Neuro Flashcards
name some of the symptoms that the term dementia describes
memory loss
difficulties with thinking, problem solving or language
change in mood or behaviour
what is the most common cause of dementia?
Alzeimer’s disease
name some functions of the frontal lobe
voluntary & planned motor behaviours
motor speech area [broca’s]
personality
planning
what is the presentation of a subarachnoid haemorrhage?
headache which reaches max intensity within seconds of onset
described as worst ever
what symptoms and signs suggest meningeal irritation?
neck stiffness
positive Kernig’s sign
how might giant cell arteritis present & in which epidemiological group?
headache with generalized aches and pains
in the elderly
what urgent treatment is required for giant cell arteritis and why?
steroids
prevent blindness
indications for brain imaging in patients with headache
sudden onset new headache in patient >50 headache that changes w/posture, coughing [^ICP] cancer history HIV history fever abnormal neurological signs
causes of acute severe headache [onset in mins/hrs]
intracranial haemorrhage cerebral venous thrombosis carotid/vertebrobasilar dissection meningitis head injury migraine drugs alcohol infection e.g. malaria
vasovagal syncope occurs as a result of..?
reflex bradycardia
peripheral & splanchnic vasodilatation
effort syncope on exercise may occur in patients with..
aortic stenosis
hypertrophic cardiomyopathy
where does the upper motor neurone of the corticospinal tract originate and terminate?
motor cortex
motor nuclei of cranial nerves & ant. spinal horn cells
where do corticospinal pathways decussate?
pyramids of the medulla
an upper motor neurone lesion shows signs on same or opposite side?
opposite
a lower motor neurone lesion shows signs on same or opposite side?
same side
fasciculation occurs with upper or lower motor neurone lesions?
lower
what kinds of motor neurone lesions present with wasting?
lower
what kinds of motor neurone lesions present with spasticity +/- clonus?
upper motor neurone lesions
what kinds of motor neurone lesions present with hypotonia?
lower
how does weakness present in upper motor neurone lesions?
weakness in extensors of arms
& flexors of legs
what is fasciculation?
visible contraction of single motor units, appears as a twitch
how do upper and lower motor neurone lesions tend to affect tendon reflexes?
upper: exaggerated tendon reflexes
lower: loss of tendon reflexes
what is paraparesis?
weak legs
what is hemiparesis?
weakness of limbs on one side
hemiparesis is usually caused by a lesion where?
within the brain or brainstem
paraparesis is most often due to a lesion where?
in the spinal cord below T1
what is tetraparesis?
weakness of arms and legs
tetraparesis indicates damage where?
high cervical cord damage
[most commonly from trauma]
describe the pathway of the lower motor neurone
from anterior horn cell or cranial nerve
via peripheral nerve
to motor endplate
what signs are seen below, at the level of, and above a cord lesion?
UMN signs below lesion
LMN signs @ level of lesion
unaffected muscles above lesion
how does the presentation of muscle disease differ from a lower motor neurone lesion?
in muscle disease, reflexes are usually preserved
LMN lesions are most commonly caused by lesions in which 3 areas?
anterior horn cell lesions
spinal root lesions
peripheral nerve lesions
what is the most common disease of the neuromuscular junction?
myasthenia gravis
how does myasthenia gravis typically present in terms of weakness & wasting?
weakness of skeletal muscle
rarely wasting
give an example of a plasma muscle enzyme which when elevated is highly suggestive of muscle disease
creatine kinase
diseases that cause anterior horn cell lesions
motor neurone disease
poliomyelitis
diseases that cause spinal root lesions
cervical and lumbar disc lesions
causes of peripheral nerve lesions
trauma
compression
polyneuropathy
describe the path of sensory peripheral nerves
nerve endings dorsal root ganglia cord thalamus cerebral cortex
posterior columns carry sensory modalities for what?
vibration, proprioception, 2-point discrimination, light touch
where does the dorsal column decussate?
medulla
the spinothalamic tract conveys which senses?
