neurology Flashcards
causes of generalised seizures
- idiopathic
- infections - meningitis, encephalitis
- electrolytes - hypoglycaemia, hyponatraemia, toxins, hypomagnesiumaeia, hypocalcaemia
- syndromes - tuberous sclerosis, NF1
- trauma
diagnostic tests for seizures
- EEG
- MRI head
rescue medications in seizures
- bucall midazolam - to be given 5 mins after onset
management of seizures
- anti epileptics
- ketogenic diet (ketones 4-6)
- vagal nerve stimulation
- surgery - if >2 meds failed
EEG in absence seizures
3 sec spike and wave discharge
1st line medication of tonic clonic seizure
boys = sodium valproate
girls = lamotrigine
side effects of sodium valproate
teratogenic to women
nausea and vomiting
tremors
weight gain
insulin resistance
deranged LFTS
hair loss
reduces metabolism of other anti epileptics
mechanism of action of lamotrigine
inhibits voltage gated sodium channels
side effects of lamotrigine
rash
diplopia
headache
arthritis
mechanism of action of carbamazepine
blocks voltage gated Na channels
side effects of carbamazepine
ataxia
steven johnson syndrome
leukopenia
thrombocytopenia
diplopia
sedation
1st line medication for absence seizures
ethosuximide
mechanism of ethosuximide
blocks T type calcium channels
side effects of ethosuximide
GI upset
rash
side effects of topiramate
sedation
weight loss
paraesthesia
mechanism of action of phenytoin
non specific voltage Na channel blocker
side effects of phenytoin
gingival hyperplasia
vit D deficiency
nystagmus, ataxia
hair growth
dizziness
steven johnsons syndrome
folate deficiency
mechanism of action of levetiracetam
binds to synaptic vesicle protein SV2A and stabilises neuronal activity
side effects of levetiracetam
insomnia
irritable behaviour
anxiety, psychotic symptoms
reduced appetite
steven johnsons syndrome
pancytopenia
prolonged QT
mechanism of action of vigabatrin
GABA transaminase inhibitor to increase GABA concentration
side effects of vigabatrin
sedation
visual field abnormalities
hypotonia
causes of focal seizures
- focal brain lesions e.g. tumours, traumatic brain injury (hIE), congenital malformations (tuberous sclerosis )
- benign idiopathic epilepsy syndromes e.g. rolandic, panayiotopoulous
- temporal lobe epilepsy
- rasmussen encpehalitis
presentation of infantile spasms
present at 4-8 months old….
b/l symmetrical rhythmic jerking movements/ brief contraction movements, last few seconds and occur in clusters
deviation of eyes, nystamus
developmental regression
diagnosis of infantile spasms
EEG = hypsarrthymia (random spike and wave, disorganised)
MRI brain
management of infantile spasms
1st line = vigabatrin
prednisolone high dose for 2/52
describe lennox gastraut syndrome
visual auras
difficult to control seziures (10% seizure free on medications)
describe landua kleffner syndrome
subacute onset of aphasia
residual language impairment
self limiting seizures
EEG in landau kleffner syndrome
bitemporal abnormalities
presentation of benign rolandic epilepsy
frequent short lived night seizures, focal motor aware seizures (twitching/ dribbling)
stop after puberty
linked to sudden death
EEG in benign rolandic epilepsy
centro temporal spikes
presentation of panayiotopoulous syndrome
autonomic features e.g. vomiting, retching, pallor during seizure
EEG in panayiotopoulous syndrome
occipital spikes
describe juvenile myoclonoc epilepsy
absence seizures and myoclonic jerks in the morning e.g. clumsy in morning
GTC first present 13-18 y/o
provoked by sleep deprivation and alcohol
EEG in JME
generalised polyspike and wave 4-6 hz
management of JME
keppra
describe reflex anoxic seizure
unexpected noise/ pain/ startle triggers brief cardiac asytole followed by excessive activity of vagus nerve
looks pale/ apnoea/ change in tone
presentation of dravet syndrome
severe myoclonic epilepsey
triggered by fever
developmental delay
describe benign epilepsy with occipital spikes
early childhood - focal seizures with impaired consciousness
