Diagnosis and surgical management of a fractured atlas in a cat

Dendritic Spines and Pain Memory

Neuropathic pain is a debilitating form of pain arising from injury or disease of the nervous system that affects millions of people worldwide. Despite its prevalence, the underlying mechanisms of neuropathic pain are still not fully understood. Dendritic spines are small protrusions on the surface of neurons that play an important role in synaptic transmission. Recent studies have shown that dendritic spines reorganize in the superficial and deeper laminae of the spinal cord dorsal horn with the development of neuropathic pain in multiple models of disease or injury. Given the importance of dendritic spines in synaptic transmission, it is possible that studying dendritic spines could lead to new therapeutic approaches for managing intractable pain. In this review article, we highlight the emergent role of dendritic spines in neuropathic pain, as well as discuss the potential for studying dendritic spines for the development of new therapeutics.

Optimal safe implantation corridors in feline cervical vertebrae (C2-T1): CT study in 16 domestic shorthair cats

OBJECTIVES

The objective of this study was to define safe corridors for the optimal placement of bicortical implants in the feline cervical spine (C2-T1) using CT.

METHODS

CT images of feline cervical spines (n = 16) were reviewed retrospectively. Multiplanar reconstructions were used to define the optimal safe corridors. Safe corridors were defined by their angle of insertion, width and length. The insertion point within the vertebral body was also described. Vertebral measurements were compared between vertebrae using multilevel linear regression, and left and right measurements within vertebrae were compared with the paired samples Wilcoxon signed-rank test. A P value <0.05 was considered significant for all analyses.

RESULTS

The safe corridor insertion points were located within the caudal third of the vertebral body in C2 (mean cranial vertebral ratio 0.73) and in the cranial third of the vertebral bodies from C3-T1 (mean cranial vertebral ratios 0.34-0.38). Mean safe corridor widths ranged from 1.04 mm in C2 to 2.30 mm in C7 and T1. The mean right and left optimal angles of implantation were, respectively, 21.79° and 21.49° for C2, 45.26° and 46.19° for C3, 51.48° and 51.04° for C4, 53.52° and 54.30° for C5, 56.36° and 56.65° for C6, 63.40° and 64.92° for C7, and 53.90° and 52.90° for T1. There were statistically significant differences between vertebrae in almost every measurement.

CONCLUSIONS AND RELEVANCE

Cervical vertebral safe corridors in cats are narrow and differ to those reported in dogs. Safe corridors are located in the caudal third of C2 and cranial third of the C3-T1 vertebral bodies. Current recommendations for implant sizes should be reviewed, as 1.5-2 mm implants would be oversized for bicortical implantation in most of the feline cervical vertebrae.