pain
temp
crude touch
where does the spinothalamic tract decussate?
anterior white commissure
which fibres of the corticospinal tract decussate [75-90%] at the medullary pyramids and which do not?
limb decussate
axial don’t
where do the axial fibres of the corticospinal tract decussate?
anterior white commissure in spinal cord
what are the principal symptoms of lesions in the sensory pathways below thalamus level?
paraesthesia [pins & needles]
numbness
pain
where are symptoms of a sensory spinal root lesion felt?
symptoms are referred to the dermatome supplied by that root
lesion in spinothalamic tract in brainstem or spinal cord results in loss of pain-temp sensation below the lesion contra/ipsilaterally?
contralaterally
lesion in dorsal column of spinal cord results in loss of propprioception etc. below the lesion contra/ipsilaterally?
ipsilaterally
loss of pain/temp sensation in right leg & loss of proprioception in left leg suggests a lesion where?
spinal cord
describe sensory loss following pontine lesion
loss of all forms of sensation on opposite side to lesion
drugs that block dopamine receptors and may induce parkinsonian syndrome
reserpine [antipsychotic, antihypertensive]
phenothiazines [antipsychotic]
butyrophenones [antipsychotic]
diseases that can cause resting tremor
Parkinson’s
parkinsonism
Wilson’s
intention tremor suggests disease of which part of the brain?
cerebellum
causes of cerebellar lesions
MS space-occupying [tumour, abscess] haemorrhage chronic alcohol use antiepileptic drugs paraneoplastic syndrome
causes of papilloedema [optic disc oedema]
^ICP
retinal vein obstruction [thrombosis/compression]
optic neuritis
accelerated hypertension
3 branches of the trigeminal nerve
opthalmic
maxillary
mandibular
anticonvulsant drug used to suppress attacks of trigeminal neuralgia
carbamazepine
damage to the facial nerve in the temporal bone may be associated with what symptoms?
undue sensitivity to sounds
loss of taste to ant. 2/3rds of tongue
what structure extending from brainstem to thalamus influences the state of arousal/wakefulness?
central reticular formation
what does the AVPU score stand for [rapid assessment of unstable patient
Alert
responds to Voice
responds to Pain
Unresponsive
brain death means irreversible loss of which 2 capacities?
capacity for consciousness
capacity to breathe
define stroke
rapid onset of neurological deficit
result of vascular lesion
associated w/ infarct of CNS tissue
define polycythaemia
^ haemoglobin in the blood
[^RBCs or decreased plasma vol]
which heart condition increases risk of embolic stroke?
AF
treatment for TIA
aspirin [immediately and continued long term]
dipyridamole
(clopidogrel if aspirin intolerant)
what does dipyridamole do?
vasodilatation
reduce platelet aggregation
Tx for TIA pateints with AF, valvular lesions or DCM
long-term warfarin
the most common stroke is caused by occlusion of which cerebral artery and infarction of which structure?
middle cerebral
internal capsule
what are lacunar infarcts
and where do they occur?
small infarcts that produce local deficits
e.g. pure motor stroke or pure sensory stroke
deep cerebral white matter, basal ganglia, pons
what is locked-in syndrome and what is it caused by?
all voluntary muscles are paralysed except those that control eye movement
upper brainstem infarction
immediate investigation in stroke patient? and why
brain CT
distinguishes ischaemic/haemorrhagic
identifies conditions mimicing stroke e.g. tumour
what treatment is used to reverse the effects of anticoagulants in patients with intracerebral haemorrhage?
prothrombin complex concentrate
what causes subarachnoid haemorrhage in 70% of cases?
saccular (Berry) aneurysms
at branching points of circle of willis
what is the investigation of choice for subarachnoid haemorrhage which should be undertaken as soon as possible?
