ppt

1. Seizure and Epilepsy
Presenter: Dr Ayalneh S (R1)
Moderator: Dr Samson Y (Neurologist)

2. Outlines
• Definition
• Epidemiology
• Classification
• Causes
• Pathogenesis
• Clinical evaluation
• Management
• Special population

5. Definition
• Seizure: A paroxysmal event due to abnormal excessive or synchronous neuronal
activity in the brain.
• Epilepsy:
1. Two or more unprovoked seizures occurring at least 24 hours apart
2. A single seizure accompanied by evidence of future seizure recurrence
3. When an epilepsy syndrome is diagnosed

6. Epidemiology
• 5–10% of the population will have at least one seizure.
• Globally the incidence of epilepsy is ~0.3–0.5%
• The prevalence has been estimated at 5–30 persons per 1000
• In Ethiopia- the Prevalence is 5.2/1000
– GTC - 81%
– Complex Partial - 13.9%
– Simple Partial - 5.1%
• Incidence=64/100,000

7. • 27-year-old man presented after experiencing an episode of
loss of awareness. His friend reported that he had been eating
dinner when he acutely stared off, which was followed by lip
smacking, chewing movements, and clenching of his left hand,
lasting a total of 90 seconds. He then appeared confused and
was back to baseline approximately 10 minutes after the
episode began

8. • The patient’s past medical history was notable for a prolonged
febrile seizure at age 18 months but was otherwise
unremarkable. He took no medications and had no family
history of seizures. He drank two to three glasses of wine a
week. He denied tobacco or illicit drug use. Physical and
neurologic examination were unremarkable

9. • Brain MRI revealed atrophy of the right mesial temporal region
and increased T2 signal in the right hippocampus
• EEG revealed right temporal slowing and epileptiform sharp
waves

12. The prevalence of epilepsy in the Zay Society,
Ethiopia–—An area of high prevalence
* Shitaye Alemu , Zerihun Tadesse , Paul Cooper c, Richard Hackett
* Seizure (2006) 15, 211—213
• Results
• Screening data were obtained from 1154 individuals of whom 82 were positive
for epilepsy. Detailed neurological assessment identified 43 subjects with a
history of seizures. The subjects conforming to the definition of active epilepsy
were 34, the prevalence rate being 29.5 per 1000. Of those with active epilepsy,
28 (82%) had primary GTC seizures, two secondary generalised partial seizures,
one had complex partial seizures and one had myoclonic seizures. Every subject
with active epilepsy or epilepsy in remission (n = 39) had a family history . 15
(44%) of the cases of active epilepsy were receiving no treatment, 13 (38%) were
on anticonvulsants, mostly phenobarbitone, three used traditional medicines .

15. Focal seizure
• Arise from a neuronal network localized within one cerebral
hemisphere.
• Usually associated with structural abnormality of the brain.
• Divided into
• Focal seizures without dyscognitive features.
• Focal seizures with dyscognitive features
• Focal seizures with secondary generalization.

16. Focal seizures without dyscognitive features
• Can cause motor, sensory, autonomic, or psychic symptoms without impairment of
cognition.
 May manifest as changes in
• Somatic sensation (e.g., paresthesia ),
• Vision (flashing lights , hallucinations)
• Equilibrium (sensation of falling or vertigo)
• Autonomic function(flushing, sweating, piloerection)

17. Focal seizures with dyscognitive features
• Accompanied by a transient impairment of the patient’s ability to maintain
normal contact with the environment.
• Unresponsive to visual or verbal commands during the seizure.
• The seizures frequently begin with an aura.

18. GENERALIZED SEIZURES
• Arises at some point in the brain but rapidly engage neuronal networks in both
cerebral hemispheres.
• Result from cellular, biochemical, or structural abnormality.
Typical Absence Seizures:
• Sudden, brief lapses of consciousness without loss of postural control
• Accompanied by subtle, bilateral motor signs
• Onset in childhood (4–8 years) or early adolescence.
• EEG symmetric, 3-Hz spike and wave discharge that begins and ends suddenly

19. Atypical Absence Seizures:
• Clinical and EEG features deviating from the typical
• Associated with diffuse or multifocal structural abnormalities of the brain
• Less responsive to treatment.

