S. Diana Garcia

1. Seizures S. Diana Garcia

2. What is a seizure? • A seizure is a manifestation of abnormal hypersynchronous discharges of cortical neurons. • It can manifest as an alteration in mental state, tonic or clonic movements, convulsions, and various other psychic symptoms (such as déjà vu or jamais vu). • The medical syndrome of recurrent, unprovoked seizures is termed epilepsy, but seizures can occur in people who do not have epilepsy.

3. Pathophysiology • Seizures are paroxysmal manifestations of the electrical properties of the cerebral cortex. • A seizure results when a sudden imbalance occurs between the excitatory and inhibitory forces within the network of cortical neurons in favor of a sudden-onset net excitation.

4. Seizures: Two Main Types • Focal seizures, also called partial seizures, happen in just one part of the brain. • Simple partial - consciousness unaffected otherwise called Complex partial • Generalized seizures are a result of abnormal activity on both sides of the brain. All involve loss of consciousness

5. Seizure Classification • Generalized seizures: affect both cerebral hemispheres • Absence- 2 to 15 seconds -Stare, Eyes fluttering, Automatisms (such as lip smacking, picking at clothes, fumbling) if prolonged Amnesia for seizure events, No confusion, Promptly resumes activity • Atonic -produce an abrupt loss of muscle tone • Tonic-clonic 1 to 2 minutes-A cry, Fall, Tonicity (rigidity), Clonicity (jerking phase lasts less than a minute), May have cyanosis Amnesia for seizure events, Confusion, Deep sleep • Myoclonic -rapid, brief contractions of bodily muscles

6. Seizures have differential diagnosis Possible pathophysiological causes include: • Benign paroxysmal positional vertigo • Breath-holding spells of childhood • Cataplexy • Hyperekplexia, also called startle syndrome • Hypoglycemia and associated neuroglycopenia • Migraine • Narcolepsy • Non-epileptic myoclonus • Opsoclonus • Parasomnias, including night terrors • Paroxysmal kinesiogenic dyskinesia • Reflex anoxic seizures • Primary central nervous system lymphoma • Repetitive or ritualistic behaviors • Syncope (fainting) • Tics • Trauma Induced Seizure

7. Causes • sleep deprivation • cavernoma or cavernous malformation • arteriovenous malformation (AVM) • head injury may cause non-epileptic post-traumatic seizures or post-traumatic epilepsy, in which the seizures chronically recur. • intoxication with drugs • drug toxicity • normal doses of certain drugs that lower the seizure threshold, such as tricyclic antidepressants • infection, such as encephalitis or meningitis • fever leading to febrile convulsions

8. Causes (continued) • metabolic disturbances, such as hypoglycaemia, hyponatremia or hypoxia • withdrawal from drugs (anticonvulsants, antidepressants, and sedatives such as alcohol, barbiturates, and benzodiazepines,) • space-occupying lesions in the brain (abscesses, tumors) • seizures during (or shortly after) pregnancy can be a sign of eclampsia. • seizures in a person with hydrocephalus may indicate severe shunt failure. • binaural beat brainwave entrainment may trigger seizures in both epileptics and non-epileptics • haemorrhagic stroke can occasionally present with seizures, embolic strokes generally do not (though epilepsy is a common later complication); cerebral venous sinus thrombosis, • multiple sclerosis sufferers- rarely experience seizures

9. Tests • It is important to distinguish primary epileptic seizures from secondary causes. • Blood tests • lumbar puncture • toxicology screening • electroencephalogram (EEG, brain wave activity) • brain imaging with CT scan or MRI scan in the work-up.

10. Treatment – Ketogenic Diet • Diets very low in carbohydrates and high in fat and protein shift metabolism to Beta oxidation of fats and production of ketone bodies. These diets are therefore known as ketogenic diets. The only recommended use of ketogenic diets is for children under 10 who have epilepsy who is not responding fully to drug therapy. Reasons are not well understood.