seizures and epilepsy Flashcards
what is the pathophysiology of epilepsy
epilepsy is a neurological disorder that affects the brain and causes recurrent seizures which occurs due to an abnormal sudden burst of electrical signals resulting in a variety of symptoms depending on the part of brain that is affected
normally, the brain communicates via electrical signals between neurons but in epilepsy, there is hypersensitivity and hypersynchronisation
what are the type of seizures
acute
- occurring as a result of an immediately recognisable stimulus (timely assoc of ~1w)
remote
- occurring >1w after a disorder that is known to increase the risk of developing epilepsy
unprovoked
- occurring in the absence of a potentially responsible clinical condition
what are the common etiology of epilepsy
structural
- hippocampal atrophy
- brain tumors
- vascular malformations
- glial scarring
neurodegenerative
- alzheimer’s
infectious
- bacterial meningitis
- encephalitis
- neurocysticerosis
metabolic
- inborn errors of metabolism
- mitochondrial disorders
genetic
- dravet syndrome
what are the common etiology of acute symptomatic seizures
metabolic
- hypoNa
- hypoCa
- hypoMg
- hypoglycemia
structural
- stroke
- traumatic brain injury
infection/ inflamm
- febrile illness
- CNS infection
toxic substances
- drugs
- alcohol intoxication and withdrawal
- BZP withdrawal
what are the phases of a seizure
prodromal
early-ictal “aura” (1-10mins)
ictal (2-3mins)
post-ictal (15mins-2hrs)
list seizure triggers
- hyperventilation
- photostimulation
- sensory stimuli
- sleep disturbances
- physical and emotional stress
- infection
- hormonal changes
- drugs that lower seizure threshold (theophylline, alcohol, high dose phenothiazines, carbapenems, tramadol, antidepressants esp bupropion)
what is the classification of seizures (ILAE)
mode of onset
- focal (begin in one hemisphere)
- generalized (begin in both hemisphere)
- secondary generalized (begin in one hemisphere then spread to the other)
impairment of consciousness (w/wo dyscognitive features)
- defined as loss of awareness to an external stimuli or inability to respond to external stimuli in a purposeful and appropriate manner
if focal onset with dyscognitive features, it is also called complex partial seizure
if focal onset without dyscognitive features, it is also called simple partial seizure
generalised seizures can be further classified into tonic, clonic, atonic, myoclonic, absence (petite mal), and tonic-clonic (grand mal)
what is the clinical presentation of a simple partial seizure
motor
- jerking
- speech arrest
sensory
- visual disturbances
- numbness and tingling
- rising epigastric sensation
autonomic
- sweating, salivation, pallor
- increased HR, BP
psychic
- hallucinations
- flashbacks
- affective sx like fear, anger, irritability, depression
differentiate the types of generalized seizures
tonic
- asymmetrical and irregular jerking
clonic
- sudden loss of consciousness, rigid posture (lasts 10-20secs)
myoclonic
- rapid brief contractions of bodily muscles, usually occurring on both sides concurrently
atonic
- classic drop attack
tonic-clonic (grand mal)
- sudden rigid posture f/b jerking
- decreased or ceased breathing during tonic phase
- cyanosis of nail bed, face and lips
- clonic phase ~1min
- noisy and laboured breathing, may bite tongue/ inside of mouth, incontinence
- pt likely feel lethargy, confused, sleepy, and HA after
- takes a few mins to hrs to recover fully
absence (petite-mal)
- basic lapse in awareness that ends abruptly, sometiems mistaken as persistent staring
- lasts a few seconds, no warning and no after effects
what are the classical characteristics of a seizure
- aura
- cyanosis
- loss of consciousness
- generalized stiffness of the limbs and body
- jerking of limbs
- tongue biting
- urinary incontinence
- post-ictal confusion
- muscle soreness
what are the type of investigations conducted for seizures
- scalp EEG (essential tool for diagnosis and classification)
- video EEG (to correspond what’s happening inside with outside)
- MRI (to identify presence of focal lesions)
- toxicology/ biochemical (to rule out electrolyte imbalances, CK elevated after GTC)
what are the goals of therapy for epilepsy
- absence of epileptic seizures
- absence of ASM s/e
- attainment of optimal QoL
what are the non-pharmacological management for epilepsy
- ketogenic diet (low carb high fat to induce a state of ketosis such that the body utilises fat for energy instead of using glucose)
- vagus nerve stimulation (VNS) (electrodes around left branch of vagus nerve connected to a programmable stimulator to provide cyclical stimulation)
- responsive neurostimulator system (RNS) (implantable device below scalp with implantable leads into brain to provide brief pulses of stimulation based on patient-specific pattern)
- surgery
what are the key points relating to seizure first aid for grand mal seizures
- ease the person to the floor
- lie the person onto their side to help with breathing
- clear surrounding area of sharp or hard objects to prevent injury
- place a soft and flat item under head
- remove eyeglasses and loosen ties
- time the seizure, call 995 if >5mins
DO NOT
- hold down or stop movements
- put objects into mouth
- give mouth to mouth
- offer water until fully alert
list common examples of first gen and second gen ASM
first gen
- CBZ
- PB
- VPA
- PHT
second gen
- LTG
- LEV
- TPM
- GBP
