spinal nerve roots

Question 0

at 6 months of age the spinal cord terminates at what vertebral level

Answer 0

the conus medullaris is at the level of S1

Question 1

describe the organisation of the spinal cord

Answer 1

8 cervical spinal nerve roots
12 throacic
5 lumbar
5 sacral and
1 coccygeal

Question 2

in adulthood the conus medullaris is located at the level of

Answer 2

T12, L1 or L2

Question 3

the cauda equina

Answer 3

are spinal nerve roots which contain no spinal cord but are surrounded in CSF and extend below L1/2

Question 4

filum terminale

Answer 4

connective tissue in the centre of the cauda equina which projects from the conus medullaris and provides support to the spinal cord

Question 5

intervertebral discs contain

Answer 5

a central nucleus pulposis and a disc annulus which absorb force and provide mobility

Question 6

the ligamentum flavum and the posterior longitudinal ligaments are located where

Answer 6

posterior and anterior to the vertebral bodies, respectfully

the ligamentum flavum is prominent in cervical and lumbar regions and can contribute to nerve root compression when hypertrophied

Question 7

for both cervical and lumbosacral disc herniations

Answer 7

the nerve root corresponds to the lower of the two nerve roots

Question 8

the dermatome level for the nipples is

Answer 8

T4

Question 9

dermatome for the umbilicus

Answer 9

T10

Question 10

dermatome for the shoulder

Answer 10

C5

Question 11

dermatome for the lateral arm including thumb and first digit

Answer 11

C6

Question 12

middle finger dermatome

Answer 12

C7

Question 13

dermatome for last two digits

Answer 13

C8

Question 14

L4 and L5 represent the

Answer 14

anteromedial and anterolateral shin

Question 15

define these terms: neuropathy, mononeuropathy, mononeuropathy multiplex, polyneuropathy, myelopathy, radiculopathy

Answer 15

neuropathy is a general term for nerve disorder

mononeuropathy suggests a focal neuropathy

mononeuropathy multiplex suggests a multifocal neuropathy

polyneuropathy suggests a generalised neuropathy and is common in diabetes and has a glove and stocking pattern of sensory loss, while mononeuropathies are fairly common also in diabetes

myelopathy suggests any spinal cord pathology which can be traumatic, inflammatory or degenerative

radiculopathy suggests a subtype involving the spinal nerve roots and is associated with a burning, tingling pain that radiates or shoots down a limb and is associated with disc protrusion, lateral recess stenosis, forminal osteophyte formation or spondylolithesis (fracture of the pars interarticularis)

Question 16

disc protrusions can be graded in terms of degree of severity, name these grades

Answer 16

1- bulge
2- protrusion
3- extrusion - disc annulus has disintergrated
4- sequestration - loss of nucleus pulposis

Question 17

Guilliane Barre Syndrome

Answer 17

is a type of peripheral neuropathy that is associated with progressive weakness and parasthesias, the patient is areflexic

there is an immune mediated demyelination of peripheral nerves and it occurs post a viral illness, Camphylobacter jejuni enteritis or HIV

CSF shows no cells and elevated protein

EMG studies prove demyelination

treatment involves plasmaphoresis and IV IgG, patient may need to be intubated and ventilated if the demyelination occurs in the trunk

Question 18

Myasthenia gravis

Answer 18

is a neuromuscular junction disorder whereby immunoglobulins binds to actylcholine receptors on the motor end plate

the disease is characterised by symmetrical weakness of eyes, neck, proximal limbs and bulbar muscles (weakness is caused by fatigue)

all will have a nasal sounding voice, and there is usually dysphagia

15% may have extraocular involvement - ocular myasthenia

diagnosis - anticholinesterase antibodies, MuSK, EMG

20% will have thymoma and require thymectomy

Tx - anticholinesterase drugs, sometimes they may require plasmaphoresis, or IV IgG, or immunosuppressants

Question 19

common disc herniations in the leg

Answer 19

1- L5,S1
2- L4,5
3- L3,4

Question 20

common cervical radiculopathies

Answer 20

1- C6,7
2- C5,6
3- C4,5

Question 21

cauda equina syndrome

Answer 21

impaired function of nerve roots below L1,L2

accompanied with urinary retention, saddle anaesthesia, incontienence, needs to be treated promptly

can be caused by disc herniation, local neoplastic disease ie schwannoma, meningioma, trauma, epidural abcess, arachnoiditis, cytomegalovirus polyradicultitis