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1.
Cortical somatosensory-evoked potentials (SEP) were recorded from thoracic and pelvic limbs in 15 horses (13 Thoroughbreds and 2 Quarter Horses). Ulnar nerve SEP were evoked by electrical stimulation of the lateral palmar branch of the ulnar nerve at the level of the metacarpophalangeal joint. Recordings were taken between electrodes at 2 cm lateral to the vertex (contralateral to the stimulated limb) and the midpoint of the interorbital line. Four peaks were found in all recordings: N1, P1, N2, and P2. Latencies to the peaks were 39.0 +/- 2.7, 45.5 +/- 5.3, 50.4 +/- 5.2, and 62.3 +/- 3.7 ms (mean +/- SD), respectively. Tibial nerve SEP were evoked by stimulation of the lateral plantar nerve branch of the tibial nerve at the level of the metatarsophalangeal joint. Recordings were taken between electrodes at the vertex (contralateral to the stimulated limb) and the midpoint of the interorbital line. Four peaks were also found in all tibial nerve SEP recordings: N1, P1, N2, and P2. Latencies to the peaks were 64.6 +/- 11.8, 84.5 +/- 9.7, 121.2 +/- 11.6, and 134.0 +/- 11.1 ms, respectively. Amplitude variability was high for the ulnar nerve and the tibial nerve SEP. There was no effect of sex seen on peak latency or amplitude, and peak latencies were not affected by body length.  相似文献   

2.
OBJECTIVE: To determine somatosensory evoked potentials (SEPs) in dogs with degenerative lumbosacral stenosis (DLS) and in healthy dogs. STUDY DESIGN: Clinical and experimental study. ANIMALS: Dogs with DLS (n = 21) and 11 clinically normal dogs, age, and weight matched. METHODS: Under anesthesia, the tibial nerve was stimulated at the caudolateral aspect of the stifle, and lumbar SEP (LSEP) were recorded percutaneously from S1 to T13 at each interspinous space. Cortical SEP (CSEP) were recorded from the scalp. RESULTS: LSEP were identified as the N1-P1 (latency 3-6 ms) and N2-P2 (latency 7-13 ms) wave complexes in the recordings of dogs with DLS and control dogs. Latency of N1-P1 increased and that of N2-P2 decreased as the active recording electrode was moved cranially from S1 to T13. Compared with controls, latencies were significantly delayed in DLS dogs: .8 ms for N1-P1 and 1.7 ms for the N2-P2 complex. CSEP were not different between groups. CONCLUSIONS: Surface needle recording of tibial nerve SEP can be used to monitor somatosensory nerve function of pelvic limbs in dogs. In dogs with DLS, the latency of LSEP, but not of CSEP, is prolonged compared with normal dogs. CLINICAL RELEVANCE: In dogs with lumbosacral pain from DLS, the cauda equina compression is sufficient to affect LSEP at the lumbar level.  相似文献   

3.
The aim of the present study was to evaluate to what extent the distal tibia and the trochlear ridges of the talus can be examined with ultrasound (US) in the dog and to establish a protocol for an optimal US examination of these ridges. Six hind limbs of deceased adult mixed-breed dogs were used. In two limbs, needles were placed using US guidance on the trochlea of the talus, just dorsal to and plantar to the distal tibia: one with the tarsal joint in extension and one with the joint in flexion. Then mediolateral (ML) radiographs of both joints were made with the needle in place to determine the percentage of the trochlear ridge of the talus that can be seen using US imaging. An US examination of the tarsal joint was performed on the four other limbs using microconvex (8 MHz) and linear (12 MHz) transducers (Logiq 7) and compound imaging. A three-step protocol was performed including a dorsal approach with the limb extended and the linear transducer (step I), a plantar approach with the limb flexed and the linear transducer (step II), and a plantar approach with the limb flexed and the microconvex transducer (step III). After the US examination, the four limbs were frozen and sectioned, two in a transverse and two in a sagittal plane. Bony structures on the US images were matched with the corresponding anatomic sections. The distal tibia and both trochlear ridges of the talus were easily recognized on the US images using the proposed protocol. When combining the dorsal and plantar approaches, it was possible to visualize up to 75% of the trochlear ridges of the talus in the dog.  相似文献   