20. Generalized Tonic Clonic Seizure
• The most common seizure type _ 10% of all persons with epilepsy
o The tonic phase (10-20 seconds)
 Tonic contraction of muscles throughout the body
 EEG - generalized high-amplitude rapid spiking
o The clonic phase:
 Rhythmic jerking
o The postictal period : the period of brain recovery

21. Atonic Seizures
• Sudden loss of postural muscle tone lasting 1–2 s
• Consciousness is briefly impaired but no postictal confusion
• EEG shows brief, generalized spike-and-wave discharges

22. Myoclonic Seizures
• A sudden and brief muscle contraction
• There is no loss of consciousness
• EEG shows bilaterally synchronous spike-and-wave discharges

23. Epilepsy SYNDROMES
• Disorders in which epilepsy is a predominant feature, and there is sufficient evidence
(clinical, EEG, radiologic, or genetic observations) to suggest a common underlying
mechanism.
• Three important epilepsy syndromes:
1 Juvenile Myoclonic Epilepsy(JME)
A generalized seizure disorder of unknown cause.
Appears in early adolescence
Characterized by bilateral myoclonic jerks(single or repetitive)
Treatment –respond well to appropriate anticonvulsant

24. Con…
2.Lennox-Gastaut Syndrome (LGS)
• Associated with CNS disease or dysfunction
• Commonly occurs in children defined by the following triad
• 1 multiple seizure types.
• 2 EEG slow (<3 Hz) spike-and-wave discharges.
• 3 Impaired cognitive function in most cases.
• Many patients have a poor prognosis due to the underlying CNS disease

25. 3. MESIAL TEMPORAL LOBE EPILEPSY SYNDROME
• The most common syndrome associated with focal seizures with dyscognitive features.
• High resolution MRI → hippocampal sclerosis
• Treatment: responds well to surgical intervention.

26. CAUSES OF SEIZURES AND EPILEPSY
• Seizures are a result of a shift in the normal balance of excitation and inhibition
within the CNS
 Factors that determine the occurrence of seizure:
1.Endogenous factors
2.Epileptogenic factors
3.Precipitating factors

29. MECHANISMS OF EPILEPTOGENESIS
• Neuronal circuits are composed of excitatory and inhibitory neurons and their
dendrites and axons, synapses, and glial cells.
• Two major types of ion channels are responsible for inhibitory and excitatory
activity:
1.Voltage-gated channels
• Depolarizing currents are excitatory and are mediated by inward sodium and
calcium conductance
• Hyperpolarizing currents are inhibitory and mediated by inward chloride and
outward potassium conductance
2.Ligand-gated receptors
Mediate signals from neurotransmitters such as glutamate and GABA

30. Psychogenic Seizures
• Nonepileptic seizures are episodes of altered movement, sensation, or
experience distinguished from epileptic seizures by the lack of associated ictal
abnormal electrical brain discharges.
• About 88% of patients with nonepileptic seizures are deemed to have a
psychogenic etiology.
 psychogenic seizure commonly present
-Side-to-side turning of the head
-Asymmetric and large-amplitude shaking movement of the limbs
-Twitching of all extremities without loss of consciousness,

32. Approach to the Patient with Seizure
• If the patient have first seizure, then the emphasis will be to:
– (1) Establish whether the reported episode was a seizure rather than
another paroxysmal event.
– (2) Determine the cause of the seizure by identifying risk factors and
precipitating events.
– (3) Decide whether anticonvulsant therapy is required in addition to
treatment for any underlying illness.

33. History
• The first goal is to determine whether the event was truly a
seizure.
o An in-depth history is essential
o Questions should focus on the symptoms before , during , after and
the episode.
o Witnesses to the event should be interviewed carefully.

34.  History should also focus on risk factors:
• Febrile seizure
• Family history of seizures
• Prior head trauma , stroke, tumor, or infection the nervous system
 Precipitating factors:
 Sleep deprivation, systemic diseases, electrolyte or metabolic
derangements
 Acute infection, drugs that lower the seizure threshold or alcohol
or illicit drug use.

35. Physical examination
• Search for signs of infection or systemic illness
• HEENT – head trauma
• CVS-- Auscultation of the heart and carotid arteries.
• GIS- HSM - a metabolic storage disease.
• INTEGU- neuro cutaneous disorders, such as tuberous sclerosis or
neurofibromatosis, or chronic liver or renal disease.
• CNS - All patients require a complete neurologic examination.

36. Investigations
• CBC , ESR , Serum electrolytes , glucose , OFT.
• Screen for toxins in blood and urine.
• autoantibodies in the serum and CSF.
• Lumbar Puncture
– If any suspicion of meningitis or encephalitis.
– Mandatory in all patients infected with HIV.

37. EEG
• All patients who have a possible seizure disorder should be evaluated with an EEG.
 Abnormal, repetitive, rhythmic activity having an abrupt onset and termination—
clearly establishes the diagnosis.
 Normal EEG does not exclude a seizure disorder.
→ Focal seizures may originate from a region of the cortex that cannot be detected
by standard scalp electrodes.
 The EEG is always abnormal during generalized tonic-clonic seizures.

