EPILEPSY (??)

1
EPILEPSY (??)

• Department of Neurology
• Ruijin Hospital, SSMU

2
Definition

• Epileptic seizure can be defined clinically as an
  intermittent,stereotyped,disturbance of
  consciousness,behavior, emotion,motor function,or
  sensation, arising from abnormal, sudden,
  excessive, and rapid neuronal discharges.
• Epilepsy is a chronic disorder, or a group of
  chronic disorders, in which the indispensable
  feature is recurrence of seizures that are
  typically unprovoked and usually unpredictable.

3
Definition

• Status epilepticus is a state of continued or
  recurrent seizures, with failure to regain
  consciousness between seizures for more than 30
  minutes.This is a medical emergency.
• Prodrome refers to premonitory changes in mood or
  behavior-these may precede the attack by some
  hours.

4
Definitions

• Aura is the subjective sensation or phenomenon
  that precedes and marks the onset of the
  epileptic seizure-it may localize the seizure
  origin within the brain.
• Ictus is the attack or seizure itself.
• Postictal period is the time after the ictus
  during which the patient may be drowsy, confused,
  and disoriented.

5
Etiology

• Primary epilepsy
• Secondary epilepsy
• Prenatal and perinatal factors
• Trauma and surgery
• Metabolic cuases
• Toxic causes

6
etiology

• Infectious and inflammatory causes
• Cerebral vascular diesease
• Intracranial tumors
• Hypoxia
• Degenerative disease
• photosensitivity

7
pathophysiology

• Electrical discharges between neurons are usually
  restricted, and produce the nornal rhythm
  recorded on the EEG (electroencephalogram).
• When a seizure occurs, large groups of neurons
  are activated repetitively and hypersynchronously,
  with dysfunction of the inhibitory synaptic
  contact between neurons. This produces the
  high-voltage spike-and-wave activity on the EEG.

8
pathophysiolosy

• The onset of the epileptic discharge may include
  the whole cortex (primary generalized), may be
  confined to one area of the cortex(partial), or
  may start focally and then spread to involve the
  whole cortex (secondary generalization of a
  partial seizure).

9
(No Transcript)
10
Classification of seizures

• The classification used today is the 1981
  classification of epileptic seizures developed by
  the international league against epilepsy(ILAE)
• This system classifies seizures by clinical
  symptoms supplemented by EEG data.
• Inherent in the classification are two important
  physiologic principles.

11
Classification of seizures

• First, seizures are fundamentally of two types
  those with onset liminted to a part of one
  cerebral hemisphere(partial seizures) and those
  that seem to involve the brain diffusely from the
  beginning(generalized seizures).
• Second, seizures are dynamic and evolving
• Clinically expression is determined as much by
  the sequence of spread of electrical discharge
  within the brain as by the area where the ictal
  discharge originates.

12
Classification of seizures

• Both generalized and partial seizures are further
  divided into subtypes.
• For partial seizures, the most important
  subdivision is based on consciousness, which is
  preserved in simple partial seizures or lost in
  complex partial seizures.
• For generalized seizures, subvisions are based
  mainly on the presence or absence and character
  of ictal motor manifestations.

13
Clinical features(partial seizures)

• Simple partial seizures result when ictal
  discharge occurs in a limited and often
  circumscribed area of cortex, the epitogenic
  focus. Almost any symptom or phenomenon can be
  the subjective (aura)or observable
  manifestation of a simple partial seizure,
  varying from elementary motor and unilateral
  sensory disturbance to complex emotional,
  psychoillusory, hallucinatory, or dysmnesic
  phenomena.

14
Clinical featurespartial seizures(simple)

• Especially common auras include an epigastric
  rising sensation, fear, a feeling of unreality or
  detachment, déjà vu and jamais vu experiences,
  and olfactory hallucinations. Patients can
  interact normally with the environment during
  simple partial seizures except for limitations
  imposed by the seizure on specific localized
  brain functions.

15
Clinical featurespartial seizures(simple)

• In the postictal state, a focal neurologic
  deficit such as hemiparesis(Todds paralysis)
  that resolves over a period of 1/2 36 hours is
  manifestation of an underlying focal brain
  lesion.
• Clonic movement of a single muscle group may
  spread to contiguous regions of the motor cortex
  (Jacksonian march).