4.
OBJECTIVE: To establish normal predictive values for cord dorsum potential (CDP) onset latency after thoracic and pelvic limb sensory or mixed nerve stimulation in adult dogs. ANIMALS: 26 clinically normal adult dogs. PROCEDURE: Sensory nerve action potentials (SNAP) were recorded proximally from tibial and lateral superficial radial nerves after distal stimulation. The CDP were recorded from the L4-L5 interarcuate ligament for the tibial nerve and from the C7-T1 interarcuate ligament for the radial nerve. Linear regression analyses were performed for CDP onset latency, and mean +/- SD was calculated for CDP onset to peak latency differences and sensory nerve conduction velocities (SNCV). RESULTS: For the tibial nerve, expected CDP onset latency (CDPOL) = -1.194 + 0.014 X pelvic limb length (mm; R2 = 0.912); CDPOL = -2.156 + 0.011 X pelvic limb/spinal length (mm; R2 = 0.911); and CDPOL = 0.941 + 2.197 X tibial nerve SNAP latency (milliseconds; R2 = 0.903). For the radial nerve, CDPOL = -0.9 + 0.014 x thoracic limb length (mm; R2 = 0.873); and CDPOL = 1.454 + 1.874 X radial nerve SNAP latency (milliseconds; R2 = 0.903). Mean +/- SD for CDP onset to peak latency difference for tibial and radial nerves was 3.1+/-0.3 and 3.0+/-0.4 milliseconds, respectively. CONCLUSIONS: Strong linear associations exist between CDPOL and a number of easily measured peripheral independent variables in dogs. There is also a narrow range of normal values for CDP onset to peak latency differences that is independent of limb length. CLINICAL RELEVANCE: CDP evaluation can be used to accurately assess functional severity and distribution of abnormalities in proximal sensory nerves, dorsal nerve roots, and spinal cord dorsal horns in dogs with suspected neuropathy, radiculopathy, or myelopathy involving the brachial or lumbosacral intumescences.  相似文献   

5.
OBJECTIVE: To establish a method of F-wave examinations and to determine values of F-wave conduction velocity (FWCV) and F-wave latency for the tibial nerve of clinically normal dogs. ANIMALS: 21 clinically normal dogs. PROCEDURE: The F-waves were elicited from the interosseous muscles via stimulation of the tibial nerve. The FWCV was determined by using the F-wave shortest value and the surface distance corresponding to the tibial nerve length. Correlation between the smallest latency value of the F-wave and the length of the tibial nerve and between the FWCV and rectal temperature were closely examined. RESULTS: F-wave latency was proportional to the length of the tibial nerve (correlation coefficient, 0.929). Mean +/- SD FWCV was 77.98 +/- 8.62 m/s. Regression equation was as follows: F-wave latency = 2.799 + (0.029 X length of the tibial nerve).The FWCV was increased when the measured rectal temperature was high. Correlation coefficient between FWCV and rectal temperature was 0.665. CONCLUSIONS AND CLINICAL RELEVANCE: In the study reported here, we established a reliable method for clinical evaluation of the F-wave. When assessing nerve conduction velocity, it is essential to measure nerve length along the pathway that the nerve impulse travels. This method of F-wave examination is a useful diagnostic tool for the evaluation of suspected dysfunction of the peripheral nervous system.  相似文献   

6.
H-reflexes were recorded consistently from the plantar muscles of pentobarbitone-anaesthetised dogs following supramaximal stimulation of the caudal cutaneous sural nerve (CCSN). As the amplitude, shape and latency of successive H-reflex potentials fluctuated from trial to trial, 16 consecutive sweeps were averaged to quantify the response. The averaged H-reflex had an amplitude of 1–6 ± 0–9 mV (mean ± SD] and a latency of 20 ± 2 ms. The CCSN-evoked H-reflex was recorded together with the CCSN-evoked compound muscle action potential (SurCMAP), which had a shorter latency (6 ± 1 ms) but comparable size (1–9 ± 1–3 mV). H-reflex afferents in the CCSN had overlapping but slightly higher electrical thresholds than plantar motoneurone axons. A ‘pure’ H-reflex could be obtained by injecting local anaesthetic below the site of nerve stimulation. Halothane/nitrous oxide anaesthesia substantially reduced the amplitude of H-reflex potentials in a reversible fashion.  相似文献   

