Seizures and Epilepsy Presented by Chan Hau Yee

Seizures and Epilepsy Presented by Chan Hau Yee Chan Wai Chung Kwok Vansie Lee Kin Tong

Seizure VS Epilepsy What is the difference? l Seizure: l l manifestation of paroxysmal involuntary disturbance of brain function Abnormality/dysfunction of l l Consciousness, motor activity, behaviour, sensory, or autonomic functions Epilepsy: l l Recurrent seizures Unrelated to fever or to an acute cerebral insult

Local Data l l The period prevalence rate of epilepsy in 1997 (January to December) is estimated to be 4. 5 per 1000 children aged < 19 years Wong V. Study of seizure and epilepsy in Chinese children in Hong Kong: period prevalence and patterns. J Child Neurol. 2004 Jan; 19(1): 19 -25

Classification of seizures l l Partial seizure (55. 4%) Generalized seizure(38. 7%) Unclassified Epilepsy syndrome Fong GC, et al. A prevalence study of epilepsy in Hong Kong Med J. 2003 Aug; 9(4): 252 -7. l What is the difference between partial and generalised seizures?

Partial Seizure l Simple partial l l l With motor signs With somatosensory or special symptoms With autonomic symptoms With psychic symptoms Complex partial Partial seizure with secondary generalisation How can we differentiate between simple partial and complex partial seizure?

Simple partial seizure Complex partial seizure Conscious Impaired Duration Aura Automatisms 10 -20 s 1 - 2 min + - +/- Common Post-ictal phenomenon - + Consciousness EEG Spikes or sharp waves bilaterally or unilaterally or a multifocal spike pattern Interictal EEG anterior temporal lobe sharp waves or focal spikes and multifocal spikes (80%)

Generalized seizure l l l Absence Myoclonic Clonic Tonic-clonic atonic

Status epilepticus l l Consciousness does not return in between attacks Lasts more than 30 mins May be life threatening Terminate the seizure as soon as possible

Category Localization-related Generalized Idiopathic (42%) Benign epilepsy of childhood with centrotemporal spikes (benign rolandic epilepsy) Benign occipital epilepsy Benign familial neonatal convulsions Benign myoclonic epilepsy in infancy Childhood absence epilepsy Juvenile myoclonic epilepsy Epilepsy with generalized tonicclonic seizures on awakening Symptomatic (of underlying structural disease) (40. 8%) Temporal lobe Frontal lobe Parietal lobe Occipital lobe Early myoclonic encephalopathy Early infantile epileptic encephalopathy with suppression-burst (Ohtahara syndrome) Cortical dysgenesis Metabolic abnormalities West syndrome Lennox-Gastaut syndrome Cryptogenic (16. 8%) Any occurrence of partial seizures without obvious pathology Epilepsy with myoclonic-astatic seizures Epilepsy with myoclonic absences West syndrome (with unidentified pathology) Lennox-Gastaut syndrome (with unidentified pathology)

Cont’d (Epilepsy Syndromes) l Special syndromes l l l Febrile convulsions Isolated unprovoked seizures or isolated status epilepticus Seizures occurring only with toxic or metabolic provoking factors Neonatal seizures of any etiology Epilepsy with continuous spike-wave of slow wave sleep (electrical status epilepticus of sleep) Acquired epileptic aphasia (Landau-Kleffner syndrome Modified ILAE Classification of Epilepsy Syndromes Kwong KL et al. Epidemiology of childhood epilepsy in a cohort of 309 Chinese children. Pediatr Neurol. 2001 Apr

Video demonstration of seizures

Simple partial seizure with motor signs l - may remain strictly focal or epileptic “march” Speech: - - speech arrest occasionally vocalization partial dysphasia Todd’s paralysis

Simple partial seizure with somatosensory symptoms 1. 2. 3. 4. 5. 6. Pins-and-needles, feeling of numbness, proprioception, spatial perception Visual Auditory Olfactory Gustatory Vertiginous

