Neurofibromatosis

 

 

Background 

 

  • Cafe au lait spots are the most characteristic finding 

  • 2 types: NF-1 (more common) & NF-2 

  • Neurofibromas nearly always involve the skin, but they can also occur in the deeper peripheral nerves & nerve roots & in or on viscera or blood vessels innervated by the autonomic nervous system

 

 

Considerations

 

  • Potential difficult airway:

    • Airway obstruction/distortion from laryngeal, pharyngeal, tongue, cervical tumors

    • Macrocephaly & macroglossia

    • Tumors can be very vascular

  • Respiratory:

    • Restrictive lung disease (kyphoscoliosis ~25%)

    • Potential for pulmonary fibrosis from parenchymal tumours

    • Pulmonary hypertension/RV failure 

    • Mediastinal neurofibroma: may present with cardiopulmonary complaints 

  • Cardiovascular:

    • Hypertension

      • Usually essential, secondary: RAS >> pheochromocytoma (<1%)

    • Dysrhythmias, idiopathic cardiomyopathy

    • RV outflow tract tumour

  • CNS:

    • ↑ ICP (5-10% have intracranial tumors, hydrocephalus) +/- contraindication to neuraxial

    • Seizure disorder

    • Cognitive deficits, learning disabilities

    • Peripheral neuropathy 

  • Unpredictable response to NMB drugs:

    • Variable responses (sensitivity or resistance to succinylcholine, sensitivity to NDMR)

  • Difficult regional & epidural/spinal, may be contraindicated if spinal neurofibroma

  • Possible endocrine problems: pheochromocytoma, hypoglycemia, pituitary tumours, hyperparathyroidism, medullary thyroid carcinoma

 

 

Optimization/Consults 

 

  • Neurology: optimize ICP, antiepileptics

  • Cardiology/endocrine: optimize antihypertensives (phenoxybenzamine) if pheochromocytoma

  • Consider MRI (r/o ↑ICP) if planning regional technique

  • Respirology: if restrictive lung disease

  • Conflicts: 

    • ↑ICP vs neuraxial 

    • Spinal neuromas vs neuraxial

    • ↑ ICP vs difficult airway 

 

 

Pregnancy Considerations 

 

  • Higher maternal complications 

  • If pelvic/abdominal neurofibromas → cesarean section necessary (dystocia, obstructed labor or respiratory embarrassment)

  • Higher fetal complications: preterm labor, IUGR, abortion 

  • GA: very cautious of difficult airway & underlying hypertension 

  • Neuraxial: must have imaging (MRI/CT) of spine before epidural/spinal