7.
The spinal nerve root origins of the cutaneous nerves innervating the canine pelvic limb were determined in 12 barbiturate-anesthetized, healthy dogs by stimulating the dorsal roots L1-S3 and recording the evoked-action potentials from each cutaneous nerve. The dogs were then euthanatized, identification of each dorsal root and cutaneous nerve was verified by dissection, and the type of lumbosacral plexus (prefixed, median fixed, or postfixed) was determined. With one exception, the dorsal cutaneous branches and lateral cutaneous branches of L1-L3 originated only from their corresponding spinal nerve roots. The genitofemoral nerve received afferent fibers predominantly from L3-L4 nerve roots. The lateral cutaneous femoral nerve originated from L3-L5 nerve roots, and the saphenous nerve from L4-L6 nerve roots. The proximal caudal cutaneous sural nerve originated from L6-S1. The lateral cutaneous sural nerve originated from L5-S1; the deep and superficial fibular nerves arose primarily from L6-L7. The distal caudal cutaneous sural nerve originated predominantly from L7-S1, and the medial cutaneous tarsal nerve originated from L6-S1. The medial plantar nerve originated predominantly from L6-S1 roots, whereas the lateral plantar nerve originated from L6-S2 roots. The middle clunial nerve received afferent fibers primarily from S1-S2; the caudal clunial nerve received fibers from S1-S3. The caudal cutaneous femoral nerve originated predominantly from L7-S2. The dorsal nerve of the penis originated predominantly from S1-S2, and the superficial perineal nerve originated from S1-S3. One dog had a prefixed plexus, 8 dogs had median-fixed plexuses, and 1 dog had a postfixed plexus.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

8.
Supramaximal percutaneous nerve stimulation was used in motor nerve conduction velocity studies conducted in ten middle-aged, clinically normal dogs. Dogs were separated into two groups; dogs in one group weighted less than or equal to 7.5 kg and dogs in the other group weighted greater than or equal to 15.9 kg. Mean values and SEM were recorded for radial (72.1 +/- 1.9 m/s), median 65.6 +/- 2.1 m/s), ulnar (58.9 +/- 1.0 m/s), tibial (68.2 +/- 1.4 m/s), and peroneal (79.8 +/- 1.8 m/s) nerves. Values for latency, amplitude, and duration for proximal and distal evoked potentials were recorded. Analysis of mean nerve conduction velocity values for all nerves between the two groups indicated no statistical difference (P greater than 0.05). However, the two groups were statistically different (P less than 0.05) when values for distal latency and measurements of nerve length were compared. These data suggest that if latency is substituted for velocity measurements, various populations of dogs must be considered to clarify interpretation.  相似文献   

9.
OBJECTIVE: To document simple and reliable local, infiltrating nerve blocks for the saphenous, tibial and common peroneal nerves in the dog. STUDY DESIGN: Laboratory technique development; in vivo blind, controlled, prospective study. ANIMALS: Twenty canine cadavers and 18 clinically normal, client-owned dogs. METHODS: A peripheral nerve blockade technique of the tibial, common peroneal, and saphenous nerves was perfected through anatomic dissection. Injections were planned in the caudal thigh for the tibial and common peroneal nerves, and in the medial thigh for the saphenous nerve. Cadaver limbs were injected with methylene blue dye and subsequently dissected to confirm successful dye placement. Clinically normal dogs undergoing general anesthesia for unrelated, elective procedures were randomly assigned to treatment (bupivacaine; n = 8) or control (saline; n = 8) nerve blocks of the nerves under study. Upon recovery from general anesthesia, skin sensation in selected dermatomes was evaluated for 24 hours. RESULTS: Cadaver tibial, common peroneal, and saphenous perineural infiltrations were successful in nonchondrodystrophoid dogs (100, 100, and 97%, respectively.) Intraneural injection was rare (1%; 1/105; tibial nerve) in cadaver dogs. In the treatment group of normal dogs, duration of loss of cutaneous sensation in some dermatomes (saphenous, superficial and deep peroneal nerve) was significantly different than control dogs; the range of desensitization occurred for 1-20 hours. No clinical morbidity was detected. CONCLUSIONS: This technique for local blockade of the tibial, common peroneal, and saphenous nerves just proximal to the stifle is easy to perform, requires minimal supplies and results in significant desensitization of the associated dermatomes in clinically normal, nonchondrodystrophoid dogs. CLINICAL RELEVANCE: This technique may be an effective tool for post-operative analgesia to the femoro-tibial joint and distal pelvic limb. Other applications, using sustained-release drugs or methods, may include anesthesia/analgesia in high-risk patients or as a treatment for chronic pelvic limb pain or self-mutilation.  相似文献   

