Abstract
Multiple sclerosis (MS) has been estimated to affect 450,000 persons in the United States and 2.3 million worldwide. The peak incidence is age 30 and it appears up to three times more often in women as compared to men. It affects Caucasians more frequently than other races. There are four common clinical courses in MS: clinically isolated syndrome, relapsing-remitting MS, secondary progressive MS, and primary progressive MS. MS can be diagnosed if there is evidence of two attacks disseminated in time and space with clinical, laboratory, or imaging evidence of at least two lesions in the brain or spinal cord. Symptoms of MS involve multiple systems including musculoskeletal, bowel and bladder, visual, and cognitive, leading to varied and extensive functional limitations. The patient may require involvement of a comprehensive multidisciplinary rehabilitation team.
Definition
Multiple sclerosis (MS) can be defined as an inflammatory disorder that results in damage, primarily to myelin sheaths and oligodendrocytes and less so to axons and nerve cells, in the central nervous system.
The prevalence of MS has been estimated at 450,000 in the United States and 2.3 million worldwide. The disease usually becomes clinically apparent between the ages of 20 and 40 years, with a peak incidence at age 30 and onset as late as the seventh decade. The disease appears up to three times as likely to develop in women as in men, and Caucasians are more frequently diagnosed than are other races. A recent study suggested that asymptomatic first-degree relatives of persons with MS may deserve further monitoring for early subclinical manifestations of MS. African Americans may experience more active disease compared to Caucasians.
There are four common clinical courses in MS:
- •
Clinically isolated syndrome (CIS): Patients experience the first clinical presentation of a disease that shows characteristics of inflammatory demyelination that could be MS but have not shown dissemination in time.
- •
Relapsing-remitting MS: Patients experience episodes of acute worsening of neurologic function followed by periods of remission. Patients may exhibit residual deficits after the episode of exacerbation. Most patients start with this course.
- •
Secondary progressive MS: Patients initially experience a relapsing-remitting course followed by progression of the disease with or without additional episodes of exacerbation and improvement. Most patients eventually transition to this disease course.
- •
Primary progressive MS: Patients experience a relentless progression of symptoms from the onset.
MS can be diagnosed if there is evidence of two attacks disseminated in time and space with clinical, laboratory, or imaging evidence of at least two lesions in the brain or spinal cord. Evidence may be obtained from clinical findings, magnetic resonance imaging, cerebrospinal fluid analysis, or visual evoked potentials. Other diseases that could explain the symptoms must be excluded (see the box “Differential Diagnosis” ). The most recent guidelines and revisions do not recommend the use of “clinically definite MS” or “probable MS;” the outcome of a diagnostic evaluation is MS, “possible MS,” or “not MS” ( Table 135.1 ).
| Clinical Presentation | Additional Data Needed for MS Diagnosis |
|---|---|
| Two or more attacks Objective clinical evidence of 2 or more lesions | None |
| Two or more attacks Objective clinical evidence of 1 lesion | Dissemination in space, demonstrated by MRI or Two or more MRI-detected lesions consistent with MS plus positive CSF or Await further clinical attack implicating a different site |
| One attack Objective clinical evidence of 2 or more lesions | Dissemination in time, demonstrated by MRI or Second clinical attack |
| One attack Objective clinical evidence of 1 lesion (monosymptomatic presentation; clinically isolated syndrome) | Dissemination in space, demonstrated by MRI or Two or more MRI-detected lesions consistent with MS plus positive CSF and Dissemination in time, demonstrated by MRI or Second clinical attack |
| Insidious neurologic progression suggestive of MS | Positive CSF and Dissemination in space, demonstrated by (1) 9 or more T2 lesions in brain, or (2) 2 or more lesions in spinal cord, or (3) 4–8 brain lesions plus 1 spinal cord lesion or Abnormal VEPs associated with 4–8 brain lesions, or with fewer than 4 brain lesions plus 1 spinal cord lesion demonstrated by MRI and Dissemination in time, demonstrated by MRI or Continued progression for 1 year |
Symptoms
Symptoms of MS may involve multiple systems ( Table 135.2 ). Motor symptoms typically include weakness and spasticity. Up to 85% of patients with MS may experience spasticity, and as many as a third may be affected by spasticity that is severe enough to diminish their quality of life. Patients with MS may report paroxysmal spasms or nocturnal spasms.
