232 - Epilepsy Flashcards
What is an epileptic seizure?
A transient event experienced due to synchronous and excessive discharge or cerebral neurones
Why do people get epilepsy?
Idiopathic - ? genetic link
Symptomatic - as a symptom of a cause eg. tumour
Cryptogenic - suggestive of a cause buy can’t find one
What are some differentials for epilepsy?
Syncope Non-epileptic attack disorder Panic attacks Sleep disorders Migrane TIAs Hypoglucaemia
What are the 3 Ps related to syncope?
Prodrome
Posture
Provocation
What are some signs that point to a seizure?
Stereotyped cyanosis unprovoked lateral tongue biting shoulder dislocation post-ictal confusion
What are the 2 main categories of epileptic seizures? What are the subtypes seen in each?
Generalised - starts in both hemispheres, sudden onset
- tonic clonic, absence, myoclonic
Partial/focal - Starts in 1 place then spreads
- simple (aware). complex (unaware)
What are the characteristics of a generalised tonic-clonic seizure? GTCS
Sudden onset, sterotyped
Tonic stiffening - then syncrhonised clonic movements
Cyanosis, stertorous breathing, tongue biting, incontinance, injuries, post-ictal confusion.
What are the characteristics of idiopathic generalised epilepsy?
Mixture of seizures - tonic clonic, absences and myoclonic
Starts in childhood/teens/young adults
EEG abnormal - generalised spike-wive
Triggers - eg. sleep deprivation and alcohol excess
What are the characteristics of JME - Juvenile myoclonic epilepsy?
A form of generalised epilepsy Onset 8-18 FH common Upper limb jerks, GTCS, absences. Seizures on waking, triggers: alcohol, sleep deprivation, photosensitivity MRI ok, EEG abnormal Good treatment response
What are the characteristics of Temporal lobe complex partial epilepsy?
3As
- Aura - olfactory, gustatory, psychic, limbic…
- Arrest - motor and speech
- Automatism - manual or oro-facial movements
Lasts 2-10 minutes, gets post ictial confusion
Descirbe NEAD: Non epileptic attack disorder
Psychologically mediated, altered consciousness + behaviour
Markers:
- awareness maintained
- Gradual onset, prolonged seizure
- Frequant
- No drug response
- Autonomic arousal preceeds it
- Asynchronous movements
- Eyes closed
- Back arching
- Carpet burns
- normal colour
- Tip of tongue bitten
What is catamenial epilepsy?
Seizures around menstruation
What drugs are available for epilepsy?
Sodium valproate (epilim)
Carbamazepine (tegretol)
Lamotrigine (lamictal)
Levetiracetam (keppra)
Sodium valporate
Generalised epilepsy
Na channels / GABA
S/e: weight gain, tremor, teratogenic
Carbamazepine
Partial/focal epilepsy
Na channels
S/e: Rash, ataxia, double vision, interacts with enzyme inducers eg. warfarin and OCP
Lamotrigine
1st line in partial/focal
2nd line for generalised
Na channels
s/e: rash
Levetiracetam
1st line in partial/focal
2nd line for generalised, add in as 2nd line in partical/focal
SV2A protein
s/e: psychiatric issues
What is SUDEP?
Sudden unexpected death in epilepsy
a non-traumatic, unwitnessed death
Normal post mortem
1/1000 a year risk
Why? cardiac arrhythmias?
What is status epilepticus?
Seizures lasting 30minutes or more without regaining consciousness inbetween
20% mortality - treat after 5 min of seizure, don’t wait for 30!
What can cause status epilepticus?
50% new cause - encephilitis, trauma…
50% known epilepsy - missed medication
Why is status epilepticus so dangerous?
associated with severe psychological and metabolic compromise + neuronal damage
How do you treat status epilepticus?
1st: IV lorazepam or buccal midazolam
If established: IV phenytoin or AEDs
Then if refractory - ITU, sedation, ventillation
What is a coma?
A state of unrousable unconsciousness
No meaningful interaction
Unaware of external stimulus - eye opening to pain at best
What is arousal? Where in brain is it based?
Level or consciousness / alertness
Reticular activating system in Pons/midbrain + thalamus
What is awareness? Where in brain is responsible?
Content of consciousness - awareness of self + environment
Cortical areas
What are 4 key categories of causes of coma?
Significant structural injury to cerebral hemispheres
Brainstem dysfunction
Diffuse physiological brain disfunction
Metabolic + endocrine causes
What can cause diffuse physiological brain dysfunction leading to coma?
