MS Flare vs. Pseudoflare: Diagnosis and Treatment
A pseudoflare in multiple sclerosis is a temporary worsening of existing MS symptoms due to external factors like infection or temperature changes, while a true MS flare represents new inflammatory demyelinating activity requiring different treatment approaches. 1
Diagnostic Differences
True MS Flare (Exacerbation/Relapse)
- Represents a genuine episode of neurological disturbance caused by inflammatory and demyelinating lesions 1
- Must last for at least 24 hours to be classified as a true attack 1
- Involves new symptoms or worsening of existing symptoms that cannot be attributed to other causes 1
- Requires objective clinical findings of a new lesion for diagnosis 1
- Often shows evidence of new or enhancing lesions on MRI 1
- Separate attacks must be at least 30 days apart to be considered distinct events 1
Pseudoflare (Pseudoattack)
- Temporary worsening of existing MS symptoms without new inflammatory activity 1
- Commonly triggered by external factors such as:
- Does not represent new disease activity or progression 1
- MRI typically shows no new or enhancing lesions 1
- Symptoms typically resolve when the triggering factor is addressed 1
Key Diagnostic Tools
Clinical Assessment
- Thorough neurological examination to determine if symptoms represent new deficits or exacerbation of existing ones 1
- Assessment for potential triggers of pseudoflares (infection, fever, stress) 1
- Evaluation of symptom duration (must be at least 24 hours for a true flare) 1
MRI Imaging
- Critical for distinguishing between flare and pseudoflare 1
- True flares often show:
- Standardized MRI protocols should include:
Additional Diagnostic Tests
- Cerebrospinal fluid analysis may be helpful in atypical presentations 1
- Visual evoked potentials can provide additional support in cases with few MRI abnormalities 1
- Laboratory tests to rule out infection or other causes of symptom worsening 1
Treatment Approaches
True MS Flare Treatment
- Corticosteroids are the mainstay of treatment for acute exacerbations 2, 4
- Standard regimen: high-dose methylprednisolone (equivalent to 200 mg prednisolone daily for a week followed by 80 mg every other day for a month) 2
- Plasmapheresis may be considered for patients who don't respond adequately to steroids 4
- Evaluation for adjustment of disease-modifying therapy may be necessary 4
Pseudoflare Management
- Identify and treat the underlying trigger rather than using MS-specific treatments 1
- For infection-related pseudoflares: appropriate antimicrobial therapy 1
- For temperature-related pseudoflares: cooling strategies 3
- For stress-related pseudoflares: stress management techniques 2
- Symptomatic treatment of specific symptoms (e.g., fatigue, spasticity) 5
- Corticosteroids are typically not indicated for pseudoflares 2
Clinical Pitfalls and Caveats
- Misdiagnosing a pseudoflare as a true relapse can lead to unnecessary steroid treatment with potential side effects 2
- Conversely, misinterpreting a true flare as a pseudoflare may delay appropriate treatment 1
- Some patients may experience both a true flare and concurrent factors that worsen symptoms (e.g., infection triggering both inflammation and pseudoflare symptoms) 1
- The distinction between flare and pseudoflare is critical for:
- MRI findings must be interpreted in clinical context, as some patients with true flares may not show new MRI activity 1