Paeds: Epilepsy (DrClarke) presentation Flashcards Preview

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Flashcards in Paeds: Epilepsy (DrClarke) presentation Deck (47):
1

Definition

Recurrent transient paroxysmal attacks of disturbed consciousness and sensorimotor function, resulting from abnormal electrophysiological discharges of cerebral neurons

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Epidemiology
Incidence
Age range
Sex distribution

I: 500/100,000 of UK population (~37,000 people)
A: extremes (congenital in kids/degeneration in elderly)
SD: M:F --> 1:1

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Pathophysiology

Electrical activity spread of between cortical neurones is normally restricted. In seizures there is a failure of inhibitory synaptic contact between neurones --> overall excitation of large groups of neurones.
Each individual has a threshold for seizure activity. Some individuals have a low threshold -> having seizures in response to flashing lights stimulus.

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International league Against Epilepsy: Classificaton

1. Generalised
2. Partial
3. Unclassified

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Generalised

- Tonic-clonic seizures (grandmal)
- Typical absence seizures (petit mal)
- Myoclonic seizures
- Tonic seizures
- Atonic seizures/akinetic seizures/Drop attacks

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Partial (focal)

- Simple partial seizures (Jacksonian seizures)
- Complex partial seizures
- Partial seizures with 2ndry generalised tonic-clonic seizures

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Tonic-clonic presentation

- Vague warning - unconsciousness and generalised tonic-clonic convulsions
- Tonic phase: body becomes rigid for up to a mintute, pt utters a cry then falls -> serious injury sometimes, tongue usually bitten may be incontinent of urine or faeces
- Clonic phase then begins: generalised convulsions, frothing at mouth and rhythmic jerking lasting secs -> mins.
Self-limiting -> drowsiness, confusion or coma for several hrs.

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Typical absence seizures (petit mal)

- Begins in childhood - dev. abnormality of neuronal growth
- Brief episodes of unconsciousness with little or no motor component
- Accompanied by3 Hz spike + wave ECG activity
- Activity ceases, pt stares and is spaced out for a few secs. Interruption mid-sentence carries on as normal afterwards.
- Eyelids twitch, a few muscles may jerk
- After attack, normal activity is resumed
- Usually develop generalised tonic-conic seizures in adult life.

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Myoclonic seizures

- Single/multple sudden or uncontrollable isolated muscle jerking
- Juvenile myoclonic epilepsy: common, ocurs b/t 8&26 yrs of age, but usually stars between 12 and 16.
- Girls>boys affected

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Myoclonic seizures 3 types of epilepsy can occur

1. Tonic-clonic (usually occurs AM with 1/2hrs of waking, lack of sleep)
2. Myoclonic (soon after waking up & when getting dressed or at brekkie, can also occur in evening if tired)
3. Absence (any time of the day, more in the morning)

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Tonic seizures

Intense stiffening of body NOT followed by convulsive jerking

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Atonic seizures/Akinetic seizures/Drop attacks

Sudden loss of tone with falling and LOC.
May have severe injury from falls

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Partial (focal) seizures description

An 'aura' describes effects of initial focal electrical events e.g. unusual smell, tingling in a limb or strange inner feeling usually recognised by pt as a WARNING SIGN

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Simple partial seizures (Jacksonian seizures

- Originates in motor cortex
- Typically begins at angle of mouth or in thumb & index finger spreading to the limbs on the side opposite epileptic focus (jacksonian march pattern)
- WEakness of convulsive limbs for several hrs (Todd's paralysis)
- No impairment of consciousness!

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Complex partial seizures

- Impairment of consciousness
- Prodrome symptoms experiences: changed hearing, Visual disturbances, smell sensations, mood changes, muscle pain, muscle tremor

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Complex partial seizures location

Temporal lobe seizures
Frontal cortex
Parietal cortex
occipital cortex

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Temporal lobe complex partial seizures

Simple or comples -> feelings of unreality (jamais vu) or familiarity (deja vu).
May have absence attacks, vertigo, visual hallucinations

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Complex partial seizures Frontal cortes

autonomic disturbances - piloerectin, flushing, overbreathing, strange smells

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complex partial seizures parietal cortex

sensory disturbance.

