Chronic inflammatory demyelinating polyneuropathy

Background

• Prevalence of 1 to 2 per 100,000 adults
• Acute variant is Guillain-Barre syndrome
  • GBS is self limited whereas CIPD is progressive for more than two months

Clinical Features

• Symmetrical proximal and distal muscle weakness that is progressive for GREATER than two months
• Impaired sensation
• Areflexia
• Elevated CSF protein
• EMG studies consistent with demyelination
• Nerve demyelination on nerve biopsies
• Can be relapsing or chronic and progressive

Differential Diagnosis

Weakness

• Neuromuscular weakness
  • Upper motor neuron:
    • CVA
    • Hemorrhagic stroke
    • Multiple sclerosis
    • Amyotrophic Lateral Sclerosis (ALS) (upper and lower motor neuron)
  • Lower motor neuron:
    • Spinal and bulbar muscular atrophy (Kennedy's syndrome)
  • Spinal cord disease:
    • Infection (Epidural abscess)
    • Infarction/ischemia
    • Trauma (Spinal Cord Syndromes)
    • Inflammation (Transverse Myelitis)
      • Acute flaccid myelitis
    • Degenerative (Spinal muscular atrophy)
    • Tumor
  • Peripheral nerve disease:
    • Guillain-Barre syndrome
    • Toxins (Ciguatera)
    • Tick paralysis
    • Diabetic peripheral neuropathy
  • Neuromuscular junction disease:
    • Myasthenia gravis crisis
    • Botulism
    • Organophosphate toxicity
    • Lambert-Eaton myasthenic syndrome
  • Muscle disease:
    • Rhabdomyolysis
    • Dermatomyositis
    • Polymyositis
    • Alcoholic myopathy
• Non-neuromuscular weakness
  • Can't miss diagnoses:
    • ACS
    • Arrhythmia/Syncope
    • Severe infection/Sepsis
    • Hypoglycemia
    • Periodic paralysis (electrolyte disturbance, K, Mg, Ca)
      • Hypokalemic periodic paralysis
      • Thyrotoxic periodic paralysis
    • Respiratory failure
  • Emergent Diagnoses:
    • Symptomatic Anemia
    • Severe dehydration
    • Hypothyroidism
    • Polypharmacy
    • Malignancy
    • Aortic disease - occlusion, stenosis, dissection
  • Other causes of weakness and paralysis
    • Acute intermittent porphyria (ascending weakness)

Evaluation

Workup

'	American Academy of Neurology	Saperstein Criteria	Inflammatory Neuropathy Cause and Treatment Group
Presentation	Motor and sensory dysfunction in > 1 limb	Major: symetric proximal and distal weakness; Minor: Exclusive distal weakness or sensory loss	Progressive or relapsing motor and sensory dysfunction of > 1 limb
Time course in months	≥ 2 months	≥ 2	> 2
Reflexes	Reduced or absent	Reduced or absent	Reduced or absent
EMG criteria	Any 3 of the following 4 criteria: partial conduction block of ≥1 motor nerve, reduced conduction velocity of ≥2 motor nerves, prolonged distal latency of ≥2 motor nerves, or prolonged F-wave latencies of ≥2 motor nerves or the absence of F waves	2 of the 4 AAN electrodiagnostic criteria	Partial conduction block of ≥2 motor nerves and abnormal conduction velocity or distal latency or F-wave latency in 1 other nerve; or, in the absence of partial conduction block, abnormal conduction velocity, distal latency, or F-wave latency in 3 motor nerves; or electrodiagnostic abnormalities indicating demyelination in 2 nerves and histologic evidence of demyelination
CSF	WBC < 10/mm^3, negative VDRL' elevated protein	Protein > 45mg/dL; WBC <10/mm^3	Recommended but not mandatory
Biopsy	Demylelination and remyelination	Demyelination	Not mandatory