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Flashcards in Epilepsy Deck (27)
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1
Q

possible triggering factors? nondrug

A
 Sleep deprivation 
 Sensory overstimulation 
 Hyperventilation (e.g., breathlessness, asthma attacks)  Allergies 
 Emotional stress 
 Hormonal changes (e.g., during puberty, pregnancy) 
 Infections & illnesses 
 Head trauma 
 Congenital/perinatal complications
2
Q

possible triggering factors? drug

A

Certain drugs (e.g., anaesthetics, antibiotics, antidepressants, NSAIDs, opioid analgesics) may lower the threshold for induction of seizures

Withdrawal of drugs (e.g., alcohol, benzodiazepines, drugs of abuse)

Excessive intake of AED –> supratherapeutic AED-induced ADRs

Missed AED medication –> subtherapeutic serum AED concentration

? Pertussis vaccine (apparent increased risk of febrile seizures)

3
Q

Basic physiology of a seizure episode can be traced to instability in a single neuronal cell membrane or group of cells around it

Seizure activity is characterised by synchronised paroxysmal discharges occurring in a large population of neurons within the cortex

A

Basic physiology of a seizure episode can be traced to instability in a single neuronal cell membrane or group of cells around it

Seizure activity is characterised by synchronised paroxysmal discharges occurring in a large population of neurons within the cortex

4
Q

Excess excitability spreads in Local region

A

 Partial seizure

5
Q

Excess excitability spreads in Widespread region

A

Generalised seizure

6
Q

Biochemical mediators of epileptic seizures:

A

 Abnormal K+ conductance
 Defects in voltage-sensitive ion channels
 Deficiencies in membrane ion-linked ATPases (usually  neuronal membrane instability)
 Excessive release of excitatory neurotransmitters (e.g., acetylcholine, histamine, cytokines, etc)
 Insufficient release of inhibitory neurotransmitters (e.g., GABA, dopamine)
 Abnormalities in intra- & extracellular substances (e.g., Na+, K+, O2, glucose, etc) that may affect normal neuronal activity
 Reductions in neuronal threshold to electrical/mechanical stimuli
 Excessive tendency for propagation of seizure discharge from focus

7
Q

Accurate history is best provided is a person who has observed the patient’s repeated events, not necessarily from the patient himself

A

Accurate history is best provided is a person who has observed the patient’s repeated events, not necessarily from the patient himself

8
Q

Patient is useful in describing details of auras, preservation of consciousness, and post-ictal state

A

Patient is useful in describing details of auras, preservation of consciousness, and post-ictal state

9
Q

Positive identification of the classical characteristics

A

 Aura
 Cyanosis
 Unconsciousness

 Motor manifestations

  • Generalised stiffness of limbs and body
  • Jerking of limbs
  • Tongue biting
  • Urinary incontinence
  • Post-ictal confusion
  • Muscle soreness
  • Headaches
10
Q

Diagnostic procedures

A

Electroencephalogram (EEG)
- Critical for identifying seizure type & for elderly patients
- False positive results are possible where:
 Loss of consciousness is due to syncope
 Results do not correlate with other presenting features

Repeated assessment may be useful if first EEG was not conclusive

Magnetic resonance imaging

  • Currently the imaging method of choice
  • Useful for detecting brain lesions/anatomic defects
  • Also recommended for patients refractory to 1st-line antiepileptics

Computed tomography
- Used in urgent cases or if MRI is contraindicated

Video diagnosis
- Increasingly being used for diagnosis in patients with suspected psychogenic non-epileptic seizures (PNES)

Biochemical/toxicology
- Helps to rule out electrolyte abnormalities, renal/hepatic diseases and exogenous toxicity

Serum prolactin
- May help differentiate between PNES in adults and adolescents

Lumbar puncture
- Helps to rule out presence of meningitis or encephalitis in cases where patient exhibits signs of sepsis

11
Q

Misdiagnosis

A
Diagnosis may be complicated by resemblance of similar symptoms in other clinical conditions: 
 Loss of consciousness can be due to 
- Transient cardiac arrhythmia 
- Transient ischaemic attacks 
- Hypoglycaemia 
- Panic attacks

 Abnormal kinetic movement

  • Movement disorders in sleep and wake
  • Tremors / paroxysmal choreoathetosis / dystonia
  • Drop attacks or cataplexy
 Provoked seizure 
- Refers to seizures with an obvious and immediate cause 
- Most commonly associated with: 
 Strokes 
 Trauma 
 Infections 
 Effects of alcohol (intoxication and withdrawal) 
 Sleep deprivation
12
Q

Determining the type of seizure that has occurred is essential for:

A

Determining the type of seizure that has occurred is essential for:
 Focusing the diagnosis on particular aetiologies
 Selecting the appropriate therapy
 Providing potentially vital information on prognosis

