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Epilepsy and seizure. Specialty Clerkship Student Seminar Group B2 Chan Ying Ting, Purdy Siu Lok Man, Joanne Lee Wai Yip, Jacky. OUTLINE. Prevalence and genetics Etiology Terminology Classification of seizure Epilepsy syndromes Case studies General management of seizures.
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Epilepsy and seizure Specialty Clerkship Student Seminar Group B2 Chan Ying Ting, Purdy Siu Lok Man, Joanne Lee Wai Yip, Jacky
OUTLINE • Prevalence and genetics • Etiology • Terminology • Classification of seizure • Epilepsy syndromes • Case studies • General management of seizures
PREVALENCE IN CHILDHOOD • 75% with onset before age of 20 years • Prevalence: • 4.1/1000 in children up to 11 years old(National Child Development study,1983); • 4.71/1000 in children up to 19 years old(Oklahoma study,1989) • Incidence: 49/100,000 population
Offspring risk for epilepsy to age 20 • General population:1% • Mother with epilepsy: 6% • Father with epilepsy: 2.4% • Sibling risk for epilepsy to age 20 • General population: 1% • Proband with epilepsy: 3% • Proband with 1 parent affected: 8%
ETIOLOGY Febrile • Febrile convulsion • Convulsion with fever • Intracranial infection Non-febrile • Metabolic disturbance • Trauma • Poisons / toxins / recreational drugs • Cerebral dysgenesis / malformation • Cerebral damage / cerebral tumor • Neurocutaneous syndromes
TERMINOLOGY • Seizure—transient involuntary alteration of consciousness, behavior, motor activity, sensation and/or autonomic function due to abnormal discharge of cortical neurons; an episodic event, may have provoking factors, e.g. anoxia, alcohol, drugs • Convulsion– seizure with prominent alteration of motor activity • Epilepsy—a disorder with recurrent seizures(2 or more), unprovoked by a specific event such as fever, trauma, infection, or chemical change, stereotypic • Aura—a component of seizure which occurs before consciousness is lost and for which memory is retained afterwards; it localizes attack to the point of origin in the CNS • Automatisms--coordinated adapted involuntary motor activity occurring during the state of clouding of consciousness; usually followed by amnesia of the event
Tonic seizure: excessive motor outflow, giving rise to a tetanic state of the muscles involved. • Atonic seizure: muscle tone drops to a very low values resulting in a sudden fall of the body • Clonic seizure: a tonic seizure with periodic interruptions • Tonic-clonic seizure: starts as a generalized tonic seizure and then interrupted during clonic phase and ending in complete relaxation. • Myoclonic seizure: short involuntary contraction of one or more muscles (local or generalized)
CLASSIFICATION OF SEIZURE Seizures Partial Generalized Absence seizures Myoclonic seizures Clonic seizures Tonic seizures Tonic-clonic seizures Atonic seizures Simple Complex Partial with secondary generalization * ILAE classification of seizures 1981
Partial vs Generalized • Partial: if only one hemisphere is involved • Simple—no impairment of consciousness, features depend on the region of the brain that is affected • Complex—consciousness impaired, may have automatisms e.g. chewing, wandering off, dressing, undressing • Generalized: most or both hemispheres are involved, loss of consciousness • Primary VS secondary
Simple Partial Seizures • Preserved consciousness (“aura”) • Symptoms related to involved brain regionsa • Frontal lobe: movement, thought, speech • Temporal lobe: memory, speech, smell, taste, abdominal sensations • Parietal lobe: body sensations • Occipital lobe: vision
Complex Partial Seizures • Altered consciousness • Unresponsive or less responsive, staring • Impaired memory after seizure -Automatisms: hand and mouth movements (lip smacking, grabbing) • Hypermotor: wild flailing movements (frontal)
Generalized Seizures • Most have abnormal, unnatural movements • Tonic (stiffening) • Clonic (repetitive jerking) • Tonic-clonic (“grand mal”) • Atonic (limp) • Myoclonic (irregular jerking, may retain awareness) • Atonic (falling suddenly) • Absence (“petit mal”): staring, may blink, arrest of activity
EPILEPSY SYNDROMES • Genetic causes: • Familial neonatal convulsions • Benign familial convulsions of infancy • Benign partial seizures of infancy • Febrile seizures • Epilepsy syndromes: • Infantile spasms(West syndrome) • Lennox-Gastaut syndrome • Absence epilepsies • Juvenile myoclonic epilepsy • Benign rolandic epilepsy
(1)Infantile spasms (West syndrome) • Onset: between 4 and 6 months of age • ‘salaam spasms’ • Flexor spasms last 1-2 s and are often multiple, occurring in bursts of 20-30 spasms, frequently on waking • Infants will have developmental delay and later learning disability or epilepsy. • Treatment: vigabatrin or corticosteroids.
