Cleta Sue Bailey

Congenital Spinal Malformations

When presented with an animal that has a congenital spinal malformation, the veterinarian needs to consider the clinical significance of the malformation, the possible presence of other anomalies--spinal and nonspinal, the heritability of the malformation, and potentially innovative treatment options. This article includes explanations of the conditions and information regarding diagnosis and treatment of hemivertebrae and block vertebrae, malformations at the cranial-vertebral junction, osteocartilaginous exostoses, spinal bifida, and spinal stenosis.

Spinal Nerve Root Origin of the Median, Ulnar and Musculocutaneous Nerves and their Muscle Nerve Branches to the Canine Forelimb

The contribution individual ventral spinal nerve roots made to the canine median nerve, ulnar nerve, musculocutaneous nerve, and their muscle nerve branches was determined electrophysiologically. Each spinal nerve root was sequentially stimulated. Utilizing quantitative signal averaging techniques, the evoked potential was measured at each tested peripheral nerve. Evoked potential to the median nerve originated from the seventh cervical sinal root (C7) through the second thoracic spinal root (T2) with most input from C8 and TI. The ulnar nerve received evoked potential from C7‐T2. Although T1 provided the major input to both the median and ulnar nerves, the relative contribution of T1 was greater in the ulnar nerve. The musculocutaneous nerve received input from ventral spinal roots C6‐Tl with C6 and C7 providing most of the evoked potential. The ventral spinal roots which supplied the bulk of the evoked potential to a particular muscle nerve were consistent between individual dogs. Variation of evoked potential input was greatest from spinal roots which supplied less than 10% of the total potential.

Chapter 27 – Cerebrospinal Fluid

Publisher Summary The analysis of cerebrospinal fluid (CSF) is described as the central nervous system equivalent of the complete blood count and the analogy is a good one. A CSF analysis provides a general index of neurologic health, and it often provides evidence of the presence of disease. Similar to a complete blood count, CSF analysis has reasonable sensitivity but low specificity. The possible alterations of CSF are relatively limited compared to the varieties of neurologic diseases that exist. Additionally, the type and degree of CSF abnormality seems to be related as much to the location of disease as to the cause or the severity of the lesion; meningeal and paraventricular diseases generally produce greater abnormalities than deep parenchymal diseases. Previous therapy may affect the type, degree, and duration of CSF abnormalities as well. The CSF abnormalities identified upon analysis are also dependent on the CSF collection site with respect to lesion location. CSF analysis only occasionally provides a specific diagnosis.

Spinal Root Origin of the Radial Nerve and Nerves Innervating Shoulder Muscles of the Dog

The ventral spinal root origin of the radial nerve, its muscle branches, and brachial plexus nerves which supply shoulder and thoracic musculature was determined in the dog. Electrophysiological signal averaging techniques measured evoked potential from specific ventral spinal roots to individual muscle nerves. The entire radial nerve received input from the sixth cervical (C6) through the second thoracic (T2) spinal roots. The most significant (p < .05) input to triceps brachii came from C8 while the deep ramus of the radial nerve received its largest input from C7. The brachiocephalicus, suprascapular, and subscapular nerves all received their most significant (p < .05) innervation from C6. Approximately 90 % of the evoked potential to the axillary nerve originated from C7. The thoracodorsal nerve received most of its innervation from ventral roots C7 and C8. The lateral thoracic nerve which innervates the cutaneous trunci muscle was supplied by ventral roots C8–T2. Examination of innervation patterns suggests that only modest variation of spinal root input to specific nerves occurred between individual dogs.

Dorsal Nerve Root Origins of the Cutaneous Nerves of the Feline Pelvic Limb

The dorsal root origins of cutaneous nerves supplying the feline pelvic limb were determined electrophysiologically in 11 cats. Cutaneous nerves were surgically exposed and the presence or absence of an evoked potential in response to stimulation of individual dorsal roots was noted. The dorsal cutaneous branches of L3–L5 and S3, and the lateral cutaneous branch of L3 each arose solely from their parent spinal nerves. The L7, SI, and S2 dorsal cutaneous branches had multiple dorsal root origins. The lateral cutaneous femoral nerve originated from L3–L6 dorsal roots in 4 patterns of origin, and the saphenous nerve originated from L4–L6 dorsal roots in 2 patterns of origin. The lateral and caudal cutaneous sural nerves originated from L6–SI roots in 2 and 3 patterns, respectively. The lateral and medial plantar nerves arose from L6–S2 roots in 4 and 2 patterns, respectively. The superficial and deep peroneal nerves originated from L6–SI roots in 2 and 3 patterns, respectively. The caudal cutaneous femoral nerve or its branches arose from L7–S3 in 8 origin patterns. The dorsal nerve of the penis and the superficial perineal nerve arose from L.7–S3 and SI –S3 roots, respectively, each in 4 patterns. A subtle correlation between plexus type and dorsal root origins of the cutaneous nerves was noted.