•Seizure- A seizure is defined as a paroxysmal involuntary disturbance of brain function that may manifest as impairment or loss of consciousness,behaiviural abnormalities, abnormal motor, sensory or autonomic function due to abnormal, excessive, hypersynchronise discharges from a aggregate of CNS.

•Convulsion-It is the motor phenomenon of seizure manifested as a sudden episode of decerebrale posturing followed by chronic jerking.

•Epilepsy- It is recurrent seizure due to chronic, underlying process in the brain (Tendency to have recurrent seizure).

PATHOPHYSIOLOGY

•The generation of seizure is an incompletely understood process & involve abnormalities in the ion channels & receptor of the cell membrane& neuronal circuits, In the normal functioning cortex, synchronous discharge among the neighbouring groups of neurons is limited by recurrent & collateral inhibitory circuits.

•The important excitatory transmission are Acetylcholine & Aminoacids- Glutamate & Aspertate & the inhibitory neurotransmitter is GABA.

•Seizures are essentially results of a shift in the normal balance of excitation and inhibition within the CNS. It is likely that both reduction in inhibitory system and excessive excitation play a part in the genesis of a seizure.

•In partial seizure (Focal) the paroxysmal neuronal activity is limited to the one part of the cerebram and in generalized seizures the electrophysiogical abnormality involve both the hemispheres simultaneously and synchronically.

INTERNATIONAL CLASSIFICATION OF EPILEPTIC SEIZURES

A.Partial seizures – Upto 50% cases

                  i. Simple partial (Consciousness retained)

                               - Motor

                               - Sensory

                               - Autonomic

                               - Psychic

                  ii. Complex partial (Consciousness impaired)

                              - Simple partial, followed by impaired 

                                consciousness.

                              - Consciousness impaired at the onset

                  iii. Partial seizure with secondary generalization

B.Generalized seizure –

i.Absence – Typical, Atypiacal

ii.Generalized tonic- clonic

iii.Tonic

iv.Clonic

v.Myoclonic

vi.Atonic

vii.Infantile spasm

C.Unclassified seizure

SIMPLE PARTIAL SEIZURE
(SPS)

•Motor activity is the most common symptoms without any alterations in consciousness & characterized by asynchronous tonic or clonic movement of one part of the body and tend to involve the face, neck and extremities versine seizures consisting of head turning and  conjugate eye movement are particularly common in SPS. Aura may present. Persists 10-20 seconds. The patient may remain conscious and may verbalize during the seizure. No postictal state. It may be confused with ties (shoulder shrugging, eye blinking, and facial grimacing and primarily involve the face and shoulders). Ties can be briefly suppressed but SPS can not be controlled.

COMPLEX PARTIAL SEIZURE
(CPS)

•CPS begins with a SPS with or without AURA, followed by an impaired consciousness o begins with and altered state of consciousness.

•The presence of aura always indicates a focal onset of the seizure.

•Automatism are a common feature of CPS in infants and children, occurring 50-70% of cases. The older the child, the greater the frequency of automatism. It may persists into postictal phase, but they are not recalled by the child. Duration 1-2 min.

GENERALIZED TONIC CLONIC SEIZURE

•This seizure are extremely common and follow a partial seizure with a focal onset (secondary generalization) or occur de novo. The patient suddenly loss consciousness, the eyes roll back and the patient goes rigid with entire body in tonic phase. The child rapidly becomes cyanotic with apnoea. After a few moments the clonic phase starts with the periodic relaxation of rigidity with rhythmic contractions of all muscle groups. The clonic phase rests for a few minutes and then stops abruptly as the patients has 1 or 2 long breaths.

•The child may bite tongue and lose sphincter control during seizure (usually of bladder).

•In postictal phase, the child may be in semicoma and typically may remain in deep sleep from ½ to 2 hours. During this period the deep reflexes may be hyperactive with clonus and a Babinski reflex. There may be trankal ataxia or intense headache when the patient wakes up.

INFANTILE SPASM
(SALAAM FITS)

•Age- Usually between 4-8 months of age.

•Spasms are characterized by brief symmetric contraction of the neck and the extremities.

•There are at least 3 types of infantile spasm- Flexor, Extensor and Mixed.

    Mixed type is most common. The spasm occur during sleep and arousal but have a tendency to develop while patients are drowsy immediately on awaking.

•Two groups- Cryptogenic (10-20% of cases)

                         Symptomatic (80-90% cases)

ØCryptogenic- H/O uneventful pregnancy and birth history as well as normal developmental milestones before seizures. The patients have a good prognosis.

ØSymptomatic- Are related to several prenatal, perinatal & postnatal factors.80-90% cases have a risk for mental retardation. The underlying CS disorder has a major role in the neurologic outcome.