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Simple partial seizure with psychic symptoms Dysphasia Dysmnesic symptoms 1. 2. • 3. 4. 5. 6. Déjà vu, jamais-vu Cognitive symptoms Affective symptoms Illusions Structured hallucinations

Simple partial seizure with autonomic symptoms l l l l Vomiting Pallor Flushing Sweating Piloerection Pupil dilatation Borborygmi Incontinence

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Complex partial seizures l l Primary involvement of only one hemisphere (but often bilateral involvement in the course of seizure) Impaired consciousness (gradually increasing)

Partial Seizures with Secondary Generalization l l Onset: Spontaneous Description of Seizure l Simple partial Takes his left hand in his right to prevent it from shaking l Turn to the right, left arm starts jerking l Coarse jerking of arms, stretching of back, tonic contraction of face, open mouth l Jerks predominant in left arm and eye, eye blinking, head and eyes to the left l

Partial Seizures with Secondary Generalization l Secondary generalization Generalized jerks in face, arms and legs l Left arm bent, right arm stretched l l Relaxation and Postictal sleep

Absence Seizures l l Onset: provoked by hyperventilation Description of Seizure l l l Stop hyperventilation Slight loss of tone in neck muscles 2 eye blinks about 1 second apart Regains awareness 1. 5 second before paroxysm stops The duration of impaired consciousness is often shorter than the duration of spike and wave discharge series. It starts later and ends earlier.

Absence Seizures with atonic components l l Onset: Spontaneous Description of Seizure l Head drop

Atonic Seizure vs Atonic Absence l Atonic Seizure: general loss of tone often resulting in a sudden fall l Atonic Absence: loss of tone is often restricted to the head that gradually goes down

Absence Seizure with tonic component l l Onset: Spontaneous Description of Seizure l l Upward movement of the eyeballs for 15 seconds Immediate regain of consciousness

Tonic Seizure vs Tonic Absence l l Tonic Seizure: tonic seizure affects the whole body resulting in bending forward with abduction of the arms and reddening of the face, sometimes a loss of balance Tonic Seizure: Head is mainly affected, often with retropulsion of the head and upward deviation of the eyes

Myoclonic seizure Single or multiple, sudden, brief, shock-like jerky contraction l Generalized / face & trunk / one or more extremities / individual muscles or group of muscle l Around hr of going to sleep / awake from sleep l Myoclonic jerks can also be seen in: - spinal cord diseas - dyssynergia cerebellaris myoclonica - subcortical segmental myoclonus l

Clonic seizure l l l Tonic seizure with periodic interruptions (shaking) The diagnosis is rare When a generalized seizure occasionally lack a tonic component / as a co-existing event in other type of seizure

Myoclonic seizure l jerky contraction of muscles l Regarded as an isolated event l Considered as a separate epilepsy type Clonic seizure l tonic seizure with periodic interruption (shaking) l rarely as a diagnosis l usu get involved in other type of seizure (eg. Absence seizure with mild clonic components)

Tonic seizure l l l Rigid, violent muscular contraction, fixing the body & limbs in strained position Usu deviation of eyes and head Colour of face distorted: unchanged pale flushed ultimately livid(black & blue; as spasm of respiratory muscle)

Tonic-clonic seizure Most common type of generalized seizure l Also known as ‘grand mal’ l Tonic phase (~10 sec): - falls - stridor, cry or moan, cyanosis - incontinence l Clonic phase (~1 -2 mins): l Postictal phase: - muscles relax - remain unconscious - go into deep sleep l

Atonic seizure l l l Sudden reduction in muscle tone ‘drop attack’ Prolonged atonic attacks: progressive drop in a rhythmic, successive relaxation manner