(2)Lennox-Gastaut Syndrome • Affects children of 2-5 years old • Multiple presentation of seizures • Later, neuro-developmental arrest or regression and behaviour disorder • Treatment: Sodium valproate • Poor prognosis
(3)Childhood Absence Epilepsy • Onset at 3-12 years • Peak at 6-7 years • Second peak at 11-12 years • Females more than males • Family history in 15-44% • Rarely associated with developmental problems. • Can be induced by hyperventilation.
Treatment: Sodium valproate • Good prognosis with 95% remission in adolescence. • Risk of generalized TC seizures is 30-40%(increased risk if begin after the age of 8 years)
(4)Juvenile Myoclonic Epilepsy (JME) • Autosomal dominance with variable penetrance • A common cause of tonic-clonic seizures in teenagers and young adults(myoclonus paricularly in morning) • Myoclonic seizures precede tonic-clonic seizures by 2-3 years; tonic-clonic seizures typically occur when patient reaches 10-17 years • Prognosis excellent but requires lifelong treatment
(5)Benign Rolandic Epilepsy • Most common partial epilepsy • Onset 2-12 years • M:F 1.5:1 • Usually occuring in sleep-wake transition states • 10-13% have a single seizure • 20% have frequent seizures • 65% nocturnal • 15% nocturnal or diurnal • 10-20% waking state only
Typical presentation: • On waking, fully conscious, mouth to one side, salivating and focal twitching of one side of the face • Duration 1-2 mins; • Child may recall a sensation of numbness, pins and needles or “electricity” in the tongue, gums or cheeks; • Remains conscious but aphasic post-ictally • Secondary generalization may be seen • Remits spontaneously in adolescence; no sequelae • No medication if infrequent seizures.
History • M/9 • Normal development until 9 years old • Encephalitis at age 9 with coma and 2 generalized seizures • P/E: stupor, ?visual hallucinations, ataxia • CT and MRI normal • Medullobastoma discovered at age 11, died at age 16
Complex partial seizure evolving into secondary generalized seizure • Seizure started as complex partial motor seizure because there is impaired consciousness • Classical Jacksonian march is observed but it’s not a Jacksonian seizure since it’s not a simple partial seizure • Then evolves into a generalized tonic-clonic seizure
History • M/20 • Caesarian section, anoxia, hemiconvulsions at birth, normal development • Seizure onset again at 9 years old • CT atrophic parieto-occipital zone; MRI large right parieto-occipital lesion probably due to birth trauma • Tx: carbamazepine, clobazam, vigabatrin, clorzepate, lamotrigine • Lives independently with a job
Complex partial seizure with automatisms • Aura (secs-mins): unresponsive, dreamy (may also have hallucinations, affect changes, déjà vu) • Automatism (occur in 90%): turning head to left, lip smacking (basically any continuation of an activity that was going on when the seizure occurred) • Alterations of mood, memory, perception (hence complex partial) • Posticteral drowsiness: confused and disoriented for minutes afterwards
History • F/28 • Previously healthy, no neurologically relevant diseases or family history • Age of onset 7 • MRI shows slight dilatation of R lateral ventricle; discrete hyperintense signals in frontal lobes • SPECT: low-flow area in L temporal and frontal lobes and R temporal lobe
Simple then complex seizure with secondary generalization • Starts off as simple partial seizure with autonomic involving ie. epigastric rising sensation • Although she is unable to speak, she raises as left hand as if to signal that she can understand • This is followed by a complex partial seizure as there is automatism (hand-rubbing and lip smacking) and unresponsiveness • Finally there is a tonic-clonic generalized seizure
History • F/8 • Previously health, no neurologically relevant diseases, remote family history of epilepsy • P/E normal, neruoimaging not done • Frequent daily spells with LOC since 8 • interictal EEG: generalized regular 3Hz spike with some polyspikes; normal background activity
Absence seizure - typical • Onset in childhood • Child stops activity, stares, blink/roll eyes, unresponsive • Usually lasts 5-10 secs but may occur hundreds of times/day • Usually there is an additional feature like automatism, mild clonus, or change in tone (eg. drop attacks) • May be induced by hyperventilation
