Epilepsy

Question 1

What qualifies epilepsy

Answer 1

• At least 2 unprovoked seizures
• 1 unprovoked + high probability of recurrence (over 10yrs)
• Epilepsy syndrome

Question 2

How common is it

Answer 2

1% prevalence

Question 3

Who gets it

Answer 3

Starts in children or +60yrs

+++ likely if disabled

Question 4

What are the causes/risk factors

Answer 4

• 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

Question 5

How do you classify seizures

Answer 5

• 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)

Question 6

Describe a simple partial seizure

Answer 6

• Awareness unimpaired
• focal motor/sensory (olfactory, visual) / autonomic pr psychic symptoms
• No post-ictal symptoms

Question 7

Describe a complex partial seizure + where does it happen most commonly

Answer 7

• 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)

Question 8

Describe a partial seizure w/ 2o generalisation

Answer 8

• 2/3rd pt w. partial seizures –> electrical disturbances spreads causing 2o generalised seizure (generally convulsive)

Question 9

What types of generalised seizures are there

Answer 9

• Absent
• Tonic clonic
• Myoclonic
• Atonic
• Infantile

Question 10

Describe an absent seizure

Answer 10

• Brief (<10sec) pauses e.g. stop talking mid sentence
• continue where left off
• presents in childhood

Question 11

Describe a tonic-clonic seizure

Answer 11

• Loss of consciousness
• Limbs stiffen (tonic) + then jerk (clonic)
• May have 1 w/out other
• Post-ictal drowsiness/confusion

Question 12

Describe a myoclonic seizure

Answer 12

• Sudden jerk limb, face or trunk

- May be thrown to ground or have violently disobedient lung

Question 13

Describe an atonic (akinetic) seizure

Answer 13

• Sudden loss of muscle tone
• fall (rag-doll)
• No LOC

Question 14

What is an infantile seizure associated with

Answer 14

tubular sclerosis

Question 15

How does genetic generalised epilepsy present

Answer 15

• Childhood/teen onset
• Triggered by sleep deprivation + alcohol
• Early morning (tonic-clonic or myoclonic jerks)

Question 16

How does focal epilepsy present

Answer 16

• Hx potential cause
• Aura
• Focal motor activities during
• Automatisms

Question 17

How do complex focal seizures present

Answer 17

• Motor = automatisms, lip-smacking, plucking at hair/clothes
• Sensory = transient paraesthesiae
• Autonomic = odd epigastric sensation, nausea, abnormal taste/smell
• Psychiatric = deja vu, fear, unreality

Question 18

What are the signs of epilepsy

Answer 18

• Examination usually unremarkable

- Skin –> cafe-au-lait spots (neurofibromatosis) + adenoma sebaceum (tuberous sclerosis)

Question 19

What investigations do you perform

Answer 19

• Full physical exam
• FBC, U+E, LFTs, glucose, Ca
• ECG, EEG

Question 20

How do you treat it

Answer 20

• 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)

Question 21

What are the side effects of epilepsy medication

Answer 21

• 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

Question 22

What must you tell women who have epilepsy about medication

Answer 22

• 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)