11. Generalised seizures
Tonic-clonic (in any combination)
Absence
- Typical
- Atypical
- Absence with special features
Myoclonic absence
Eyelid myoclonia
Myoclonic
- Myoclonic
- Myoclonic atonic
- Myoclonic tonic
Clonic
Tonic
Atonic
12.
13.
14. Focal seizures
• Without impairment of consciousness or awareness
– Previous term: simple partial
– With observable motor or autonomic components
• eg. focal clonic, autonomic, hemiconvulsive
– With subjective sensory or psychic phenomena
• Aura - specific types
• Where alteration of cognition is major feature
– Previous term: complex partial
– Dyscognitive
15.
16. Semiological classification (Luders et al.)
• 1. Auras
a. Somatosensory auras b. Visual auras c. Auditory auras d. Gustatory auras e. Olfactory auras f. Autonomic
auras g. Abdominal auras h. Psychic auras
• 2. Autonomic Seizures
• 3. Dialeptic Seizures
• 4. Motor Seizures
a. Simple Motor Seizures
i. Myoclonic seizures ii. Clonic Seizures iii. Tonic Seizures iv. Versive Seizures v. Tonic-Clonic Seizures vi.
Epiletic Spasms
b. Complex Motor Seizures
i. Automotor seizures ii. Hypermotor seizures iii. Gelastic Seizures
• 5. Special Seizures
a. Atonic seizures b. Akinetic seizures c. Astatic seizures d. Negative myoclonic seizures e.
Hypomotor seizures f. Aphasic seizures
18. Syncope
• Precipitating factor apparent
• Warning/aura beforehand
• Multifocal arrhythmic jerks in up to 90%
• Head turns, oral automatisms in 70%
• Initial upward deviation of eyes common
• Consciousness may be partially preserved
• Short duration, rapid recovery
21. Dissociative seizures
• Tend to wax and wane
• Nature/frequency/amplitude of the movements
• Longer duration and build up
• Often quick recovery
• ?Thrashing, ?flailing, pelvic-thrusting,
opisthotonus
• May be distracted
• May cause injury
• ‘absences’
• May or may not be obvious precipitants
24. • Detailed description:
• Precipitating factors
• Onset of seizure
• Frequency of attacks
• Duration of attacks
• State of consciousness
• Age at onset
• Previous febrile seizures
• Perinatal and developmental history
• History of CNS infections or head trauma
• Family history of epilepsy
25. Aids to diagnosis….
• EEG
• MRI
• Others..
ECG,Echo,24 Hr or longer monitoring
Tilt test….
26. EEG
• An EEG should be performed only to support a diagnosis of epilepsy in
adults in whom the clinical history suggests that the seizure is likely to be
epileptic in origin.
• An EEG should be performed only to support a diagnosis of epilepsy in
children and young people. If an EEG is considered necessary, it should be
performed after the second epileptic seizure but may, in certain
circumstances, as evaluated by the specialist, be considered after a first
epileptic seizure.
• An EEG should not be performed in the case of
probable syncope because of the possibility of a false-positive result.
• The EEG should not be used to exclude a diagnosis of epilepsy in a child,
young person or adult in whom the clinical presentation supports a
diagnosis of a non-epileptic event.
• The EEG should not be used in isolation to make a diagnosis of epilepsy.
• An EEG may be used to help determine seizure type and epilepsy
syndrome in children, young people and adults in whom epilepsy is
suspected. This enables them to be given the correct prognosis.
• In children, young people and adults presenting with a first unprovoked
seizure, unequivocal epileptiform activity shown on EEG can be used to
assess the risk of seizure recurrence.
27. Neuroimaging
• Neuroimaging should be used to identify structural abnormalities
that cause certain epilepsies.
• MRI should be the imaging investigation of choice in children,
young people and adults with epilepsy.
• MRI is particularly important in those:
who develop epilepsy before the age of 2 years or in
adulthood
who have any suggestion of a focal onset on history, examination or
EEG (unless clear evidence of benign focal epilepsy)
In whom seizures continue in spite of first-line medication.
• Children, young people and adults requiring MRI should have the
test performed soon.
• Neuroimaging should not be routinely requested when a diagnosis
of idiopathic generalised epilepsy has been made.
32. Practical clinical definitions
“ two unprovoked seizures occurring at least 24
hours apart…..”
‘Unprovoked’: Absence of a temporary or a
reversible factor lowering the seizure threshold
‘Provoked’: Transient factor acting on an otherwise
normal brain to temporarily lower the seizure
threshold
33. Current practical definition
• At least two unprovoked (or reflex) seizures
occurring greater than 24 hours apart.
• One unprovoked (or reflex) seizure and a
probability of further seizures similar to the
general recurrence risk (at least 60%) after two
unprovoked seizures, occurring over the next 10
years.
• Diagnosis of an epilepsy syndrome
Epilepsy is considered to be resolved for individuals who had an age-
dependent epilepsy syndrome but are now past the applicable age or those
who have remained seizure-free for the last 10 years, with no seizure
medicines for the last 5 years
34. • What is the chance it can happen again?
• How long does it take to know it won’t
happen again?
• How effective is treatment?
• If treatment is delayed does it change my
chances of getting seizure control?
35. Risk of recurrence after first seizure
In prospective series….
• Meta-analysis by Berg and Shinnar 1991
36% by 2 years (Treated and untreated)
• FIRST Trial (Italy) 1993
51% in 2 years in untreated
• MESS Trial (MRC UK) 2005
39% in 2 years in the deferred treatment group
36.
37.
38. Treatment
• Sure of diagnosis?
• Risk of recurrence
• Severity of seizures
• Patient’s wishes
• Driving/employment
• Other factors eg pregnancy
43. • 47% of patients become seizure-free on 1st
antiepileptic drug
• 14% of patients become seizure-free on 2nd or
3rd antiepileptic drug
• Chance of becoming seizure-free after this
?4%
Kwan and Brodie(2000 NEJM)
45. Implications of diagnosis
• Legal restrictions eg driving
• Loss of independence
• Effect on work/loss of job
• Injuries
• Responsibilities eg childcare
• Anxiety/depression
• Underlying cause of seizures
Here is a diagram that shows a conceptual network for generalized seizures involving the corticothalamic circuitry. Theoretically a generalized seizure could start at different points in the network and engage bilaterally distributed networks. Thus a seizure could start frontally or even parietally.The key point is that a generalized seizure can start from a focal point.
Here is a diagram that shows a conceptual network for generalized seizures involving the corticothalamic circuitry. Theoretically a generalized seizure could start at different points in the network and engage bilaterally distributed networks. Thus a seizure could start frontally or even parietally.
Here the conceptual diagram of the network is superimposed on a functional MRI of generalized spike wave activity.