Hypothermia
sudden hypertension
Status epilepticus
Drugs/toxins
What metabolic/endocrine disterbances can lead to coma?
Hypothyroid -> high or low Na
Addisons -> high Ca
Pan-hypopituitarism -> High or low glucose
Renal or hepatic failure
What clues should you look for to try find cause of coma?
Temperature
Breath
Skin - rash, needle tracts, head injury
RR - low: opiates? high: hyperuricemia, pneumonia
Pulse - high:drugs + infection, low:hypertyroid
BP- Low: trauma, shock, cardiac failure, high: CVAm SAH, RICP, drugs
What 4 things mean you can’t reliably interpret somones coma + signs?
Hypothermia
Metabolically deranged
Sedated
Endocrine disterbances
- must correct before final judgement
What signs do you look for in coma?
Papilloedema - raised ICP
UMN signs - unilateral?
Meningism - meningitis or SAH
Pupil responses + eye movements
What do different pupil responses mean in a coma?
Pinhole - opioids or pontine lesion
Large - MDMA, cocaine
Unilateral large - Raised ICP (about to cone), CNIII damage
What do eye movement signs show in coma?
Roving - intact brainstem
Corneal reflex - intact brainstem
Horizontal deviation - siezure, frontal lobe damage, pontine damage
Oculocephalic response - dolls eyes - abnormal if low brainstem damaged
How do you asses brainstem function?
Pupils, corneal reflex, gaf reflex, response to hypercapnia, vestibuloocular reflex
What are the possible outcomes of coma?
Death
Regions consciousness - good, dependant, minimally conscious
Persistant vegetative state
What is persistent vegetative state?
Recovery of arousal but not awareness
- no awareness, language or comprehension
- have roving eye movements, brainstem reflexes are ok.
- Maintains resp + circulatory independence, and sleep-wake cycle
- due to diffuse cortical/subcortical damage
When is persistent vegetative state considered permanent?
> 6 months if non-traumatic
>12 months if traumatic
What is minimally conscious state?
May make eye contact
Turn head when spoken to
Grasp objects, moths words, tracks objects
Very severely disabled
What is locked-in syndrome?
De-efferenated motor tracts - no motor output below CNIII
Blinking and vertical eye movements possible
Awareness and arousal retained
why? Pontine infarction, eg. basilar artery issue.
What us a psychogenic coma?
Psychologically generated coma - no organic cause
Must exclude other causes
Reflexes preserved
Tuning fork in nose!
Case:
77 year old lady, medical ward, progressively more drowsy and disorientated, now unable to rouse.
HAs roving eye movements, pupils are midsized and reactive, opens eyes in response to pain, makes grunts, reflexes symetrical and brisk.
What are her possible causes of coma and what investigations are needed?
Metabolic - do BM
Stroke - CT head
Tumour - CT Head
Post-MI - ECG
Accidental OD - look at chart
Meningitis/encephalitis - Temp, FBC
23 year old girl brought into A+E in coma.
Shallow resp, hypoxic, small pupils, absent corneal reflex, absent oculo-vestibular reflexes, flaccid limbs, no response to pain, refleces absent.
BP was 80/50. GCS 3.
What possible causes?
What history needed?
What action?
? Opiate OD
? Basilar artery thrombosis, Trauma?
- Drug history, self harm? onset, what happened before?
- ABCDE, naloxone, BM, blood toxicity, MRI or MRA
What is an example of an autosomal dominant neuogenetic disease?
TS - tuberous sclerosis complex
What features are seen in tuberous sclerosis?
Ashleaf macules Cafe au lait spots Dermal neurofibromas Optic nerve glioma Astrocytic harmatoma (lesion on eye) Periungal fibromas (nails) Facial angiofibromas (liek acne) Rhabdomyoma (polps on heart) Angiomyolipoma (fatty tumour on kidney)
What is an example of an autosomal recessive neurogenetical disorder?
Tay Sachs - course features, neuro-degeneration secondary to lipofuscin deposition in brain.
Cherry red spot on retina
What are some X linked genetic disorders?
Duchenne muscular dystrophy
Becher Muscular dystrophy
Fragile X
Heamophillia
What are some mitochondirally inherited genetic disorders?
Leber’s herediatary optic neuropathy
Kearn’s sayre
Pearsons syndrome
MELAs
