Posterior thoracic laminoplasty with dorsal, intradural identification of ventral defect and transdural discectomy for a spontaneous cerebrospinal fluid leak: case report.

Spontaneous intracranial hypotension (SIH) has been increasingly reported in the literature concomitant with the improved sensitivity of imaging modalities. Although typically associated with meningeal weakening, a handful of cases of SIH secondary to thoracic disc osteophytes have been reported. Five of 7 reported cases were treated with epidural blood patch (EBP) alone while 2 required surgical management. There is no standard operative approach; both anterior and posterolateral approaches can be cumbersome and associated with morbidity, particularly in young, healthy patients. The authors report a case of SIH in which a ventral dural tear secondary to a calcified thoracic disc was repaired via posterior thoracic laminoplasty with dorsal durotomy and intradural exposure of the ventral defect with transdural discectomy followed by primary closure. A 34-year-old man presented with low-pressure headaches following axial load injury from a ski accident 5 years earlier. The patient's symptoms were refractory to a trial of conservative treatment and EBP, and he developed bilateral upper-extremity paresthesias. MRI of the spine demonstrated an extrathecal collection spanning the thoracic spine, and dynamic CT myelography identified contrast extravasation adjacent to a calcified paramedian disc at T9-10. The patient underwent posterior laminoplasty with neuromonitoring. A ventral dural defect was visualized via a dorsal durotomy, the penetrating disc osteophyte was removed transdurally, and the ventral and dorsal dura maters were closed primarily. Both somatosensory and motor evoked potentials were unchanged during surgery. The patient has remained asymptomatic more than 10 months postoperatively and he has resumed work as a surgeon. Cases of SIH secondary to a calcified thoracic disc are rare with little precedent as to optimal surgical intervention. This case illustrates the potential usefulness of posterior laminectomy in nonmyelopathic patients in whom there is no evidence of canal compromise and for whom neuromonitoring is available. Additionally, surgeon experience and patient preference may guide surgical planning.