Neuro intro

Question 1

How do messages pass from the brain to muscle and which motor neurone are they?

Answer 1

UMN:
Primary motor cortex
Medulla oblongata
Decussation in pyrmaids/spinal cord
Anterior horn

LMN:
Motor neurone
Neuromuscular junction
skeletal muscle

Question 2

For the PNS, what investigations can you do to check its working?

Answer 2

Nerve conduction study
EMG (Electromyography)

Question 3

On Nerve conduction study, what does it mean if it is small or slow?

Answer 3

small = axon loss
slow = demyelination (MS, GBS)

Question 4

On EMG, what does it mean if there is myopathy?

Answer 4

low motor unit with same/normal NCS - MND

Question 5

For the CNS, what investigations can you do to check its working?

Answer 5

EEG (Seizure classifying)
Evoked potentials Test
Non contrast CT
MRI

Question 6

What is a non contrast CT used to see?

Answer 6

1st modality for stroke, intracranial bleed, high ICP

Question 7

when would you add contrast to a CT in neurology?

Answer 7

if there is an abscess

Question 8

what is an MRI and evoked potentials test used to detect?

Answer 8

MRI = MS, myelopathy

EPT = Optic neuritis, optic glaucoma - Dx eye and brain effect by pathology

Question 9

what is included in a Mini neurology exam?

Answer 9

Vitals = BP, HR, Temp, RR, Sp02
GCS
Lateralsining signs (near Sx)
Pupils

Question 10

What is examined in a full neurology exam?

Answer 10

cognitive testing (GCS)
Cranial nerves
motor strength and control
walking (gait)
reflexes
mental status

Question 11

What does GCS stand for?
what is it out of?
acronym for it?

Answer 11

glasgow coma scale
/15
MoVE

Question 12

What does each section assess and score?

Answer 12

Motor /6
Verbal /5
Eyes /4

Question 13

on GCS, what do these mean?
15/15
<8/15
<3/15

Answer 13

good
intubate
comatose

Question 14

What are the 6 points from motor?

Answer 14

1. No response
2. Abnormal extension (bad)
3. Abnormal flexion
4. withdraw from painful stimulus
5. incomprehensible sounds to painful stimulus
6. obeys commands

Question 15

What are the 5 points for verbal?

Answer 15

1. No speech
2. incoherent speech
3. inappropriate words
4. confused
5. orientated

Question 16

What are the GCS 4 points for eyes?

Answer 16

1. no eye opening
2. eyes to painful stimulus
3. eyes open to voice
4. Spontaneous open eyes

Question 17

What does lateralising signs mean?

Answer 17

Localise CNS pathology
eg. pronator drift, homonymous hemianopia, unilateral weakness

Question 18

What are the tracts divided into?

Answer 18

ascending
descending

Question 19

Name me 4 ascending tracts?

Answer 19

DCML
Spinothalamic
Spinocerebellar
Spinoreticular

Question 20

For the DCML tract, how does it go up the cord, where does it decussate and terminate, and what is it responsible for?

Answer 20

Fasiculus cuneautus (inner) - upper body –> cuneate tubercule (medulla)

Fasicilus gracilis (outer) - lower body –> gracile tubercule

Decussate at medulla

Fine touch, 2pt discrimination, vibration, proprioception

Question 21

Spinothalamic tract
what is it responsible for?
Where does it decussate?
pathway?

Answer 21

lateral = pain and temp
medical = crude touch

spine –> anterior horn –> thalamus

decussate 1-2 spinal levels above anterior horn (spinal cord)

Question 22

Spinocerebellar and spinoreticular tracts, what are they responsible for?

Answer 22

spinocerebellar = proprioception

Spinoreticular = deep/chronic pain

Question 23

What are the 2 categories of the decending tracts?

Answer 23

pyramidal (conscious)

Extrapyramidal (unconscious)

Question 24

What does pyramidal and extrapyramidal mean?

Answer 24

pyramidal = medulla decussation, voluntary muscle control, originate from cerebral cortex and brainstem

extrapyramidal = Non medulla decussating, autonomic muscle control, originate in brainstem

Question 25

What are the 2 pyramidal tracts?

Answer 25

corticospinal
corticobulbar

Question 26

Corticospinal:
pathway?
where do they decussate?
what do they do?

Answer 26

Motor movement

Lateral corticospinal (85% decussate at medulla) - contralateral, supplies limb muscles (fine motor movements)

Medial corticospinal (15% remain ipsilateral) - decussate at level of effector muscle - supplies trunk

Question 27

Corticobulbar:
what do they innervate?

Answer 27

innervate skeletal muscles of head and neck via cranial nerves

Question 28

Extrapyramidal:
what are the names of the tracts?

Answer 28

Decussating:
Rubrospinal
Tectospinal

Non decussating:
Vestibulospinal
Reticulospinal

Question 29

What are the rubrospinal and tectospinal tracts responsible for?

Answer 29

Rubro (cats) = fine hand movements (fine control) - red nucleus

Tecto - head turning in response to visual stimuli - Tectum (superior colliculus)

Question 30

What are the vestibulospinal and reticulospinal tracts responsible for?

Answer 30

vestibulo = posture and balance - vestibular nuclei (CN8)

Reticular - spinal reflex and muscle tone - pons

Question 31

C5 + 6
Dermatome?
Myotome?
Reflex?

Answer 31

lateral forearm, thumb + index

elbow flexion, shoulder abduction + flexion

Bicep jerk
C6 = Supinator

Question 32

C7
Dermatome?
Myotome?
Reflex?

Answer 32

Middle finger

wrist flexion
finger extension

tricep

Question 33

C8-T1
Dermatome?
Myotome?

Answer 33

medial forearm
medial 2 fingers

Hand C8 = Flexion
T1 = Hand adduction and abduction

Question 34

L4 Reflex?

Answer 34

knee jerk

Question 35

L5
Dermatome?
Myotome?

Answer 35

big toe and dorsum

dorsiflexion

Question 36

S1
Dermatome?
Myotome?
Reflex?

Answer 36

Heel and sole

plantar flexion

ankle

Question 37

L5 Radiculopathy vs common peroneal
ankle jerk reflex?
foot drop?
inversion/eversion?

Answer 37

L5 Radiculopathy:
-positive ankle jerk reflex
- positive food drop
- poor inversion

Common Peroneal:
- Negative ankle jerk reflex
- positive food drop
- poor inversion