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C H A P T E R 2 3 Antiseizure agents

4. Febrile seizures are related to very high fevers and usually involve tonic–clonic seizures. Febrile seizures most frequently occur in children; they are usually self-limited and do not reappear. 5. Jacksonian seizures are seizures that begin in one area of the brain and involve one part of the body, and then progressively spread to other parts of the body; they can develop into generalised tonic–clonic seizures. 6. Psychomotor seizures are complex seizures that involve sensory, motor and psychic components. They usually begin with a loss of consciousness and people have no memory of the event. People may exhibit automatic movements, emotional outbursts, and motor or psychological disturbances. 7. Status epilepticus , potentially the most dangerous of seizure conditions, is a state in which seizures rapidly recur again and again with no recovery between seizures. Partial seizures Partial seizures , or focal seizures, are so called because they involve one area of the brain, usually originating from one site or focus and do not spread throughout the entire organ. The presenting symptoms depend on exactly where in the brain the excessive electrical dis­ charge is occurring. Partial seizures can be further classified as follows: • Simple partial seizures, which occur in a single area of the brain and may involve a single muscle movement or sensory alteration. • Complex partial seizures, which involve a series of reactions or emotional changes and complex sensory changes such as hallucinations, mental distortion, changes in personality, loss of consciousness and loss of social inhibitions. Motor changes may include involuntary urination, chewing motions, diarrhoea and so on. The onset of complex partial seizures usually occurs by the late teens. ■■ Epilepsy is characterised by seizures that result from sudden discharge of excessive electrical energy from nerve cells in the brain. ■■ There are two major categories of seizures: generalised and partial seizures. ■■ Generalised seizures include the following types: tonic–clonic, absence, myoclonic, febrile, Jacksonian, psychomotor and rapid recurring (status epilepticus). ■■ Partial seizures may be simple or complex. KEY POINTS

Seizures

Generalised (involves both hemispheres; loss of consciousness)

Partial (involves one hemisphere)

Simple (consciousness not impaired)

Complex (consciousness impaired)

Tonic- clonic

Status epilepticus

Atonic

Absence

Myoclonic

Febrile

FIGURE 23.1  Classification of seizures. [From Aschenbrenner, D. S. & Venable, S. J. (2008). Drug Therapy in Nursing (3rd edn). Philadelphia: Lippincott Williams & Wilkins; p. 332, Figure 21.2.]

grouping them into two main categories: generalised or partial seizures. Each of these categories can be further subdivided (see Figure 23.1). Generalised seizures Generalised seizures begin in one area of the brain and rapidly spread throughout both hemispheres. People who have a generalised seizure usually experience a loss of consciousness resulting from this massive electrical activity throughout the brain. Generalised seizures are further classified into the following seven types: 1. Tonic–clonic seizures involve dramatic tonic–clonic muscle contractions (involuntary muscle contraction followed by relaxation appearing as an aggressive spasm), loss of consciousness and a recovery period 5-second) periods of loss of consciousness. Absence seizures occur commonly in children, starting at about 3 years of age, and frequently disappear by puberty. Absence seizures do not usually involve muscle contractions. 3. Myoclonic seizures involve short, sporadic periods of muscle contractions that last for several minutes. They are relatively rare and are often secondary seizures. characterised by confusion and exhaustion. 2. Absence seizures involve abrupt, brief (3- to