A Shunt in a Funk: A Case Report on Shunt Malfunction and Hydrocephalus

Case Diagnosis: Ventriculoperitoneal Shunt Failure

Case Description or Program Description: A 59-year-old with hydrocephalus and prior ventriculoperitoneal shunt placement (Strata at 1.0), presented to rehab following a hemicraniectomy and cranioplasty after sustaining a subdural hematoma from a fall-associated head strike. On admission, she received a computed tomography of the head (CTH) for monitoring purposes, which demonstrated a new midline shift, leading neurosurgery to increase the shunt settings to 1.5 due to concern for over-drainage. Following that initial shunt change, the patient had gradually worsening confusion, ataxia, vision, and participation in therapy, all of which was initially attributed to a urinary tract infection.

Setting: Acute inpatient rehabilitation.

Assessment/Results: Despite antibiotics, the patient worsened over a week, and a repeat CTH was performed demonstrating severe hydrocephalus. This prompted shunt setting reversal to 1.0 due to under-shunting. Even with reversal to her original settings, and later to a decreased shunt level of 0.5, her hydrocephalus remained unchanged and she became obtunded, leading to urgent transfer for shunt revision due to ventriculoperitoneal shunt failure.

Discussion (relevance): In patients with ventriculoperitoneal shunts, both shunt misalignment and failure need to be considered in those with worsening clinical status and radiologic evidence of worsening hydrocephalus. If patients do not gradually improve shortly after shunt settings are changed, serial CTHs and shunt series x-rays should be ordered to assess for potential shunt failure or mispositioning. Shunt series imaging can visualize the shunt dial and confirm successful interrogation after any setting changes.

Conclusions: When ventriculoperitoneal shunt settings are adjusted, it cannot be assumed that the adjustment is performed without complications. Documentation of functional status by therapy is beneficial in monitoring hydrocephalus improvement, as worsening therapy participation can be a direct consequence of undershunting or overshunting. Patients undergoing shunt readjustments greatly benefit from acute rehab, where their long-term functional and cognitive status can be monitored more effectively.