| Bladder symptoms | Urgency, frequency, hesitancy, retention, incontinence |
| Bowel symptoms | Constipation, urgency, incontinence |
| Cerebellar symptoms | Incoordination, imbalance, tremor |
| Cognition | Concentration, memory, executive dysfunction |
| Fatigue | Lassitude, reduced endurance |
| Mood disorders | Depression, anxiety, emotional lability |
| Motor | Weakness, spasticity |
| Sensory symptoms | Loss of sensation, positive sensations |
| Sexual dysfunction | Decreased libido, erectile dysfunction |
| Vision | Visual loss and double vision |
MS may be the cause of decreased or even absent sensation in various body parts, including sensory levels that most often affect the trunk. Paresthesia (uncomfortable abnormal sensation that may be described by the patient as pain, pins and needles, or tingling) can occur in up to 50% of patients with MS and most commonly is neuropathic. Lhermitte sign is an electric shock-like sensation that radiates down the spine to the legs when the neck is flexed. It may occur in up to 40% of patients with MS. Multiple pain syndromes may occur in patients with MS ( Table 135.3 ). Visual symptoms may include optic neuritis that results from inflammation of the optic nerves and typically is manifested as retro-orbital pain or painful eye movements. Visual deficits can range from mild distortions to complete visual loss. Scotoma may be present as an area in the visual field with absent or impaired vision and dyschromatopsia as imperfect color vision. Ocular motor deficits usually include internuclear ophthalmoplegia and nystagmus and are manifested as diplopia, blurry vision, and reading fatigue.
| Pain Syndrome | Acute or Chronic | Clinical Example | Treatment Approaches |
|---|---|---|---|
| Neuralgia | Both | Trigeminal neuralgia | Gabapentin, 100–900 mg three or four times daily Carbamazepine, 200–400 mg three times daily (extended-release form also available) Dilantin, 300–600 mg daily Oxcarbazepine, 150–900 mg daily Amitriptyline, 10–100 mg daily at bedtime Other tricyclic antidepressants Baclofen (oral or intrathecal) as adjuvant therapy |
| Meningeal irritation | Acute | Optic neuritis | Intravenous corticosteroids directed at underlying inflammation |
| Sensory pain | Both | Paresthesias | Same as for neuralgia |
| Skeletal muscle pain | Chronic | With spasticity or limited mobility | Rehabilitation (physical and occupational therapy) Assistive devices Nonsteroidal anti-inflammatory drugs |
Cerebellar symptoms may include tremor, which can range from mildly annoying to disabling, be gross or fine, and occur at rest or with purposeful actions. Various parts of the body may be involved, including the head, the upper or lower limbs, and the trunk.
Constipation and bowel incontinence may occur in up to 73% of patients with MS. More than 70% of patients with MS may suffer from bladder dysfunction. MS lesions in the spinal cord can result in a small spastic bladder due to detrusor overactivity. This usually is manifested as urinary urgency, frequency, voiding of small amounts of urine, and eventually incontinence. Bladder under-activity can result in retention and overflow incontinence. Bladder dysfunction is often associated with urinary tract infections (UTIs) that can worsen MS symptoms. Sexual dysfunction commonly includes erectile and ejaculatory dysfunction in men, vaginal dryness in women, and increased time to arousal, decreased genital sensation, and decreased libido in men and women. Factors contributing to sexual dysfunction include disease progression, antidepressants, fatigue, and depression.
Involvement of cranial nerves VII, IX, X, and XII may result in dysphagia or swallowing difficulties. These are manifested as coughing, frequent throat clearing, complaints of food “sticking” in the throat, weight loss, weak voice, choking, or even aspiration pneumonia.
