Can a partially empty sella be a sign of a cerebrospinal fluid (CSF) leak?

From the Guidelines

Yes, a partially empty sella can be a sign of a cerebrospinal fluid (CSF) leak, as it may indicate herniation of the subarachnoid space into the sella turcica, which can be associated with low CSF pressure and brain sagging 1. This condition occurs when the pituitary gland appears flattened or smaller than normal within the sella turcica, with the remaining space filled with CSF. In the context of CSF leaks, low CSF pressure from the leak can cause the brain to sag downward, allowing more CSF to enter the sella turcica and compress the pituitary gland.

Key Points to Consider

• A partially empty sella can suggest a CSF leak, but it's not specific to this condition alone and can be found in other situations such as idiopathic intracranial hypertension, following pituitary surgery, or as a normal variant in some individuals 1.
• Other symptoms that might accompany this condition include positional headaches (worse when upright, better when lying down), neck stiffness, nausea, vomiting, and hearing changes.
• Proper diagnosis typically requires additional imaging studies such as MRI with contrast, CT myelography, or cisternography to confirm the presence and location of a CSF leak 1.
• The cumulative presence of intracranial findings, including a partially empty sella, has been shown to correlate with a likelihood of finding a spinal leak source 1.

Diagnostic Approach

• Imaging plays a critical role in the diagnostic evaluation of intracranial hypotension, with goals of confirming the diagnosis and localizing the source of the leak 1.
• MRI imaging is often used to evaluate patients with suspected CSF leaks, and findings such as brain sagging, venous distension, and a partially empty sella can support the diagnosis 1.
• CT myelography or cisternography may be used to confirm the presence and location of a CSF leak, particularly in cases where MRI is inconclusive or unavailable 1.

From the Research

Partially Empty Sella and CSF Leak Association

• A partially empty sella can be associated with a cerebrospinal fluid (CSF) leak, as evidenced by studies that have found a correlation between the two conditions 2, 3.
• The presence of a partially empty sella may indicate elevated intracranial pressure, which can lead to CSF leaks 2.
• Research has shown that patients with spontaneous CSF leaks often have empty or partially empty sellae, suggesting a common pathophysiology 2, 3.
• A study found that 100% of patients with spontaneous CSF leaks had empty or partially empty sellae, with 10 patients having completely empty sellae and 5 having partially empty sellae 2.
• Another study found that 15 out of 16 patients with spontaneous encephaloceles/CSF leaks had empty or partially empty sellae, with 10 patients having empty sellae and 5 having partially empty sellae 3.

Clinical Characteristics

• Patients with spontaneous CSF leaks and empty or partially empty sellae often present with similar clinical characteristics, such as obesity and increased intracranial pressure 2, 3.
• The majority of patients with spontaneous CSF leaks and empty or partially empty sellae are obese women, with a mean body mass index of 35.9 kg/m2 3.
• The association between partially empty sella and CSF leak suggests that patients with this condition may require more aggressive surgical and medical treatment to prevent recurrent or multiple leaks 2.

Diagnostic Considerations

• Magnetic resonance imaging (MRI) is useful in diagnosing empty sella and can help identify patients with CSF leaks 4, 5.
• Lumbar puncture with measurement of CSF pressure can also be used to diagnose CSF leaks and elevated intracranial pressure 3.
• The presence of a partially empty sella on MRI should prompt further evaluation for CSF leak, particularly in patients with spontaneous CSF leaks or encephaloceles 2, 3.