G91.3
BillablePost-traumatic hydrocephalus, unspecified
HCC Category Mapping
V28HCC 127 — Dementia, Mild or Unspecified
0.464What This Code Means
Post-traumatic hydrocephalus is excess cerebrospinal fluid accumulation in the brain that develops after a head injury, when the specific timing or severity details are not specified.
Coding Tips
- •Link this code to the original head injury code for complete clinical picture
- •Document the temporal relationship between the head trauma and hydrocephalus development
Clinical Significance
Post-traumatic hydrocephalus develops as a complication of traumatic brain injury, typically weeks to months after the initial injury, due to impaired cerebrospinal fluid absorption from blood products or scarring in the subarachnoid space. It is an important complication to identify because it is surgically treatable and can significantly improve neurological recovery after brain injury. This code captures the ongoing resource utilization of trauma patients with this complication.
Documentation Requirements
- ✓History of antecedent traumatic brain injury with documentation of temporal relationship
- ✓Imaging demonstrating progressive ventriculomegaly after traumatic brain injury
- ✓Clinical deterioration or failure to improve as expected post-trauma (worsening cognition, gait, or incontinence)
- ✓Differentiation from ex-vacuo ventriculomegaly (brain atrophy) which does not represent true hydrocephalus
- ✓Treatment plan or surgical intervention documentation (shunt placement or endoscopic procedure)
Commonly Confused Codes
G91.0 — Communicating hydrocephalus: non-traumatic etiology; use G91.3 when trauma is the documented causeG91.1 — Obstructive hydrocephalus: use when post-traumatic swelling or hemorrhage causes focal obstructionS06.9X0A — Unspecified intracranial injury, initial encounter: the original injury code, not the hydrocephalus complicationG93.1 — Anoxic brain damage: may coexist with post-traumatic hydrocephalus but represents a different pathology
Code Hierarchy
└G91Hydrocephalus└G91.3Post-traumatic hydrocephalus, unspecified
└G91.3Post-traumatic hydrocephalus, unspecified