multi coloured halos - visual aura
triggered by screens
causes of encephalitis
VIRAL (most common)
1. herpes simplex ** - HSV 2 <3 mo old, HSV 1 >3 mo old
2. CMV
3. adenovirus
BACTERIAL
1. lyme disease
2. listeria
3. TB
4. mycoplasma
presentation of encephalitis
flu like illness
fever
seizures
impaired consciousness
signs of raised ICP
investigations for encephalitis
- lumbar puncture - CSF PCR for HSV 1 +2, varicella, CMV, enterovirus
- contrast enhanced MRI head
- EEG
MRI head results in encephalitis
oedema in frontal and temporal lobes
necrotising encephalitis with haemorrhagic necrosis
EEG in encephalitis
spike and slow or periodic sharp wave in frontal and temporal lobes
management of encephalitis
IV aciclovir 14-21 days +/- IV benpen
describe acute disseminated encephalomyelitis
recent viral illness (measles)
rapdi onset + resolution of encephalopathy
polyfocal neurological signs
seziures, fever
MRI head in acute disseminated encephalomyelitis
multifocal disease with white matter changes
causes of meningitis
- VIRAL **
- Enterovirus (most common)
- coxsackie
- herpes - BACTERIAL
- neonates: GBS, HSV 2, e.coli
- older: h.influenza, s.pneumonia, meningococcal
management of meningitis
- lumbar puncture and blood culture prior to abx
- FBC, CRP, coag
- meningococcal and pneumococcal blood PCR
- IV ceftriaxone +/- aciclovir
CSF lumbar puncture results in viral vs bacterial
VIRAL - clear, increased lymphocytes, normal protein, normal glucose
BACTERIAL - turbid, increased neutrophils, increased protein, reduced glucose
household contact prophylaxis in meningitis
ciprofloxacin or iM ceftriaxone if pregnant
causes of guillain barre syndrome
- gastroenteritis e.g. campylobacter
- Viral URTI e.g. mycoplasma
- vaccines
presentation of guillain barre syndrome
- gradual ascending pattern of progressive symmetrical weakness (starting in lower extremities)
- neuropathic pain
- reduced reflexes and sensory loss
- autonomic symptoms
- breathing difficulties
investigations for guillain barre syndrome
- lumbar puncture - raised CSF protein, normal WCC
- nerve conduction studies
- spirometry - FVC -> ITU admission?
- ECG - 2nd or 3rd degree AV block
management of guillain barre syndrome
- iV immunoglobulin plasma exchange
- iTU - intubation and ventilation
presentation of transverse myelitis
after infectious illness
reduced sensation to lower limbs and flaccid weakness
increased tendon reflexes
dorsal column (sensory pathway) carries…
fine touch, vibration and proprioception
neurones decussate in medulla
ipsilateral
anterior / lateral spinothalamic pathways (sensory) carries..
anterior - crude touch and pressure
lateral - pain and temperature
contralateral
causes of raised ICP
- traumatic brain injury
- brain tumour
- hydrocephalus
- obstruction of venous sinuses
- cerebral oedema - encephalitis, meningitis, SAH, leukaemia
- benign intracranial HTN
presentation of raised ICP
headache - first thing in morning, wake at night
vomiting
papilloedema
fluctuating consciousness
visual disturbance
seizures
severe ICP signs…
- cushings - bradycardia, hypertension, abnormal resp pattern
- sun setting - eyes medial and inferior
- decorticate posturing
management of raised ICP
- CT HEAD
- intubation if GCS <8, APNOEAS
- lie with head at 20-30 degrees
- mannitol or hypertonic 3% saline
- neuro surgical review
risk factors for idiopathic intracranial hypertension
- obesity
- female
- drugs - contraceptive pill
presentation of idiopathic intracranial hypertension
- headaches
- papilloedema -> loss of visual acuity
- neck and shoulder pain
- nausea/ vomiting
diagnosis of idiopathic intracranial hypertension
diagnosis of exclusion
MRI head - normal
CSF - normal
CSF opening pressure >25cm
management of idiopathic intracranial hypertension
- azetazolamide - carbonic anhydrase inhibitor, reduces volume of CSF
- topiramate
- weight loss
presentation of migraine
