-IBIS-1.5.0-
tx
nervous system
seizure disorders/epilepsy
diagnoses

definition and etiology

definition:
A group of disorders recognized by chronic, recurrent, paroxysmal changes in cerebral function; and brief attacks of altered consciousness/motor activity/sensory phenomena due to abnormalities of the electrical system of the brain. Also known as "epilepsy".

etiology:
Epilepsy is defined as symptomatic or idiopathic. At least 75% of adult sufferers, and a small minority of children, have idiopathic epilepsy that does not lend itself to specific treatment leading to cures. The condition can occur at any age from a number of causes:

• From 1-2 years old (Infants): Paranatal hypoxia and ischemia; intracranial birth injury; acute infection with high fever; genetic disorders; metabolic conditions (hypoglycemia, hypomagnesemia, etc.).

• 2-12 years old (Children): Idiopathic; acute infection (especially if have similar history as an infant); trauma.

• 12-18 years old (Adolescent): Idiopathic; trauma; alcohol or drug withdrawal; arteriovenous malformations.

• 18-35 years old (Young adults): Trauma; alcoholism; brain tumor.

• >35 years old (Older adult): Brain tumor; cerebrovascular disease; alcoholism, metabolic conditions (uremia, hepatic failure, etc.).

Seizure classification:
• Partial or focal seizures.
• Primary generalized seizures.
• Unilateral seizures.
• Unclassified epileptic seizures.

signs and symptoms

signs and symptoms: vary depending on the type of seizure.

• Simple partial seizure: May have motor, sensory , autonomic or psychic expressions. Muscle activity may remain in one area or spread to include more musculature (Jacksonian March).

• Complex partial seizures: These cause episodic changes in consciousness where the patient will lose contact with others and his/her surroundings. An aura may precede the attack (unusual smell, perception, Deja vu, etc.). Often most motor activity stops excepts for a specific motor motion such as picking at one's clothes, or lip smacking.

• Tonic-clonic (grand mal): The attack usually begins suddenly with no warning. The seizure follows a typical pattern: loss of consciousness; tonic muscle contraction; loss of postural control and a cry as the respiratory muscles contract. Then a rhythmic contraction of muscles begins in all four limbs: this clonic phase lasts until the muscles relax (often minutes). As the patient recovers, he/she is often confused and drowsy (post-ictal phase).

• Tonic seizures: These seizures have the rigid posturing of the body from overall muscle contractions without the clonic phase.

• Absence seizures (petit mal): These seizures consist of sudden loss of conscious connection to the environment without any associated muscle activity. They typically last only seconds or minutes and can be so brief that they are hardly noticeable. There is no post-seizure confusion and the patient regains consciousness rapidly.

• Myoclonic seizures: These seizures are characterized by sudden, brief, single or repetitive muscle contractions of one body part or the entire body.

lab findings and exams:
• CT scan.
• CSF analysis.
• General and neurologic physical exam.
• Blood studies (ChemScreen).
• EEG.
• MRI.
• Arteriograms.
• Amino acid analysis: for low levels of taurine.

course and prognosis

The course depends on the cause. Infantile fever convulsions often disappear as the child ages. Epilepsy in an older adult has a more serious prognosis. In patients with idiopathic epilepsy, the course is chronic and recurrent: conventional treatment consists of anticonvulsant drug therapy. The most serious sequela of epilepsy (aside from the potential of injury during the fall to the ground) is status epilepticus. Status epilepticus is diagnosed when the initial seizure continues without interruption or when repeated seizures occur without a normal recovery period. This is a medical emergency because of the potential for the development of hyperpyrexia and acidosis from the intense, prolonged muscle contractions.

differential diagnosis

• Fainting.
• TIA.
• Migraine.
• Psychological disorder: "hysterical seizure".


footnotes