Novel Association Between Intrathecal Drug Administration and Arachnoiditis Ossificans.

BACKGROUND: We present a case of delayed progression of adhesive arachnoiditis to arachnoiditis ossificans (AO) in a patient being treated with a high-dose polypharmaceutical intrathecal regimen. CASE DESCRIPTION: The patient is a 39-year-old Caucasian male who was implanted with an intrathecal pump in 2006 to control severe low back pain and administered intrathecal pain medication for a period of 10 years. In 2016, he developed new-onset radicular pain and worsened sensation in his lower extremities. Computed tomography scan of the lumbar spine at that time demonstrated profound calcification of the arachnoid consistent with a diagnosis of AO. It was presumed that prolonged high-dose intrathecal medication precipitated this condition, and his intrathecal medications were titrated down with removal of the pump. CONCLUSIONS: It is unlikely that his condition occurred as a result of prior surgery, with the more likely cause being hyperplasia of the spinal arachnoid, leading to scarring and calcification, due to the high-dose intrathecal regimen. This case highlights the delayed progression from stable arachnoiditis to AO concurring with a regimen of high-dose intrathecal medications. Clinicians should closely monitor patients undergoing intrathecal drug administration, particularly at elevated doses, for indications of damage to the spinal arachnoid mater.

Previously unreported complications associated with integrated cage screws following anterior lumbar interbody fusion: report of 2 cases.

Anterior lumbar interbody fusion (ALIF) is a widely performed surgical treatment for various lumbar spine pathologies. The authors present the first reports of virtually identical cases of complications with integrated screws in stand-alone interbody cages. Two patients presented with the onset of S-1 radiculopathy due to screw misplacements following an ALIF procedure. In both cases, an integrated screw from the cage penetrated the dorsal aspect of the S-1 cortical margin of the vertebra, extended into the neural foramen, and injured the traversing left S-1 nerve roots. Advanced neuroimaging findings indicated nerve root impingement by the protruding screw tip. After substantial delays, radiculopathic symptoms were treated with removal of the offending instrumentation, aggressive posterior decompression of the bony and ligamentous structures, and posterolateral fusion surgery with pedicle screw fixation. Postoperative radiographic findings demonstrated decompression of the symptomatic nerve roots via removal of the extruded screw tips from the neural foramina.

Severe holocord syrinx in a child with megalencephaly-capillary malformation syndrome.

The authors present the case of a child with megalencephaly-capillary malformation syndrome who developed a rapidly progressive holocord syringomyelia that was treated surgically. A 3-year-old boy with megalencephaly-capillary malformation-polymicrogyria (MCAP) syndrome presented with several months of right leg weakness, worsening scoliosis, and increased seizures. An MRI study of the brain demonstrated a Chiari I malformation and massively dilated syringomyelia extending from C-2 to the conus medullaris. The patient underwent an urgent suboccipital craniectomy with C1-3 laminectomies to relieve the CSF outflow obstruction with significant clinical improvement. Surgery was complicated by bleeding from intracranial vascular malformations. This report describes a very rapidly developing, massive holocord syringomyelia related to CSF obstruction due to an unusual congenital brain malformation and associated vascular overgrowth at the site. Serial, premorbid MRI studies demonstrated the very rapid progression from no Chiari malformation, to progressively greater cerebellar tonsillar herniation, to holocord syrinx. This complication has never been reported in MCAP syndrome and should be considered in any affected MCAP patient with a progressive neurological decline, even if previous spine imaging findings were normal. Surgical complications due to hemorrhage also need to be considered in this vascular brain malformation.

Metastatic renal cell carcinoma, with a radiographically occult primary tumor, presenting in the operative site of a thoracic meningioma: long-term follow-up: Case report.

Lesions metastatic to the site of a meningioma resection from a different primary tumor are rare. Metastasis of a tumor without a known primary tumor is also rare. Metastasis of a renal cell carcinoma, without an identifiable primary tumor, to the bed of a meningioma resection has not been previously reported. The authors describe the case of a 54-year-old man who presented with decreased sensory and motor function in the lower extremities. He underwent T3-5 laminectomies and gross-total removal of an intradural, extramedullary meningioma. The postoperative course was uneventful, and the patient regained full neurological function. After a 3-year period, he developed progressive upper thoracic pain and lower-extremity paresthesias. Imaging studies showed an epidural mass at the T2-4 levels and what appeared to be blastic involvement of the T2-4 vertebrae. A metastatic workup was negative. Emergency revision laminectomies yielded a fibrous, nonvascular mass. Neuropathology was consistent with metastatic renal cell carcinoma. After 6 months, the patient's symptoms of pain and paresthesias recurred. Repeat excision, with decompression of the spinal cord, revealed tumor cells morphologically and immunophenotypically similar to those obtained from the prior surgery. Cytogenetic analysis confirmed the presence of metastatic renal cell carcinoma. A novel case of an epidural metastatic renal cell carcinoma, of unknown primary origin, in the same operative bed of a previously resected intradural, extramedullary meningioma of the thoracic spine is reported.