Causes of seizures l Epileptic l l l Idiopathic( ~70%) Congenital dysgenesis or malformation Cerebral trauma Space occupying lesion Neurogenerative disorder Syndrome l Non-epileptic l l Infection: fever, meningitis, encephalitis, sepsis Metabolic: acidosis, hypoglycaemia Drugs, toxins Trauma

Approach to a patient with seizure attack l l l History of present illness Review of systems Important relevant aspects l Perinatal l Development l Past medical l Drug l Social l Family l Diet What would you ask in a patient with epilepsy?

l Physical exam l l l General Neurological Other systems when indicated (e. g. trauma, fever)

Investigations of Convulsion l Depends on the clinical presentation and history l l l CBC LFT, RFT, blood glucose level, ABG Infection screen Toxicology screen EEG CT, MRI

l EEG l indicated when epilepsy is suspected l CT/MRI l l Late onset of seizure Partial seizure Interictal neurological signs Progression of seizure despite good complicance

Medical Treatment

Anti-epileptic drug (AED) Seizure Type Drug recommended Partial Carbamazepine Valproate Phenytoin Tonic-clonic Valproate Carbamazepine Phenytoin Phenobarbital Absence, Atonic, Myoclonic Valproate Clonazepam

Drug complication Carbamazepin Drowsiness; visual disturbance; aplastic anemia; SLE Valproate Drowsiness; Transient hair loss; GIT disturbance; pancreatitis; hepatitis; thrombocytopenia Phenytoin Gingival hyperplasia; hirsutism; Steven-Johnson syndrome; SLE Phenobarbital Sedation; Reduced cognition; Hyperactivity; Steven-Johnson Syndrome; Clonazepam Ataxia; Lethargy

Principle of medical treatment Start if seizure becomes recurrent l Monotherapy preferred - decrease drug interaction & toxicity - increase compliance - decrease cost - 50% of children have satisfactory control l

Treatment- Pharmacological l l Aim: fit free Common agents l Sodium valporate l Phenytoin l Phenobarbitone l Carbamazepine Most of them have known side effects and monotherapy is preferred for the sake of side effects Withdrawal of drug therapy can be considered in a patient with no relapse of seizure for 3 or more years; it should be withdrawn slowly

Treatment: Diet l Ketogenic Diet l l l For recalcitrant seizures Complex myoclonic epilepsy with associated tonicclonic convulsions Restricts the quantity of carbohydrate and protein (most calories provided as fat) Mechanism of action unknown ? Anticonvulsant effect secondary to elevated levels of beta-hydroxybutyrate and acetoacetate resulting from the ketosis

Surgical Treatments l l Considered for children with l intractable seizures unresponsive to anticonvulsants l Well-defined focus of epileptogenic activity + identical structural lesion on CT/MRI Options l Lobectomy and cortical resection l Hemispherectomy l Corpus Callosotomy l Multiple Sub-pial Transection l Vagal nerve stimulation

Education and support l l l Good compliance is very important May disturb the child’s school life Management during fits Side effects of the anticonvulsants Avoid known provoking factors

References l l l l Fong GC, Mak W, Cheng TS, Chan KH, Fong JK, Ho SL. A prevalence study of epilepsy in Hong Kong Med J. 2003 Aug; 9(4): 252 -7. Kwong KL, Chak WK, Wong SN, So KT. Epidemiology of childhood epilepsy in a cohort of 309 Chinese children. Pediatr Neurol. 2001 Apr; 24(4): 276 -82 Leung GK, Fan YW, Fong KY. Temporal lobe resection for intractable epilepsy: review of 11 cases. Hong Kong Med J. 1999 Dec; 5(4): 329336 Wong V. Study of seizure and epilepsy in Chinese children in Hong Kong: period prevalence and patterns. J Child Neurol. 2004 Jan; 19(1): 19 -25 Modified ILAE Classification of Epilepsy Syndromes Nelson’s Textbook of Pediatrics Ch. 602 Video Atlas of epileptic seizures - Classical examples, International League against epilepsy

Special Thanks to Prof. V. Wong