STATUS EPILEPTICUS

•It is defined as  a continuous convulsion lasting longer than 20-30 min or the occurrence of serial convulsions between which there is no return of consciousness.

•Classification:- 1. Generalized (Tonic, Clonic, Absence)

                              2. Partial (Simple, Complex or Secondary 

                                  generalization)

•Generalized tonic clonic seizure predominant in cases of status epilepticus.

•Etiological types:-3 types-

                     1. Prolong F. seizure-usually <3 years of age, most common.

                     2. Idiopathic- No detectable underlying CNS lesion or insult,

                         usually after sudden withdrawal of drugs.

                     3. Symptomatic – Occurs in association with a long standing

                         neurological or metabolic abnormalities.

•The mortality and morbidity among pt with prolong febrile seizures and idiopathic status epilepticus are low but higher in symptomatic cases.

•D/D:- Encephalitis,

               Meningitis,

               Electrolyte abnormalities-hypocalcaemia

               Hypoglycaemia

               Lead interaction

               Brain tumour

•

            

CONDITIONS THAT MIMIC SEIZURE

•Several conditions share common features with epilepsy. Because these disorders may be associated with altered levels of consciousness, tonic or clonic movements or cyanosis. They are often confused with epilepsy.

ü Breath- holding spells- Cyanotic spell

                                         Palid spell

ü Night terrors-

ü Benign paroxysmal vertigo

ü Syncope

ü Benign paroxysmal torticolis of infancy

INVESTIGATIONS

•Investigations in first seizure (non-neonatal)-

1.Infants :

 - Well infants : EEG, Ca++, BUN, Glucose,              

                         Urine analysis & Cranial US, Perhaps 

                         CT or MRI.                        

- ill infants : Ca++, Mg++, CBC, BUN, Electrolytes,

                    Blood CS, LP, EEG,Possibly CT or MRI. 

2.Older child :

-  Well : EEG, Consider CT or MRI

-ill : CBC, Glucose, BUN, LP, EEG, CT or MRI

3.At all ages : EEG, CT, MRI

     If progressive worsening-consider lysosomal enzymes, CSF.

•Diagnostic value of EEG :

1.  Helps to confirm and classification of seizure type.

2.Select appropriate therapy.

3.Response therapy.

4.Differentiate convulsive equivalents from HCR.

5.Detection of presence of structural lesion. e.g.- tumour, encephalitis.

•Indications for CT or MRI :-

1. All children with epilepsy starting 1st year of life.

2.All children with focal neurological sign.

3.All children with partial seizure.

4.All pts. with intractable seizure and seizure that are becoming worse.

5.Follow up scans in pts. with continuing poorly controlled epilepsy.        

TREATMENT OF EPILEPSY

•The first step in the management of epilepsy is to ensue that the pt has a seizure disorder & not a condition that not mimics epilepsy.

    Previously healthy child with first afebrile convulsion if there is a negative FH, normal P/E and EEG- Antiepileptic should be withheld. Approximately 70% of these children will not experience another convulsion. Approximately 75% of these with 2 or 3 unprovoked seizures have additional seizures.

    A recurrent seizure, particularly if it occurs in close proximity to the first seizure, is an indication to begin an anticonvulsant.

•The second step involves choosing an anticonvulsant. The drug of choice depends on the classification of the seizure, determined by the history & EEG findings.

•Antiepileptic drugs should be given in-

1.A recurrent seizures, particularly occurring close proximity to the first seizure.

2.Seizures that impair consciousness, which tend to impair function so frequently.

3.An isolated seizure having normal history & examinations but with abnormal EEG.

•The goal for every pts should be the use of only one drug with the fewest possible side effects for control of seizure. The drug is increased slowly until seizure control is accomplished or until undesirable side effects develop.

•Side effects:-

v Carbamazepine:- Blood dyscrasia, Hepatotoxic effect, Steven-Johnson syndrome.

v Phenobarbitone:- Hyperactivity, Irritability, SJS, Depression of cognitive function.

v Phenytion:- Hirsectism, Gum hypertrophy, SJS, Blood dyscrasia.

v Valproic acid:- Wt gain, Otopecia, Hepatotxicity.

v Phenytion, Valproic acid, Carbamazepine, Primidone:- Birth defect e.g.. Facial and limb anomalies, Spinal dysraphism.

•Duration of treatment:-

       If complete seizure control is accomplished by an AED, a minimum of 2 seizure free years are adequate & safe period of treatment for a pt with no risk factors. When the decision is made to discontinuation of drug, the weaning process should occur over 3-6 months, because abrupt withdrawal may cause status epilepticus.

•Others treatment:-

1.Ketogenic diet.

2.Surgery for epilepsy

3.Vagal nerve stimulation

4.Councelling of the pt  

 

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