13
Q

Partial seizures

A

Simple partial seizures
Complex partial seizures
Partial seizures with secondary generalisations

14
Q

Generalised Seizures

A
Absence seizures
Tonic-clonic seizures 
Tonic seizures 
Clonic seizures 
Myoclonic seizures 
Atonic seizures
15
Q

Unclassified Seizures

A

Neonatal seizures

Infantile spasms

16
Q

ILAE 2017 Classification of Seizure Types

A
ILAE 2017 Classification of Seizure Types 
Based on 3 key features: 
- Where seizures begin in the brain 
- Level of awareness during the seizure 
- Other features of the seizure
17
Q

The clinical characteristics of a seizure will depend on:

A

The clinical characteristics of a seizure will depend on:
 Site of the focus
 Degree of ‘irritability’ of the areas of the brain surrounding the focus
 Intensity of the impulse

18
Q

the desired outcomes in the treatment of epilepsy are:

A

The desired outcomes in the treatment of epilepsy are:  Absence of epileptic seizures
 Absence of anti-epileptic drug (AED)-related side effects
 Attainment of optimal quality-of-life

19
Q

Treatment

General approach involves:

A

General approach involves:
 Identification of goals of therapy
 Must be patient-specific
 Goals may change with time

New-onset epilepsy

  • Absence of seizures
  • Absence of drug-related side effects
  • Excellent quality of life

Chronic epilepsy

  • Minimisation of incidence of seizures
  • Alleviation of drug-related side effects
  • Decent quality of life
20
Q

Good and proper patient assessment
 Accurate diagnosis of seizure type determines initial choice of therapy

 Early treatment
- DECREASE in risk of seizure recurrence by 50%
 no effect on long-term prognosis

A

Good and proper patient assessment
 Accurate diagnosis of seizure type determines initial choice of therapy

 Early treatment
- DECREASE in risk of seizure recurrence by 50%
 no effect on long-term prognosis

21
Q

what Patient-related factors also need to be considered when deciding on the tx

A
 Age 
 Comorbid conditions 
 Concomitant medications 
 Risk of non-compliance to treatment or medications 
 Family support 
 Occupational/financial status
22
Q

 Development of a care plan

Compare advantages and disadvantages of various anti-epileptic drugs

Monotherapy is ideal but combination therapy must be considered if monotherapy is inadequate

 Follow-up evaluation
Allows for re-assessment, updating and if necessary, revision of care plan

A

 Development of a care plan

Compare advantages and disadvantages of various anti-epileptic drugs

Monotherapy is ideal but combination therapy must be considered if monotherapy is inadequate

 Follow-up evaluation
Allows for re-assessment, updating and if necessary,

23
Q

Non-Drug Treatment

A

Surgery
Dietary modification
compementary / alternative medicine
Vagus nerve stimulation

24
Q

Surgery

A

 May be useful in up to 90% of patients with selected forms of epilepsy to achieve improvement of symptoms or seizure free status
 Usually advocated as early therapy for specific epileptic syndromes e.g.,
- Temporal lobe epilepsy with vs without mesial temporal sclerosis (70% vs 50%)
- Frontal lobe epilepsy with vs without identifiable lesion on MRI scan (50% vs 25%)

 Also considered as a last option (vs continued drug therapy) for certain refractory cases

25
Q

Dietary modification

A

 Ketogenic diet may be used for patients who cannot tolerate or have not responded well to AED treatment

 Comprises low carbohydrate, high fat in diet

  • induction of ketosis and production of decanoic acid
  • decanoic acid associated with reduction in incidence of certain types of seizures or epileptic syndromes

 Supplemental vitamins/minerals (e.g., vitamin B, magnesium) may also sometimes be prescribed
- More useful in replacing any vitamins/minerals lost from the body due to the effects of AEDs (cf. seizure prophylaxis)

 Evidence is controversial

  • More commonly prescribed in children
  • Usually recommended if >2 different treatments have failed
26
Q

Complementary/alternative medicine

A

 Should not be advised to the epileptic patient
 No evidence that acupuncture, chiropractic, herbal medicine, homeopathy, ostopathy, or yoga improve seizure control
 Drug interactions may give rise to changes in serum AED concentrations
- St John’s wort phenytoin / carbamazepine
 ? Evening primrose oil phenytoin / carbamazepine

 Some aromatherapy oils may produce an alerting effect on the brain –> increased risk of seizure
- Hyssop, rosemary, sweet fennel, sage, wormwood

27
Q

Vagus nerve stimulation

A

 Indicated only for intractable partial seizures

 Electrodes attached around left branch of vagus nerve as well as connected to programmable stimulator  Stimulator delivers cyclical stimulation
 During a seizure, ‘on demand’ stimulation can be achieved by placing a magnet next to subcutaneously-implanted stimulator