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Epilepsy

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					        Epilepsy

Dr. Abdelkawi Hammad
  Prof. Internal Medicine-Cairo University
        The commoner types of
               epilepsy
Abridged from International League against Epilepsy


1-Generalized seizure types
   A-Absence seizures
       (I) Typical absences with 3 Hz spike-and-wave discharge (petit
            mal)
       (II) Atypical absences with other EEG changes
   B-Myoclonic seizures
   C-Tonic-clonic seizures (grand mal, major convulsion)
   D-Tonic seizures
   E-Akinetic seizures
    The commoner types of
           epilepsy
2-Partial seizure types
These start by activation of a group of neurones in one
  part of one hemisphere. They are also called 'focal
  seizures'
   A-Simple partial seizures (without impairment of
     consciousness) (e.g. Jacksonian seizures)
   B-Complex partial seizures (impairment of consciousness)
   C-Partial seizures evolving to tonic-clonic seizures
   D-Apparent generalized tonic-clonic seizures, with EEG but not
     clinical evidence of focal onset
3-Unclassifiable seizures
  Seizures which do not fit one of the above categories
 Aetiological and precipitating
       factors in epilepsy
 Genetic predisposition
 Developmental, e.g. hamartomas, neuronal migration abnormalities
 Trauma and surgery
 Pyrexia
 Intracranial mass lesions, e.g. tumour, neurocysticercosis
 Vascular, e.g. cerebral infarction, arteriovenous malformation
 Drugs and drug withdrawal
 Encephalitis and inflammatory conditions
 Metabolic abnormalities, e.g. porphyria, hypocalcaemia
 Neural degenerative disorders
 Provoked seizures, e.g. photosensitivity, sleep deprivation
       Principal antiepileptic drugs and
            common seizure types
     Drug            Partial    2°Generalized        Tonic-        3 Hz  Myoclonic
                                                     clonic      absence
Carbamazepine           +               +               +             -        -

 Ethosuximide           0               0                0           +         0

 Phenobarbital          +               +               +            0        +(?)

   Phenytoin            +               +               +             -        -

   Primidone            +               +               +            0         ?

   Valproate            +               +               +            +         +

+, efficacy proven/probable; 0, ineffective; - worsens seizures; ?, unknown
After Brodie MJ (2000) Lancet 356: 324
Doses and therapeutic levels of
      antiepileptic drugs

    Drug        Usual adult daily dose (mg)   Therapeutic range
                                                  (μmol/L)
  Phenytoin              300-500                    40-80

Carbamazepine            400-1000                   20-50

  Valproate              800-2000                   20-50
Some idiosyncratic unwanted effects
       of anticonvulsant drugs

        Drug          Non-dose-related side-effects
      Phenytoin     Rashes
                    Blood dyscrasias
                    Lymphadenopathy
                    Systemic lupus erythematosus
                    Toxic epidermal necrolysis
    Carbamazepine   Rashes
                    Blood dyscrasias, particularly
                    severe leucopenia
                    Toxic epidermal necrolysis
Some idiosyncratic unwanted effects
      of anticonvulsant drugs

         Drug          Non-dose-related side-effects



    Sodium valproate             Anorexia
                                 Hair loss
                              Liver damage
      Lamotrigine       Toxic epidermal necrolysis



       Vigabatrin      Retinal damage (visual field
                        constriction)Psychological
                                  change
          Newer antiepileptic drugs and
                 common seizure types
   Drug        Partial   2°Generalized       Tonic-clonic       3 Hz           Myoclonic
                                                              absence
Gabapentin       +              +                +(?)             0               -(?)

Lamotrigine      +              +                  +              ?                +

Levetiraceta     +              +                  +              0                0
     m
Oxcarbazepi      +              +                  +              +                +
    ne
 Tiagabine       +              +                  ?              ?                ?

Topiramate       +              +                  +              ?                +

Vigabatrin       +              +                +(?)              -               -

+, efficacy proven/probable; 0, ineffective; -, worsens seizures; ?, unknown
Management of Status Epilepticus

Several treatment schedules exist. Issues of
prime importance are the speed with which
convulsive activity is treated, the accuracy of
diagnosis and need for continued monitoring
and cardiorespiratory support - this must be
available. An ITU is essential for optimum
management.
Management of Status Epilepticus

At home, give immediate diazepam 10-20 mg i.v. at 5
 mg/min and repeat once. If immediate i.v. access is
 impossible, give rectally diazepam or paraldehyde.
Arrange immediate admission to hospital.
Administer oxygen, monitor ECG, BP, routine bloods
 (include alcohol, calcium, magnesium, drug screen,
 anticonvulsant levels). Exclude hypoglycaemia: treat if
 present.
Give thiamine i.v. (250 mg) if nutrition poor or alcohol
 abuse suspected. (In the UK parenteral vitamin B and
 C, one pair of high-potency i.v. ampoules over 10
 minutes.
    Management of Status Epilepticus
Anticonvulsants
 1-Give lorazepam i.v. 4 mg at 2 mg/min. Respiratory
     depression, hypotension and cardiac dysrhythmias
     may occur. (Lorazepam 4 mg vial.)
 2-Reinstate previous anticonvulsant drugs. Establish
    whether the patient has had adequate phenytoin
    recently. Measure levels as an emergency if service
    available
     Management of Status Epilepticus
Anticonvulsants
    3-If seizures continue, consider i.v. phenytoin or fosphenytoin (if
      patient is not already loaded with these drugs).
            I-Phenytoin: give 15 mg/kg i.v. diluted to 10 mg/mL in normal
              saline into a large vein at less than 50 mg/min. (Phenytoin
              sodium 250 mg 5 mL ampoule.)
            II-Fosphenytoin: this is a pro-drug of phenytoin and can be given
              faster than phenytoin. Doses are expressed in phenytoin
              equivalents (PE): fosphenytoin 1.5 mg = 1 mg phenytoin
            III-Give 15 mg/kg (PE) fosphenytoin (15 mg × 1.5 = 22.5 mg)
              diluted to 10 mg/mL in normal saline at 50-100 mg (PE)/min.
              (Fosphenytoin sodium 750 mg 10 mL ampoule.)
    Management of Status Epilepticus
Anticonvulsants


   4-If status continues, give phenobarbital 10 mg/kg
   diluted 1 in 10 in water for injection at < 100 mg/min.
   (Phenobarbital 200 mg/mL 1 mL vial in propylene glycol
   90% with water for injection 10%.) Intravenous
   clonazepam, paraldehyde and clomethiazole are also
   used
   5-If, despite these measures, status persists > 90
   minutes, use thiopental or propofol anaesthesia with
   assisted ventilation
Management of Status Epilepticus

 EEG monitoring is valuable if there is doubt about the
  nature of status.
 CT scanning may reveal an underlying cause for
  status.
 Remember: 25% of apparent status turns out to be
  pseudostatus.
 Remember: potential unwanted effects of the drugs
  (e.g. hypotension, cardiac arrest) and the need for
  continuous cardiorespiratory monitoring
Thank
YOU

				
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posted:8/31/2012
language:English
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