epilepsy.pptx

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1. EPILEPSY

2. EPILEPSY Epilepsy is defined by the occurrence of at least two unprovoked seizures with or without convulsions (i.e. violent, involuntary contraction of the voluntary muscles). A seizure results from an excessive discharge of cortical neurons and is characterized by changes in electrical activity as measured by the electroencephalogram (EEG).

3. EPIDEMIOLOGY There are over 2.5 million people diagnosed with epilepsy every year. Epilepsy is one of the most common serious neurological disorders affecting about 65 million people globally. It affects 1% of the population by age 20 and 3 % of the population by age 75 . It is more common in males than females with the overall difference being small. Most of those with the disease ( 80%) are in the developing world . Epilepsy is usually present in childhood or adolescence but may occur for the first time at any age. About 5% of the population suffers a single seizure at some time . About 0.5-1% of the population have recurrent seizure epilepsy . About 70% patients are well controlled with drugs (prolonged remissions) and 30% epilepsy patients are at least partially resistant to drug treatments.

4. ETIOLOGY Epilepsy has no identifiable cause in about half of those, with the condition. In about half the people with epilepsy the condition may be traced to various factors. Genetic Influence: Some types of epilepsy, which are categorized by the type of seizure experience, run in families. Certain genes may make a person more sensitive to environmental conditions that trigger seizures . Head trauma: Head trauma that occurs due to a car accident or other traumatic injury can cause epilepsy. Brain conditions: Brain conditions that result in damage to the brain, such as brain tumors or strokes also can cause epilepsy. Stroke is a leading cause of epilepsy in adults older than age 35.

5. Infectious diseases: Infectious diseases, such as meningitis, AIDS and viral encephalitis, can cause epilepsy. Prenatal injury: Before birth, babies are sensitive to brain damage that could be caused by several factors, such as an infection in the mother, poor nutrition or oxygen deficiencies. This brain damage can result in epilepsy or cerebral palsy. Developmental disorders : Epilepsy can sometimes be associated with developmental disorders, such as autism(inability to communicate & interact) and neurofibromatosis(formation of tumors in the brain & spinal cord). Stroke and other vascular diseases: Stroke and other blood vessel (vascular) diseases can lead to brain damage that may trigger epilepsy. Dementia: Dementia can increase the risk of epilepsy in older adults.

6. Neonates (<1 month) Perinatal hypoxia, ischemia, Intracranial hemorrhage and trauma, Acute CNS infection, Metabolic disturbances (hypoglycemia, hypocalcemia, hypomagnesemia, pyridoxine deficiency), Drug withdrawal, Developmental disorders and Genetic disorders. Infants and children (>1 month and <12 years) Febrile seizures, Genetic disorders (metabolic, degenerative, primary epilepsy syndromes), CNS infection, Developmental disorders, Trauma and Idiopathic. Adolescents (12–18 years) Trauma, Genetic disorders, Infection, Brain tumor, Illicit drug use and Idiopathic. Y o ung a d u l ts ( 1 8 – 35 years) Trauma, Alcohol withdrawal, Illicit drug use, Brain tumor and Idiopathic. Older adults (>35 years) Cerebrovascular disease, Brain tumor, Alcohol withdrawal, Metabolic disorders (uremia, hepatic failure, electrolyte abnormalities, hypoglycemia), Alzheimer's disease and other degenerative CNS diseases and Idiopathic.

7. TYPES OF EPILEPTIC SEIZURES 7

8. TYPES OF EPILEPSY On the basis of the Intensity of seizures Grandmal Epilepsy (See tonic- clonic seizures) Petitmal epilepsy ( See absence seizures) Other types: Juvenile myoclonic epilepsy : age groups- 8 to 20 years Benign partial epilepsy in childhood: patients below 12 years of age. It starts with partial seizures which progresses into generalized tonic- clonic seizures. Solitary parenchymal cysts: Single small cyst if present in the nervous system causes the infection known as neurocysticercosis. Reflex epilepsy: The specific event or action that becomes responsible for the attack of epilepsy like photosensitivity, hot water, cold water, or visual stimuli.

9. CLINICAL MANIFESTATIONS & TYPES The clinical manifestation of a seizure will depend on the location of the focus and the pathways involved in its spread. Seizures are divided into two main groups according to the area of the brain in which the abnormal discharge originates . If it involves initial activation of both hemispheres of the brain simultaneously, the seizures are termed ‘ generalised ’. If a discharge starts in a localised area of the brain , the seizure is termed ‘ partial’ or ‘focal’.

10. Generalised seizures Generalised seizures result in impairment of consciousness from the onset Tonic seizures: Tonic seizures cause stiffening muscles . These seizures usually affect muscles in back, arms and legs and may cause to fall to the ground. Clonic seizures : Clonic seizures are associated with rhythmic, jerking muscle movements . These seizures usually affect the neck, face and arms . Myoclonic seizures: These usually appear as sudden brief jerks or twitches of arms and legs.

11. Tonic clonic convulsions : Often called ‘grand mal’ attacks , these are the commonest of all epileptic seizures. Without warning, the patient suddenly goes stiff, falls and convulses, with laboured breathing and salivation. Cyanosis and tongue biting may occur. The convulsion ceases after a few minutes and may often be followed by a period of drowsiness, confusion, headache and sleep.

