EPILEPSI

Dalam masyarakat Indonesia, banyak istilah yang digunakan dalam menggambarkan kejang seperti step atau ayan. Kadang seorang tenaga medis juga mengalami kesulitan ketika melakukan wawancara kepada pasien atau keluarga tentang kejang tersebut, mereka biasa mendeskripsikan sebagai tubuh yang bergetar atau gerakan-gerakan otot yang berkontraksi. Apakah itu sebuah bangkitan kejang atau gangguan pergerakan(movement disorder) atau jangan-jangan sebuah badan menggigil. Sehingga faktor anamnesis yang akurat sangat menentukan arah diagnosa nantinya. Sedangkan dalam terminologi kedokteran kejang(seizure) adalah aktivitas kelistrikan yang abnormal pada otak dengan adanya manifestasi klinis motorik atau tidak (Lancet, 1998). Maka tidak semua bangkitan kejang adalah epilepsi, dari data yang disampaikan oleh WHO tahun 2003 terdapat sekitar 50 juta orang diseluruh dunia menderita epilepsi, lalu apakah yang dimaksud dengan epilepsi tersebut.

Berdasarkan International Leaque Agains Epilepsy (ILAE), epilepsi adalah suatu penyakit otak yang ditandai dengan kondisi (1) Terdapat minimal 2 bangkitan tanpa provokasi atau 1 bangkitan refleks dengan jarak waktu antar bangkitan pertama dan kedua lebih dari 24 jam. (2) Suatu bangkitan tanpa provokasi atau 1 bangkitan refleks dengan kemungkinan terjadinya bangkitan berulang dalam 10 tahun kedepan sama dengan (minimal 60%) bila terdapat 2 bangkitan tanpa provokasi/bangkitan refleks(contohnya bangkitan pertama yang terjadi 1 bulan setelah kejadian stroke, bangkitan pertama pada anak yang disertai lesi struktural dan epileptiform discharges). (3) Sudah ditegakkan diagnosa sindrom epilepsi (Epilepsia, 2014).  Bangkitan refleks adalah bangkitan yang muncul akibat induksi oleh faktor pencetus spesifik, seperti stimulasi visual,auditorik, somatosensitif, dan somatomotor. 

Telah dilakukan penyerderhanaan klasifikasi epilepsi yang sudah ada sejak ILAE 1989, dimana klasifikasi internasional epilepsi saat ini melakukan penyusunan berdasarkan keperluan klinis untuk deskripsi kejang berdasarkan lokasi lesi yang mendasari tetapi tidak diperlukan deskripsi yang spesifik, selain itu juga perlu dihindari penggunaan terminologi berupa kriptogenik, idiopatik atau simtomatik untuk menjelaskan penyebab epilepsi (Epilepsia, 2010). 

Tipe bangkitan epilepsi (Epileptic Seizure Types):

•  Generalized seizures
  • Tonic-clonic seizures (in any combination)
    • associated with sudden onset and tonic stiffening, then rhythmic, clonic jerking of limbs
    • most common seizure type on presentation
  • Absence seizures - characterized by behavioral arrest and generalized spike and wave activity on electroencephalogram (EEG)
    • typical absence seizures - occur frequently, have abrupt onset and offset, and short duration (usually < 10 seconds)
    • atypical absence seizures - may not be as abrupt in onset or offset, usually longer in duration (> 20 seconds), and loss of consciousness may not be complete
    • absence with special features
      • myoclonic absence seizures
      • eyelid myoclonia
  • Myoclonic seizure types
    • myoclonic seizures - sudden, brief involuntary single or multiple contraction(s) of muscle(s) or muscle groups of variable limb location
    • myoclonic atonic
    • myoclonic tonic
  • Clonic seizures
  • Tonic seizures - abrupt generalized muscle stiffening that may cause patient to fall, usually last < 1 minute, and associated with rapid recovery
  • Atonic seizures - sudden onset of loss of muscle tone that may cause patient to fall, in conjunction with an EEG change; more commonly seen as part of an epilepsy syndrome

•  Focal seizures (originating within networks limited to 1 hemisphere) should be described by manifestations, such as
  • with or without impairment of consciousness or awareness
  • with observable motor or autonomic components
  • involving subjective sensory or psychic phenomena only
  • evolving to bilateral, convulsive seizure
• Unknown
  • epileptic spasms

