Download Epilepsy

Epilepsy
Dr Desiree Fernandez
UCC 7th March 2010
Definitions
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Seizure: manifestation of an abnormal and excessive
synchronised discharge of a set of cerebral neurones
Epilepsy: a condition in which the sufferer is prone to
experience recurrent seizures (eg person having had 2 or more
seizures)
Status epilepticus: traditionally defined as a condition in which
epileptic seizures continue, or are repeated without regaining
conciousness, for a period of 30 mins or more (different
authorities debate time range of 5-60 mins)
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Provoked seizures: seizures which have an obvious and
immediate preceding cause (eg acute systemic, metabolic or toxic
insult; or acute cerebral event such as stroke, trauma, infections)
Seizure Types
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International League Against Epilepsy (ILAE)
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Partial onset seizures
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Generalised onset seizures
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Unclassified epileptic seizures
Partial (Focal) Seizures
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Simple partial seizures
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Complex partial seizures
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Partial seizures evolving to secondarily
generalised seizures
Partial (Focal) Seizures
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Simple partial seizures
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Focal motor with or without march
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usually occur in epilepsy arising from frontal or central
regions
Somatosensory or special sensory symptoms:
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clonus (jerking) is the commonest;
Tingling/ numbness/ electric shock-like feeling (less
common)/ burning/ pain/ feeling of heat
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Visual, auditory, gustatory, olfactory, vertiginous
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Simple hallucinations
Autonomic symptoms
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Changes in skin colour, blood pressure, heart rate, pupil
size, piloerection
Usually occurs as part of generalised or complex partial
seizures of frontal or temporal origin
Partial (Focal) Seizures
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Simple partial seizures
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Psychic symptoms (auras), are more common in complex partial
than in simple partial seizures.
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Dysphasic symptoms: cortical speech areas (dominant frontal/
temporoparietal cortex). Repetitive vocalisation with formed
words may occur with complex partial seizure originating from
non-dominant temporal lobe.
Dysmnestic symptoms (disturbance of memory): flash backs,
deja vu, jamais vu, panoramic experiences (recollections of
previous experiences, former life or childhood memory). Most
common in mesial temporal lobe seizures
Cognitive symptoms: dreamy states/ sensations of unreality/
depersonalisation. Most common in temporal lobe seizures.
Affective symptoms: fear (commonest), depression, anger,
elation,irritability, erotic thoughts, serenity. Most commonly seen
in mesial temporal lobe seizures. Laughter without mirth occurs
in epilepsy of frontal origin.
Illusions: of size, shape, weight, distance, sound. Usually
features in temporal or parieto-occipital epileptic foci.
Structured hallucinations (visual, auditory, gustatory, olfactory):
crude/ elaborate hallucinations caused by temporal or parietooccipital epileptic foci.
Partial (Focal) Seizures
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Complex partial seizures
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Aura (as in simple partial seizures): usually lasting few seconds;
only rarely prolonged
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Altered conciousness: follows the aura or occur simultaneously.
This may occur as an absence and motor arrest. The patient may
have no outward sign apart from appearing vacant or glazed.
There may be associated spasm, posturing or mild tonic jerking
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Automatisms: defined as involuntary motor actions which occur
during or in the aftermath of epileptic seizures, in a state of
unconciousness. There is total amnesia for the event. Most
commonly occurs in temporal or frontal lobe seizures.
Partial (Focal) Seizures
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Complex partial seizures
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Types of automatisms:
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Oro-alimentary: orofacial movements such as lip smacking,
chewing, swallowing or drooling. Most common in mesial
temporal lobe seizures
Mimicry: displays of laughter/ fear/ anger/ excitement
Gestural: fiddling movements with hands, tapping, patting,
rubbing, ordering, tidying movements. Complex actions eg
undressing, genitally directed actions
Ambulatory: walking, circling, running
Verbal: meaningless sounds, humming, whistling, grunting,
repeated words, formed sentences
Responsive: quasi-purposeful behaviour, seemingly responsive
to environmental stimuli
Violent behaviour: these are never premeditated, never
remembered, never highly coordinated or skilful and never goal
directed
Partial (Focal) Seizures
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Complex partial seizures
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Arise from temporal lobe in 60% of cases
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Arise from frontal lobe in 30% of cases
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10-50% of scalp EEG may be unchanged
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EEG: localised spike and wave/ spikes/ sharp waves/ slow
activity/ flattening may be seen
Partial seizures evolving to secondarily generalised seizures (tonic/
clonic/ tonic-clonic)
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Simple partial to generalised
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Complex partial to generalised
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Simple partial to complex partial to generalised
Generalised Seizures (Non-Convulsive)
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Typical absence seizures(petit mal)
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Abrupt, sudden loss of conciousness (absence) and cessation of motor
activity.
