OSCE learning points

Learning points 

- This is a case of 65 year old female with Generalised Tonic Clinic seizures 

Osce questions

1) Reasons for seizures in old age people 

* Neurodegenerative disorders

* Cerebrovascular disorders 

* Dementia 

* Metabolic disorders 

    - Hypoglycemia 

    - electrolyte imbalances

    - uraemia

* Physical or mental exhaustion 

2) pathophysiology of seizures 

* To function normally brain must maintain a continual balance between excitation and inhibition , remaining responsive to environment while avoiding continued unrestrained  spontaneous activity

* GABA inhibitory neurotransmitter acts on ion channels , enhances inflow of chloride and reduces formation of action potential 

* Excitatory amino acids allow  influx of sodium and calcium and producing opposite effects 

* It is likely that many seizures results from an imbalance between this excitation and inhibition.

 ( From Davidson medicine text book )

3) Drug of choice for different seizure disorders 

4) phenytoin and levetiracetam 

Phenytoin  - 

- It delays recovery of sodium ion channels from inactivated state , thereby reduces neuronal activity 

- It exhibits dose dependent elimination , so therapeutic monitoring of phenytoin is essential for adjustment of dosage 

- It has dose dependent toxicity 

- Adverse effects : Hypersensitivity reactions, hypertrophy and hyperplasia of gum , hyperglycemia , osteomalacia

Levetiracetam

- not exactly known , binds to synaptic vesicle protein and modulates release of neurotransmitters like GABA

- Adverse effects : sedation , dizziness , fatigue 

 

— points to be noted in a case of epilepsy presenting in old age

* The late onset epilepsy is very common  and incidence in those over 60 is rising

* The antiepileptic drug regimen should be kept as simple as possible and care should be taken to avoid drug interactions being prescribed

* Withdrawal of antiepileptic should be attempted only where benefits exceed risk of harm from seizures.