Tag: seizure

  • Aetiological Classification of Seizures

    Causes of seizures stratified by age-group:

    Approximately 30% of those with a seizure will have a positive family history.

    Infant (0-2 years)

    • Perinatal hypoxia and ischaemia
    • Intracranial birth injury
    • Acute infection
    • Metabolic disturbances
      • hypoglycaemia
      • hypocalcaemia
      • hypomagnesaemia
      • pyridoxine deficiency
      • hyponatremia
    • congenital malformations
    • genetic disorders

    Child (2-12 years)

    1. idiopathic
    2. acute infection – meningitis / encephalitis
    3. trauma
    4. febrile convulsions – < 5 minutes duration, no abnormality → good prognosis

    Adolescent (12-18 years)

    1. idiopathic
    2. trauma
      1. 40-50% seizure rate if post-traumatic amnesia for 24 hours
      2. depressed skull fracture
      3. cerebral contusion
    3. drug, alcohol withdrawal
    4. arterio-venous malformations

    Young Adult (18-35 years)

    1. trauma
    2.  alcoholism – drugs, alcohol and drug withdrawal
    3. brain tumour

    Older adult (> 35 years)

    1. brain tumour
    2. cerebrovascular disease – most common > 50 years old
    3. metabolic disorders – any age
      1. uraemia
      2. hepatic failure
      3. electrolyte abnormality
      4. hypoglycaemia
      5. acute hypoxia
      6. hypo- or hyper- calcemia, natremia, and glycemia
        1. myoclonic / tonic-clonic
    4. alcoholism
    5. infection – encephalitis / chronic meningitis / abscess
    6. neurosurgery – any surgery to cerebral hemispheres is complicated by seizures in 10%

    Investigations

    • FBC + ESR – WCC (encephalitis, meningitis, abscess)
    • EUC (C/M/P)– Na+, Ca++, uraemia
    • VDRL – neurosyphilis
    • lumbar puncture
    • CT / MRI
    • EEG + video recordings (telemetry)
    • Drug levels – e.g. phenytoin, urinary drug screen, blood ethanol level