**Core Concept**
Febrile convulsions, also known as febrile seizures, are a type of seizure that occurs in children between the ages of 6 months and 5 years, often in association with a rapid rise in body temperature. The exact pathophysiology is not fully understood, but it is thought to involve the interaction of genetic predisposition, fever, and other factors that affect the brain's electrical activity.

**Why the Correct Answer is Right**
The risk of febrile convulsions is highest in children with a family history of the condition, indicating a possible genetic component. The seizures are usually generalized tonic-clonic, meaning that the child may experience convulsions involving the entire body. The febrile convulsions are typically brief, lasting less than 15 minutes, and most children recover without any long-term neurological consequences. The exact mechanism of febrile convulsions is not fully understood, but it is thought to involve the release of excitatory neurotransmitters, such as glutamate, and the inhibition of inhibitory neurotransmitters, such as GABA.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because febrile convulsions are not typically associated with a prolonged fever; rather, they often occur with a rapid rise in body temperature.
**Option B:** This option is incorrect because febrile convulsions are not typically associated with an elevated white blood cell count; rather, they occur in the absence of any underlying infection.
**Option C:** This option is incorrect because febrile convulsions are not typically associated with a history of previous seizures; rather, they are a distinct entity from other types of seizures.

**Clinical Pearl / High-Yield Fact**
A child with a family history of febrile convulsions is at increased risk of developing the condition, and parents should be educated on how to recognize the signs of a febrile seizure, such as the child becoming limp, losing consciousness, or experiencing a convulsion.

**Correct Answer: A. Febrile convulsions are typically brief, lasting less than 15 minutes.**