Epilepsy Flashcards
How to differentiate between seizure and epilepsy?
Seizure - transient occurence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain
Epilepsy - brain disorder characterised by an enduring predisposition to generate epileptic seizures
Describe the underlying pathophysiology processes in seizures and epilepsy
Hyperexcitability and hypersynchronisation of neurons within the cortex
Etiology of epilepsy
- Genetic - gene or chromosome
- Structural - eg traumatic brain injury, tumours
- Metabolic - mitochondrial disorders, glucose transporter 1 deficiency
- Immune - antibody mediated
- Infectious - bacterial meningitis, HIV, meningo-TB
- Unknown
Discuss common clinical presentation of focal seizures without dyscognitive features
(motor, sensory, autonomic, psychic)
- Motor symptoms (twitching, speech arrest)
- Sensory (feelings of numbness or tingling, visual disturbances - flashing lights, rising epigastric sensation)
- Sweating, salivation, or pallor
- BP,HR increase
- Flashbacks
- Visual, auditory, gustatory or olfactory hallucinations
- Fear, depression, anger, irritability
Describe laboratory tests and investigations that are used in the diagnosis and management of seizures
Scalp electroencephalography
MRI
Biochemical/toxicology
What toxic substances or drugs can provoke seizures?
Illicit drugs (cocaine, amphetamine)
Drugs (TCA, carbapenems, baclofen)
ETOH (withdrawal and intoxication)
Benzodiazepine withdrawal
Describe appropriate first aid for a person with seizures
Ease person to the floor
Turn patient gently onto one side
Clear the area around the person of anything hard or sharp
Put something soft under his or her head
Remove eyeglasses
Loosen ties or anything around teh neck that may make it hard to breathe
Time the seizure. Call 911 if the seizure lasts longer than 5 minutes.
Describe common psychosocial challenges in people with epilepsy
Social stigma (marriage, starting a family)
Employment (PwE may require more time away from work for medical follow up, higher medical costs borne by employer)
Prohibited from driving
Caregiver burden
Discuss the non-pharmacological options available for epilepsy?
Ketogenic diet
Vagus nerve stimulation
Responsive neurostimulator system
Surgery
How is epilepsy classified?
- Based on mode of onset (focal onset - seizures only begin in one hemisphere, generalised onset - seizures begin in both hemispheres)
- Impairment of consciousness - loss of awareness to external stimuli or inability to respond to external stimuli in a purposely and appropriate manner - described as “with or without dyscognitive features”
What are focal onset seizures without dyscognitive features called?
Simple partial seizures
What are focal onset seizures with dycognitive features called?
Complex partial seizures
How is epilepsy classified?
- Based on mode of onset (focal onset - seizures only begin in one hemisphere, generalised onset - seizures begin in both hemispheres)
- Impairment of consciousness - loss of awareness to external stimuli or inability to respond to external stimuli in a purposely and appropriate manner - described as “with or without dyscognitive features”
- Other features of the seizure
Discuss common clinical presentation of focal seizures with dyscognitive features
Motor, sensory, autonomic, psychic symptoms (as with non-dyscognitive seizures)
Impaired consciousness
Automatisms - lip smacking, chewing or picking at their clothing unpurposefully
Discuss common clinical presentation of generalised onset tonic-clonic seizures
- stiffening of the limbs, followed by jerking of limbs and face
- cyanosis of nail beds, lips and face
- incontinence may occur, along with biting of the tongue or inside of the mouth; breathing may be noisy and appear to be laboured
- following the seizure, patient may have a headache and appear lethargic, confused or sleepy
- full recovery takes several minutes to hours
What is diagnosis based on?
History taking (description of onset, duration and characteristics of seizure) - positive identification of classical characteristics
Neurologic examination
Concomitant medical conditions
What are some classical characteristics that help to confirm the diagnosis of epilepsy
Aura Cyanosis Loss of consciousness Motor manifestations Generalised stiffness of limbs and body Jerking of limbs Tongue biting Urinary incontinence Post-ictal confusion Muscle soreness
What are some differential diagnoses of epilepsy that must be ruled out?
Syncope
Transient ischemic attack
Migraine
Psychogenic nonepileptic seizures
How can scalp electroencephalography help in the diagnosis and classification of seizures?
if diagnosis of seizures or epilepsy is considered, epileptiform discharges on EEG confirm diagnosis
A normal EEG does not exclude possibility of epilepsy
What are limitations of scalp EEGs?
Not all epileptic patients have an abnormal EEG
EEG can be abnormal in normal persons (false positives)
When would an MRI be ordered?
For adult patients who presents with first seizure, patients with focal neurologic deficits, suggestion of focal onset seizure
Identify focal lesions.
When would biochemical/toxicology investigations be useful?
To rule out electrolyte abnormalities
CK - raised after GTC
Risk of second seizure is higher in the presence of
- Epileptiform abnormalities on EEG
- prior brain insult (eg stroke, brain trauma)
- structural abnormality in brain imaging
- nocturnal seizure
Do we start all patients on AEM after first seizure?
No, only if they have risk factors that put them at higher risk of second seizure
Treatment goals for epilepsy
- Absence of epileptic seizures
- absence of AED-related side effects
- attainment of optimal quality of life
How should AED treatment strategy be individualised?
According to seizure type, co-medication and comorbidity
What considerations if patient has history of migraine or depression/anxiety?
Migraine - topiramate
Depression/anxiety - use levitiracetam with caution
What should you choose in women with child bearing potential?
Avoid valproate, consider levetiracetam/lamortrigine
Do we start all patients on AEM after first seizure?
No, only if they have risk factors that put them at higher risk of second seizure
Risk of recurrent seizures after 2 unprovoked seizures at 4 years ~70% - start treatment
Algorithm for initiation of treatment
Start with low doses of 1st line AED appropriate for the particular seizure type
If seizures continue but no side effects occur, gradually increase dose of AED
If seizures continue despite maximum tolerated dose of 1st line AED:
-diagnosis should be reviewed
-ensure that patient has received the appropriate drug for seizure type/epileptic syndrome
-check adherence
When should we consider substitution?
If the first AED produces an adverse drug reaction or is not tolerated at low doses or does not improve seizures
When should we consider combination therapy?
If patient tolerates the first or second AED but with a suboptimal response
Factors to consider when combining AEDs
Patients previous clinical response to each drug alone
Drugs mechanism of action
Drugs tolerability profile
Drugs PK profile
What is drug resistant epilepsy?
Failure of adequate trials of two tolerated, appropriately chosen and used antiepileptic drug schedules
In which population does ketogenic have evidence in?
Young children
Seizure triggers
Hyperventilation Photostimulation Physical and emotional stress Sleep deprivation Electrolytes imbalance Sensory stimuli Infection Hormonal changes (time of menses, puberty or pregnancy) Drugs (eg theophylline, alcohol, high dose phenothiazines, antidepressants esp bupropion, tramadol, carbapenems)
What to log in seizure diary?
Seizure frequency and types How long they last Changes in AEDs AED side effects Seizure triggers
If status epilepticus, what kind of drugs do we avoid?
Avoid drugs that require slow titration - lamotrigine and topiramate
We want to give a drug that can be given fast and titrate dose fast enough
