Types of Multiple Sclerosis and Their Treatments
Multiple sclerosis is classified into four main types: relapsing-remitting, secondary progressive, primary progressive, and benign, each requiring different treatment approaches based on disease activity and progression. 1
Types of Multiple Sclerosis
1. Relapsing-Remitting MS (RRMS)
- Represents 85-90% of initial MS cases 1
- Characterized by clearly defined relapses with full or partial recovery
- Periods of stability between relapses with no disease progression
- Most commonly diagnosed in white women in their 20s 2
- First attack is known as a "clinically isolated syndrome" 2
2. Secondary Progressive MS (SPMS)
- Develops in approximately two-thirds of patients with RRMS 1
- Characterized by progressive deterioration in neurological function following an initial relapsing course
- Can occur with or without superimposed relapses 3
- Transition from RRMS to SPMS lacks clear clinical, imaging, or pathologic markers 4
3. Primary Progressive MS (PPMS)
- Represents 5-10% of MS cases 1
- Characterized by deterioration from disease onset without relapses or remissions 3
- Typically presents with progressive spastic paraparesis or cerebellar syndrome 2
- Shows significantly less inflammatory activity on MRI compared to other types 1
4. Benign MS
- Characterized by minimal or no disability (usually EDSS < 3) after at least 10 years of disease 3, 1
- Requires regular monitoring despite minimal symptoms 1
Treatment Approaches by MS Type
Relapsing Forms of MS (RRMS, active SPMS, CIS)
Disease-Modifying Therapies (DMTs) are the first-line treatment for relapsing forms of MS, including RRMS, clinically isolated syndrome, and active secondary progressive disease. 1, 5, 6, 7
First-Line Options:
- Interferons beta (Rebif, Betaseron) - reduce relapse rates by about one-third 6, 7, 2
- Glatiramer acetate - similar efficacy to interferons 1, 2
- Teriflunomide - oral option for relapsing forms 1
- Sphingosine 1-phosphate receptor modulators (e.g., siponimod) - FDA approved for relapsing forms including active SPMS 5
High-Efficacy Options for Active Disease:
- Natalizumab - for patients with highly active disease, particularly those with negative JCV status 1
- Ocrelizumab - reduces clinical relapses and MRI lesions 1, 8
- Ofatumumab - newer monoclonal antibody option 1
Treatment Considerations:
- DMTs reduce annual relapse rates by 29-68% compared to placebo 1, 8
- Early initiation is crucial for reducing neurological damage 1
- Consider washout periods when switching between DMTs 1
- Regular monitoring with annual brain MRI and clinical evaluations 1
Primary Progressive MS (PPMS)
- Ocrelizumab is the only FDA-approved DMT for PPMS 8
- Limited treatment options compared to relapsing forms
- Management focuses on symptom control and rehabilitation
Secondary Progressive MS without Activity
- Limited evidence for DMT efficacy in non-active SPMS
- Treatment focuses on symptom management and preventing complications
- Consider clinical trials where available
Monitoring and Treatment Adjustments
- Annual brain MRI recommended for monitoring disease activity 1
- Regular clinical evaluation for new neurological symptoms 1
- Consider treatment change when there is evidence of active disease (clinical or radiological) 1
- For patients on natalizumab, monitor JCV status and antibody index level 1
Special Considerations
- Complete hepatitis B vaccination before starting potent MS therapy 1
- Administer vaccines 4-6 weeks before starting or 4-6 months after ending certain treatments (e.g., ocrelizumab) 1
- High-dose vitamin D supplementation has not shown significant benefits in reducing relapse rates 1
- IVIG therapy is considered experimental and not recommended for routine MS treatment 1
Treatment Sequencing
When planning treatment sequences, consider:
- Mechanism of action of current and future DMTs
- Reversibility of immune system effects
- Individual risk factors and comorbidities
- Disease activity and progression 9
The heterogeneity of MS, individual patient response, and medication toxicities continue to challenge treatment decisions, requiring regular reassessment and potential adjustment of therapeutic strategies 10.