History • M/17 • Newphew of father and son of the newphew both have epilepsy • Onset of seizure at age 15, treated with carbamazepine but still has daily convulsions
Myoclonic – juvenile myoclonic epilepsy • Sudden, brief, generalized muscle contractions • Most common type is the juvenile myoclonic epilepsy (Janz syndrome) which occurs after puberty and doesn’t remit with age • Also occurs in degenerative and metabolic disease • Another type is themyoclonic absence type
History • M/6 • Good past health and no family history • P/E: hypotonic muscles • CT showed mild diffuse cerebral atrophy • Refractory to all available antiepileptic drugs
Generalized clonic seizure • Clonic seizure is quite rare, even in this caes there is a very short tonic start • Differentiate from myoclonic seizures by the sustained rhythmical nature of the jerks
History • M/14 • Good past health, no family history • Onset at 2 years 9 months • One month before onset, he had severe measles • Refractory to all available antiepileptic drugs
Generalized tonic seizure • This particular case is unusual in that despite the tonic bending posture, the boy keeps on walking without falling
History • M/7 • Normal pregnancy and delivery and no family history • P/E: marked ataxia, severe MR, dull, protruded tongue, hypertonia, hyper-reflexia, spontaneous mild jerks of limbs • CT showed central and peripheral cerebral atrophy
Generalized tonic-clonic seizure • Many generalized tonic-clonic seizure have more than one tonic and clonic phase • Tonic phase: contraction of muscles – flexion/extension of limbs, twitching of eyelids, respiratory muscles in spasm (cyanosis), LOC • Clonic phase: violent jerking of face and limbs, tongue biting, incontinence • In this case there is a pronounced tonic stretching of the limbs follow by a clonic phase
History • M/4 • Premature birth with injury • Febrile convulsions in paternal cousin • P/E: sever MR • CT showed moderate diffuse cerebral atrophy
Generalized Atonic seizure • Many seizures in this type of children are a mixture of atonic, tonic, and myoclonic elements • Differentiation depends on analysis by combine EEG and EMG to see which element is more predominate
Aim • To confirm it is a genuine seizure attack • Etiology of the seizure attack • Epilepsy + classification • Convulsion with a febrile illness • Simple febrile convulsion • CNS infection • Severity of the attack / any associated injury • Management plan • Prognosis
Is it a genuine seizure attack? • Symptoms before onset of seizure (prodrome) • Aura (sensation / motor) • Behavioural change (mood / behaviour) Presence of prodrome strongly suggest partial onset seizures
Symptoms during the seizure • Loss of consciousness? • Temporal relationship with other symptoms • LOC right from the beginning? • Secondary generalization? • Other symptoms • Vocal symptoms • Motor symptoms • Respiration • Autonomic symptoms
Symptoms following seizure • Amnesia of the event • Confusion / lethargy / sleepiness • Headache or muscle ache • Transient focal weakness (Todd’s paresis) • Nausea or vomiting
The child is febrile • Simple febrile convulsion? • Check for the criteria • CNS infection? • Ask more on associated symptoms of meningitis / encephalitis • Epilepsy? • Any provoking factors • Trauma • Toxin / drug / alcohol consumptions • Flashes / sleep deprivation / physical exhaustion • Causes • Previous CNS insult / developmental milestones • Preceding neurological deficits • Intracranial SOL / increased ICP • Associated symptoms of neurocutaneous syndrome • Family history
Systemic screening • Pediatric history • Past health • Drug history • Birth history • Immunization history • Developmental history • Social history
Known history of epilepsycurrently on medication • Possible causes of breakthrough seizure • Poor drug compliance • Sleep deprivation • Infection / fever • Recent change of drug regimen
Physical examination • Febrile • General condition / vital signs septic? • Anterior fontonelle pressure / GCS / neck stiffness / kernig’s sign / papilloedema CNS infection? • Rash / focal signs of infection source of febrile illness • Epilepsy • Dysmorphism / head circumference • Skin features (adenoma sebaceum / shagreen patch / multiple cafe-au-lait spots / nevus flammeus) • Neurological examination any focal neurological deficits