My Clinical Notes

• Caused by abnormal electrical discharge of the brain
• Major form is a generalised tonic clonic seizure which involves sudden unconsciousness, violent movement and is often followed by a coma. Called a grand mal
• Do not use the term epilepsy if patient has only had one attack

 

Aetiology

• 62% idiopathic
• 15% CVD
• 6% tumour
• 6% alcohol
• 2% trauma
• 6% other

 

Common forms of epilepsy

• Generally two types, primary generalised and focal
• In primary generalised epilepsy, electrical discharges arise from deep midline structures and spread rapidly and simultaneously to all parts of the cortex
• In focal epilepsy, electrical discharge starts in one area of the cortex and spreads to other regions
• Focal seizures can start in one area and spread to all the cortex – called secondary generalised tonic-clonic seizure

 

Primary generalised tonic-clonic seizures

 

• 3 types;
  • Primary generalised tonic clonic seizures
  • Absence seizures
  • Myoclonic seizures
• Patients may have a mixture of types

 

Primary generalised tonic-clonic seizures

• No warning or aura
• Tonic phase
• Patient loses consciousness and muscles stiffen.
• Makes a large groan as are is forced out of your lungs through tightened vocal cord
• Stops breathing and becomes cyanosed
• Usually only lasts secs
• Clonic phase
• Random, disorganised jerks involving any and all muscles
• May result in tongue biting
• Urinary incontinence
• Noisy, uncoordinated breathing
• Frothing at the mouth
• Typically lasts a couple of mins
• Coma
• Breathing becomes regular
• Period of time relates to the duration of the tonic-clonic phase
• State of confusion, restlessness, headache and drowsiness before recovery
• For several days afterwards patient may have a sore tongue and aching limbs

 

Absence seizures

• Less dramatic
• Sudden onset, lasts about 10 secs, sudden recovery
• Patient suddenly stops what they are doing, stares off into space
• If it occurs when walking the person stops
• May occur several times a day
• Usually commence in childhood

 

Myoclonic seizures

• Abrupt muscle jerks, typically causing the upper arms to flex and the patient to drop whatever they are holding
• Jerks may occur singly or in a brief run
• Consciousness is usually not affected
• Often happens in first hour of day especially if patient has drank alcohol the pervious evening
• Always occur in association with other generalised seizure types and can aid diagnosis of primary generalised epilepsy – often in a specific syndrome juvenile myoclonic epilepsy

 

Focal epilepsy

 

• When the site of abnormal electrical discharge is situated in one cerebral cortex
• Often accompanied by an aura
• Phenomenon depends on area of cortex affected
• If motor cortex is affected then there are disorganised convulsive movement on the other side of the body
• Common forms of focal epilepsy
  • Focal motor seizure
  • Focal sensory seizure
    • Strong, unpleasant, painful, warm, tingling or electrical sensations in one part of the face, body or limbs
  • Frontal lobe epilepsy
    • Strong convulsive turning of the eyes, head and neck to the contralateral side or comlex posturing with one arm flexed and the other arm extended
  • Temporal lobe epilepsy
    • Most common form
    • May result in subjective experience;
      • Déjà vu
      • Memories rushing through the mind
      • Loss of memory during an attack
      • Hallucinations of smell/taste
      • Sensation rising up the body
    • Or objective observations;
    • Diminished contact with the environment
    • Confusion
    • Repetitive utterances
    • Repetitive movement
    • Lip smacking and sniffing movements

 

• Todd’s paresis, post epileptic unilateral weakness. Indicates a tonic clonic seizure is due to a localised cortical cause

 

 

Epilepsy syndromes

 

Juvenile myoclonic epilepsy

• Commonist form of tonic clonic seizures starting in teenagers
• Form of primary generalised epilepsy
• Often follow a late night or excessive alcohol

 

Lennox-Gastaunt syndrome

• Where a range of metabolic and genetic disorders can give rise to severe learning disabilities and epilepsy
• In addition to the seizure types described patients can also get atonic seizures in which there is an abrupt loss of consciousness, muscle power and tone

 

DDx

 

• Tonic-clonic seizures
  • Cardiovascular disorders
  • Faints/vasovagal syncope
  • Arthymias
  • Postural hypotension
  • Hypoglycaemia
• Focal sensory seizures may be difficult to differentiate from transient cerebral ischaemia
• Frontal lobe seizures can be confused with dystocia or can be thought to have a behavioural basis
• Temporal lobe seizures have to be distinguished from anxiety or panic attacks

 

Establishing the cause of epilepsy

 

• Focal epilepsy suggests intracranial pathology;
  • Following birth trauma
  • Following head trauma in adult life
  • Following meningitis, encephalitis or a cerebral abcess
  • Due to cerebral infarction, haemorrhage or SAH
  • Neurosurgical trauma
• May be caused by biochemical insults;
  • Alcohol or drug withdrawl
  • Hepatic, uraemic or hypoglycaemic comas
  • Whilst on major tranquilising or antidepressant drugs
• May be due to SOL – tumour

 

EEG

• 10% of normal population will have an abnormal EEG
• 30% of patients with epilepsy will have a normal EEG
• Can do a stress EEG where the patient is sleep deprived
• Can do long term EEG monitoring - ambulatory

 

• Image brain with MR to find cause of focalised epilepsy
  • Small benign tumours
  • Small strokes
  • Childhood defects

 

Management

 

• On the spot
  • Protect airway
  • Prevent self injury
  • Await recovery

 

Explanation

• Start by asking patient what epilepsy means to them
• Should state that children can out grow epilepsy and it can be well treated with medication in the majority of cases

 

Drug therapy

• First line drugs for primary generalised epilepsy are;
  • Sodium valproate
  • Lamotrigine
• Second line drugs;
  • Phenytoin
  • Topiramate
  • Levetiracetam
  • Gabapentin
  • Phenobarbitone

 

Â	Idiosyncratic side effects	Dose-dependant side-effects	Approx teratogenic risk
Valproate	Weight gain, transient hair loss, liver dysfunction	Tremor, sedation	>10%
Carbamazepine	Rash, hyponatraemia	Ataxia, sedation	5%
Lamotrigine	Rash, flu-like symptoms	Sedations	2-3%

 

Prognosis

 

• 65% remission at 10 years
• More likely with rapid control

 

History

 

• Ask if there were any seizures in childhood
• Any warning of ‘funny turn’?
• Any palpitations? Chest pain? Breathlessness?
• Posture?
• Alcohol?

 

Explanation

 

• ‘Everyone has the capacity to have fits, its just that some people need different amounts of pushing’
• ‘Different wiring’
• Point out the dangers of cooking on own, looking after children, crossing the road
• Patient is more at risk of sudden unexpected death due to autonomic dysfunction of the heart

 

Advice

 

• Driving – DVLA website
• Alcohol – don’t binge
• Work – risk management
• Tell colleagues and friends
• Make sure pregnancy is planned. Patient is more likely to fit during pregnancy

This entry was posted on Sunday, November 4th, 2007 at 5:26 pm and is filed under Neurology. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.