Intracranial hypotension with a sixth cranial nerve palsy subsequent to massive thoracic CSF hygroma: a rare complication of thoracic disc excision

Thoracic cerebrospinal fluid (CSF) hygroma is a rare and potentially devastating complication of the anterior thoracic approach to the spine. We present two cases in which this complication resulted in acute cranial nerve palsy and discuss the pathoanatomy and management options in this scenario.

Two male patients presented to our department with neurological deterioration due to a giant herniated thoracic disc. The extruded disc fragment was noted pre-operatively to be calcified in both patients. A durotomy was performed at primary disc prolapse resection in the first patient, whereas an incidental durotomy during the procedure caused complication in the second patient. These were repaired primarily or sealed with Tachosil^®. Both patients re-presented with acute diplopia. Imaging of both patients confirmed a massive thoracic cerebrospinal fluid hygroma and evidence of intracranial changes in keeping with intracranial hypotension, but no obvious brain stem shift. The hemithorax was re-explored and the dural repair was revised. The first patient made a full recovery within 3 months. The second patient was managed conservatively and took 5 months for improvement in his ophthalmic symptoms.

The risk of CSF leakage post-dural repair into the thoracic cavity is raised due to local factors related to the chest cavity. Dural repairs can fail in the presence of an acute increase in CSF pressure, for example whilst sneezing. Intracranial hypotension can result in subsequent hygroma and possibly haematoma formation. The resultant cranial nerve palsy may be managed expectantly except in the setting of symptomatic subdural haematoma or compressive pneumocephaly.