16
Clinical featurespartial seizures(complex)

• Complex partial seizure, on the other hand, are
  defined by impaired consciousness
• In addition to loss of consciousness, patients
  with complex partial seizures usually exhibit
  automatisms, such as lipsmacking, repeated
  swallowing, clumsy perseveration of an onging
  motor task, or some other complex motor activity
  that is undirected and inappropriate.

17
Clinical featurespartial seizures(complex)

• Postictally, patients are confused and
  disoriented for several minutes, and determining
  the transition from ictal to postictal state may
  be difficult without simultaneous EEG recording.
• Of complex partial seizures, 70-80 arise from
  the temporal lobe foci in the frontal and
  occipital lobes account for most of the remainder.

18
Clinical featuresgeneralized seizures(grand mal)

• Generalized tonic-clonic seizures (grand mal) are
  characterized by abrupt loss of consciousness
  with bilateral tonic extension of the trunk and
  limbs (tonic phase), often accompanied by a loud
  vocalization as air is forcedly expelled across
  contracted vocal cords (epileptic cry), followed
  by synchronous muscle jerking (clonic phase).

19
(No Transcript)
20
Clinical featuresgeneralized seizures(grand mal)

• Postictally, patients are briefly unarousable,
  then lethargic and confused, often preferring to
  sleep.
• Many patients report inconsistent nonspecific
  premonitory symptoms include ill-defined anxiety,
  irritability, decreased concentration, and
  headache or other uncomfortable feelings.

21
Clinical featuresgeneralized seizures(grand mal)

• Indicative clinical features during an attack
  include pupil dilation, raised blood pressure and
  heart rate, extensor plantar responses, and
  central and nail-bed cyanosis.
• In generalized seizures, the PO2 and pH are
  lowered, the creatine phosphokinase (CPK) is
  elevated, and there is a marked elevation of
  serum prolactin.

22
(No Transcript)
23
Clinical featuresgeneralized seizures(absence)

• Absence seizures have an onset between 4 and 12
  years of age.
• Absence (petit mal) seizures are momentary lapses
  in awareness that are accompanied by motionless
  staring and arrest of any onging activity.
  Absence seizures begin and end abruptly they
  occur without warning and postictal period.
• Longer attacks may be accompanied by mild
  myoclonic jerks of the eyelid or facial muscles,
  variable loss of muscle tone, and automatisms.

24
Clinical featuresgeneralized seizures(absence)

• When the beginning and end of the seizure are
  less distinct, or if tonic or autonomic
  components are included, the term atypical
  absence seizure is used.
• Atypical seizure are seen most often in retarded
  children with epilepsy or in epileptic
  encephalopathies, such as the Lennox-Gastaut
  syndome.

25
(No Transcript)
26
Clinical featuresgeneralized seizures(myoclonic)

• Myoclonic seizures are characterized by rapid,
  brief ,shocklike muscle jerks that can occur
  bilaterally, synchronously, or asynchronously, or
  unilaterally. Myoclonic jerks range from isolated
  small movements of face, arm, or leg muscles to
  massive bilateral spasms simultaneously affecting
  the head, limbs, and trunk.
• myoclonic seizures may be idiopathic or
  associated with a variety of rare hereditary
  neurodegenerative disorders. Not all myoclonic
  jerks have an epileptic basis.

27
Clinical featuregeneralized seizures(atonic)

• Atonic seizures, also called drop attacks, are
  characterized by sudden loss of muscle tone,
  which may be fragmentary (e.g., head drop) or
  generalized, resulting in a fall.
• When atonic seizures preceded by a brief
  myoclonic seizure or tonic spasm, an acceleratory
  force is added to the fall, thereby contributing
  to the high rate of self-injury with this type of
  seizure.

28
Classification of epilepsy

• Attempting to classify the kind of epilepsy a
  patient has is often more important than
  describing seizures, because the formulation
  includes other relevant clinical data of which
  the seizures are only a part. The other data
  include historical information, findings on
  neurologic examination, and results of EEG, brain
  imaging, and biochemical studies.