CT
if there is a strong clinical suspicion of subarachnoid haemorrhage but CT scan is normal, what test would you carry out?
and what findings would support SAH diagnosis?
lumbar puncture
^ in RBC lysis/phagocytosis pigments (bilirubin, oxyhaemoglobin)
what drug is given to subarachnoid haemorrhage patients to prevent cerebral artery spasm? [>ischaemia & further neurological damage]
nimodipine [calcium-channel blocker]
what causes subdural haematoma?
rupture of a vein running from the hemisphere to the sagittal sinus
almost always due to head injury [often minor]
which groups are particularly susceptible to subdural haematoma & why?
elderly & alcoholics.
accident prone & atrophic brains make connecting veins more susceptible to rupture
what causes extradural haematomas?
injuries that fracture temporal bone
& rupture underlying middle meningeal artery
what is the clinical picture of an extradural haematoma?
head injury with brief period of unconsciousness
followed by lucid interval of recovery
then rapid deterioration
define seizure
convulsion or transient abnormal event
caused by paroxysmal discharge of cerebral neurones
define epilepsy
continuing tendency to have seizures
define partial seizure
involves only a portion of the brain at onset e.g. temporal lobe
[but may become generalized]
describe generalized tonic-clonic seizure [grand mal] & how long episode lasts
sudden onset of rigid tonic phase
followed by convulsion [clonic phase] - muscles jerk rhythmically
seconds to minutes
describe absence seizure [petit mal] & how long it lasts
usually children
cease activity, stares, pales
for few seconds only
describe myoclonic seizure
isolated muscle jerking
describe tonic seizure
intense stiffening of the body
describe akinetic seizure
cessation of movement
falling
loss of consciousness
describe simple partial seizure
epileptic activity in a part of the brain
not affecting consciousness or memory
describe complex partial seizure
epileptic activity in a part of the brain
affecting awareness or memory before/during or immediately after
emergency management of status epilepticus
administer O2 IV access [large vein] cardioresp, pulse oximetry monitoring vit B & C lorazepam [or rectal diazepam]
which antiepileptic drug is contraindicated in women of child bearing age?
sodium valproate
give an example of surgical treatment for patients with poorly controlled epilepsy
amputation of the anterior temporal lobe
the extrapyramidal system is a general term for what structure/s?
basal ganglia
& their connections with other brain areas [particularly those concerned w/ movement]
describe the akinetic-rigid syndrome type of movement disorder and give an example
slowed movement, increased muscle tone
idiopathic Parkinson’s disease
describe dyskinesias movement disorders and give an example
added uncontrollable movements
essential tremor
what causes the clinical features of idiopathic Parkinson’s disease?
progressive depletion of dopamine-secreting cells in the substantia nigra
what are the main clinical features of Parkinson’s disease?
rest tremor rigidity/ ^tone akinesia/bradykinesia stooped posture poor balance
what is the most common cause of death in parkinson’s disease patients?
bronchopneumonia
other than Parkinson’s disease, what can cause “parkinsonism”?
multi-infarct dementia
repeated head injury
what is the options for initial therapy in parkinson’s disease?
- Levodopa [L-dopa]
with a peripheral dopa-decarboxylase inhibitor - dopamine agonists
- monoamine oxidase B inhibitors
how do monoamine oxidase B inhibitors work?
inhibit catabolism of dopamine in the brain
what is “parkinsonism plus”?
rare disorders
parkinsonism + evidence of a separate pathology
what is the most common parkinsonism plus disorder?
progressive supranuclear palsy
what drugs improve benign essential tremor?
propanolol
primidone [anticonvulsant]
mirtazapine [antidepressant]
what are the symptoms of Huntingdon’s disease?
relentlessly progressive course
chorea
personality change
dementia
what is the genetic cause of huntingdon’s disease?
autosomal dominant
expansion of CAG repeats in Huntingdon’s gene on chromosome 4
leads to production of mutant huntingtin protein
what causes the symptoms of Huntingdon’s disease?
loss of neurones within basal ganglia
depletion of GABA and ACh [SPARES DOPAMINE]
management of huntingdon’s
no treatment arrests disease
symptomatic treatment of chorea
genetic counselling of family members
what is multi infarct dementia?
series of small strokes
leads to loss of brain function
name a peripheral dopa-decarboxylase inhibitor
benserazide
carbidopa
name a dopamine agonist
ropinirole
what causes MS?
autoimmune
disseminated plaques of demyelination
exposure to which infectious agent in childhood may predispose to later development of MS in a genetically susceptible host?