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Occipital cortex

Crude visual shapes

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Unclassified seizures

Seizures that don't fit in any of the categories

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Aetiology

- Trauma/hypoxia/surgery
- Genetic/developmental abnormalities
- Pyrexia
- Brain tumours/absences
- Vascular
- Alcohol/drugs/drug withdrawal
- Encephalitis and inflammatory conditions
- Metabolic abnormalities
- Degenerative brain disorders
- Provoked seizures (e.g. photosensitivity)
- sleep deprivation

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Trauma/hypoxia/surgery

-Post traumatic epilepsy in 2%
-Perinatal trauma and fetal anoxi are common in childhood seizures
-Hypoxic damage to hippocampi ->childhood epilepsy
- May get early epilepsy within a week brain injury, or late epilepsy months/yrs later.
- 10% of neurosurgical ops on crebral hemispheres leads to seizures

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Genetic/ developmental abnormalities

- 30%
- 1st degree relative with seizures Hx
- Inheritance mode uncertain
- Generalised typical absence seizures: autosomal dominant with variable penetrance.
- Developmental abnormalities e.g. harmatomas, neuronal migration abnormalities

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Pyrexia

Can lead to febrile convulsions in pyrexic kids

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Brain tumours/abscessess

Cerebral tumours -->6%
- Mass cortex lesions -> epilepsy, (partial/secondary generalized seizures)
- Hydrocephalus also lowers the seizure threshold.

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Vasuclar

May follow cerebral infarctions (esp elderly) ~15% of seizures.
- A brain arteriovenous malformation may present with a seizure

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Alcohol/drugs/drug withdrawal

Alcohol - 6% - drinking heavily, withdrawal or alcohol induced hypoglycaemia.
- (overdose, theraputic levels): Phenothiazines, MAO inhibitors, tricylic antidepressants, amfetamines, lignocaine and nalidixic acid can lead to fits .
- Anticonvulsant withdrawal.

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Encephalitis and inflammatory conditions

Often presenting feature of encephalitis, cerebral abscess, cortical venous thrombosis, neurosyphilis, chronic meningitis (e.g. TB) and rarely bacterial meningitis

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Metabolic abnormalities

- Hypoglycaemia
- Hypocalcaemia
- Hyponatraemia
- Acute hypoxia
- Porphyria
- Uraemia
- Hepatocellular failure
- Mitochondrial disease

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Degenerative brain disorders

e.g. alzheimers, 3 times more common in MS

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Provoked seizures (e.g. photosensitivity)

e.g. flashing lights, flickering TV, music

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Sleep deprivation

Missing a nights slepp - seizure in susceptible people

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Diagnosis of epilepsy

- Confirm pt has epilepsy based on Hx and examination
- Do FBC, glucose, U+E's, LFT, ESR, CRP? metabolic, infective or inflammatory cause
- EEG to investigate suspected epilepsy: ambulatory EEG, video telemetry ->? nature of attacks\- CT?MRI indications: if epilepsy after 20, EEG shows focal seizure type, seizures have focal features, difficult to control seizures -> intracranial masses

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Differential diagnosis

1. Hyperventilation and panic attacks
2. Breath-holding attacks
3. Day dreaming
4. Migraine
5. TIA
6. Transient global amnesia
7. movement disorders
8. Hypoglycaemia
9. Vertigo
10. Syncope/vasovagal attacks
11. Non-epileptic attacks (pseudoseizures)
12. febrile convulsions

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Hyperventilation and panic attacks

- During stress periods
- Altered awareness, dizziness and LOC
- May get chest pain, dyspnoae, blurred visions, parasathesia
- Hyperventilation and palpitations, sweating, abdo discomfort
--> occasionally similar pattern to TEMPORAL seizures

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Breath-holding attacks

- Occurs when child is angry
- Period of crying - cessation of breathing
- cyanosis and child becomes limp and unresponsive
- Trembling and few clonic movements
- Persists for 2 mins - rapid recovery

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Day dreaming

Can be mistaken for absence seizures
Child however can be easily altered here

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Migraine

- Syncope may occur when vomiting
- Basilar migraine may -> LOC followed by headache. differentiated on FH and brainstem symptoms
- Migraine preceded by visual or sensory disturbance may be mistaken for partial seizures

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TIA

- Weakness and sensory symptoms
- TIAs usually last longer and theres raraely LOC
- Sensory phenomenon may spread like Jacksonian march, not seen in TIA

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Transient global amnesia

- Usually an isolated episode lasting several hrs
- Pt unable to remember
- Pt alert & communicative during the episode but may repeatedly ask the same question
- Recovery afterwards normally complete

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Movement disorders

- Tics and chorea sometimes confused with myoclonus
- paroxysmal choreoathetosis -> no LOC

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Hypoglycaemia

- Uncommon: pts with DM on insulin or oral hypoglycaemic, very rarely due to insulinoma
- Usually pt gets warning signs of autonomic changes e.g pallor, sweating, tachycardia
- Loss of hypoglycaemic awareness/no warning signs -> coma ensues -> genuine seizures

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Vertigo

- Often paroxysmal - >epilepsy
- Very occasionally is a symptoms of an epileptic seizure particularly PARIETAL LOBE EPILEPSY

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Syncope/vasovagal attacks

-LOC

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Non-epileptic attack (pseudoseizures)

- Often resembles grand mal seizures
- Prolactin levels however are normal here (increased in a true grandmal)

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Febrile convulsions

Occurs in children when there is a rapid increase in body temp

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