Conference: The Back Part 2 (8/14/13) Flashcards
Which anatomical feature make the lower lumbar best to perform a spinal tap?
1) No spinal cord below L2 but still have subarachnoid space until S1-S2
2) Lumbar spinous processes don’t overlap
3) Large interlaminar space
What type of nerve lesion causes muscle spasm and diminished distal sensation and muscle weakness?
Irritative lesion
Given the following symptoms where would a lesion likely be? -lateral bending of lumbar spine to left, bilateral erector spinae spasm, diminished sensation in right L5 dermatome, muscle weakness in right L5 myotome
In the right L5 spinal nerve (or both of it’s root or rami)
When the nucleus pulposus has partially escaped the annulus OR when the annulus itself bulges at a weakened area.
Herniated or protruded intervertebral disc
Describe the natural curvature of spine
Dorsal concavity of cervical and lumbar regions and dorsal convexity of thoracic and sacrum regions
When viewing an MRI what are some cues of a herniated disk?
1) Reduced disk height
2) Reduced fluid content (darker)
3) Posterior herniation
What forces act on the disc during flexion of the spine?
Posterior tensile stress
Anterior compression forces
What anatomic features predispose intervertebral discs to posterolateral herniations during spine flexion?
1) No ligamentous support posterolaterally
2) Annulus fibrosus thinner in posterior
3) Eccentric position of nucleus pulposus
4) Flexion increases tensile stress on posterior disc
Correlation between specific motor and sensory symptoms with level of herniation follows this common rule
When the herniation is small, the disc involved is the one above the vertebra of the same number as the involved spinal nerve.
Why does compression of the spinal cord at T11 causes pain in the upper lumbar region?
Disparity between length of the spinal cord and vertebral column. The spinal cord segment for the upper lumbar spinal nerves are located at the T11 vertebral level.
