G91.0

HCC Category Mapping

What This Code Means

Communicating hydrocephalus is a condition where excess cerebrospinal fluid accumulates in the brain because the fluid cannot be properly absorbed, even though the normal flow pathways are open.

Coding Tips

• •Distinguish from obstructive hydrocephalus where there is a blockage in fluid flow
• •Document imaging findings (CT or MRI) confirming ventricular enlargement and patent flow pathways

Clinical Significance

Communicating hydrocephalus occurs when cerebrospinal fluid absorption is impaired while flow between ventricles remains open, leading to increased intracranial pressure and ventricular enlargement. This condition requires ongoing monitoring and often surgical intervention (ventriculoperitoneal shunt or endoscopic third ventriculostomy). It significantly impacts resource utilization through neurosurgical management, imaging surveillance, and treatment of complications.

Documentation Requirements

• ✓Imaging (CT or MRI) demonstrating ventriculomegaly consistent with communicating hydrocephalus
• ✓Clinical symptoms documented (headache, gait disturbance, cognitive changes, urinary incontinence)
• ✓Etiology specified when known (post-hemorrhagic, post-infectious, post-surgical)
• ✓Treatment status including presence and function of any shunt or drainage device
• ✓Neurological examination findings and functional impact assessment

Commonly Confused Codes