10.
Objective-To identify gait characteristics during trotting on a treadmill in nonlame Labrador Retrievers presumed predisposed or not predisposed to cranial cruciate ligament disease (CCLD). Animals-Clinically normal Labrador Retrievers presumed predisposed (n = 10) or not predisposed (7) to CCLD. Procedures-The right hind limb of each dog was classified by use of a predictive score equation that combined tibial plateau angle and femoral anteversion angle as presumed predisposed (high score [> -1.5]) or not predisposed (low score [≤ -1.5]) to CCLD. Tarsal joint, stifle joint, and hip joint kinematics, net moments, and powers were computed. Results-The stifle joint was held at a greater degree of flexion in limbs presumed predisposed to CCLD (130.9° vs 139.3°). More power was generated by muscles acting on the stifle joint in the early stance phase of limbs presumed to be predisposed to CCLD (2.93 vs 1.64 W/kg). The tarsal joint did not reach the same degree of extension in limbs presumed predisposed to CCLD, compared with that in limbs presumed not predisposed to CCLD (179.0° vs 161.0°). Velocity, stance time, vertical and craniocaudal forces, angular velocities, and net joint muscle moments did not differ between groups. Conclusions and Clinical Relevance-Gait mechanics of dogs with high (> -1.5) and low (≤ -1.5) tibial plateau angle and femoral anteversion angle scores were characterized on a treadmill, which may help in the identification of dogs predisposed to CCLD.  相似文献   

11.
A nerve fascicular biopsy technique that preserves the functional integrity of the parent nerve is reported in the dog. Fascicular biopsies from ulnar and peroneal nerves did not produce clinical sensory or motor deficits. Electrodiagnostic testing for the modalities of latency, duration, amplitude, and conduction velocities were not markedly altered after fascicular biopsies. Morphometric analysis of muscle fiber types, delineated by histochemic techniques, revealed no statistical (P greater than 0.05) difference between muscles from biopsied or control limbs. Fascicular biopsies resulted in small neuromas in all dogs.  相似文献   

12.
Motor nerve conduction parameters in the cat   总被引：1，自引：0，他引：1  
The electrophysiological characteristics of motor conduction in normal cats have been determined using an alligator clip as a surface electrode to record the compound muscle action potential (CMAP) following stimulation of the tibial, ulnar and fibular nerves. Data on nerve conduction velocity, residual latency and the amplitude and area of the CMAP have been determined using a computerised electromyography unit. Motor nerve conduction was substantially faster in cats than dogs and the site of stimulation had less effect on the size and area of the CMAP. Although a small decline in the amplitude of successive CMAPs was observed following repetitive stimulation of the tibial and ulnar nerve at 20 Hz, the decrement was less marked than in the dog.  相似文献   

13.
Brain stem and cerebrocortical potentials were evoked by electrical stimulation of the infraorbital nerve of dogs and recorded through needle electrodes placed adjacent to the contralateral parietal bone. Five individual, short latency peaks were recorded in each averaged trigeminal nerve-evoked potential and were identified as I, II (A and B), III (A and B), PI (A, B, and C), and NI. Mean peak latencies +/- 1 SD were as follows: I = 0.9 +/- 0.1 ms, IIA = 1.7 +/- 0.1 ms, IIB = 2.5 +/- 0.1 ms, IIIA = 3.6 +/- 0.15 ms, IIIB = 4.1 +/- 0.2 ms, PIA = 5.2 +/- 0.15 ms, PIB = 6.4 +/- 0.2 ms, PIC = 7.3 +/- 0.3 ms, and NI = 11.0 +/- 0.6 ms. Trigeminal nerve-evoked potentials recorded through needle electrodes were essentially the same as potentials evoked by direct stimulation of the infraorbital nerve and recorded directly from the dura mater overlying the contralateral rostral suprasylvian gyrus. The specificity of the stimulating site was verified by recording before and after the infraorbital nerve was cut proximal to the stimulating site.  相似文献   

