EPILEPSY AND SEIZURES Flashcards
What is epilepsy?
A condition where there is a propensity to have recurrent and unprovoked seizures.
What is an epileptic seizure?
A paroxysmal, synchronous and excessive discharge of neurons in the cerebral cortex manisfesting as a stereotyped disturbance of consciousness, behaviour, emotion, motor function or sensation. It is usually sudden in onset, lasts seconds to minutes and usually ceases spontaneously.
What is status epilecticus?
A state of continued or recurrent seizures, with failure to regain consciousness between seizures over 30 minutes. It is a medical emergency and has a mortality rate of 50%.
What is prodrome with regard to epilepsy?
Changes in mood or behaviour which come before a seizure. They may precede the attack by several hours.
What is aura with regard to epilepsy?
Subjective sensation or phenomenon which may precede and mark the onset of the seizure. It can localise the seizure within the brain if being monitored at the time.
What is the ictus with regard to epilepsy?
The attack or seizure itself.
What is the postictal period?
The time after the ictus (seizure) during which the patient may be drowsy, confused and disorientated.
In terms of epidemiology of epilepsy, when are the two age peaks in the incidence of grand mal seizures?
In children and adolescents, where there is often no cause found.
Then in patients in their fifties and sixties, where the disease is probably due to ischaemic changes as a result of hypertension.
What are the known causes and risk factors for epilepsy or epileptic seizures?
Alcohol abuse Vascular disease (such as stroke) Cerebral tumours Head injury Degenerative diseases Family history (especially in absence seizures) Antenatal factors (such as rubella infections, maternal drug abuse and irradiation) Perinatal factors (such as anoxia) Drugs Photosensitivity Sleep deprivation
Which medications are known to either cause epilepsy or increase the likelihood of experiencing a seizure?
Phenothiazines Monoamine oxidase inhibitors Tricyclic antidepressants Amphetamines Lidocaine and lignocaine Nalidixic acid Withdrawal from benzodiazepines
Which toxic agents are known to either cause epilepsy or increase the likelihood of experiencing seizures?
Alcohol
Carbon monoxide
Lead
Mercury
Other than epilepsy, what might cause seizures in a patient?
Metabolic causes: Hyponatraemia Hypernatraemia Hypocalcaemia Hypomagnesaemia Hypoglycaemia
Infectious and inflammatory causes: Encephalitis Meningitis Cerebral abscess Neurosyphilis
What is a partial seizure?
A seizure that arises from a localised area of cerebral cortex.
Where do most partial seizures arise from?
The temporal lobes
Where do partial seizure that do not arise from the temporal lobes most often arise from?
The frontal lobes
What are the features of the aura associated with a temporal lobe seizure?
Epigastric sensation
Olfactory or gustatory hallucinations
Autonomic symptoms (eg change in pulse or BP, facial flushing)
Affective symptoms (eg fear, depersonalization)
Deja vu
What are the clinical features of a seizure that originates in either temporal lobe?
Motor arrest
Absence
Automatism (eg lip smacking, chewing, fidgeting, walking)
Automatic speech
Contralateral dystonia
The seizure is slow to evolve (1-2 minutes)
What are the postictal features of a temporal lobe seizure?
Confusion Postictal dysphasia (if dominant hemisphere is affected)
What are the features of the aura associated with frontal lobe seizures?
Abrupt onset
Forced thinking
Ideational or emotional manisfestations
What are the clinical features of a seizure that originates in either frontal lobe?
Vocalisation / shrill cry Violent or bizarre automatism Cycling movements of the legs Ictal posturing Tonic spasms Head and eyes move away from affected side 'Fencing' posture - Extension and abduction of one arm with rotation of head to same side, whilst flexing other arm Sexual automatisms with pelvic thrusting Obscene gestures Genital manipulation Usually very brief (30 seconds)
What are the postictal features of a frontal lobe seizure?
Brief confusion
Rapid recovery
What are clinical features of a seizure that originates in either parietal lobe?
Somatosensory symptoms (eg pain, tingling, numbness, prickling, vertigo, distortions of space) Automatisms may occur
What are the clinical features of a seizure that originates in either occipital lobe?
Visual hallucinations (eg seeing flashes of light or geometrical figures; rarely complex hallucinations of figures)
Eyelids flutter
Automatisms
What is a simple partial seizure?
Seizures in which consciousness is not impaired, and in which the discharge remains localised. They are brief and involve focal symptoms.
What is a complex partial seizure?
Similar features to simple partial seizures but by definition consciousness is impaired. Patient often remains standing despite losing consciousness. They typically last 2-3 minutes but can continue for several hours as part of non-convulsive status epilepticus.
What is a secondary generalised seizure?
Partial seizure in which epileptic discharge spreads to both cerebral hemispheres resulting in a generalised seizure. The spread may be so rapid that no localised features are detected.
What is a generalised seizure?
Seizure involving both hemispheres at the onset of the seizure. Patients lose consciousness at onset, so there is often no warning.
What is a generalised tonic-clonic seizure?
A generalised seizure where there are two distinct phases once the patient has lost consciousness. The tonic phase and the clonic phase.