Fatigue has been reported to occur in as many as 90% of MS patients and is regarded as the most disabling symptom in as many as 60% of these patients. MS-related fatigue has been described as an overwhelming feeling of tiredness, lack of energy, or exhaustion exceeding the expected.
As many as 50% of patients with MS may have cognitive deficits that are manifested as problems with memory, planning, concentration, judgment, problem solving, and processing speed. MS patients frequently report heat intolerance with an exacerbation of symptoms in warm or humid environments.
Physical Examination
Inflammation of the optic nerve may result in optic or retrobulbar neuritis manifesting as acute vision loss. Even after treatment, vision deficits may persist in the form of poor vision, especially in dim light, or blind spots in the visual field known as scotomas. Demyelination in the medial longitudinal fasciculus may result in varying degrees of horizontal nystagmus; involvement of the third cranial nerve may be manifested as a persistently enlarged pupil. Double vision may be attributable to weakened strength and coordination in the eye muscles. Cataracts may develop at an earlier age in the MS population because of the use of steroids. Visual problems may worsen with stress, increased temperature, and infection.
Speech dysfunction may include dysarthria with diminished fluency, slurring, decreased speed, and eventually incomprehensibility.
Sensory testing may reveal deficits in pinprick, temperature, proprioception, or vibration. A sensory level may be evident.
Manual muscle testing can show varying degrees of muscle weakness. The patient may exhibit poor control of a limb or insufficient clearance of the foot during gait. Spastic gait may be another motor finding. Cerebellar involvement may be manifested as dysmetria with past pointing on finger to nose testing and uncoordinated heel to shin movements. The Ashworth scale (or modified Ashworth scale) is commonly used to measure the amount of spasticity, and the 88-item Multiple Sclerosis Spasticity Scale is a reliable and valid measure of the impact of spasticity in patients with MS.
Early in the course, deep tendon reflexes tend to be hyperactive. Decreased or absent reflexes can represent segmental levels of deficit. Corticospinal tract involvement may be evident with an asymmetric plantar response or loss of the abdominal reflex. Deep tendon reflexes can also be asymmetric; testing them in more than one position can determine the consistency of the findings.
Cognitive testing may reveal multiple deficits including in memory, problem solving, judgment, and concentration.
Functional Limitations
The combinations of deficits in MS lead to difficulties with activities of daily living and mobility. Weakness, incoordination, spasticity, or sensory deficits may each or in combination contribute to falls. In addition to possible injuries, these falls may lead to decreased mobility due to fear of repeated falls. Decreased mobility itself leads to further weakness, decreased endurance, and less independence. Weakness or spasticity can also lead to difficulties with feeding and self-care, resulting in the need for personal care attendants. The MS functional composite (MSFC) is a clinical measure developed by a task force of the National MS Society and is mostly used in clinical trials. It measures ambulation, arm and hand function, and cognition and has been found to have greater reliability, sensitivity, and validity than the Kurtzke Expanded Disability Status Scale.
Bowel and bladder dysfunction can contribute to many embarrassing moments in the community, causing patients with MS to fear leaving home or to become distracted by seeking out the locations of bathrooms in areas they plan to visit. Many resort to wearing diapers or catheters. Fear of bladder incontinence may also lead a patient to decrease fluid intake, resulting in dehydration.
Depression, insomnia, and fatigue can all contribute to activity intolerance.
Visual deficits may limit activities such as driving and reading, thus limiting participation in work and recreation.
Diagnostic Studies
Magnetic resonance imaging is the most important test in the diagnosis and management of MS. The use of gadolinium allows enhancement of active inflammatory lesions that represent areas with blood-brain barrier breakdown. These hyperintense lesions on T2-weighted images are more specific for MS if they are located in the cerebral white matter, especially the corpus callosum, periventricular area, and brainstem.
Cerebrospinal fluid studies, visual evoked potentials, and brainstem auditory evoked potentials can assist in the diagnosis of MS when magnetic resonance imaging findings but not clinical findings support a diagnosis of MS.
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