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Patient is unaware (appears glazed/vacant) and is inaccessible.
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Tone is usually preserved and there is no fall.
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Attack ends abruptly and previous activity is resumed.
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Patient has no recollection of event
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There is no confusion
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> 80% of attacks last < 10 sec., but attacks can be repeated and often
cluster
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Attacks are often worse when the patient is awakening or drifting to
sleep
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Attacks may be precipitated by fatigue, drowsiness, photic stimulation,
hyperventilation, relaxation.
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Typically develop in childhood or adolescence
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EEG: 3 Hz spike and wave. Interictal EEG is normal
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Other phenomena eg blinking, slight clonic movements, alterations in
Generalised Seizures
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Atypical absence seizures. Differ from typical absence seizures:
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Longer seizure duration, attacks may wax and wane
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Incomplete loss of awareness
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Incomplete amnesia of event
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Onset and cessation of attacks are not as abrupt
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Tone changes are more severe and there may be atonic/ clonic/ tonic
phenomena, automatisms, autonomic disturbance
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EEG: Diffuse, but assymetrical and irregular spike and wave bursts (22.5 Hz), but may be variable also. Interictal EEG is abnormal:
continuous slowing, spikes or irregular spike and wave activity.
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Seizures often not induced by hyperventilation or photic stimulation
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Associated learning diificulties or other neurological abnormalities may
be present
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Patients may also have other (multiple) seizure types
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May manifest at any age
Generalised Seizures
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Myoclonic seizures
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Brief contraction of a muscle, muscle group, or several muscle
groups caused by cortical discharge
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Can be single or repetitive
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Severity range from imperceptible twitch to severe jerking (may
result in propulsion of hand-held objects/ fall)
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Recovery is immediate and conciousness is not lost
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Myoclonus can be induced by action, noise, startle, photic
stimulation or percussion
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If occuring as part of idiopathic generalised seizures, myoclonus
occurs on waking or on dropping off to sleep
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May occur at any age
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EEG: generalised spike/ spike and wave/ polyspike and wave,
often assymmetrical and irregular, frequently predominant in
frontal area. Interictal EEG varies depending on underlying
epilepsy aetiology.
Generalised Seizures
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Clonic seizures
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Clonic jerks, which are often asymmetrical and irregular
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Most frequent in neonates, infants or young children
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Always symptomatic
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EEG: fast activity (10 Hz)/ fast activity mixed with larger
amplitude slow waves/ rarely, polyspike and wave or spike and
wave discharges
Generalised Seizures
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Tonic seizures
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Tonic muscle contraction with altered conciousness without a clonic
phase
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There is extension of the neck, contraction of facial muscles,eyes
opening widely with upturning of eyeballs; contraction of respiratory
muscles; and spasm of the proximal upper limb muscles, which causes
abduction and elevation of shoulders and semiflexed arms.
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If the tonic contraction spreads distally, the arms rise up and are held as
if defending the head against a blow and the lower limbs become
forcibly extended or contracted in triple flexion.
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The spasm may fluctuate causing head nodding, or slight alterations in
limb posture. There may be a cry followed by apnoea.
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Seizures usually last <60 secs
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EEG: flattening (desynchronisation)/ fast activity (15-15 Hz) with
increased amplitude as the attack progresses/ rhythmic discharges (10
Hz). Scalp EEG recording is also often obscured by artefacts from
muscle contraction. Interictal EEG is seldom normal.
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Occurs at all ages
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Occurs in the diffuse cerebral damage and learning disability
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Often associated with other seizure types
Generalised Seizures
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Tonic-clonic seizures (Grand mal seizures)
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Seizure is initiated with loss of conciousness, patient will fall if standing
and there is a brief period of tonic flexion, followed by a longer phase of
rigidity and axial extension. The eyes would rolled up, jaw clamped shut,
limbs stiff, adducted and extended with the fist clenched or held in the
main d'accoucheur position. Respiration ceases and cyanosis is
common. This tonic stage lasts 10-30 secs.