38. • However, even in an individual who is known to have epilepsy,
the initial routine interictal EEG may be normal up to 60% of
the time.

39. seizures are typically infrequent and unpredictable, it is often
not possible to obtain the EEG during a clinical event. In such
situations, activating procedures are generally undertaken
while the EEG is recorded in an attempt to provoke
abnormalities. These procedures commonly include
hyperventilation (for 3 or 4 min), photic stimulation, sleep, and
sleep deprivation on the night prior to the recording

40. Con…
• The clinical applications of EEG include:
• Diagnosis of epilepsy.
• Selection of AED therapy.
• Evaluation of response to treatment.
• Determination of candidacy for drug withdrawal.
• To assess the prognosis of seizure disorders.
• Surgical localization.
• The EEG is also used for classifying seizure disorders and aiding in
the selection of anticonvulsant medications

41. • For example, episodic generalized spike-wave activity is usually
seen in patients with typical absence epilepsy and may be seen
with other generalized epilepsy syndromes. Focal interictal
epileptiform discharges would support the diagnosis of a focal
seizure disorder such as temporal lobe epilepsy or frontal lobe
seizures, depending on the location of the discharges

42. video-EEG
 Record EEG continuously ≥24 h.
 For accurate diagnosis.
 For Seizures that are difficult to control
Brain Imaging:
• Almost all patients with new-onset seizures should have a brain imaging study.
• MRI preferable than CT for the detection of cerebral lesions associated with
epilepsy

43. Magnetoencephalography (MEG
• it measures the small magnetic fields that are generated by
this activity

44. GENETIC TESTING

47. Treatment of seizure and Epilepsy
o Principles:
• Treatment of underlying conditions that cause or contribute
to the seizures.
• Avoidance of precipitating factors.
• Suppression of recurrent seizures by prophylactic therapy
with AED or surgery.
• Addressing a variety of psychological and social issues.

48. con..
 Treatment of Underlying Conditions
 Serum electrolytes or glucose, medication
 Brain tumor, vascular malformation, or brain abscess
 Avoidance of Precipitating Factors:
Stress
Alcohol intake
Sleep deprivation

49. Antiepileptic Drug Therapy
• AED is the mainstay of treatment for most patients with
epilepsy
o The Overall goal is
– controlling seizures
– avoiding treatment side effects
– maintaining or restoring quality of life

50. Mechanisms of Action of AED
• Antiepileptic drugs appear to act primarily by blocking the initiation or spread of seizures.
1. Inhibition of Na+-dependent action potentials.
( phenytoin, carbamazepine, lamotrigine, topiramate,zonisamide, lacosamide, rufinamide)
2. Inhibition of voltage-gated Ca2+ channels → phenytoin ,gabapentin, pregabalin.
3. Potentiation of GABA receptor function → benzodiazepines and barbiturates
4. Increase in the availability of GABA  valproic acid, gabapentin, tiagabine.
5. Decrease of glutamate release lamotrigine.
6. Modulation of release of synaptic vesicles  levetiracetam

51. When to Initiate Antiepileptic Drug Therapy
 Recurrent seizures of unknown etiology or a known cause that cannot be reversed
 For Single seizure treatment is controversial
o Identified lesion such as a CNS tumor, infection, or trauma.
o Unprovoked or idiopathic seizure
→ recurrence risk 31 to 71% in the first 1 year after the initial seizure.

52. Con..1000299038827
• Risk factors associated with recurrent seizures :
– An abnormal neurologic examination
– Seizures presenting as status epilepticus
– Postictal Todd's paralysis
– A strong family history of seizures
– An abnormal EEG

53. Selection of Antiepileptic Drugs
Factors affecting initial drug selection;
– Efficacy, convenience of dosing,
– Side effects and Interactions with other medications
– Comorbid medical conditions hepatic and renal disease
– Availability and cost
o Older Drugs
– Generally used as first-line therapy for most seizure disorders
o Newer drugs:
– Add-on or alternatives
– Some are used as first line

58. When to Discontinue Therapy
• 70% of children and 60% of adults who have their seizures completely controlled with
antiepileptic drugs can eventually discontinue therapy.
 Following patient profile yields greatest chance of remaining seizure-free after drug
withdrawal:
1 Complete medical control of seizures for 1–5 years;
2 Single seizure type
3 Normal neurologic examination
4 Normal EEG.

