S. Diana Garcia Seizures

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.

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.

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

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

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

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

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

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.

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.