The intriguing encounters of Pavlov and Cushing.

Ivan Petrovich Pavlov and Harvey William Cushing were two of the most prominent neuroscientists of the early 20th century. Their contributions helped advance the understanding of the brain and its disorders, and propelled neuroscience into a new era of research and treatment. Although separated geographically and culturally, Pavlov and Cushing exchanged letters and followed one another's careers from afar. They met only a few times, during international scientific gatherings in the US and abroad. These encounters were captured in journal entries, letters, and photographs, and provide a glimpse into the lives of these two great men and the history of neuroscience at the turn of the last century.

Efficacy of osteogenic protein-1 in a challenging multilevel fusion model.

STUDY DESIGN: A therapeutic study compared the influence of osteogenic protein-1 to autograft and collagen carrier in multilevel sheep spine fusions. OBJECTIVE: To evaluate the efficacy of osteogenic protein-1 compared to autograft and collagen carrier in achieving fusion in a challenging multilevel lumbar spine ovine model. SUMMARY OF BACKGROUND DATA: Bone morphogenetic proteins can successfully augment spinal fusion. To date, all the preclinical and clinical studies using bone morphogenetic proteins have evaluated single-level fusion. In practice, multiple level fusions are commonly required for various conditions, like spinal deformity. METHODS: Eighteen sheep underwent three-level spine fusion. Six sheep were treated with osteogenic protein-1 and its carrier, autograft, or with the carrier alone. Specimens were analyzed for evidence of fusion by palpation, radiographic and histologic analysis, and biomechanical testing. RESULTS: Manual palpation testing for the presence of fusion showed none of the specimens fused all three levels or fused at the lumbosacral junction. No statistically significant difference was found between the osteogenic protein-1 and autograft groups' fusion rates based on radiographic grading (P = 0.65) or biomechanical testing. Histologic analysis showed no qualitative difference in bone morphology or cellularity of fusion masses when comparing the autograft and osteogenic protein-1 specimens. CONCLUSIONS: No model before this exists that tests the efficacy of bone morphogenic proteins in as challenging an environment. Extrapolation of single-level preclinical and clinical studies with bone morphogenic proteins for use in multilevel fusion requires careful review. Autograft and osteogenic protein-1 had similar rates of fusion. A high rate of nonunion is seen with this multiple level fusion to the sacrum using autograft or osteogenic protein-1. The biologic enhancement with osteogenic protein-1 is not able to overcome this mechanically rigorous model.

Thoracic vertebral body exostosis as a cause of myelopathy in a patient with hereditary multiple exostoses.

The posterior thoracic vertebral body appears to be a novel origin for an exostosis causing myelopathy. A patient with hereditary multiple exostoses and myelopathy caused by an exostosis originating from the posterior aspect of the T5 vertebral body was treated with a staged anterior decompression/corpectomy and posterior spinal fusion. The patient had near-complete resolution of his myelopathy immediately after undergoing removal of the exostosis through a right-sided lateral thoracotomy approach. This was a unique origin for an exostosis causing spinal cord compression in a patient with hereditary multiple exostoses. The delivery of the exostosis was performed en bloc during the anterior decompression and corpectomy portion of the surgery. This resulted in the expected favorable outcome.