29
Classification of epilepsy

• The ILAE classification separates major groups of
  epilepsy first on the basis of whether seizures
  are partial (localization-related epilepsies) or
  generalized (generalized epilepsies), and second
  by cause(idiopathic, symptomatic, or cryptogenic
  epilepsy).
• Subtypes of epilepsy are grouped according to the
  patients age and, in the case of
  localization-related epilepsies by the anatomic
  location the presumed ictal onset zone.

30
Classificatin of epilepsy

• Classification of the epilepsies had been less
  successful and more controversial than the
  classification of seizure types.

31
(No Transcript)
32
(No Transcript)
33
(No Transcript)
34
epidemiology

• In China, annual incidence rates for epilepsy
  range from 50-70 per 100,000.
• Of persons with epilepsy, 60-70 achieve
  remission with antiepileptic drug therapy.
• Mortality is increased in persons with epilepsy,
  higher death rates are related primarily to the
  underlying disease rather than epilepsy.
  Accidental deaths, especially drowning, are more
  common, in all patients with epilepsy.

35
Diagnosis

• The diagnostic evaluation has three objections
• First, to determine if the patient has epilepsy
• Second, to classify the type of epilepsy and
  identify an epilepsy syndrome
• Third, if possible, to define the specific
  underlying cause.

36
Diagnosis

• Because epilepsy comprise a group of conditions
  and is not a single homogeneous disorder, and
  because seizures may be symptoms of both diverse
  brain disorders and otherwise normal brain, it is
  neither possible nor desirable to develop
  inflexible guidelines for what constitutes a
  standard or minimal diagnostic evaluation.

37
Diagnosis

• The clinical data from the history and physical
  examination should allow a reasonable
  determination of probable diagnosis, seizure and
  epilepsy classification, and likelihood of
  underlying brain disorder.
• Based on these considerations, diagnostic testing
  should be undertaken selectively.

38
Diagnosis

• HISTORY
• A complete history is the cornerstone for
  establishing a diagnosis of epilepsy. An adequate
  history should provide a clear picture of the
  clinical features of the seizures and the
  sequence in which manifestations evolve the
  course of the epileptic disorder seizure
  precipitants, risk factors for seizures, and
  response to previous treatment. In children,
  developmental history is important.

39
Diagnosis

• HISTORY
• In describing the epileptic seizure, care should
  be taken to elicit a detailed description of any
  aura. Aura is actually a simple partial seizure
  that precede many complex partial or generalized
  seizures. It confirms the suspicion that the
  seizure begins locally within the brain and it
  may also provide direct clues about the location
  or laterality of the focus.

40
Diagnosis

• HISTORY
• Information about later events in the seizure
  must usually be obtained from an observer because
  of the patients impaired awareness or postictal
  amnesia.
• The nature of repetitive automatic or purposeless
  movements, sustained postures, presence of
  myoclonus, and the duration of the seizure help
  to delineate specific seizure types or epileptic
  syndromes.

41
Diagnosis

• HISTORY
• Information about risk factors may suggest a
  particular cause and assist in prognosis. Age at
  seizure onset and course of the seizure disorder
  should be clarified, because these features
  differ in the various epilepsy syndromes.

42
Diagnosis

• Physical examination
• Findings on neurologic examination are usually
  normal in patients with epilepsy, but
  occasionally may provide etiologic clues.
• Focal signs indicate an underlying cerebral
  lesion.

43
Diagnosis

• EEG
• EEG is the most important laboratory test in
  evaluating patients with seizure.
• It helps both to establish the diagnosis of
  epilepsy and to characterize specific epileptic
  syndromes. It may also help in management and in
  prognosis.

44
Diagnosis

• EEG
• Epileptiform discharges are recorded in 30-50 of
  epileptic patients on the first routine EEG and
  in 60-90 by the third routine EEG. Further EEGs
  do not increase yield appreciably. Sleep ,sleep
  deprivation, hyperventilation, and photic
  stimulation increase the likelihood of recording
  epileptiform discharges in some patients.

