Cervical Root Disease

Epidemiology

  • xx

Etiology

  • Cervical Osteoarthritis (with bilateral C3-C5 compression)
  • Cervical Spine Manipulation/Mass Lesion (with bilateral C3-C5 compression)
  • Herpes Zoster (bilaterally involving C3-C5)
  • Neuralgic Amyotrophy (bilaterally involving C3-C5): usually affects brachial plexus
  • Multiple sclerosis (bilaterally involving C3-C5)

Physiology

  • Pulmonary hypertension due to neuromuscular disease (bilateral diaphragmatic paresis or paralysis)
    • Hypoventilation leads to hypoxia/ acidosis (with resultant pulmonary vasoconstriction)

Pathology

  • xxx

Diagnosis

  • ABG: hypoxemia/hypercapnia
  • PFT’s: restriction
    • Decreased FEV1 (about 50% predicted)
    • Decreased VC (about 45% predicted/ due to muscle weakness, decreased lung and chest wall compliance): supine VC <75% of upright VC
    • Decreased TLC,RV,FRC
    • Decreased MVV
    • Decreased MIP
    • Decreased lung compliance (due to chronically low lung volumes: microatelectasis/ reduced surface tension/ altered interstitial elastic fibers)
  • CXR: low volumes/elevated diaphragms
  • Sniff test: paradoxic motion of diaphragms (normal in some cases due to expiratory abdominal muscle contraction with upward diaphragm motion, passive inspiratory downward motion)
  • Phrenic nerve stimulation (percutaneous/ needle electrodes): observe diaphragm
  • Transdiaphragmatic pressure (more specific for diaphragm than MIP:) using NG balloon (Pga-Pes)/normal change >25 cm H2O (to TLC), usually 2-20 cm H2O in bilateral paralysis
  • EMG/NCV: normal (?)

Clinical

  • Bilateral Diaphragmatic Paralysis (severe symptoms):
    • Severe exert dyspnea
    • Orthopnea (due to vis-ceral pressure on dia-phragm)
    • Dullness/ decreased BS at bases
    • Tachypnea
    • Prominent scalene/ SCM contractions
    • Paradoxic inspiratory inward movement of abdomen (classic sign)
    • Respiratory failure/ atelectasis/ aspiration pneumonia/ sleep-disordered breathing/ pulmonary HTN/cor pulmonale
    • Acute/Chronic Hypoventilation (see Acute Hypoventilation, [[Acute Hypoventilation]] and Chronic Hypoventilation, [[Chronic Hypoventilation]])

Treatment

  • Treat underlying disease
  • Spontaneous recovery (takes up to 2 years in some cases): may occur if a progressive generalized neuropathy is not present
  • Ventilation: rocking bed/ CPAP/ ventilator
  • Phrenic nerve pacing: not useful (due to injured phrenic nerve/ pacing beyond site of injury is usually not possible due to atrophy of nerve)
    • Direct pacing of muscle requires high thresholds