual and may benefit from medications such as Ditropan (Oxybutinin), Detrol (Tolterodine), Enablex (Darifenacin), Vesicare (Solifenacin), Myrbetriq and others. Botlinum toxin injected into the bladder muscle may also be useful. Those with urinary retention should not use these agents, as they may increase retention and subsequent infections or hydronephrosis. Rather, patients experiencing urinary retention may benefit from Flomax (tamsulosin) or may need to use a drainage system such as a Foley or suprapubic catheter. For those with nocturnal enuresis, nasal or oral vasopressin (DDAVP) may transiently decrease urine production. Sodium needs to be followed, as hyponatremia is a risk when using DDAVP. This will allow people to remain dry at night without getting up multiple times, thus aiding sleep and lessening fatigue. It is recommended that MS patients experiencing recurring urinary issues should meet with a urologist to determine treatment.
  • Bowel Problems: MS patients often have problems with constipation and (less so) incontinence, though because these problems are well represented in the general population, they are not always recognized as MS symptoms. Treatment is essentially the same as for those with constipation not due to MS, eg fluids, fiber, and bowel training, with judicious use of mild laxatives.
  • Dysphagia: Chewing and swallowing problems can be substantial, especially in older MS patients, those with other motor disability (eg wheelchair-or bed-bound), and those with bad dentition. Swallowing studies and visits with Speech Pathologists after a modified barium swallow evaluation can be very helpful.
  • Sexual Problems: Studies estimate that 40-85% of women and 50-90% of men with MS experience periodic sexual dysfunction. This can present as decreased genital sensation, pain, vaginal dryness, erectile dysfunction, and an overall decreased sex drive. Sexual problems often have a psychological as well as a physical component. MS can also lead to low self-esteem, decreased communication in a relationship, lack of intimacy, depression and anxiety. Sexual problems in MS are categorized into three groups; primary sexual dysfunction refers to damage that is caused by damage to the CNS from the disease itself. Secondary sexual dysfunction happens as an effect of MS symptoms or treatments, and tertiary dysfunction results from the psychological, emotional, and interpersonal consequences of living with a chronic disease. To read more about sexual problems in MS and treatment therapies, please read our Spring 2017 InforMS Issue titled MS in the Bedroom.
  • Sleep Troubles: Sleep disturbances in MS are common and can affect fatigue and cognitive function in a negative way. If patients are awakening and still feel tired, they are not achieving refreshing sleep. Trouble getting quality sleep can be caused by increased napping during the day due to fatigue, reduced physical activity, anxiety, depression, bowel or bladder problems, heat sensitivity/temperature dysregulation, and/or pain. Primary sleep disturbances such as obstructive sleep apnea are also common in MS, and patients should seek treatment if they suspect irregular breathing or excessive snoring throughout the night. Drugs used in the treatment of MS or MS symptoms can also affect sleep and should be considered when identifying the cause of sleep troubles. This especially includes agents used to treat fatigue, such as modafinil and stimulants. It is important to avoid polypharmacy, such as using stimulants to aid in treating fatigue during the day, and then sleeping agents to attain sleep at night.

Symptom Management Drugs

As a provider that will not be primarily monitoring your MS patient’s DMTs, you may still find yourself needing to prescribe medications to mitigate the varying symptoms of MS. Please visit our symptom management page for a list of commonly-prescribed medications for various symptoms that may be related to MS.