Rostral Spinal Cord
Rostral spinal cord
injuries (C1 to C2 level) are usually traumatic. They produce apnea by
interrupting the fibers that conduct the impulses from the ventral and
dorsal respiratory groups to the phrenic center and the intercostal alpha
It is usually diagnosed by MRI (Figure 31.1). Cervical spine radiography
may demonstrate a C1-2 subluxation.
Figure 31.1.— MRI
of the brain demonstrating cervico-medullary junction atrophy.
The classic clinical presentation
of rostral spinal cord injury consists of absence of movements of the
upper and lower extremities in an alert neonate with normal midbrain,
pontine, and medullary cranial nerve functions. This classic presentation
is not always present because: (1) trauma, the most frequent cause of
spinal cord injury, often involves the brain and leads to coma; (2) damage
to the fibers of cranial nerve XI as they ascend in the spinal canal produces
head tilt; and (3) damage to the hypoglossal motor nuclei or nerve in
the lower medulla produces a weak tongue.
Rostral spinal cord injury produces
central, obstructive, and mixed apnea. Central apnea occurs because of
disconnection of the dorsal and ventral respiratory groups from the phrenic
center. Obstructive and mixed apnea may also occur due to hypoglossal
motor nuclei and nerve damage, or due to lack of temporal coordination
between upper airway muscles and diaphragmatic
contractions. The latter occurs as a result
of delay in signal transmission from the ventral and dorsal respiratory
groups to the phrenic motor center.
The diagnosis of rostral
spinal cord injury is established by MRI and radiography. They may show
vertebral fracture, C1-C2 subluxation, extraaxial hematoma, parenchymal
lesion, or atrophy.
Pathological findings may reveal a hemorrhagic discoloration of the rostral
cervical cord (Figure 31.2). Treatment of the primary disease may be surgical.
Tracheostomy with mechanical ventilation and diaphragmatic pacemaker are
Rostral cervical cord showing dark gray-blue discoloration.