Seizures and Epilepsy

Presented by Chan Hau Yee

Chan Wai ChungKwok VansieLee Kin Tong

Seizure VS Epilepsy What is the difference?

Seizure: manifestation of paroxysmal involuntary disturban

ce of brain function Abnormality/dysfunction of

Consciousness, motor activity, behaviour, sensory, or autonomic functions

Epilepsy: Recurrent seizures Unrelated to fever or to an acute cerebral insult

Local Data

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

Partial seizure (55.4%) Generalized seizure(38.7%) Unclassified Epilepsy syndrome

Fong GC, et al. A prevalence study of epilepsy in Hong Kong. Hong Kong Med J. 2003 Aug;9(4):252-7.

What is the difference between partial and generalised seizures?

Partial Seizure Simple partial

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

Consciousness Conscious Impaired

Duration 10-20s 1- 2 minAura + +/-Automatisms - Common

Post-ictal phenomenon

- +

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

Absence Myoclonic Clonic Tonic Tonic-clonic atonic

Status epilepticus

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 convulsionsBenign myoclonic epilepsy in infancyChildhood absence epilepsyJuvenile absence epilepsyJuvenile myoclonic epilepsyEpilepsy with generalized tonic-clonic seizures on awakening

Symptomatic (of underlying structural disease) (40.8%)

Temporal lobeFrontal lobeParietal lobeOccipital lobe 

Early myoclonic encephalopathyEarly infantile epileptic encephalopathywith suppression-burst (Ohtahara syndrome)Cortical dysgenesisMetabolic abnormalitiesWest syndromeLennox-Gastaut syndrome

Cryptogenic (16.8%)

Any occurrence of partial seizures without obvious pathology

Epilepsy with myoclonic-astatic seizuresEpilepsy with myoclonic absencesWest syndrome (with unidentified pathology)Lennox-Gastaut syndrome (with unidentified pathology)

Cont’d (Epilepsy Syndromes)

Special syndromes Febrile convulsions Isolated unprovoked seizures or isolated status epilepticus Seizures occurring only with toxic or metabolic provoking fa

ctors Neonatal seizures of any etiology Epilepsy with continuous spike-wave of slow wave sleep (el

ectrical status epilepticus of sleep) Acquired epileptic aphasia (Landau-Kleffner syndromeModified 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

may remain strictly focal or epileptic “march”- Speech:

- speech arrest - occasionally vocalization- partial dysphasia

- Todd’s paralysis

Simple partial seizure with somatosensory symptoms

1. Pins-and-needles, feeling of numbness, proprioception, spatial perception

2. Visual

3. Auditory

4. Olfactory

5. Gustatory

6. Vertiginous

13

Simple partial seizure with psychic symptoms

1. Dysphasia

2. Dysmnesic symptoms • Déjà vu, jamais-vu

3. Cognitive symptoms 4. Affective symptoms 5. Illusions

6. Structured hallucinations

Simple partial seizurewith autonomic symptoms

Vomiting Pallor Flushing Sweating Piloerection Pupil dilatation Borborygmi Incontinence

18

Complex partial seizures

Primary involvement of only one hemisphere (but often bilateral involvement in the course of seizure)

Impaired consciousness (gradually increasing)

Partial Seizures with Secondary Generalization Onset: Spontaneous Description of Seizure

Simple partialTakes his left hand in his right to prevent it

from shakingTurn to the right, left arm starts jerkingCoarse jerking of arms, stretching of back,

tonic contraction of face, open mouthJerks predominant in left arm and eye, eye

blinking, head and eyes to the left

Partial Seizures with Secondary Generalization

Secondary generalizationGeneralized jerks in face, arms and legsLeft arm bent, right arm stretched

Relaxation and Postictal sleep

Absence Seizures

Onset: provoked by hyperventilation Description of Seizure

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

Onset: Spontaneous Description of Seizure

Head drop

Atonic Seizure vs Atonic Absence

Atonic Seizure: general loss of tone often resulting in a sudden fall

Atonic Absence: loss of tone is often restricted to the head that gradually goes down

Absence Seizure with tonic component

Onset: Spontaneous Description of Seizure

Upward movement of the eyeballs for 15 seconds Immediate regain of consciousness

Tonic Seizure vs Tonic Absence

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

Generalized / face & trunk / one or more extremities / individual muscles or group of muscle

Around hr of going to sleep / awake from sleep Myoclonic jerks can also be seen in: - spinal cord diseas - dyssynergia cerebellaris myoclonica - subcortical segmental myoclonus

Clonic seizure

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 jerky contraction of mus

cles Regarded as an isolate

d event Considered as a separ

ate epilepsy type

Clonic seizure tonic seizure with per

iodic interruption (shaking)

rarely as a diagnosis usu get involved in othe

r type of seizure (eg. Absence seizure with mild clonic components)

Tonic seizure

Rigid, violent muscular contraction, fixing the body & limbs in strained position

Usu deviation of eyes and head Colour of face distorted: unchangedpaleflushed

ultimately livid(black & blue; as spasm of respiratory muscle)

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

Atonic seizure

Sudden reduction in muscle tone ‘drop attack’ Prolonged atonic attacks:

progressive drop in a rhythmic, successive relaxation manner

Causes of seizures

Epileptic Idiopathic( ~70%) Congenital dysgenesis or

malformation Cerebral trauma Space occupying lesion Neurogenerative disorder Syndrome

Non-epileptic Infection: fever, meningiti

s, encephalitis, sepsis Metabolic: acidosis, hypo

glycaemia Drugs, toxins Trauma

Approach to a patient with seizure attack

History of present illness Review of systems Important relevant aspects

Perinatal Development Past medical Drug Social Family Diet

What would you ask in a patient with epilepsy?

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

Investigations of Convulsion

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

EEG indicated when epilepsy

is suspected

CT/MRI Late onset of seizure Partial seizure Interictal neurological sig

ns Progression of seizure d

espite 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 Monotherapy preferred

- decrease drug interaction & toxicity

- increase compliance

- decrease cost

- 50% of children have satisfactory control

Treatment- Pharmacological Aim: fit free Common agents

Sodium valporate Phenytoin Phenobarbitone 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

Ketogenic Diet For recalcitrant seizures Complex myoclonic epilepsy with associated tonic-clo

nic convulsions Restricts the quantity of carbohydrate and protein

(most calories provided as fat) Mechanism of action unknown ? Anticonvulsant effect secondary to elevated lev

els of beta-hydroxybutyrate and acetoacetate resulting from the ketosis

Surgical Treatments Considered for children with

intractable seizures unresponsive to anticonvulsants

Well-defined focus of epileptogenic activity + identical structural lesion on CT/MRI

Options Lobectomy and cortical resection Hemispherectomy Corpus Callosotomy Multiple Sub-pial Transection Vagal nerve stimulation

Vagal nerve stimulation

Education and support

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 Fong GC, Mak W, Cheng TS, Chan KH, Fong JK, Ho SL. A prevalence study of e

pilepsy in Hong Kong. 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):329-336 Wong V. Study of seizure and epilepsy in Chinese children in Hong Kong: peri

od 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 a

gainst epilepsy

Special Thanks to Prof. V. Wong