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Clonic phase follows, involving generalised convulsions of limbs, jaw,
facial muscles. Breathing may be stertorous. Tongue biting may occur.
Mouth frothing may occur. Autonomic features (flushing, BP changes,
pulse rate changes, increased salivation) are common. This clonic
phase lasts 30-60 secs and is followed by a brief tonic muscle
contraction during which urinary incontinence may occur. The final
phase is characterised by muscle flaccidity and lasts between 2-30
mins. Consciousness is slowly regained. Plantar responses are usually
extensor and tendons are diminished. Patient may fall asleep. Muscle
soreness and headache may occur post-ictally.
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Occurs at any age
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Occurs in many variety of epilepsy syndromes, including idiopathic
generalised epilepsy
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Pre-ictal EEG: spike and wave/ spike paroxysms
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Interictal EEG variable dependent on underlying pathology.
Generalised Seizures
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Tonic-clonic seizures (Grand mal seizures)
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EEG:Tonic phase: generalised flattening, followed by low voltage
activity, which increase in amplitude. These are followed by slow waves
with increasing amplitude and decreasing frequency (3->1 Hz)
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EEG: Clonic phase: Slow waves are interrupted by bursts of faster
activity (10 Hz) corresponding to clonic jerks. As the phase progresses,
the slow waves widen and these bursts become less frequent. Readings
are often obscured by muscle artefacts.
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Post-ictal EEG: silent for few seconds, then slow delta activity develops.
This can last from minutes to hours.
Generalised Seizures
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Atonic seizures
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The classic drop attack is the most severe form, in which
all postural tone is suddenly lost, causing the patient to
collapse like a rag doll.
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Tone change can be limited with sagging at knee, bowing
of knees, nodding of head, or can develop in a stepwise
fashion.
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Seizures are short-lasting and recovery is immediate.
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Occurs at any age
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Are always associated with diffuse cerebral damage,
learning disability and are common in severe symptomatic
epilepsies
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EEG: irregular spike and wave/ polyspike and wave/ slow
wave/ low amplitude fast activity/ a mixture
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Interictal EEG: diffuse abnormalities
Management of 1st Seizure
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History taking
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Witness account of event
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Seizure risk
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prenatal/ perinatal history (eg infection during pregnancy, premature
birth etc)
family history of epilepsy,
history of head injury/ meningitis/ encephalitis/ intracranial
pathology(stroke/ tumour/ AVM)
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previous febrile convulsions
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excessive alcohol use
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illicit drug use
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sleep deprivation
Drug history
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antidepressants eg bupropion, tricyclics
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antipsychotic medications eg chlorpromazine, haloperidol, clozapine
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aminophylline
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high doses of penicillin
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lithium
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Analgesic (eg tramadol)
Management of 1st Seizure
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Investigations
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Blood/ urine test
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Electrolyte imbalance (Na, Ca, Mg)
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Renal failure/ Uremia
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Liver failure
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Hypo/ Hyperglycaemia
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Hypoxia
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Illicit drug levels
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EEG
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CT / MRI brain
Points to note:
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1st seizure may present as status epilepticus
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Usually, no AED is required unless present as status epilepticus or if
there is pathology that would cause seizure recurrence
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Advice need to be given re: driving/ lifestyle
Management of Status
Epilepticus
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General resuscitation
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Protect airways
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Give oxygen
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+/- intubation
Monitoring
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Regular neurological observation (eg GCS)
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ECG/ BP/ temperature/ oximetry
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Glucose/ electrolytes/ ABG
Emergency investigations
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Protection of cardiopulmonary function
FBC/ U&E/ LFT/ Ca/ Mg/ blood glucose/ clotting screen/ ABG/ serum
anti-convulsant levels
