Adults can develop hydrocephalus after bleeding, infection, a tumor, injury or another disturbance of CSF circulation. Some have a congenital or childhood-onset condition that remains relevant throughout adult life. Others first come to attention when a longstanding fluid-pathway problem becomes symptomatic. Adult hydrocephalus therefore describes several clinical situations rather than a single diagnosis or treatment pathway.1

Cause and course guide assessment

Clinicians consider the underlying illness, how quickly symptoms appeared, neurological examination and imaging. A rapidly developing CSF problem after a hemorrhage differs from slowly evolving difficulties over years. Communicating or obstructive describes circulation; acquired or congenital describes onset or cause. These dimensions may overlap, and none alone determines how urgently the individual needs care.2

Scans show fluid spaces and possible underlying causes. Interpretation also depends on previous images and the person's condition. Enlarged ventricles do not automatically mean that active hydrocephalus is causing every symptom. Brain-tissue loss and other disorders can also influence their appearance. Ask the clinician to explain the evidence linking the symptoms and scan findings, and what alternatives are being considered.34

NPH is a distinct assessment

Idiopathic normal-pressure hydrocephalus is generally assessed in older adults without an identified preceding cause. Secondary NPH can follow an acquired neurological event such as hemorrhage or meningitis. Childhood-onset or developmental conditions form another context. Gait, cognition and urinary symptoms can have competing or coexisting explanations. They cannot be reduced to an online three-item diagnosis. The Japanese iNPH guideline combines clinical and imaging evidence with appropriate specialist testing.5

Treatment and continuing care

A shunt diverts CSF through an implanted system. ETV creates an internal bypass in selected patients, while an external ventricular drain is a temporary supervised hospital intervention in appropriate circumstances. Treating an underlying cause may also be part of management. The purpose and limits of each intervention should be discussed in the person's specific situation. Success in controlling CSF does not guarantee disappearance of every symptom or recovery from an underlying injury.67

Adults with a childhood shunt or earlier ETV should retain their treatment records and discuss ongoing care rather than assuming the old operation no longer matters. Ask who will coordinate follow-up, what changes should trigger contact and how rehabilitation or work support fits the current needs. There is no universal replacement age, imaging schedule or activity clearance supplied here.

Possible treatment trouble needs appropriate local assessment. Promptly raise new concerning changes with the treating team; severe or rapidly worsening neurological symptoms, a seizure or reduced responsiveness require local emergency care. Do not delay urgent assessment to arrange an elective overseas consultation.8

References

  1. US National Library of Medicine. MedlinePlus Medical Encyclopedia: Hydrocephalus. Source ↩
  2. NHS. Hydrocephalus: Overview. Source ↩
  3. NHS. Hydrocephalus: Diagnosis. Source ↩
  4. AANS Neurosurgical Members. Adult-onset Hydrocephalus. 15 July 2024. Source ↩
  5. Nakajima M et al. Guidelines for Management of Idiopathic Normal Pressure Hydrocephalus (Third Edition). Neurol Med Chir. 2021;61:63–97. doi:10.2176/nmc.st.2020-0292. Source ↩
  6. NHS. Hydrocephalus: Treatment. Source ↩
  7. CNS. Pediatric Hydrocephalus Guideline, Part 2. 2014; updated 2020. Source ↩
  8. NHS. Hydrocephalus: Complications. Source ↩