EBV
which part of the CNS is never affected by MS?
peripheral nerves
name the 3 characteristic common presentations of relapsing & remitting MS
optic neuropathy
brainstem demyelination
spinal cord lesions
name some symptoms caused by brainstem demyelination
diplopia (double vision)
vertigo
dysphagia
nystagmus
causes of death in MS
recurrent UTIs
uraemia
bronchopneumonia
what is the definitive investigation in MS?
MRI of brain and spinal cord
short term management of MS replase
short courses of steroids (IV prednisolone)
reduce severity
prolonged MS treatment which reduces relapse rate
subcutaneous B-interferon
downsides of using B-interferon in MS
prolonged treatment expensive side effects (flu-like symptoms)
which 2 bacteria account for most cases of acute bacterial meningitis outside neonatal period?
neisseria meningitidis
streptococcus pneumoniae
signs of meningococcal septicaemia
[1. skin, 2. systemically]
non-blanching petechial & purpuric rash
signs of shock
immediate treatment for suspected meningitis [before hospital transfer]
benzylpenicillin
why should lumbar puncture not be performed in a patient with suspected meningococcal sepsis?
coning of the cerebellar tonsils may follow
how long is tuberculous meningitis treated for?
at least 9 months
what is encephalitis?
inflammation of the brain parenchyma
how does the presentation of encephalitis compare to meningitis in terms of cerebral function?
unlike meningitis, cerebral fn. is usually abnormal in encephalitis with altered mental status, motor and sensory deficits
common organisms in the UK to cause acute viral encephalitis
herpes simplex
echovirus
coxsackie
mumps
treatment for suspected herpes simplex encephalitis
IV aciclovir
why is lumbar puncture not performed to investigate cerebral abscess?
danger of coning in the presence of raised intracranial pressure
treatment of cerebral abscess
IV antibiotics
sometimes surgical decompression
treatment for neurosyphilis? [may arrest but not reverse the neurological disease]
benzylpenicillin
what would you expect to see on neuroimaging and lumbar puncture in a patient with benign/idiopathic intracranial hypertension ?
neuroimaging normal
lumbar puncture - raised CSF pressure
management of brain tumour
surgery
radiotherapy
corticosteroids [cerebral oedema]
when is radiotherapy given in brain tumour patients?
gliomas
radiosensitive mets
what is hydrocephalus? and why does it usually occur
excessive CSF in cranium
obstruction to CSF outflow
what causes hydrocephalus in children?
congenital malformation of the brain
meningitis
haemorrhage
treatment for hydrocephalus
surgical insertion of shunt between ventricles and right atrium or peritoneum
what is normal pressure hydrocephalus?
dilatation of cerebral ventricles without signs of raised intracranial pressure
clinical features of hydrocephalus
headache
vomiting
papilloedema
may be ataxia & bilateral pyramidal signs
name some pyramidal signs
muscle weakness
Babinski sign
increased deep tendon reflex
how does normal-pressure hydrocephalus present and in whom?
elderly people
dementia, urinary incontinence, ataxia
describe clinical features of migraine
unilateral
throbbing
builds over mins/hrs
nausea/vomiting, photophobia
differential diagnosis of migraine
meningitis
subarachnoid haemorrhage
thromboembolic TIA [headache unusual]
Tx of mild migraine attack
paracetamol/ NSAIDs w/antiemetic [metoclopramide]
Tx of moderate/severe migraine attack
triptans [serotonin agonists]
how do triptans work in migraine?
inhibit vasoactive peptide release
promote vasoconstriction
block pain pathways in brainstem
migraine prophylaxis medications
pizotifen [serotonin antagonist]
B-blockers
amitryptiline [serotonin/norepi. reuptake inhibitor]