Emergency drug treatment
Management of Status Epilepticus
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Emergency drug treatment
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50 ml of 50% glucose, if suspected hypoglycaemia
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250 mg thiamine in alcoholics / poor nutrition state (IV glucose alone can
precipitate Wernicke's encephalopathy in such individuals)
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Pre-hospital setting: 10 mg diazepam (rectal) or 10 mg midazolam
(buccal)
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IV lorazepam 4mg (2mg/min), if seizure continues or recurs, repeat dose
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IV phenytoin infusion (load at 15-20 mg/kg at 50mg/min), watch for
cardiac arrhythmias and hypotension OR IV fosphenytoin infusion (1520mg/kg at 100-150mg/min)
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General anaesthesia with IV propofol (loading dose 2mg/kg,
maintenance dose 0.1-0.2 mg/kg/min) OR phenobarbital 15-20mg/kg
(max infusion rate: 100mg/min)
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ICU monitoring is required
Other points to note:
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Valproate is useful in non-convulsive status epilepticus
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IV levatiracetam (keppra) may be useful in some refractory status
epilepticus (anecdotal evidence based on few case reports)
Diagnosis and implications of epilepsy
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Epilepsy is defined if there are 2 or more seizures
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Epilepsy impacts on:
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Driving (see later slides)
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Work: unable to perform work at heights (eg builder on
scaffolding), or near high voltage cables, or where there is a risk
of falling into water, or which involves driving
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Social: epileptics may have relationship difficulties, social life
may be curtailed due to seizure triggers, drugs/ epilepsy
syndromes may slow mentation/ learning and impact on school
performance
New Irish Driving Regulations
December 2010
Group 1: Cars, Light Vans and Motorcycles
The main seizure freedom period for personal driving in categories A1, A, B, EB, M or W (car, light van or
motorcycle) remains the same at one year of seizure freedom.
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Provoked seizures: a person who has had a provoked epileptic seizure due to a recognizable
provoking factor that is unlikely to recur at the wheel may be declared able to drive on an individual
basis subject to neurological opinion. (Previously six months)
Sleep seizures: For persons who have seizures exclusively in sleep they may be declared fit to drive
once this pattern has been established for no less than one year. (Previously 2 years). If a further
occurrence of a seizure happens in waking a one year seizure freedom period is required.
Seizures without influence on consciousness or the ability to act – persons with who have never had
any seizures other than seizures which have been demonstrated to affect neither consciousness nor
cause any functional impairment can be declared fit to drive once this pattern has been established
for no less than one year (was previously subject to neurological opinion). If there is an occurrence of
any other kind of seizure then a one year seizure freedom period is required.
Initial or isolated seizures: a person who has had an initial seizure or loss of consciousness should be
advised not to drive and a specialist report is required regarding the period of driving prohibition and
follow up to be undertaken.
First or single unprovoked seizures: a person who has had a first unprovoked epileptic seizure may
be declared fit to drive after a period of six months seizure freedom with an appropriate medical
assessment preferably a Neurological assessment.
New Irish Driving Regulations
December 2010
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Seizures associated with a physician directed change or reduction of anti‐epileptic therapy: in such
cases the person may be advised not to drive from the beginning of the period of withdrawal and for
six months after stopping of treatment. Seizures which occur during the physician advised change or
withdrawal of medication require three months off driving if previously effective treatment is
reinstated.
Surgery In cases where a person has had curative epilepsy surgery the seizure freedom period prior
to licensing is the same as the main seizure freedom period for epilepsy i.e.1 year.
The new regulations provide definitions of epilepsy and provoked seizures.
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Epilepsy: common medical disorder characterised by recurrent seizures, as defined by having had 2
or more epileptic seizures less than five years apart.
Provoked epileptic seizure: seizure which has a recognisable causative factor that is avoidable.
The new regulations state that all drivers with epilepsy should be under annual licence review until they
have been seizure free for a period of at least five years.
Persons with epilepsy will not meet the criteria for unconditional licencing (10 year licence) and
notification should be given to the licensing authority.
New Irish Driving Regulations December 2010
Group 2: Lorries, Buses, Heavy Goods Vehicles
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In the case of applicants with epilepsy for licencing in respect of heavy goods vehicles C1, C, D1,
D,EC1, EC, ED1 or ED the directive permits for persons to be licenced to drive in these categories
provided 10 years of seizure freedom have been achieved without the aid of anti‐epileptic drugs.
A permit may be granted in less time in the case of those with good prognostic indicators and in
similarly in cases of juvenile epilepsy. Appropriate medical follow up must be completed and
satisfactory result on neurological investigations. All persons are to be under licence review until they
have been seizure free for at least 5 years.
