Diastematomyelia: bony spur in spinal canal, which may compress cervical spinal cord
Syringomelia: cavitation of central cord
Spondylolisthesis/Cervical Spondylosis
Cervical Osteoarthritis:
Atlanto-Axial Subluxation: associated with RA
Cervical Spinal Cord Infarction (see [[Spinal Cord Infarction]])
Post-Cervical Cordotomy: procedure done to achieve pain control may damage ascending and descending tracts
Transverse Myelitis (see [[Transverse Myelitis]])
Thoracic Outlet Syndrome
Physiology
High Cervical (Above C3) Spinal Cord Disease
Pulmonary HTN due to cervical cord disease (hypoventilation: hypoxia/ acidosis with pulmonary vasoconstriction)
Neck muscles serve to increase the upper rib cage A-P diameter (pull the sternum cranially)
Mid-Low Cervical (C3-C8) Spinal Cord Disease
Pulmonary HTN due to cervical cord disease (hypoventilation: hypoxia/acidosis with pulmonary vasoconstriction)
Neck muscles serve to increase the upper rib cage A-P diameter (pulls the sternum cranially)
Supine: pushes viscera against diaphragm (decreases RV, FRC, and TLC/ increases MIP, VC)
Upper rib cage moves paradoxically inward with inspiration (counteracted by action of scalene muscles)
Work of breathing is moderately elevated (due to decreased compliance of abdominal viscera: more pronounced in sitting position)
Diagnosis
High Cervical (Above C3) Spinal Cord Disease
ABG
Hypercapnia
Hypoxemia (A-a gradient may be elevated)
PFT’s (restrictive):
Variable VT (60-500 mL)
Decreased VC (<20% predicted)
Decreased expiratory reserve volume (usually close to zero, due to exp-iratory muscle weakness)
RV and FRC are about equal (due to absent tone of chest wall/ atelectasis)
Decreased TLC
Decreased MVV
Decreased MIP and MEP
Normal VD/VT
Normal DLCO
EMG/NCV: normal
Mid-Low Cervical (C3-C8) Spinal Cord Disease
ABG
Normocapnia (usually) or hypercapnia
Hypoxemia (A-a gradient may be elevated)
PFT’s (restrictive):
Decreased VC (typically 52% predicted)
Increased RV (with ERV decreased at about 21% predicted, due to expiratory muscle weakness) with normal FRC
Decreased TLC
Decreased MVV
Decreased MIP (typically: 60% predicted) and decreased MEP (typically: 30% predicted): inspiratory/expiratory deficits correlate poorly with the level of cord injury (due to irregular distri-bution of injury to cord/ prior or injury-induced pulmonary abnormalities/ partial recovery of function/ recruitment of muscles that do not nor-mally have phasic respiratory function/ variabil-ity in functional status of non-paralyzed muscles)
Decreased compliance (normal specific compliance)
Normal VD/VT
Normal DLCO
EMG/NCV: normal
Clinical
High Cervical (Above C3) Spinal Cord Disease
Symptoms/signs: disruption of reticulospinal pathways with nearly complete respiratory muscle paralysis (resembles central alveolar hypoventilation) with quadriplegia
Lesions that only affect the more lateral corticospinal pathways spare automatic control of breathing (but disrupt voluntary control)
Inspiratory muscle function is somewhat better than that in high cervical cord lesions
Expiratory muscle function (with cough) is partially preserved (because clavicular head of pectoralis muscle and cranial portion of serratus anterior can provide some expiratory muscle function)
