neuroanatomy

Question 1

where do we inject an epidural and where do we lumbar puncture for CSF - what is the difference?

Answer 1

Epidural - epidural space (between dura and vetebral periosteum) contains fat and venous plexus

CSF - subaarachnoid space (between arachnoid and pia matter - posteriorly)

Question 2

where do sensory nerves have their cell bodies?

Answer 2

dorsal root ganglion

Question 3

where do motor nerves have their cell bodies?

Answer 3

in grey matter of spine

Question 4

where is a spinal anaesthetic injected?

Answer 4

subarachnoid space

Question 5

what are the grey and white matter of spine?

Answer 5

grey matter - cell bodies

white - tracts

Question 6

anterior root is

posterior root is

Answer 6

anterior root is sensory

posterior root is motor

Question 7

which tract carries pain and temperature (sensory)?

Answer 7

spinothalamic tract

takes it to contralateral side of the body

Question 8

which tract carries motor signals?

Answer 8

corticospinal tracts:

ipsilaterally - lateral (voluntary mvment) + anterior csp tract

contralaterally - anterior csp

Question 9

where do spinothalamic tracts cross?

Answer 9

at the level of the spinal cord at the anterior white commissure

anterior corticospinal (motor) tracts cross here too

Question 10

which tracts carry proprioception?

Answer 10

All ipsilateral

Spinocerebellar

Fasciculus gracilis - proprioception form lower limb

Fasciculus cuneatus - proprioception form upper limb

Question 11

which tracts carry fine touch, vibration, propioception all in one?

Answer 11

Fasciculus gracilis - from lower limb

Fasciculus cuneatus - from upper limb

Question 12

which are the only tracts which really cross over?

Answer 12

Spinothalamic - pain and temperature (travel up 1-2 segments before crossing)

anterior corticospinal - motor

Question 13

links

Answer 13

https://imperial.cloud.panopto.eu/Panopto/Pages/Embed.aspx?id=a1ebefe6-e007-4207-8002-32c3d690e328&query=neuro

Question 14

what are the order of neurons in sensory pathway

Answer 14

1st order:

• skin to spinal cord (pain temp)
• skin to medulla (touch proprioception)

2nd order:
above to thalamus

3rd order:
thalamus to cortex

Question 15

pain and temp tract crosses?

deep touch, vibration and prioception tract crosses?

motor tracts?

Answer 15

spinothalamic tract:
pain and temp, light touch tract crosses - spine

dorsal columns:
deep touch, vibration and prioception tract crosses - medial leminiscus in medulla

motor tract; medulla

Question 16

lesion of spinothalamic tract will cause?

Answer 16

flaccid paralysis

if regained, will end up as hyperreflexia or spasticity

Question 17

How does Brown sequard present?

Saying lesion is on the left

Answer 17

It is a hemisection of the spine

hIP VIP:
Ipsilateral loss of vibration, temperature, motor - paralysis (so left)

conTEMPlate:
Contralateral loss of pain and temperature

Question 18

where is the motor cortex found?

Answer 18

frontal lobe

Question 19

define paresis

Answer 19

graded weakness of movements - NOT paralysis

Question 20

define plegia

Answer 20

paralysis

Question 21

UMN lesions present how?

Answer 21

Loss of function: Paresis or Plegia

Increased tone: Spasticity
Hyperreflexia
Clonus
Babinsky sign

Question 22

LMN lesions present how?

Answer 22

weakness
hypotonia
fasciculations
hyporeflexia or mute

Question 23

what would cause a monoocular vision loss?

Answer 23

optic nerve lesion - before optic chiasm

IPSILATERAL

no vision in 1 eye

Question 24

causes of a homonymous hemianopia?

how do we differentiate cause?

Answer 24

Optic tract lesion - vascular or neoplastic

Stroke - Occipital lobe (usually macular sparing - as dual blood supply - MCA + PCA)

Stroke - Parietal lobe (usually have hemispatial neglect too)

Question 25

patient presents with left sided arm and leg weakness and right sided facial weakness. likely level of the lesion?

Answer 25

Brainstem lesion - clearly not high enoughh that its all on one side

tracts have not yet decussated.