Epilepsy syndromes

• Electrochemical syndromes, including
  • juvenile absence epilepsy
  • juvenile myoclonic epilepsy 
  • epilepsy with general tonic-clonic seizures alone
  • progressive myoclonus epilepsies (PME)
  • autosomal dominant epilepsy with auditory features (ADEAF)
  • other familial temporal lobe epilepsies
  • familial focal epilepsy with variable foci
  • reflex epilepsies
• Constellations, such as
  • mesial temporal lobe epilepsy with hippocampal sclerosis
  • hypothalamic hamartoma with gelastic seizures
  • Rasmussen syndrome
  • hemiconvulsion-hemiplegia epilepsy
  • other epilepsies that can be distinguished based on known structural or metabolic conditions and primary mode of seizure onset
• Structural or metabolic epilepsies
  • malformations of cortical development
  • neurocutaneous syndromes
  • tumor
  • infection
  • trauma
• Angioma
  • stroke
  • other insult
• Epilepsies of unknown cause

Classification of status epilepticus

• Generalized status epilepticus
  • generalized tonic-clonic status epilepticus
  • clonic status epilepticus
  • absence status epilepticus
  • tonic status epilepticus
  • myoclonic status epilepticus
• Focal status epilepticus
  • epilepsia partialis continua
  • aura continua
  • limbic status epilepticus (psychomotor status)
  • hemiconvulsive status with hemiparesis

DIAGNOSIS

- Diagnosa epilepsi ditegakkan berdasarkan kombinasi antara anamnesa didapatkan adanya 2 bangkitan atau lebih tanpa didahului faktor sakit atau pemicu lainnya dan aktivitas interictal epilepsi pada EEG. 

- Panduan untuk indikasi EEG pada epilepsi;

• National Institute for Health and Clinical Excellence (NICE) recommendations 2012 :
  • when required, EEGs should be performed within 4 weeks
  • EEG to support a diagnosis of epilepsy in adults should be done only if clinical history suggests seizure is epileptic in origin
  • EEG should not be performed if probable syncope because of possibility of false positive result
  • EEG should not be used to exclude diagnosis of epilepsy in patient with clinical presentation of nonepileptic event
  • EEG should not be used in isolation to make diagnosis of epilepsy
  • EEG can be used to determine seizure type and epilepsy syndrome
  • repeat EEGs
    • may be helpful when diagnosis of epilepsy or epilepsy syndrome is unclear
    • are not helpful if diagnosis is already established
  • repeat standard EEGs should not be used in preference to sleep or sleep-deprived EEGs
  • if standard EEG has not helped to make diagnosis or classification, sleep EEG should be done
  • long-term video or ambulatory EEG may be used in evaluation of patients with diagnostic difficulties after clinical assessment and standard EEG
  • photic stimulation and hyperventilation should be components of standard EEG; patient and family should be made aware that these activation procedures may induce seizures and that they have right to refuse them

TERAPI

Antiepileptic drugs (AEDs) are main treatment and are effective in 60%-70% of patients

• AED therapy usually started after second epileptic seizure, or after first unprovoked seizure if 
  • neurologic deficit
  • definite epileptic activity on electroencephalogram (EEG)
  • risk of having further seizures considered unacceptable
  • structural abnormality on neuroimaging
• use single AED (monotherapy) wherever possible
• if AED fails to control seizures, add second drug then slowly taper first drug to attempt monotherapy before combination therapy
• AED drug selection based on epilepsy syndrome, seizure type, adverse effect profile, and patient preferences
  • First-line drugs by epilepsy syndrome include
    • generalized tonic-clonic seizures only - carbamazepine, lamotrigine, oxcarbazepine, valproate
    • idiopathic generalized epilepsy - lamotrigine, valproate, topiramate
  • First-line drugs by seizure type include
    • generalized tonic-clonic seizures - carbamazepine, lamotrigine, oxcarbazepine, valproate
    • focal seizures (includes simple and complex partial seizures) - carbamazepine, lamotrigine, levetiracetam, oxcarbazepine, valproate
    • absence (petit mal) seizures - ethosuximide, lamotrigine, valproate
    • myoclonic seizures - levetiracetam, valproate, topiramate
    • atonic seizures or tonic seizures - valproate
• consider drug interactions (especially with hormonal contraception), and potential risk for fetal malformations if used during pregnancy (especially with valproate) (level 2 [mid-level] evidence)

consider AED discontinuation if seizure-free for > 2 years; taper one drug at a time with slow taper (≥ 2-3 months, or longer with benzodiazepines and barbiturates)

Referensi :

1. Delanty N, Vaughan CJ, French JA. Medical causes of seizures. Lancet. 1998 Aug 1;352(9125):383.

2. Berg AT, Berkovic SF, Brodie MJ, et al. Revised terminology and concepts for organization of seizures and epilepsies: report of the ILAE Commission on Classification and Terminology, 2005-2009. Epilepsia. 2010 Apr;51(4):676-85.

3. National Institute for Health and Clinical Excellence (NICE). The epilepsies: the diagnosis and management of the epilepsies in adults and children in primary and secondary care. NICE 2012 Jan:CG137