Neurology Flashcards
Describe the GCS scoring system of consciousness
max = 15, minimum = 3
< 8 consider intubation
eyes = 4 verbal = 5 motor = 6
What functions are associated with the frontal lobe?
higher intellectual function
personality, mood
social conduct + behavior
motor areas (post. frontal)
conjugate eye movements + frontal eye fields
language
what functions are associated with the temporal lobe?
memory
language
visual pathway (optic radiation)
what functions are associated with the parietal lobe?
DOMINANT HEMISPHERE
language, reading, writing
calculation
praxis
NON-DOMINANT HEMISPHERE
visuo-spatial function
BOTH
higher sensory function
visual pathway
what functions are associated with the occipital lobe?
visual cortex and visual association areas
What visual field defect would a patient present with if they have a lesion in the optic chiasm?
bitemporal hemianopia
What might cause an enlargement of a physiological blind spot?
papilloedema
what is tunnel vision?
loss of peripheral fields but preservation of central region
what are some causes of tunnel vision?
chronic glaucoma
retinitis pigmentosa
cortical disease
may be functional meaning no disease
which eye muscles does CN III supply?
superior rectus muscle, medial rectus muscle, inferior rectus muscle, inferior oblique muscle
which eye muscles does CN IV supply?
superior oblique muscle
which eye muscles does CN VI supply?
lateral rectus muscle
what are the features of CN III palsy?
ptosis
eye points down and out
if PNS fibres involved pupil fixed and usually dilated
What are causes of a third nerve (CN III) palsy?
compression:
- brainstem by tumour or basilar aneurysm
- tentorial herniation (coning)
- posterior communicating artery aneurysm
- cavernous sinus: tumous, aneurysm, thrombosis
- superior orbital fissure SOL (tumour, granuloma)
infarction:
brainstem or at nerve trunk (DM, HTN, GCA, SLE)
inflammation or infiltration of basal meninges involving nerve
features of fourth nerve palsy
isolated unilateral paralysis of superior oblique
diplopia doing down stairs
may hold head tilted to normal side
features of sixth nerve palsy
unable to abduct affected eye
diplopia looking to affected side
features of Horner’s syndrome
partial ptosis
miosis (pupil constriction)
anhydrosis
what are upper motor neurones?
neurons whose cell bodies are in the motor cortex and their axons are in the corticospinal tract synapsing with anterior horn cells
what are lower motor neurons?
motor neurons with axons extending from anterior horn cells of the spinal cord to voluntary muscles.
one supplies one motor unit
are fasciculations LMN or UMN signs?
LMN
what kind of gait may UMN lesions lead to?
spastic, scissoring, circumduction
what modalities of sensation are transmitted via the dorsal columns?
position
vibration sense
what modalities of sensation are transmitted via the spinothalamic tracts?
pain
temperature
what is the dorsal column pathway?
Ascending pathway (from PNS to CNS)
info from preceptors -> primary sensory neurone -> enter dorsal root -> cord -> ascends in dorsal columns (same side) -> brainstem (medulla) -> desiccates (crosses sides) -> third neurone -> thalamus to cerebral cortex (parietal lobe)
what is the spinothalamic column pathway?
primary sensory neurone -> enters cord via dorsal root -> desiccates -> ascends in contralateral spinothalamic tract (crosses over within a few segments) -> thalamus -> third neurone -> cortex.
what bodily functions and systems are affected by autonomic dysfunction?
pupils
BP and HR
bladder, bowel, sexual function
sweating, lacrimation, salivation
indications for a diagnostic LP?
meningitis, encephalitis
SAH
MS
Huntington’s disease
inflammatory disorders = syphilis, sarcoid, GBS
idiopathic intracranial HTN
myelography
indications for a therapeutic LP?
intrathecal chemo
removing CSF in IIH or post-op
spinal anaesthesia
Contraindications for LP
suspect or actual intracranial mass (risk of coning)
bleeding disorder
significant spinal deformity
what antibodies should be tested for if you suspect myasthenia gravis?
anti-acetylcholine receptor antibodies
anti-MuSK antibodies
What is a myasthenic crisis and how do you treat?
weakness of respiratory muscles during a relapse
ventilate if < 20mL/kg
plasma or IV Ig
treat any trigger for relapse
What are the causes of lamber-eaton myasthenic syndrome?
disorder of NM transmission due to impaired presynaptic release of ACh
causes: paraneoplastic (small cell lung CA) or autoimmune
how is lambert-eaton different to myasthenia gravis?
in lambert eaton:
- gait affected before eyes
- autonomic involvement
- hyporeflexia and weakness which improves with exercise
what criteria is used for MS?
Mcdonald criteria
what is the triad of parkinsonism?
tremor (worse at rest, pill-rolling, 4-6 cycles per second)
rigidity
bradykinesia/hypokinesia
what sort of a gait do parkinson’s patients have?
reduced arm swing, short shuffling steps with flexed trunk, freezing at obstacles/doors
what might pale optic discs indicate?
previous subclinical optic neuritis
Which is forehead sparing?
a) UMN
b) LMN
UMN
describe a spastic gait
stiff movement of legt in an arc
might be post stroke
describe the walk of a patient with sciatic nerve injury
drop foot + high stepping gait
describe sensory ataxia
board based high-stepping gait
this is due to peripheral neuropathy leading to deficits in proprioception
tender pulseless temporal arteries, jaw claudication
GCA
signs of parkinsons
lead-pipe rigidity, cog-wheel rigidity, pill rolling tremor, festinant gait with poor arm swing
onset of chorea in middle age with dementia onset later on
Huntington’s disease
gait apraxia, confusion, incontinence
normal pressure hydrocephalus
cauda equina syndrome signs
saddle anaesthesia, bowel/bladder dysfunction
triad of nystagmus + opthalmoplegia + ataxia
wernicke’s encephalopathy
nerves responsible for the supinator reflex
C5 and C6
nerves causing biceps reflex
C5 and C6
nerves causing triceps reflex
C7
unilateral weakness/sensory deficit, homonymous hemianopia, higher cerebral dysfunction (dysphasia, neglect)
anterior circulation stroke
CN palsies, cerebellar signs (vertigo, dysarthria, ataxia, choking)
isolated homonymous hemianopia
posterior circulation stroke
which cancers commonly metastasis to the brain?
thyroid
lung
breast
stomach
colorectal
prostate
what are features of SOL in the brain?
headache - worst in the morning and on lying down
nausea + vomiting
seizures
progressive focal neurological deficits
cognitive + behavioural changes
papilloedema + vision changes
what are the cardinal features of cluster headaches?
trigeminal distribution of pain
same-sided cranial autonomic symptoms
pattern to the attacks
what is the main causative organism of encephalitis?
most common is HERPES VIRUS
what is the primary bacterial cause of meningoencephalitis?
neisseria meningitides
what organisms are important to consider in an immunocompromised patient presenting with encephalitis?
CMV
toxoplasmosis
listeria