CT scan of a child brought with CNS pathology shows subdural effusion. Which of the following condition give rise to subdural effusion in children?
**Subdural Effusion in Children**
**Core Concept**
Subdural effusion in children is a collection of fluid in the subdural space, which can be a sign of underlying CNS pathology. It is often associated with increased intracranial pressure and can be caused by various conditions, including infections, trauma, and tumors.
**Why the Correct Answer is Right**
Subdural effusion in children is commonly caused by bacterial meningitis, particularly caused by *Streptococcus pneumoniae*, *Haemophilus influenzae*, and *Neisseria meningitidis*. These bacteria can lead to inflammation of the meninges, resulting in the production of excess cerebrospinal fluid (CSF) that collects in the subdural space. The increased pressure and inflammation can cause damage to the brain and surrounding structures. The subdural effusion can be diagnosed on imaging studies, such as CT or MRI scans, and may require drainage to relieve pressure and prevent further complications.
**Why Each Wrong Option is Incorrect**
* **Option A:** Meningioma is a type of brain tumor that arises from the meninges, but it is rare in children and is not a common cause of subdural effusion.
* **Option B:** Subarachnoid hemorrhage can cause increased intracranial pressure, but it typically presents with blood in the subarachnoid space, not subdural effusion.
* **Option D:** Encephalitis can cause increased intracranial pressure and inflammation, but it typically affects the brain parenchyma, not the subdural space.
**Clinical Pearl / High-Yield Fact**
In children, subdural effusion is often a sign of bacterial meningitis, and prompt treatment with antibiotics is essential to prevent long-term neurological damage and complications.
**Correct Answer:** C. Bacterial meningitis