Flashcards in Chapter 13 Park 2 Deck (37):
What can a lesion in the spinal region interfere with?
vertical tract function
both segmental and vertical tract function
What does segmental function affect?
function of a spinal cord segment
interfere with neural function only at level of lesion
What does vertical tract function affect?
Conveys ascending and descending information
result in a loss of function below the level of the lesion
What are signs of segmental dysfunction?
abnormal or lost sensation in a dermatomal distribution and/or lower motor neuron signs in a myotomal distribution
What do lesions interrupting vertical tracts result in?
in loss of communication to and/or from the spinal levels below the lesion
What are autonomic signs?
problems with the regulation of blood pressure (BP), sweating, and bladder and bowel control
Descending tract (UMN) signs include:
include paralysis, spasticity, and muscle hypertonia
When is Babinski's sign present?
if the lateral corticospinal tract is interrupted
Ascending tract signs are ipsilateral of:
dorsal column in interrupted
Ascending tract signs are contralateral if:
STTs are involved
Peripheral region lesions produce deficits in:
distribution of a peripheral nerve.
What does peripheral nerve lesions cause:
Altered or lost sensation in a peripheral nerve distribution
Decrease or loss of muscle power in a peripheral nerve distribution
No vertical tract signs
When does spinal region segmental signs occur?
nerve roots and/or spinal nerves are compromised
What is included in segmental signs?
Altered or lost sensation in a dermatome
Decreased or lost muscle power in a myotome
Decreased or lost phasic stretch reflex
What is included in spinal region vertical tract signs?
Altered or lost sensation below the level of the lesion
Altered or lost descending control of BP, pelvic viscera, and thermoregulation
What is included in UMN signs?
Decrease or loss of muscle power
If the lateral corticospinal tract is involved, positive Babinski’s sign and clonus
What are spinal region syndromes?
Syndromes are collections of signs and symptoms that occur together. Spinal cord syndrome do not indicate a specific cause,
What do syndromes result from?
tumors or trauma
What is anterior cord syndrome?
Interferes with pain and temperature sensation and motor control while preserving proprioception & discriminative touch
What is central cord syndrome?
In a small lesion, loss of pain and temperature occurs at the level of the lesion. In a large lesion, the upper limb motor function is impaired
What is Brown-Sequard syndrome?
Below the level of lesion, voluntary motor control, conscious proprioception, and discriminative touch is lost ipsilaterally; pain and temperature sensation are lost contralaterally.
What is cauda equina syndrome?
Causes sensory impairment and flaccid paresis or paralysis of lower limb muscles, bladder, and bowels
What is tethered cord syndrome?
Causes low back and lower limb pain, difficulty walking, excessive lordosis, scoliosis, problems with bowel and/or bladder control, and foot deformities
What happens immediately after a traumatic injury to the spinal cord?
cord functions below the lesion are depressed or lost (“spinal shock”)
What is spinal shock due to?
the interruption of descending tracts that supply tonic facilitation to the spinal cord neurons
What is lost or impaired during spinal shock?
autonomic regulation of BP
control of sweating and piloerection is lost
What is included in somatic signs?
including stretch reflexes, withdrawal reflexes, and crossed extension reflexes
What is included in autonomic reflexes?
including smooth muscle tone and reflexive emptying of the bladder and bowels
What is a chronic spinal cord injury?
Is the period after recovery from spinal shock when the neurologic deficit is stable
can last for decades
What are the two abnormalities that occur in interneuron activity below the level of the lesion?
Inhibitory interneuron response to type Ia afferent activity is diminished. (Correlates with hyperreflexia.)
Transmission from cutaneous afferents to lower motor neurons is facilitated.
How is a spinal cord injury classified?
whether injury is complete or incomplete
lack of sensory and motor function in the lowest sacral segment
preservation of sensory and/or motor function in the lowest sacral segment
What happens to pelvic organs during spinal shock ?
organs are depressed
What does a lesion of T6 result in?
loss of descending sympathetic control
What three dysfunctions are a result of a lesion above T6?
Poor thermoregulation (body temperature regulation)