Surgical Options for Epilepsy

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Surgical Options for Epilepsy
IN CHILDREN
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Description
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• Epilepsy is a chronic condition characterized by
  recurrent seizures
• It is frequently diagnosed in childhood, and more
  than 75 of patients have their first seizure
  before the age of 18 years
• They occur as a result of the synchronous firing
  of neurons, and can be caused by any number of
  structural, metabolic, or drug-induced changes

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• Diagnostic decision

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• Diagnosis of epilepsy is a three-step process,
  involving clinical identification of possible
  seizure, consideration of differential diagnoses,
  and classification of seizure
• Diagnosis of an epileptic syndrome may be
  possible after consideration of age at onset and
  type of seizure, cognitive development and
  neurologic examination, and electroencephalography
  (EEG) findings

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• Summary of therapies

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• Treatment of epilepsy involves three important
  steps
• (1) establish correct diagnosis of epilepsy and
  syndrome/seizure type
• (2) decide if medical management with
  anticonvulsant pharmacotherapy is necessary
• (3) select anticonvulsant, if required

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• Treatment should always be started with
  monotherapy duration of therapy depends on
  diagnosis, response, and age at onset
• The selection of anticonvulsant pharmacotherapy
  is complex and depends on the type of
  epilepsy/seizure, relative convenience of dosing
  schedule, and potential adverse events
• Prescription of anticonvulsant pharmacotherapy in
  patients who have had a single seizure is
  controversial

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• Surgical Options for Epilepsy

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• What Is Epilepsy Surgery?
• Epilepsy surgery is an operation on the brain to
  control seizures and improve the person's quality
  of life. There are two main types of epilepsy
  surgery
• 1. surgery to remove the area of the brain
  producing seizures.
• 2. surgery to interrupt the nerve pathways
  through with seizure impulses spread within the
  brain.

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• Who Is a Candidate for Epilepsy Surgery?

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Indication

• Partial seizures
• Seizures refractotory to optimal medical
  manegement
• The side effects of medication are severe
• Epilepsy affect greatly the quality of life
• Epilepsy prolong plus 2 years

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• What Tests Are Used During the Pre-surgical
  Evaluation?

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• Electroencephalography (EEG) - An EEG is helpful
  in diagnosing brain disorders by detecting
  abnormal electrical activity in the brain.
• Magnetic Resonance Imaging (MRI) -A MRI creates a
  very clear image that can show abnormalities of
  the brain in great detail.
• Magnetic Resonance Spectroscopy (MRS) - MRS uses
  the same equipment as a MRI, but uses different
  computer software that can measure the chemical
  components of brain tissue.

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• Positron Emission Tomography (PET) - PET is a
  scanning technique that measures cellular
  activity (metabolism) in the brain and other
  organs, providing information about organ
  function rather than structure. Areas of
  decreased usage glucose may point to the seizure
  focus.

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• Single Photon Emission Computed Tomography
  (SPECT) - SPECT is a test that shows blood flow
  in the brain. A small amount of a radioactive
  substance is injected into the patient's
  bloodstream through a vein in the patient's arm.
  After several hours, scanning is done to see how
  the brain has absorbed the material. This
  provides a picture of how blood flows through the
  brain.

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• EEG-video monitoring - Video cameras are used to
  record seizures as they occurThe characteristics
  of the persons behavior during a seizure can help
  to identify the seizure focus.
• Invasive monitoring - Also called intracranial
  EEG, this technique involves surgically placing
  electrodes inside the skull directly in or over a
  specific area of the brain to record electrical
  activity.

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• Neuropsychological testing - These tests can help
  to pinpoint the location of the seizure focus by
  identifying areas of decreased brain function.
  They also provide baseline information and are
  then repeated after surgery to see if there is
  any change in mental functioning.
• Psychiatric evaluation - Undergoing surgery for
  epilepsy is a long and difficult process. A
  psychiatric evaluation helps the person develop
  reasonable goals and expectations, as well as
  prepare for the surgery and recovery phases.

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• What Surgical Options Are Available?
• The surgical procedure chosen depends on the type
  and localization of the seizures

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• Temporal lobectomy EBM
• Temporal lobectomy is the most commonly performed
  invasive surgical procedure.
• Indication
• Patients who have medically refractory epilepsy
  in the temporal lobe and those with a clear focus
  of epileptic discharge on EEG analysis (routine
  or more specialized EEG testing), along with a
  compatible imaging study demonstrating typically
  the area of involvement (most commonly the mesial
  temporal lobe).