Persons who have had a provoked seizure due to a recognizable provoking factor that is unlikely to
recur at the wheel may be declared eligible to drive on an individual basis subject to neurological
opinion with appropriate assessments having been completed after the acute episode.
First or single unprovoked seizures the person may be declared fit to drive in these categories once 5
years seizure freedom has been achieved without the aid of anti‐epileptic drugs. Drivers with good
prognostic indicators may drive sooner.
Seizures due to drug or alcohol misuse, sleep deprivation or structural abnormality are not
considered provoked seizures for licensing purposes.
Reports of seizures due to side effects of prescribed medication do not automatically imply that such
events will be considered as provoked.
Seizures which may be considered provoked include eclamptic seizures, reflex anoxic seizures,
immediate seizure seconds after head injury, seizure in the first week post head injury not associated
with damage on CT or MRI nor with post amnesia of more than 30 minutes, seizures at time of
stroke/TIA or within 24 hours of same, seizures during inter‐cranial surgery or the ensuing 24 hours.
Seizures associated with acute exacerbation of Multiple Sclerosis or Migraine need to be assessed on
an individual basis by a Neurologist.
SUDEP
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SUDEP is defined as the sudden, unexpected, witnessed or unwitnessed, non-traumatic, and
non-drowning death of patients with epilepsy, with or without evidence of a seizure, excluding
documented status epilepticus, and in whom post mortem examination does not reveal a
structural or toxicological cause of death.
Incidence: 0.09/1000 person years in newly diagnosed patients to 9.3/1000 person years in
epilepsy surgery candidates
Risk factors:
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Young age
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Male gender
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Untreated seizures
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Nocturnal seizures
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Poor compliance to AEDs
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Poorly controlled seizures
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Polytherapy
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Tonic-clonic seizures
SUDEP
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Mechanism of death thought to be cardiorespiratory (ictal bradycardia and asystole/ central
apnoea). In few observed cases, ictal EEG slowing/ flattening has been noted prior to
cardiorespiratory failure--> this was interpreted as 'CNS shut-down'
Prevention
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Avoidance of seizure triggers eg avoid excessive alcohol/ sleep deprivation/
stress etc
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Good seizure control
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Supervision during sleep
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Avoidance of prone position in sleep/ use of anti-smother pillow or no pillow
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Use of permanent cardiac pacemakers in select few
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None of the above are fail safe and are based on small studies
Epilepsy in women
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Catamenial seizures
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Use of acetazolamide/ clobazam
Interaction with contraceptive drugs
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Metabolism of contraceptive hormones are affected by AEDs (via
cytochrome P450 enzyme system)
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Enzyme inducing AEDs: carbamazepine, oxcarbazepine, phenytoin,
barbiturates (phenobarbital, mephobarbital and primidone),topiramate.
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Enzyme inhibiting AEDs: valproate and felbamate
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No effect on enzyme: gabapentin, lamotrigine, levetiracetam,
tiagabine,lacosamide.
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Oral contraceptives used by women with epilepsy taking cyP450inducing AEDs may need to contain higher amounts of estrogen (50 mcg
or more), and/ or taken without the 7 day pill free break.
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Intramuscular medroxyprogesterone (DepoProvera) is usually given as
150 mg every 12 weeks. Women with epilepsy taking cyP450-inducing
AEDs may need the dosage interval of this contraceptive decreased to
every 6 to 8 weeks.
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The reliability of progesterone only contraceptives may be compromised
by AEDs affecting the cyP450 system.
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Consider IUD/ barrier methods
Epilepsy in women
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Fertility
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Lower in epileptics (psychological/ biological factors)
Teratogenicity
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Various pregnancy registries (North American, UK, Australian, Irish,
Lamotrigine etc)
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Valproate and barbiturates most teratogenic (although barbiturate
teratogenic rates were more significant in North American Register
compared to other registers)
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Lamotrigine least teratogenic
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Monotherapy vs polytherapy
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Folic acid supplementation
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Collaboration between neurologist and obstetrician
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Pre-pregnancy planning (where possible)
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Folic acid
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Monotherapy, where possible
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Advise women NOT to stop AED, if they discover that they are
pregnant
Thank you