14.
CASE DESCRIPTION: A 2-year-old Griffon Vendéen was examined because of a 1-month history of right hind limb lameness after a traumatic injury. CLINICAL FINDINGS: Neurologic examination revealed monoplegia and anesthesia of the right hind limb distal to the stifle (femorotibial) joint except for the area supplied by the cutaneous saphenous nerve. Results of electromyographic testing were consistent with a severe lesion of the tibial and peroneal nerves at the level of the stifle joint. TREATMENT AND OUTCOME: Exploratory surgery revealed an 80-mm-long gap in both the peroneal and tibial branches of the right sciatic nerve. A section of the left cutaneous saphenous nerve was interposed to graft the nerve defects. The dog received joint mechanotherapy and electrophysiologic therapy during the reinnervation process. Ten months after surgery, the dog had recovered almost completely. Neurologic examination revealed diminished flexion of the tarsal and digital joints. Repeat electromyographic testing revealed no abnormal spontaneous electrical activity in the right hind limb musculature, and small compound muscle action potentials were recorded in the right interosseous and cranial tibial muscles. CLINICAL RELEVANCE: Without surgical treatment, neurotmesis injury results in poor recovery of motor and sensory functions and may result in amputation. If a nerve defect exists, nerve grafting should be considered, even if the procedure is delayed until well after the injury. The sensory portion of the cutaneous saphenous nerve is a potential source of peripheral nerve for grafting in dogs. Reinnervation is a long-term process and physiologic support and owner involvement are necessary, but nearly complete functional recovery is possible.  相似文献   

15.
Brain stem auditory-evoked responses in the dog   总被引：1，自引：0，他引：1  
Brain stem auditory-evoked responses (BAER) were recorded from 58 dogs that did not have a known history of hearing problems. The BAER wave forms had an overall mean amplitude approximately 3.0 microV and typically consisted of a series of 4 to 5 vertex-positive peaks (peaks I through V). When acoustic clicks having intensities of 60-dB hearing level (decibels relative to the subjective hearing threshold) were used as stimuli, peak I had a latency of 1.49 +/- 0.13 ms; peak II, 2.32 +/- 0.14 ms; peak III, 3.01 +/- 0.25 ms; peak IV, 4.22 +/- 0.27 ms; and peak V, 5.55 +/- 0.37 ms. Latency values were influenced by a number of nonpathologic factors, including stimulus intensity and the body temperature of the dog. As stimulus intensity was decreased, there was a lengthening of the latency of each peak coupled with a decrease in the overall amplitude of BAER. Decreases in rectal temperature caused a similar lengthening of peak latencies. Age may have an influence on BAER, but under the conditions of the present study, the effect was not significant.  相似文献   

16.
A five-month-old, male German shepherd dog was presented with a left hindlimb deformity. Wearing a cast for a prolonged period to treat left metatarsal fractures at eight weeks of age had resulted in physeal closure of the calcaneus, metatarsals and phalanges. Hyperextension of the phalanges and ulceration of the plantar skin proximal to the main tarsal pad were seen. The left foot was 40 mm shorter than the right. At seven months of age, a modified circular external skeletal fixator (CESF) was used to perform distraction osteogenesis of the metatarsal bones for 28 days. The CESF apparatus was removed after eight weeks when there was radiographic consolidation of regenerate bone. At follow-up evaluations four and 12 months after surgery, the phalangeal hyperextension and plantar skin ulceration had resolved. No lameness was detected.  相似文献   

