EpilepsyEpilepsy

Introduction

Terms seizure and epilepsy are not synonymous

Seizure

A seizure is a paroxysmal event due to abnormal, excessive, hypersynchronous discharges from an aggregate of central nervous system (CNS)neurons (cortical neurons).

Have various manifestations.

Epilepsy

Epilepsy describes a condition in which a person has recurrent seizures due to a chronic, underlying process.

Single seizure, or recurrent seizures due to correctable or avoidable circumstances, does not necessarily have epilepsy

Epilepsy

These are group of disorders of CNS, characterised by paroxysmal cerebral dysrhythmia, manifesting as brief episodes (seizures) of loss or disturbance of consiousness, with or without characteristic body movements (convulsions)

Epilepsy has a focal origin in the brain

Causes

Seizures are a result of a shift in the normal balance of excitation and inhibition within the CNS.

...... i.e. Abnormal discharges of neurons

That may be caused by any pathological process affecting brain>>>>

1.- The normal brain is capable of having a seizure under the appropriate circumstances, and there are differences between individuals in the susceptibility or threshold for seizures.

Fever in childrens Underlying endogenous factors.

2.- Variety of conditions that have an extremely high likelihood of resulting in a chronic seizure disorder

Head trauma, stroke, infections, abnormalities of CNS development.

3.- Seizure are episodic: provocative or precipitating factor

Psychological or physical stress, sleep deprivation, or hormonal changes, exposure to toxic substances and certain medications.

Types of Epilepsy

A. GENERALISED SEIZURES

i. Generalised tonic-clonic seizures

ii. Absence seizures

iii. Myoclonic seizures

iv. Atonic seizures

v. Infantile seizures (hypsarrhythmia)

Types of Epilepsy

B. PARTIAL SEIZURES

i. Simple partial seizures

ii. Complex partial seizures

iii. Secondary generalized seizures

Types of Epilepsy

B. UNCLASSIFIED SEIZURES

i. Unclassified seizures ii. Neonatal seizures iii. Infantile spasms

Partial

Synonymous with focal Activity is restricted to discrete areas of

cerebral cortex. Typically associated with structural

abnormalities of the brain.

Generalized

Involve difusse regions of the brain simultaneously in a bilaterally symetric fashion

May result from cellular, biochemical, or structural abnormalities that have a more widespread distribution.

Partial Seizures

Partial Seizures

Discrete regions of the brain. Consciousness is fully preserved during

the seizure (Simple-partial seizure) Consciousness is impaired (Complex

partial seizure) Partial seizure and then spread diffusely

throughout the cortex (partial seizure with secondary generalization)

Simple-Partial Seizure

Motor, sensory, autonomic, or psychic symptoms.

Without an obvious alteration in consciousness.

Three additional features

Three features

“Jacksonian march” abnormal motor movements may begin in a very restricted region, and gradually progress (over seconds to minutes).

May experience a localized paresis (todd`s paralysis) minutes to many hours.

Seizure may continue for hours or days. ”epilepsia partials continua”.

Simple partial. And Aura

Other forms of simple-partial seizures include those that cause changes in somatic sensation.

Some patients describe odd internal feelings. (fear, dejà vu)

When precede a complex-partial or secondarly generalized seizure, these simple partial seizures serve as a warning or aura.

Complex-Partial Seizures

Focal seizure activity Patient is unable to respond to visual or

verbal commands during the seizure and has impaired recollection or awareness of the ictal phase.

Frequently begin with an aura.

The start of the ictal phase is often a sudden behaivoral arrest or motionless stare.

Usually acompained by automatisms. The patient is typically confused following

the seizure.(seconds up to an hour).

Partial Seizures with Secondary Generalization

Partial seizures can spread to involve both cerebral hemispheres and produce a generalized seizur, usually of the tonic-clonic variety.

Is often difficult to distinguish from a primarilly generalized tonic-clonic seizure.

Careful hystory identifies a preceding aura.

Generalized Seizures

Arise from both cerebral hemispheres simultaneously .

It is currently impossible to exclude entirely the existence of a focal region of abnormal activity that initiates the seizure prior to rapid secondary generalization .

Generalized Seizure.

Practically defined as bilateral clinical and electrographic events without any detectable focal onset.

Generalized Seizures

Absence Seizure (Petit Mal) Atypical Absence Seizures Generalized, Tonic – Clonic Seizure

(Grand Mal) Atonic Seizure Mioclonic Seizure

Absence Seizures (Petit Mal)

Sudden brief lapses of consciousness without loss of postural control.

Typically last for only seconds, consiousness returns as suddenly as it was lost.

No postictal confusion

Absence seizures are usually accompained by subtle, bilateral motor signs (rapid blinking of the eyelids, chewing movements, or small-amplitude clonic movements of the hands.

Can occur hundreds of times per day.

Always begin in childhood (ages 4 to 8) or early adolescence.

Hyperventilation tends to provoke.

Typical Absence seizure are not associated with other neurologic problems and respond well to treatment with specific anticonvulsants.

60 – 70 % will have a spontaneous remission during adolescence.

Atypical Absence Seizures:

– Lapse of consciousness is usually of longer duration.

– Less abrupt in onset and cessation– Accompained by more obvious motor signs.

Generalized Tonic – Clonic Seizures (Grand Mal)

The most common seizure type resulting from metabolic derangements.

The initial phase of the seizure is usually tonic contraction of muscles throughout the body.

After 10 to 20 s. The tonic phase of the seizure typically evolves into the clonic phase, produced by the superimposition of periods of muscle relaxion on the tonic muscle contraction.

The periods of relaxation progressively increase until the end of the ictal phase.

Usually last no more than 1 min.

Postictal phase is characterized by:– Unresponsiveness– Muscular flacciditidy – Excessive salivation– Bleadder or bowel incontinence

Patients gradually regain consciousness over minutes to hours

Tipically a period of postictal confusion.

Headache, fatigue, and muscle ache.

Atonic Seizure

Sudden loss of postural muscle tone lasting 1 to 2 s.

Consciousness is briefly impaired Usually no postictal confusion

Very brief seizure may cause only a quick head drop or nodding movement.

Longer seizure will cause the patient to collapse. (extremelly dangerous)

Myoclonic Seizure.

Sudden and brief muscle contraction that may involve one part of the body or the entire body.

Pathologic myoclonus is most commonly seen in association with metabolic disorders, degenerative CNS diseases, or anoxic brain injury.

Unclassified Seizures

Neonatal Seizure

Less than 1 month of age.

Brief episodes of apnea, eye deviation, eye blinking, or repetitive movements of the arms and legs.

Infantile Spasms

Infants under 12 months.

Abrupt movements of the head, trunk, or limbs.

The classic spasm is a sudden flexion of the neck and abdomen with extension of the limbs.

Evaluation of the patient

Laboratory studies

Electrolytes Glucose Ca Mg Liver and renal function test Urianalysis Toxicology screen Lumbar puncture

EEG CT MRI SPECT

Diferential Diagnosis

Syncope Psychological disorders Metabolic disturbances Migraine TIA Sleep disorders Movement disorders

Treatment

Partial Tonic-clonic

Absence Myoclonic Atonic

Carbamazepine

Phenitoiin

Valproic acid

Lamotrigine

Valproic acid

Lamotrigine

Ethosuximide

Valproic Acid

Valproic Acid