Hydrocephalus is ventriculomegaly due to what primary disturbance?

Hydrocephalus is ventriculomegaly due to what primary disturbance?

• A. Hydrocephalus due to brain atrophy
• B. Hydrocephalus due to obstruction of CSF flow or impaired absorption
• C. Hydrocephalus due to decreased CSF production
• D. Hydrocephalus due to hemorrhage

Answer: (B)

Hydrocephalus occurs when CSF dynamics are disrupted, causing ventricles to enlarge. The key idea is that CSF either cannot flow properly through the ventricular system or cannot be absorbed efficiently, so CSF builds up and dilates the ventricles. If there’s a blockage within the ventricles or aqueduct, CSF backs up upstream, producing noncommunicating hydrocephalus. If absorption at the arachnoid granulations is impaired, CSF continues to be produced but can’t drain well, leading to communicating hydrocephalus. This enlargement is due to fluid accumulation, not loss of brain tissue. Enlargement caused by brain atrophy happens because the brain shrinks, leaving the ventricles enlarged ex vacuo, which is not hydrocephalus. A decrease in CSF production would reduce CSF volume rather than cause buildup. Bleeding can set off hydrocephalus by causing obstruction or scarring that impairs flow or absorption, but the fundamental disturbance described here is the disrupted CSF flow or absorption.

Hydrocephalus occurs when CSF dynamics are disrupted, causing ventricles to enlarge. The key idea is that CSF either cannot flow properly through the ventricular system or cannot be absorbed efficiently, so CSF builds up and dilates the ventricles. If there’s a blockage within the ventricles or aqueduct, CSF backs up upstream, producing noncommunicating hydrocephalus. If absorption at the arachnoid granulations is impaired, CSF continues to be produced but can’t drain well, leading to communicating hydrocephalus. This enlargement is due to fluid accumulation, not loss of brain tissue. Enlargement caused by brain atrophy happens because the brain shrinks, leaving the ventricles enlarged ex vacuo, which is not hydrocephalus. A decrease in CSF production would reduce CSF volume rather than cause buildup. Bleeding can set off hydrocephalus by causing obstruction or scarring that impairs flow or absorption, but the fundamental disturbance described here is the disrupted CSF flow or absorption.