17.
To describe the ultrasonographic technique for investigation of the canine sciatic nerve, four canine cadaver pelvic limbs, two live healthy dogs, and five canine patients with suspected peripheral sciatic nerve lesions were examined with a high-resolution linear ultrasound transducer. The caudal part of the lumbosacral trunk and the origin of the sciatic nerve were visualized through the greater ischiatic foramen. The two components of the sciatic nerve, common peroneal and tibial nerves, were distinguished along the entire length of the nerve, until they branched at the level of the distal femur. In healthy live dogs they appeared as two adjacent hypoechoic tubular structures with internal echotexture of discontinuous hyperechoic bands, surrounded by a thin rim of highly echogenic tissue. The common peroneal component had a smaller diameter and was on the cranial aspect of the tibial component. An ultrasonographic lesion compatible with a peripheral nerve sheath tumor was found in one dog. Improved understanding of the ultrasonographic anatomy of the sciatic nerve supports clinical use of this modality.  相似文献   

18.
The aim of this study was to test the applicability of electrical stimulation of lumbar spinal nerve roots and obtain normative electrical root stimulation (ERS) data for L7 nerve root and sciatic nerve in dogs. For that purpose ERS and sciatic nerve stimulations were performed consecutively, in totally 40 healthy dogs. ERS was applied in the L7/S1 intervertebral space via monopolar needle electrodes. Muscle responses were recorded from the gastrocnemius muscles on the left and right hind limbs. Sciatic nerve stimulation was performed at the greater trochanter level on the left hind limb, with records obtained from the left gastrocnemius muscle. Mean root latencies of the left and right side were 5.22?±?0.49 ms and 5.29?±?0.53 ms, respectively. There was no significant difference in root latency between the right and left sides. The mean terminal latency was 3.82?±?0.46 ms. The proximal motor nerve conduction velocity of the sciatic nerve was 63.15?±?3.43 m/s. The results of this study show that ERS provides objective data about the integrity of lumbar spinal nerve roots by evaluating the entire population of motor fibres and total length of the motor axon in dogs. ERS can be considered a useful diagnostic method for confirmation of diagnoses of lumbosacral diseases.  相似文献   

19.
OBJECTIVE: To establish a method of F-wave evaluation and to determine normative values of F-wave parameters, including F-wave conduction velocity, persistence, and amplitude for the tibial nerve in cats. ANIMALS: 30 clinically normal cats. PROCEDURES: F-waves elicited in the interosseous muscles by stimulation of the tibial nerve were recorded, and linear regression analyses of the shortest latency versus the length of the tibial nerve and the limb length were performed. F-wave persistence was calculated by dividing the number of recorded F-waves by the number of stimuli. RESULTS: The correlation coefficient between F-wave latency and nerve length was 0.92, and that between F-wave latency and limb length was 0.58. Mean +/- SD F-wave conduction velocity of the tibial nerve was calculated to be 97.1 +/- 5.0 m/s. Linear regression analysis yielded the regression equation as follows: F-wave latency (milliseconds) = 2.60 + (0.02 x nerve length [mm]). Mean F-wave persistence and amplitude were 98.7 +/- 2.3% and 1.01 +/- 0.62 mV, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that nerve length should be used for nerve conduction studies of F-waves in felids. The regression equation for F-wave latency, conduction velocity, persistence, and amplitude may contribute to the diagnosis of nervous system diseases or injury in cats, such as trauma to the spinal cord or diabetic neuropathy.  相似文献   

20.
CASE DESCRIPTION: 3 kittens were examined because of a malformation affecting the hind limbs, resulting in an inability to bear weight or ambulate normally. CLINICAL FINDINGS: 2 kittens were younger than 6 weeks of age, and 1 was 4 months of age at the time of initial examination. The congenital abnormality was characterized by severe tarsal hyperextension in which weight was borne on the cranial aspect of the tarsus, and the plantar surface of the metatarsus faced dorsally. In 2 kittens, the condition affected both hind limbs, and in the older kitten, the condition was unilateral. In the 2 kittens in which radiographs were obtained, no bone abnormalities were detected. Full-cylinder fiberglass casts were applied and changed weekly to accommodate growth. Owners administered physical therapy after final cast removal. TREATMENT AND OUTCOME: Conservative management involving external coaptation and physical therapy led to favorable results in all 3 cats. CLINICAL RELEVANCE: Although further studies are needed to determine the etiology of the disorder, affected kittens may be successfully treated with conservative management. Owners should be committed to the necessity for returning cats for serial cast changes, care for pressure sores, and administration of physical therapy after cast removal.  相似文献   

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