During tonic-clonic seizures, the tonic phase is characterized by?

Appeared in: HSSC Staff Nurse - 2015

Explanation

The tonic phase is the first part of a tonic-clonic seizure.
It is defined by widespread, sustained muscle contraction, known as a tonic contraction.
This muscular activity causes the entire body to become rigid or stiff.
This phase is typically brief, lasting about 10 to 20 seconds before the clonic phase begins.

Option B: Jerking of the extremities is the defining characteristic of the clonic phase, which follows the tonic phase.
Option C: While loss of consciousness occurs at the onset of a generalized tonic-clonic seizure, it is not the specific motor characteristic that defines the tonic phase. The defining feature is the change in muscle tone.
Option D: Confusion is the hallmark of the postictal phase, which is the recovery period after the seizure has ended.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Phases of a tonic-clonic seizure as background academic context rather than a clinical decision trigger.
A nurse's primary role during a seizure is to ensure patient safety by preventing injury and maintaining a patent airway.
Accurate observation and documentation of seizure activity (onset, duration, type of movement) are critical for the medical team to diagnose the seizure type and plan effective treatment.
What if? If a tonic-clonic seizure lasts longer than 5 minutes, or if seizures occur back-to-back without recovery, it is a medical emergency called status epilepticus. The nurse must initiate emergency protocols, including administering rescue medications like benzodiazepines as prescribed.

How to Approach the Question

First, identify the key terms in the question: 'tonic-clonic seizures' and 'tonic phase'.
Recall the definitions of the different seizure phases. A helpful mnemonic is to break down the name itself.
'Tonic' relates to muscle tone. Think of 'tonic water' being stiff with carbonation, so the tonic phase involves muscle stiffening.
'Clonic' relates to clonus, which means rapid, rhythmic muscle contraction and relaxation. This corresponds to the jerking phase.
Evaluate each option against the definition of the tonic phase. 'Stiffening of the body' directly matches the meaning of 'tonic'.
Eliminate the other options by identifying which phase they belong to: 'jerking' is clonic, and 'confusion' is postictal.

Concept Tested & Keywords

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E6 Medicine Harrison 22e Part 2 p. 1314-1316

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 1407-1409

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