59. • For Patients who meets all of the above criteria reasonable to withdrawal of
therapy after 2 years.
• Reduce the dose of the drug gradually over 2–3 months
• Most recurrences occur in the first 3 months after discontinuing therapy

60. Treatment of Refractory Epilepsy
• 1/3 of patients with epilepsy do not respond to single AED.
• Combination of drugs to control seizures.
• Combine drugs with different mechanisms of action
 Focal epilepsy due to structural lesion
 Multiple seizure types
 Developmental delay

62. Surgical Treatment of Refractory Epilepsy
• 20–30% of patients with epilepsy are resistant to medical therapy.
 Temporal lobe epilepsy :
.Temporal lobectomy
.Amygdalohippocampectomy
 Extratemporal Focal seizures: lesionectomy
 Hemispherectomy or multilobar resection → severe seizures
due to hemispheric abnormalities

63. ketogenic diet
• Patients who are not candidates for epilepsy surgery
• The classic ketogenic diet is a high-fat, low-carbohydrate diet with ratio of fat to
carbohydrate is 3:1 or 4:1
• Ketone bodies created in the liver from long and medium-chain fatty acids, are
directly anticonvulsant when crossing the blood-brain barrier.
• Enhanced gamma aminobutyric acid (GABA) levels
• Reduced neuronal excitability and firing
• Stabilized synaptic function
• Reduced glucose fluctuations

64. STATUS EPILEPTICUS
• A continuous seizures or repetitive, discrete seizures with impaired consciousness in the
interictal period.
• The duration of seizure traditionally 15–30 min
• It is a neurologic emergency with a time-dependent impact on morbidity and mortality
o The most common causes of GCSE
• Anticonvulsant withdrawal or noncompliance
• Metabolic disturbances
• Drug toxicity, CNS infection
• CNS tumors
• Refractory epilepsy
• Head trauma

68. WOMEN AND EPILEPSY
• Multidirectional interactions exist between epilepsy and seizures, female sex steroid
hormones, and AEDs
• Female sex steroid hormones and their metabolites act as direct neuro steroids
• Changes in estradiol levels can also increase the clearance of some AEDs
• Both AEDs and epilepsy itself can adversely affect function of the hypothalamic-
pituitary-ovarian axis

70. con…
1 CATAMENIAL EPILEPSY:
• Increase in seizure frequency around the time of menses
 Effects of estrogen and progesterone on neuronal excitability
 Altered AED levels due to protein binding or metabolism
Treatment: -Increase antiepileptic drug dosage
- Acetazolamide or clobazam
- Medroxyprogesterone acetate (OCP)

71. PREGNANCY
• Seizure frequency remain unchanged in ~50% of women
• Increase in 30%
• Decrease in 20%
• The overall incidence of fetal abnormalities in children born to mothers with
epilepsy is 5–6%.
• The most common malformations were defects in the cardiovascular ,neural
tube and musculoskeletal system.
• Valproic acid is strongly associated with an increased risk of adverse fetal
outcomes(7—20%).

73. CONTRACEPTION
 Oral contraceptives, patches, rings, are no longer first-line contraceptive
methods for women with epilepsy who use enzyme-inducing AEDs
• Long acting reversible contraceptive (LARC) is an excellent choice.
-Progestin implant
-An intrauterine device (IUD)

74. EPILEPSY IN ELDERLY PATIENTS
• Focal seizures are the most common seizure type observed in elderly patients with
new-onset epilepsy
• Stroke and Neurodegenerative diseases are the most common etiologies
• AEDs have a decreased clearance of 20% or more in older adults
 Decreases in renal clearance
 Decreases in hepatic blood flow and liver size
 Decreases in gastrointestinal absorption
 Decreases in serum albumin
 Renally cleared AED are preferred in elderly patient.

75. Interaction between AEDs and ARVs
• The prevalence of seizures in patients with HIV infection has been reported as
11% to 20%
 significant interactions existed between
 Phenytoin and lopinavir
 Valproate and zidovudine
 Ritonavir/atazanavir and lamotrigine
• AEDs without known drug-drug interactions can be considered
--levetiracetam, lacosamide, clobazam, pregabalin, and gabapentin
• Efavirenze ??

77. Bone Disease
• Cytochrome P450 enzyme inducers AED have a direct effects on bone health
 Disturbed vitamin D-parathyroid hormone axis:
-Higher bone turnover
- Reduced serum concentration of vitamin D
-Reduced bone mineral density
• The newer AEDs lamotrigine, gabapentin, topiramate, and tiagabine found no
evidence of impaired bone health
 Employment and Driving license??

78. THANK YOU