CSF-lymphatic fistulas are a very rare, and possibly underdiagnosed, cause of spontaneous intracranial hypotension. They describe a direct communication between the spinal subarachnoid space and lymphatic vessels, allowing for the loss of cerebrospinal fluid (CSF) directly into the lymphatic system.
On this page:
Epidemiology
Descriptions of CSF-lymphatic fistulas are limited to case reports 1-7, and thus, it is likely that CSF-lymphatic fistulas are very rare. However, owing to their difficulty in the diagnosis, it is also possible that they are under-recognized among cases of cryptogenic spontaneous intracranial hypotension. Cases have been reported in both adult and pediatric patients 1-7.
Diagnosis
The diagnosis should be suspected when clinical and imaging features of spontaneous intracranial hypotension are present, there is no epidural CSF accumulation, and a CSF-venous fistula has not been identified after a comprehensive multimodal diagnostic workup.
Clinical presentation
When present at the spine, the clinical presentation is spontaneous intracranial hypotension 1-3 and is therefore discussed in that article. When present at the skull base, typical features of spontaneous intracranial hypotension may be absent, and patients may have other clinical manifestations such as rhinorrhea or otorrhea 8.
Pathology
CSF-lymphatic fistulas may be:
primary (idiopathic): aetiopathogenesis unknown 1
-
secondary
-
abnormal vascular proliferation in the setting of a lymphatic or venolymphatic spinal malformation
described cases include associations with kaposiform lymphangiomatosis 2, Gorham disease 3,4, generalized lymphatic anomaly 5, and Klippel-Trénaunay syndrome 6
trauma 7
-
Radiographic features
Similar to imaging of CSF-venous fistulas, and unlike other cases of spontaneous intracranial hypotension due to CSF leaks, no accumulation of CSF outside of the dura can be identified (e.g. no spinal longitudinal epidural collections). However, other features of spontaneous intracranial hypotension (e.g. pachymeningeal enhancement, increased venous blood volume, subdural effusions, sagging brainstem and acquired tonsillar ectopia, etc.) may be present 1-3.
The key to the diagnosis is identifying myelographic contrast opacifying lymphatic vessels or chains, with eventual contrast opacification of the thoracic duct. This can be achieved, similarly to investigation of CSF-venous fistulas, either with cross-sectional imaging (CT myelography or MR myelography) or fluoroscopy (digital subtraction myelography) 1-3. MR lymphangiography should also be performed to investigate for a contributing lymphatic or venolymphatic spinal malformation, and to pre-operatively assess lymphatic drainage pathways 1.
Off-label warning: the use of gadolinium-based contrast agents for intrathecal administration is not approved by regulatory agencies such as the FDA. Read more: intrathecal gadolinium.
Treatment and prognosis
In described cases presenting with features of intracranial hypotension, surgical ligation/disconnection 1,2 or percutaneous embolization 3 are the treatments of choice. Targeted epidural blood patches may only result in transient symptom relief 2, however, there is one described case with sustained benefit achieved from this treatment approach 5.
Unable to process the form. Check for errors and try again.