headache - frontal, hemi cranial, throbbing
N&V
lie in dark room
aura
FH of migraines
prophylaxis for migraines
- pizotifen
- propranolol
management of migraines
- analgesia
- triptans >6 y/o
non communicating causes of hydrocephalus
(obstruction of CSF reabsorption)
CONGENITAL
- arnold chiari malformation
- dandy walker malformation
- spina bifida
ACQUIRED
- mass lesions e.g. medulluoblastoma
- IVH
- infection
describe arnold chiari malformation
herniation of cerebellar tonsils through foramen magnum
causes nerve palsies and facial pain
describe dandy walker malformation
fusion of cerebellum in midline
communicating causes of hydrocephalus
(impaired secretion of CSF)
- choroid plexus papilloma
- meningitis
- haemorrhage
describe the flow of CSF
- CSF producted in ependymal cells by choroid plexus
2.flows into lateral ventricle - flows through foramen of monro to 3rd ventricle
- flows through aqueduct of sylvius to 4th ventricle
- flow sthrough foramen of magendue to posterior fossa
- absorbed by arachnoid granulations in dural venous sinuses and down spinal cord
causes of SAH
- arterio -venous malformation **
- cerebral aneurysms
- trauma
- space occupying lesions
criteria for performing cT head in 1 hour
- suspicion of NAI
- GCS <14 after 2 hours
- suspected open skull fracture
- suspected basal skull fracture
- post traumatic seizure
- focal neurological deficit
- bruise / swelling >5cm
- > 3 discrete vomiting
- amnesia >5 mins
- witnessed LOC >5mins
- dangerous mechanism - >3m fall
cause of friedrichs ataxia
GAA repeat expansion on the frataxin gene - causes iron deposits in mitochondria
presentation of friedrichs ataxia
- progressive ataxia <10 y/o
- spasticty
- absent deep tendon reflexes
- preserved intelligence
- dysarthria
- pes cavus
- progressive kyphoscolioisis
- congestive heart failure / hypertrophic cardiomyopathy
- diabetes
- optic atrophy
diagnosis of friedrichs ataxia
- nerve conduction studies / visual evoked potentials
- genetic analysis
- mRI head and spine
presentation of sub acute sclerosing panencephalitis
6-8 years after measles infection…
- initial deterioration at school
- myoclonic jerks -> GTC
- rigidity and unresponsive
- death
diagnosis of sub acute sclerosing panencephalitis
EEG - short burst of irregular sharp and slow complexes
CT - cortical atrophy
describe miller fischer syndrome
variant of GBS
- ophthalmoplegia
- abnormal muscle co-ordination
- absent deep tendon reflexes
describe acute flaccid myelitis
- triggered by enterovirus
- acute asymetrical upper limb weakness (lMN)
- febrile
cause of bitemporal hemianopia
lesion in optic chiasm (pituitary adenoma)
cause of homonymous hemianopia
lesion in optic radiation
which eye muscles does cranial nerve 3 control
- superior rectus (upward)
- inferior oblique (upward and outward)
- inferior rectus (downward movement)
3rd nerve palsy presentation
eye ‘down and out’
ptosis
proptosis
fixed dilated pupil
trochlear (4th) nerve palsy
elevated and lateral eye
(controls superior oblique muscle for inward rotation)
eye test at 4 weeks old
visual evoked potential
eye test at 10 months old
identify and pick up small objects
eye test at 3-4 y/o (if cant read yet)
optotype matching tests - identify pictures of toys at distance
eye test for children who can read
snellen test
describe moebius syndrome
underdevelopment of cranial nerve VI + VII
facial paralysis
unable to move eyes to side
missing digits
clubbed feet
presentation of horner syndrome
- ptosis (drooping eyelid)
- miosis (constricted pupil)
- reduced sweating
4 .slow response to light
causes of retinitis pigmentosa
(night blindness)
- cystinosis
- lawrence moon biedle yndrome
- post measles
- usher syndrome
- alports
- refsums
- waardenburg
- kearn sayres
how to manage corneal abrasions
- examine with slit lamp with fluorescin
- chloramphenicol eye drops 5- 7 days
presentation of optic neuritis
- acute visual loss
- eye pain/ headache
- impaired colour vision