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• Risks/benefits
• Deficits in speech or motor function or, in
  extremely rare cases, to severe brain injury,
  coma, or death.
• Transient speech deficits
• Loss of recent memory function after surgical
  intervention is not infrequent (months to a year
  or more).
• Surgery on the left temporal lobe does not impair
  intelligence to any significant degree. Long-term
  follow-up studies using precise cognitive testing
  have shown that changes in function are minimal
  in most patients.

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• Improvement in cognitive functioning.
• Double vision.
• General risks of surgery include those relating
  to anesthesia, bleeding, and infection.
• Cure is not always possible and some patients may
  still experience some seizures. If successful,
  the procedure may improve quality of life,
  prolong survival, and help prevent sudden death
  associated with epilepsy.

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• Preoperative considerations

Potential risks, complications, benefits, as
well as treatment alternatives, must be discussed
in detail with the patient and family prior to
surgery.
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• Complications Early
• Risk of infection
• Stroke
• Seizure are highest during the first 30 days
  following surgery.

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• Evidence
• At one year, temporal lobectomy significantly
  increased the likelihood of being completely
  seizure free, of being free of seizures with or
  without auras, improved quality of life, and
  increased the proportion of people who were
  employed or attending school, compared with
  medical treatment

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• Hemispherectomy
• Hemispherectomy should be performed early in life
  to improve seizure control and arrest the
  intellectual deterioration that is associated
  with intractable seizure disorder
• Indication
• Hemispherectomy early in life is the best
  treatment course in children with extensive
  hemispheric lesions.
• Risks/benefits
• Surgery can take up to 12h and there is always
  some paralysis on one side of the body. There is
  a small risk for hydrocephalus, coma, or even
  death. Quality of life is almost always improved
  and surgery does not impair intelligence.

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• Corpus callosotomy
• Indication
• Procedure has been used in Lennox-Gastaut
  syndrome. It provides most relief for patients
  with atonic seizures.
• Risks/benefits
• Complications can be severe. Complete corpus
  callosotomy produces interhemispheric sensory
  dissociation with complete and permanent
  somatosensory auditory and visual dissociation.
  Deficits can be minimized by performing a limited
  anterior two-thirds corpus callosotomy. Surgery
  can reduce (but not entirely stop) uncontrolled
  tonic-clonic seizures.

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• Vagal nerve stimulator implantation EBM
• Indication
• Adjunctive therapy for reducing the frequency of
  seizures patients aged over 12 years with
  medically intractable and inoperable seizures
• An implantable vagal nerve stimulator is suitable
  for patients with refractory partial seizures not
  amenable to resection surgery because of lack of
  resectable locus.

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• Risks/benefits
• There are short term risks of infection,
  vocal-cord paresis, lower facial weakness, and
  rarer risks of bradycardia and asystole within
  the operating room.
• Longer term risks include stimulus-related throat
  pain (superior laryngeal nerve stimulation),
  stimulus-related hoarseness (recurrent larygeal
  nerve stimulation), stimulus-related dyspnea,
  stimulusa-related paresthesia, stimulus-related
  coughing, as well as a continued risk of
  infection.
• Vagal nerve stimulation is as traightforward and
  effective treatment for epilepsy, it can be
  performed under local anesthesia, requires only
  24h hospitalization, does not interact with
  anti-ictal drugs, and no alterations in autonomic
  function has been observed. Improvement may not
  be immediate and might require up to 2 years to
  become apparent.

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• Complications
• EarlyInfection, vocal-cord paresis, and lower
  facial weakness.
• LateStimulus-related throat pain (superior
  laryngeal nerve stimulation), stimulus-related
  hoarseness (recurrent larygeal nerve
  stimulation), stimulus-related dyspnea,
  stimulus-related paresthesia, stimulus-related
  coughing, as well as a continued risk of
  infection.

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• Evidence
• VNS stimulation using the high stimulation model
  was significantly better than low stimulation
  with regard to overall efficacy. VNS was well
  tolerated, despite adverse effects of hoarseness,
  cough, pain, paresthesias, and dyspnea
  withdrawal from treatment was rare in both groups
  20Level A

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• Efficacy of therapies
• Approx. 60-70 of all children with epilepsy
  enter prolonged remission (gt5 years) with
  monotherapy. About half of these patients
  eventually become seizure-free
• 30 of patients, usually with severe epilepsy
  starting in early childhood, continue to have
  seizures and never achieve remission
• Surgical resection of epileptogenic tissue in
  patients with complex partial seizures of
  temporal lobe origin has success rates (defined
  as no seizures for 5 years after surgery, some
  auras may be present) of 55-70 (mortality rate
  lt5)

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Thanks for your attentions !