Can Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and Multiple Sclerosis (MS) occur together?

Can CIDP and MS Occur Together?

Yes, Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and Multiple Sclerosis (MS) can occur together, representing a combined central-peripheral inflammatory demyelinating syndrome, though this co-occurrence is relatively uncommon.

Understanding CIDP and MS

CIDP

• Chronic inflammatory demyelinating polyneuropathy affecting the peripheral nervous system
• Characterized by progressive weakness, sensory disturbances, and reduced/absent reflexes
• Typically responds to immunomodulatory treatments like IVIG

MS

• Chronic inflammatory autoimmune disease affecting the central nervous system
• Characterized by demyelination in brain and spinal cord
• Presents with various symptoms depending on lesion location (vision problems, weakness, sensory disturbances)

Evidence for Co-occurrence

The co-existence of CIDP and MS has been documented in medical literature, though it's relatively rare:

• A 2019 study identified 133 cases of MS with polyneuropathy, of which 11 had confirmed CIDP 1

• This study found that MS-CIDP patients showed:

  • Earlier age of neuropathy recognition (52 vs. 58 years)
  • Worse impairment scores
  • More acquired demyelinating electrophysiology features
  • One-third of tested cases had IgG4 autoantibodies to neurofascin-155

• An older 1987 study using MRI found that 6 out of 16 CIDP patients (37.5%) had central nervous system lesions consistent with MS 2

• Case reports have documented individual patients with both conditions, including a 1993 report of a pediatric case 3

Diagnostic Considerations

When evaluating a patient with suspected co-occurrence:

1. Brain and Spinal Cord MRI

   • Essential for detecting MS lesions showing dissemination in space and time 4
   • Look for T2-hyperintense and gadolinium-enhancing lesions

2. Nerve Conduction Studies/EMG

   • Critical for CIDP diagnosis
   • Will show demyelinating features (slowed conduction velocities, conduction blocks)

3. Lumbar Puncture

   • MS: Oligoclonal bands, elevated IgG index
   • CIDP: Elevated protein with normal cell count

4. Clinical Examination

   • MS-CIDP patients more commonly show absent/reduced ankle reflexes (100% vs 70%) 1
   • Look for both central and peripheral neurological deficits

Pathophysiological Connection

The co-occurrence of these conditions suggests potential shared pathogenic mechanisms:

• Both are inflammatory demyelinating disorders affecting different parts of the nervous system
• The presence of autoantibodies to neurofascin-155 in some MS-CIDP patients suggests common immunological targets 1
• May represent a "central-peripheral inflammatory demyelinating syndrome" rather than two separate coincidental diseases 2

Treatment Implications

Treatment becomes more complex when both conditions coexist:

• Some MS treatments may not benefit CIDP and vice versa 5
• IVIG is effective for CIDP but not for MS
• Newer MS drugs (dimethyl fumarate, teriflunomide, laquinimod) haven't been studied in CIDP
• Some monoclonal antibodies (natalizumab, alemtuzumab, rituximab) may potentially address both conditions

Clinical Pitfalls to Avoid

1. Misattribution of symptoms: Attributing all neurological symptoms to MS when peripheral involvement may indicate CIDP
2. Diagnostic delay: CIDP may be overlooked in MS patients as symptoms are attributed to the known MS
3. Treatment conflicts: Some treatments effective for one condition may not help or could potentially worsen the other
4. Overlooking treatable causes: CIDP is treatable, and missing this diagnosis in an MS patient means missing an opportunity to address a component of their disability

The recognition of this combined syndrome is important as proper diagnosis allows for appropriate treatment of both conditions, potentially reducing overall disability burden in affected patients.