45
Diagnosis

• EEG
• Epileptiform discharges occur in 1-3 of healthy
  adults and children.
• Epileptiform discharges occur in 2.7 of adult
  patients with various illness,but with no history
  of seizures.
• Thus, the presence of epileptiform discharges in
  the appropriate clinical setting strongly
  supports the diagnosis of epilepsy but does not
  establish it unequivocally.

46
Diagnosis

• Long-Term Monitoring
• Long-term monitoring permits EEG recording for a
  long time, thus increasing the likelihood of
  recording seizures or interictal discharges.
• Two methods of long-term monitoring are now
  widely available simutaneous closed-circuit
  television and EEG(CCTV/EEG) monitoring and
  ambulatory EEG. Both greatly improved diagnostic
  accuracy and the reliability of seizure
  classification.

47
Diagnosis

• CT or MRI may reveal structural lesions that have
  caused the seizures or in complex partial
  seizures , may show hippocampal sclerosis.
• Metabolic or toxic disorders should be excluded,
  because they do not require anticonvulsants.

48
Differential diagnosis

• It is most important to distinguish epilepsy from
  other causes of transient focal dysfunction or
  loss of consciousness.
• The most common differentials include
• 1.Syncope(arrhythmias, carotid sinus
  hypersensitivity, vasovagal attacks, postural
  hypotensia) there is usually prodromal pallor,
  nausea, and sweating. Palpitations may be
  experienced with arrhythrias.

49
Differential diagnosis

• 2. Non-specific seizures (pseudoseizures)
  hysterical, attention-seeking, feigned seizures
  are surprisingly common, especially in patients
  with known epilepsy. The following features help
  to differentiate a pseudoseizure from an
  epileptic seizure pupils, blood pressure, heart
  rate, PO2, and pH remain unchanged plantar
  response are flexor, serum prolactin levels are
  normal the EEG shows no seizure activity during
  the episode and no postictal slowing.

50
Differential diagnosis

• 3. Transient ischemic attacks these can include
  transient loss of consciousness when the
  posterior circulation is involved.
• 4. Hypoglycaemia this can cause behavioral
  disturbance and seizures.

51
Treatment

• Therapy of epilepsy has three goals
• 1. To eliminate seizures or reduce their
  frequency to the maximum extent possible.
• 2. To avoid the side effects associated with
  long-term treatment.
• 3. To assist the patient in maintaining or
  restoring normal psychosocial and vocational
  adjustment.

52
TREATMENT

• There are four key principles of anticonvulsant
  drug treatment
• 1Establish the diagnosis of epilepsy before
  starting drug therapy. Therapeutic trials of
  anticonvulsant drugs intended to establish or
  reject a diagnosis of epilepsy may yield
  incorrect diagnosis.
• 2Choose the right drug for the seizure type.
  Absence seizure, for example, do not respond to
  most drugs used for complex partial or
  generalized tonic-clonic seizures.

53
TREATMENT

• 3Treat the seizures, rather than the serum drug
  levels. Control of seizures is activated at
  different drug levels in different patients.
• 4Evaluate one drug at a time. In most cases,
  seizures can be controlled with a single drug.
  Therefore, beginning therapy with multiple drugs
  may expose patients to increased drug toxicity
  without added therapeutic benefit.

54
TREATMENT

• The anticonvulsants in current clinical use
  include tranditional drugs such as phenytoin,
  carbamazepine, sodium valproate, phenobarbital,
  primidone, and ethosuxamide, and newer drugs such
  as lamotrigine, gabapentin, felbamate,
  topiramate, and vigabatrin.
• In general, the first-line drug for generalized
  epilepsy in adults is sodium valproate or
  lamotrigine, for absence epilepsy in children is
  ethosuximide, and for partial seizure is
  carbamazepine or lamotrigine.

55
(No Transcript)
56
(No Transcript)
57
Adverse of antiepileptic drugs

• All antiepileptic drugs may produce acute
  dose-related, acute idiosyncratic, or chronic
  toxicity, and variable degrees of teratogenicity
  (damage to the developing fetus).
• Acute toxicity some drugs cause a non-specific
  encephalopathy when blood levels are high, with
  sedation, nystagmus, ataxia, dysarthria, and
  confusion. If any of these features are present,
  blood vessels must be measured.

