tailieunhanh - Ebook Rapid neurology and neurosurgery: Part 2

(BQ) Part 2 book “Rapid neurology and neurosurgery” has contents: Multiple sclerosis, other movement disorders, radiculopathy and disc herniation, peripheral neuropathies’ syndromes, motor neurone disease, diseases of the muscle, coma and brainstem death, and other contents. | EPILEPSY 17 75 Epilepsy Epilepsy is a disorder characterised by recurrent ( 2) unprovoked seizures. A seizure is a paroxysmal event marked by abnormal discharge of cerebral neurons resulting in alteration or impairment of consciousness, sensation or motor function. DEFINITION Remember: A single seizure does not lead to a diagnosis of epilepsy. EPIDEMIOLOGY Up to 5% of population may experience a single seizure; incidence similar in males and females. Generalised seizure disorders usually commence in childhood or adolescence. Focal seizures can start at any age and can be related in younger patients to hippocampal sclerosis. In older patients it may be associated with cerebrovascular disease or a structural abnormality (tumour). Aetiologies for the first seizure in adults include (i) idiopathic, (ii) acute or subacute neurological insult or injury due to stroke, head injury and infection (meningitis, encephalitis, subdural empyema and cerebral abscess), (iv) structural CNS diseases, including tumours (primary or metastatic), arteriovenous malformations and congenital CNS abnormalities, (iv) systemic disorders, including electrolyte disturbance (hyponatraemia or hypernatraemia, hypoglycaemia, hypercalcaemia, uraemia and magnesium level disturbances), hepatic encephalopathy and porphyria, (vi) toxin, illicit drug or medication related, including alcohol withdrawal or excess and (vii) eclampsia. In paediatric population, the first seizure may be due to a febrile episode or the so-called febrile convulsion, be it idiopathic or ‘symptomatic or provoked’ due to electrolyte disturbance, meningitis and so on. AETIOLOGY CLASSIFICATION AND CHARACTERISTICS This relies primarily on the mode of onset. Two main categories are primary generalised versus partial (focal) seizures with or without subsequent secondary generalisation. Primary generalised seizures (40% of all seizures): Bilateral hemispheric symmetrical and synchronous discharge associated with loss of .