Intracranial hypotension, spontaneous

This code describes a condition characterized by abnormally low cerebrospinal fluid (CSF) pressure within the skull, occurring without an identifiable external cause such as trauma or medical intervention. It typically results from a spontaneous CSF leak, leading to symptoms like orthostatic headache, nausea, and dizziness.

Use this code when documentation clearly indicates a diagnosis of intracranial hypotension that is explicitly stated as spontaneous. This diagnosis is often supported by imaging findings (e.g., diffuse pachymeningeal enhancement on MRI) and/or CSF pressure measurements confirming low pressure, in the absence of a lumbar puncture or other iatrogenic cause.

• Ensure the documentation specifies "spontaneous" to differentiate from iatrogenic or post-traumatic intracranial hypotension.
• Do not confuse with post-dural puncture headache (G97.1), which has a clear iatrogenic cause.
• Look for supporting documentation of CSF leak, such as myelography or CT cisternography findings.