Epilepsy Flashcards
What qualifies epilepsy
- At least 2 unprovoked seizures
- 1 unprovoked + high probability of recurrence (over 10yrs)
- Epilepsy syndrome
How common is it
1% prevalence
Who gets it
Starts in children or +60yrs
+++ likely if disabled
What are the causes/risk factors
- 2/3rds idiopathic - familial
- CV disease - cerebral infarct/haem, venous thrombosis
- Head injury - cortical scarring
- Cranial surgery
- CNS infection - meningitis, encephalitis
- Alzheimers
- AI/ brain neoplasm / space occupying lesion / structural development (e.g. neuro-epithelial tumour)
- DRUGS - phenothiazines, isoniazid, tricyclic antidepressants, binge drinking, recreational drugs (e.g. BZs), alcohol withdrawal
- Metabolic disorder - Uraemia, hypoglycaemia, +Na, -Na, +Ca or -Ca
How do you classify seizures
- Partial - focal onset w/ features referable to 1 hemisphere (usually underlying structural disease)
- Primary generalised - simultaneous onset electrical discharge throughout cortex –> no localising feat
- Focal seizure - originate w/in network limited to 1 hemisphere (mixed whether awareness retained)
- Aura
- Post-ictally - drowsiness, headache, confusion, myalgia, sore tongue, temporal weakness (Todd’s palsy)
Describe a simple partial seizure
- Awareness unimpaired
- focal motor/sensory (olfactory, visual) / autonomic pr psychic symptoms
- No post-ictal symptoms
Describe a complex partial seizure + where does it happen most commonly
- Awareness impaired
- Either simple partial onset (aura) or impaired awareness at onset
- Most common = temporal lobe
- Post-ictal confusion common
(if in frontal lobe recovery = rapid)
Describe a partial seizure w/ 2o generalisation
- 2/3rd pt w. partial seizures –> electrical disturbances spreads causing 2o generalised seizure (generally convulsive)
What types of generalised seizures are there
- Absent
- Tonic clonic
- Myoclonic
- Atonic
- Infantile
Describe an absent seizure
- Brief (<10sec) pauses e.g. stop talking mid sentence
- continue where left off
- presents in childhood
Describe a tonic-clonic seizure
- Loss of consciousness
- Limbs stiffen (tonic) + then jerk (clonic)
- May have 1 w/out other
- Post-ictal drowsiness/confusion
Describe a myoclonic seizure
- Sudden jerk limb, face or trunk
- May be thrown to ground or have violently disobedient lung
Describe an atonic (akinetic) seizure
- Sudden loss of muscle tone
- fall (rag-doll)
- No LOC
What is an infantile seizure associated with
tubular sclerosis
How does genetic generalised epilepsy present
- Childhood/teen onset
- Triggered by sleep deprivation + alcohol
- Early morning (tonic-clonic or myoclonic jerks)
How does focal epilepsy present
- Hx potential cause
- Aura
- Focal motor activities during
- Automatisms
How do complex focal seizures present
- Motor = automatisms, lip-smacking, plucking at hair/clothes
- Sensory = transient paraesthesiae
- Autonomic = odd epigastric sensation, nausea, abnormal taste/smell
- Psychiatric = deja vu, fear, unreality
What are the signs of epilepsy
- Examination usually unremarkable
- Skin –> cafe-au-lait spots (neurofibromatosis) + adenoma sebaceum (tuberous sclerosis)
What investigations do you perform
- Full physical exam
- FBC, U+E, LFTs, glucose, Ca
- ECG, EEG
How do you treat it
- AVOID DANGEROUS ACTIVITIES - SWIM/DRIVE
DRUGS
- Generalised tonic-clonic = SODIUM VALPORATE or LAMOTRIGINE 1st line –> carbamazepine 2nd line
- Absence = sodium valporate, lamotrigine, ethosuximide
- Myoclonic = same tonic-clonic but AVOID carbamazepine (may worsen)
- Partial +/- 2o generalisation - carbamazepine
SURGERY
- If single epileptogenic focus found - neurological resection (70% freedom symptoms)
What are the side effects of epilepsy medication
- Carbamazepine – GI upset (N+V), dizziness, ataxia, hypersensitivity (mild maculopapular rash)
- Lamotrigine – SJS or TENs –> maculopapular rash (occurs in 10%) typically in 1st 8wks. Diplopia, blurred vision, photosensitivity, tremor, agitation, vomiting, aplastic anaemia
- Phenytoin – coarse facial features, acne, hirsutism, cerebellar toxicity (nystagmus, ataxia, discoordination), osteomalacia, hypersensitivity rash, cardiac collapse + resp distress
- Sodium valproate - ^ appetite + weight gain, liver failure, pancreatitis, reversible hair loss (grows back curly), oedema, ataxia, teratogenicity, tremor, thrombocytopenia, encephalopathy
What must you tell women who have epilepsy about medication
- give advice before becoming sexually active – 5% fetal abnormality
- Enzyme-inducing antiepileptic drugs may reduce effectiveness of hormonal contraceptives
- Teratogenicity of AEDs – women should take folic acid (valproate should be avoided use Lamotrigine)