58
Adverse of antiepileptic drugs

• Idiosyncratic toxicity
• Allergic skin reactions occur in up to 10 of
  patients on phenytoin and in 15 on
  carbamazepine. Marrow aplasia is a rare
  complication of carbamazepine.
• Chronic toxicity
• Chronic toxicity is especially associate with
  phenytoin and induces the development of
  coarsened facies, acne and hirsuitism, gum
  hypertrophy, and peripheral neuropathy.

59
Adverse of antiepileptic drugs

• All anticonvulsants appear to have some effect on
  cognitive function. Carbamazepine and sodium
  valproate have fewer chronic effects than
  phenytoin.
• Teratogenicity
• Phenytoin increases the risk of major fetal
  malformation-including harelip, cleft palate, and
  cardiovascular anomalies-by 2-3 times.the use of
  sodium valproate and carbamazepine in pregnancy
  is associated with neural tube defects.

60
TREATMENT

• Discontinuance of anticonvulsants
• In view of the many adverse reactions associated
  with anticonvulsants, a patient who has achieved
  remission for over 3-5 years should be considered
  for drug withdrawal. However, there is the risk
  of recurrence of seizures, especially in some
  forms of epilepsy, and this has important
  consequences for driving, employment, and
  self-esteem. Thus, the final decision to attempt
  withdrawal must be made by the patient, and if
  undertaken, must be carried out very slowly, with
  gradually decreasing doses.

61
TREATMENT

• Neurosurgical treatment of epilepsy
• The indicatin for surgical treatment requires the
  accurate identification of a localized site of
  onset of seizures or the ability to disconnect
  epileptogenic zones and prevent spread as a
  palliative procedure.
• For temporal lobe surgery, the two conditions
  with the best surgical outcome are medial
  temporal sclerosis(Ammons horn sclerosis) and an
  indolent glioma of the medial temporal region.

62
TREATMENT

• When the diagnosis of epilepsy is made, the
  patient should be warned against working around
  moving machinery or at heights and reminded of
  the risks of swimming alone. The issue of driving
  must also be addressed. Many state governments
  have notification requirements when a diagnosis
  of epilepsy is made.

63
STATUS EPILEPTICUS

• General
• Status epilepticus may be either convulsive or
  nonconvulsive.
• Convulsive status epilepticus is a medical
  emergency, and failure to treat the condition in
  a timely and appropriate manner can result in
  serious systemic and neurologic morbidity.

64
STATUS EPILEPTICUS

• Aetiology
• Convulsive status epilepticus may be a
  manifestation either of idiopathic epilepsy or
  secondary to spread from localized epileptogenic
  brain region.

65
STATUS EPILEPTICUS

• Complication
• Convulsive status epilepticus generates metabolic
  and physiologic stress that contribute to
  permanent brain damage. These include
  hyperthermia, hypoxia, lactic acidosis,
  hypoglycemia, and hypotensia.
• Plama catecholamine levels are acutely
  elevated during the attack and may trigger fatal
  cardiac arrhythmias. Death usually results from
  the underlying condition rather than from the
  status epilepticus itself.

66
Management of Status epilepsy

• Respiratory and Cardiovascular support
• Termination of seizure
• Prevention of Seizure recurrence
• Management of precipitating causes-(hypoxia,
  electrolyte disturbances proconvulsant agents)
• Management of complications

67
Management of status epilepticus

• Termination of seizure
• Diazepam
• PHT, IV
• sodium amytal , IV
• Chloral Hydrate
• paraldehyde
• lidocaine
• If necessary, anesthetic treatment

68
Management of status epilepticus

• Prevention of seizure recurrence
• Phenobarbitol 0.1-0.2mg intramuscular, q8h.
• PHT or CBZ by nasalgastric tube

69

• ???,??,25?,???????????,????,???,?????,???????,?10?
  ??,????,????????,??????????,?????????????????,????
  ??????,??????,??,????
• ??1????????
• 2??????????
• 3???????????????,????????
• 4????????,????????