LESI LESI Anatomy and Neuroanatomy 2

Question 1

In the lumbar spine, the exiting nerve root at L4-L5 passes through which foramen?

Accepted Answer

L4 nerve exits at the L3-L4 foramen

Answer

In the lumbar spine, each nerve root exits below its named vertebra, so the L4 nerve root exits through the L3-L4 neural foramen.

Question 2

The cauda equina is the collection of nerve roots below the conus medullaris that float in which fluid?

Accepted Answer

Cerebrospinal fluid

Answer

The cauda equina nerve roots are suspended in cerebrospinal fluid within the thecal sac below the conus medullaris.

Question 3

Which lumbar level has the narrowest epidural space, making interlaminar injection most technically demanding there?

Accepted Answer

L5-S1

Answer

The L5-S1 interlaminar space can be narrow due to overlapping laminae and large spinous processes, making access more challenging.

Question 4

The dorsal root ganglion (DRG) of a lumbar nerve root is typically located where within the neural foramen?

Accepted Answer

In the middle of the foramen

Answer

The dorsal root ganglion is typically positioned in the mid-portion of the neural foramen, making it susceptible to compression by foraminal stenosis.

Question 5

Which artery, if inadvertently injected during LESI, can cause catastrophic spinal cord ischemia?

Accepted Answer

Artery of Adamkiewicz

Answer

The artery of Adamkiewicz (arteria radicularis magna) is the dominant blood supply to the lower spinal cord and inadvertent injection can cause paraplegia.

LESI - Lumbar Epidural Steroid Injection Practice Test

LESI - Lumbar Epidural Steroid Injection Practice Test

LESI LESI Anatomy and Neuroanatomy 2