12. Absence attacks: Often called ‘petit mal’, these are a much rarer form of generalized seizure. They happen almost exclusively in childhood and early adolescence. The child goes blank and stares; the fluttering of the eyelids and flopping of the head may occur. The attacks last only a few seconds and often go unrecognized even by the child experiencing them. Atonic seizures: These comprise a sudden loss of muscle tone, causing the person to collapse to the ground . Recovery afterwards is quick. Partial or focal seizures

13. Simple partial seizures: In these seizures, the discharge remains localised and consciousness is fully preserved. What actually happens during a simple partial seizure depends on the area of the discharge and may vary widely from person to person. Localised jerking of a limb or the face, stiffness or twitching of one part of the body, numbness or abnormal sensations are examples of what may occur during a simple partial seizure . If the seizure progresses with impairment of consciousness , it is termed a complex partial seizure.

14. Complex partial seizures: The person may present with altered or ‘ automatic’ behaviour : plucking his or her clothes and acting in a confused manner . Lip smacking or chewing movements , grimacing , performing aimless activities. Most of these seizures originate in the frontal or temporal lobes of the brain and can sometimes progress to secondarily generalized seizures.

15. Secondarily generalised seizures: These are partial seizures, either simple or complex, in which the discharge spreads to the entire brain. The person may have a warning, but this is not always the case. The spread of the discharge can occur so quickly that no feature of the localised onset is apparent to the person or an observer, and only an EEG can demonstrate the partial nature of the seizure . The involvement of the entire brain leads to a convulsive attack with the same characteristics as a generalised tonic- clonic convulsion .

16. Status epilepticus is defined as either continuous seizures lasting at least for 5 minutes, or two or more discrete seizures between which there is incomplete recovery of consciousness. Febrile seizures occur in upto 8 % of children between 6 months and 6 years of age. Long term treatment or prophylaxis for simple febrile seizures is not recommended. Unclassified epileptic seizures: Not all seizure types can be classified as partial or generalized. This appears to be especially true of seizures that occur in neonates and infants.

17. PATHOPHYSIOLOGY Epilepsy differs from most neurological conditions as it has no pathognomonic lesion. A variety of different electrical or chemical stimuli can easily give rise to a seizure in any normal brain. The hallmark of epilepsy is a rather rhythmic and repetitive hyper-synchronous discharge of neurones either localised in an area of the cerebral cortex or generalised throughout the cortex, which can be observed on an electroencephalogram (EEG).

18. Neurones are interconnected in a complex network in which each individual neurone is linked through synapses with hundreds of others. A small electrical current is discharged by neurones to release neurotransmitters at synaptic levels to permit communication with each other. Neurotransmitters fall into two basic categories: inhibitory or excitatory . Therefore, a neurone discharging can either excite or inhibit neurones connected to it. An excited neurone will activate the next neurone whereas an inhibited neurone will not. In this manner, information is conveyed, transmitted and processed throughout the central nervous system.

19. PATHOPHYSIOLOGY If neurones are damaged, injured or suffer a chemical or metabolic insult , a change in the discharge pattern may develop. ↓ In the case of epilepsy, regular low-frequency discharges are replaced by bursts of high-frequency discharges usually followed by periods of inactivity. ↓ A single neuron discharging in an abnormal manner usually has no clinical significance. ↓ It is only when a whole population of neurons discharge synchronously in an abnormal way that an epileptic seizure may be triggered.

20. This abnormal discharge may remain localised or it may spread to adjacent areas, recruiting more neurones as it expands. ↓ It may also generalise throughout the brain via cortical and subcortical routes, including collosal and thalamocortical pathways. ↓ The area from which the abnormal discharge originates is known as the epileptic focus.

21. TESTS AND DIAGNOSIS Physical examination Neurological examination: A neurological examination looks at how well brain and the rest of nervous system are functioning and may test behaviour , motor abilities, mental function and other areas to diagnose condition and determine the type of epilepsy. Blood tests: There are a number of blood tests that may be recommended to check for signs of infections, genetic conditions or other conditions like electrolyte imbalances which may be associated with seizures .

22. Electroencephalogram (EEG): An electroencephalography test can help to diagnose a seizure. These tests measure brain waves. Viewing brain waves can help to diagnose the type of seizure. Neuroimaging: Imaging scans such as a Computerized tomography (CT) scan, Magnetic resonance imaging (MRI), Functional MRI (fMRI), Positron emission tomography (PET) or Single-photon emission computerized tomography (SPECT) also can help by providing a clear picture of the brain. These scans allow to see abnormalities like blocked blood flow or a tumor. Neuropsychological tests: These tests are performed to assess thinking, memory and speech skills. The test results help to determine which areas of brain are affected.

23. TREATMENTS AND DRUGS Goals of Treatment: The goals are to control or reduce the frequency and severity of seizures , minimize side effects, and ensure compliance , allowing the patient to live as normal a life as possible. The type of treatment prescribed will depend on several factors including the frequency and severity of the seizures as well as the person’s age, overall health, and medical history.

24. Surgery: Surgery includes removal of the area of the brain causing the seizures. Other therapies: Vagus nerve stimulation: The vagus nerve is stimulated to reduce the frequency and intensity of seizures. This can be suitable for some people with seizures that are difficult to control with medication. Ketogenic diet: A diet very high in fat, low in protein and almost carbohydrate free. This can be effective in the treatment of difficult-to-control seizures in some children.

25. COMPLICATIONS Complications of complex partial seizures are easily triggered by emotional stress. Patients may develop cognitive and behavioural difficulties like memory loss, poriomania (wandering), violent behaviour etc . Complications associated with tonic- clonic seizures may involve injury such as aspiration, skull or vertebral fractures, shoulder dislocation, tongue or cheek injuries caused by biting & status epilepticus.

26. Questions Define epilepsy. Explain the clinical features of different types of epilepsy Explain different types of leprosy. Describe the signs and symptoms of various forms of epilepsy Describe the treatment of grand mal epilepsy in detail