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Flashcards in Epilepsy Deck (26)
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1
Q

What is epilepsy

A

A tendency to recurrent, usually spontaneous, epileptic siezures

2
Q

What is an epileptic seizure

A

a sudden, synchronous discharge of cerebral neurone causing symptoms or signs that are apparent either to the patient or an observer

3
Q

What are the two main variations of seizures?

A

Partial/focal= caused by electrical discharge restriced to a limited part of the cortex of one cerebral hemisphere.
Generalised- simultaneous involvement of both hemispheres, always associated with loss of consciousness or awareness

4
Q

How can partial/focal seizures be further subdivided?

A
Simple= without loss of awareness e.g. one limb jerking (Jacksonian seizure)
Complex= loss of awareness e.g. temporal lobe seizure
5
Q

Why do some people get an ‘aura’ before a generalized seizure?

A

They have a partial seizure which spreads due to failure of inhibitory mechanisms and then go on to have a secondnary generalized seizure.
The patient may remember the partial seizure but not the generalized one, resulting in an ‘aura’

6
Q

How can generalized seizures be subdivided?

A
  • Typical absence seizures (petit mal)
  • Generalised tonic-clonic seizures (GTCS, grand mal)
  • Myoclonic, tonic and atonic seizures
7
Q

Describe the events of an absence seizure.

A

Usually begins in childhood.
Loss of awareness and a vacant expression for less than 10 seconds before returning to normal with no recollection of the seizure.
No motor manifestations except slight fluttering of the eyelids.
Never due to acquired lesiosn eg tumours.
Children with this condition may go on to have grand mal seizures.
These seizures are sometimes confused as temporal lobs seizures.

8
Q

What are the phases of a grand mal seizure

A

Prodrome- often no warning or can have aura
Tonic-clonic phase- initial tonic stiffening followed by clonic phase with synchronous jerking of limbs, reducing in frequency over about 2 mins until the convulsions stop.Eyes may remain open, may bite tongue, may be incontinent of urine/faeces
Post-ictal pahse- a period of flaccid unresponsiveness followed by gradual return of awareness with confusion and drowsiness- usually lasts around 15 mins to an hour. Head ache common.

9
Q

What are myoclonic, tonic and atonic seizures

A

Myoclonic- momentary brief contractions of a muscle or muscle groups eg hand twitching. Common in primary generalized epilepsies.
Tonic- just have tonic phase and no clonic phase
Atonic- a sudden collapse with loss of muscle tone and consiousness

10
Q

Describe the mechanism of a simple partial seizure?

A

An example would be a focal MOTOR seizure know as a Jacksonian seizure which originates in the motor cortex.

11
Q

What are the features of a complex partial seizure

A
  • usually arise in temporal or frontal lobe
  • preceding aura can include nausea and a variety of psychihc phenomena or hallucinations such as deja vu, jamais vu, olfactory hallucinations, visuall halluncination or misperceptions (micropsia or macropsia), fer
  • follow a period of complete or partial loss of awareness for about 1-2 mins
  • this stage can be accompanied by speech arrest or automatisms such as lip smackin, or even more complex motor behabrous like walking in a circle or undressing
  • attacks can be followed by a post ictal phase of confusion
  • can go on to have secondary generalized seizure
12
Q

When does epilepsy tend to present

A

Children and teenagers- genetic, perinatal, congenital
Young adults- trauma, drugs, alchohol
Older age( over 60)- CVD or neoplasm

13
Q

When does generalized epilepsy usually present

A

genetic predisposition

14
Q

What abnormalities are present on EEG in generalized epilepsy

A

spike-wave abdnormality

15
Q

What are the main types of epilepsy syndromes

A

Primary generalized epilepsies (Childhood, absence epilepsy, Juvenile myoclonic epilepsy, monogenic disorders)
Symptomatic and localization relates epilsepsy (LRE)

16
Q

When do PGE usually present

A

childhood

17
Q

What is childhood absence epilepsy

A

absence seizures in childhood- typically resolves spontaneously at 18yrs

18
Q

What is juvenile myoclonic epilepsy

A

Myoclonic jerks start in teenage years, followed by GTCS, one third also have absences.
Seizures often occur in the morning

19
Q

What can trigger a seizure in JME

A

sleep deprivation, alchohol, strobe lights - risk factors

20
Q

What is the treatment of PGE usually

A

sodium valproate

21
Q

What is the downside of sodium valproate

A

tetatrogenic

can uses lamotrigine as alternative

22
Q

What is focal onset epilepsy (LRE)

A

epilepsy due to an underlying structural cause

onset can occur at any age

23
Q

How is LRE treated

A

Carbamazepine or lamotrigine first line

24
Q

What is a frequent cause of LRE

A

hippocampal sclerosis

childhood febrile convulsions is the main risk factor

25
Q

How common is ‘drug resistant epilepsy’

A

about one third of pts

26
Q

What other things can cause an increased risk of epilepsy

A
trauma
cerebral palsy
brain surgery
tumours
vascular disorders- CVD, arteriovenous malformations, cavernous haemangiomas
Alzheimer's
encephalitis
TB meningitis
alchohol and drugs
metabolic problems- hypocalcaemia, hypoglycaemia, hyponatraemia, acute hypoxia, uraemia, porphryia