Could a partially empty sella, along with other noted imaging findings, be a sign of a cerebrospinal fluid (CSF) leak?

From the Guidelines

A partially empty sella can be a sign of a cerebrospinal fluid (CSF) leak, as it is one of the radiological findings associated with intracranial hypotension, which is commonly caused by CSF leaks. This condition occurs when the pituitary gland appears flattened or smaller than normal within the sella turcica, with the space being filled with CSF instead, as a result of the reduced CSF volume and pressure allowing the brain to sag downward 1. Other imaging findings that may accompany a CSF leak include subdural fluid collections, engorgement of venous structures, pachymeningeal enhancement, and downward displacement of the brain structures.

The presence of a partially empty sella, along with other noted imaging findings such as mild degenerative changes in the spine, tortuosity of the nasal septum, small metallic densities along the lateral aspect of the mandible, a small thyroid gland, and subcentimeter short axis diameter lymph nodes in the neck, should prompt further investigation for a CSF leak. The diagnosis of a CSF leak can be challenging, and a comprehensive diagnostic workup, including imaging studies such as MRI and myelography, may be necessary to confirm the diagnosis and locate the exact site of the leak 1.

Key imaging features suggestive of intracranial hypotension include qualitative signs such as engorgement of venous sinuses, pachymeningeal enhancement, midbrain descent, superficial siderosis, subdural hygroma or hematoma, and convex superior surface of the pituitary, as well as quantitative signs such as pituitary height, pontomesencephalic angle, suprasellar cistern, prepontine cistern, midbrain descent, venous-hinge angle, mamillopontine angle, tonsillar descent, and area cavum veli interpositi 1.

In patients with suspected CSF leaks, MRI complete spine without and with IV contrast can be useful in the initial evaluation, particularly when performed with 3-D T2-weighted fat saturated sequences, which increases sensitivity for detecting fluid collections outside of the thecal sac 1. The contrast component of this examination may demonstrate dural enhancement and engorged epidural venous plexus, which are also imaging features that support a diagnosis of SIH.

Therefore, based on the strongest and most recent evidence, a partially empty sella, along with other imaging findings, can be a sign of a CSF leak, and further investigation is warranted to confirm the diagnosis and guide treatment. Patients with CSF leaks typically present with orthostatic headaches, neck pain, nausea, and sometimes hearing changes or visual disturbances, and prompt diagnosis and treatment are essential to prevent long-term complications and improve quality of life 1.

From the Research

Imaging Findings and CSF Leak

• A partially empty sella, as noted in the imaging findings, can be associated with a cerebrospinal fluid (CSF) leak, as suggested by studies 2, 3.
• The presence of a partially empty sella may indicate elevated intracranial pressure, which can lead to idiopathic, spontaneous CSF leaks 2.
• Other imaging findings, such as mild degenerative changes in the spine, tortuosity of the nasal septum, and small metallic densities along the lateral aspect of the LEFT mandible, are not directly related to CSF leaks.
• The small size of the thyroid gland and subcentimeter short axis diameter lymph nodes in the neck are also not directly related to CSF leaks.

Empty Sella Syndrome and CSF Leaks

• Empty sella syndrome (ESS) is a radiographic finding that can be associated with elevated CSF pressures and may represent a radiographic indicator of intracranial hypertension 2.
• The incidence of ESS in patients with CSF leaks is high, with one study finding that 100% of patients with spontaneous CSF leaks had a partially or completely empty sella 2.
• The presence of an empty sella may be a sign of elevated intracranial pressure that leads to idiopathic, spontaneous CSF leaks 2.

Diagnosis and Management

• Magnetic resonance imaging (MRI) is the gold standard for radiological diagnosis of empty sella 3.
• Patients with a finding of empty sella require endocrinologic and ophthalmologic evaluation 4, 5.
• Treatment of empty sella syndrome includes replacement of hormone deficiencies and occasionally surgical measures to relieve obstructive intracranial lesions 4.
• Targeted epidural blood patches can be an effective treatment for persistent spinal CSF leaks 6.