Stimulation techniques and response characteristics of the M and F waves and H reflex in dogs

Knecht, Charles D.; Redding, Richard W.; Hyams, Deborah

doi:10.1007/bf02214904

Cited by 16 publications

(10 citation statements)

References 5 publications

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“…In our study, the three cats were presumably fed tachyzoites and bradyzoites within cysts, but no infection was noted in their tissues. Although both immunocompetent and immunosuppressed cats have previously been shown to be capable of developing systemic infections (after ingestion or subcutaneous injection of tissue cysts/tachyzoites) and of transmitting the infection to their offspring, they have also not shown any stages similar to those of the oocyst of T. gondii in their feces.16,' 8 The lack of organisms in the initial biopsies from both pups and the necropsy material from pup 1 suggests that immunosuppression secondary to corticosteroid administration may have been responsible for the significant number of organisms seen in pup 2. Although this increase in organisms could have occurred due to the natural progression of the disease, a direct relationship between immunosuppression and organism proliferation is supported by previous data on experimental infection in dogs and m i~e .…”

Section: Discussionmentioning

confidence: 99%

Neospora caninurn Infectionin English Springer Spaniel Littermates

Cuddon¹,

Lin

Bowman

et al. 1992

Veterinary Internal Medicne

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Progressive paraparesis developed in four male English Springer Spaniel pups from a litter of five during the first 10 weeks of life. Two of the pups, which had the earliest onset of neurologic signs, were euthanatized without further workup. However, a detailed investigation was completed on the remaining two littermates at 12 weeks of age. Both pups had progressive paraparesis for 3 to 4 weeks before presentation, with one dog developing subsequent asymmetric pelvic limb extensor rigidity. Based on results from neurologic examination, cerebrospinal fluid (CSF) analysis, electrophysiology, and muscle/ nerve biopsy, a presumptive diagnosis of protozoal polyradiculitis and polymyositis was made. Necropsy of the most severely affected pup confirmed the clinical diagnosis of inflammatory nerve root and muscle disease but no organisms were found. To increase the potential yield of organisms, the second pup was placed on immunosuppressive doses of corticosteroids and euthanatized 2 weeks later. Numerous organisms were found in lesions in muscle and the central nervous system. Organisms grew in tissue culture and were isolated from the peritoneal fluid of gerbils inoculated with infected tissue. Organisms were not isolated from inoculated mice, guinea pigs, rabbits, and hamsters. No parasites were seen in feces or tissues of three cats fed infected dog tissues. Serologic testing demonstrated a strong positive titer to Neospora caninurn in both pups, and electron microscopy showed the characteristic morphology of this parasite. (Journal of Veterinary Internal Medicine 1992; 6:325-332) NEOSPOROSIS is a recently recognized protozoan infection of dogs and other mammals.',2 The causative protozoa, Neospora caninurn, was first recognized as a new species in 1988. Diagnostic tests to distinguish N.

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Section: Discussionmentioning

confidence: 99%

Neospora caninurn Infectionin English Springer Spaniel Littermates

Cuddon¹,

Lin

Bowman

et al. 1992

Veterinary Internal Medicne

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“…These findings demonstrate that H-reflex afferents in the CCSN have overlapping, but slightly higher electrical thresholds than plantar motor axons. The slower conduction velocity of H-reflex afferents compared to motor axons (Knecht andRedding 1981, Sims andSelcer 1981, Knecht andothers 1983, Nafe andLee 1983) is not unexpected given these findings. The inability to increase the amplitude of the H-reflex with two-and fourfold increases in stimulus intensity suggests that this reflex results largely from activation of group Ia spindle afferents from the plantar muscles.…”

Section: Characteristics Of the Ccsn-evoked H-reflexmentioning

confidence: 84%

A new method for recording H‐reflexes from the plantar muscles of dogs

Malík¹,

1991

J of Small Animal Practice

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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.

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“…Although both waves involve conduction in the proximal nerve and ventral roots, the H reflex also depends on conduction in the dorsal roots and transmission across a synapse in the grey matter. Various characteristics can differentiate these waves in man and both have been described in dogs (Knecht & Redding, 1981;Sims & Selcer, 1981;Knecht, Redding & Hyams 1983), although experimental procedures such as dorsal rhizotomy may be necessary to establish which is being recorded. In these present studies the late wave appeared at the same or a slightly greater stimulation threshold as the direct response (M wave) and did not decline in amplitude with increasing stimulus intensity.…”

Section: A T E R I a L S A N D M E T H O D Smentioning

confidence: 99%

“…In these present studies the late wave appeared at the same or a slightly greater stimulation threshold as the direct response (M wave) and did not decline in amplitude with increasing stimulus intensity. Based on the information in man and the report by Knecht, Redding & Hyams (1983) it has been designated an F-wave. Routine blood and CSF samples were examined from 11 of the 14 dogs at least once during the illness.…”

Section: A T E R I a L S A N D M E T H O D Smentioning

confidence: 99%

Progressive axonopathy: an inherited neuropathy of Boxer dogs. 1. Further studies of the clinical and electrophysiological features

Griffiths

1985

J of Small Animal Practice

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The clinical and electrophysiological findings in 14 Boxer dogs with progressive axonopathy (PA) are described. The salient clinical features are hind‐limb ataxia which may later involve forelegs, proprioceptive defects, hypotonia, patellar areflexia, absence of muscle atrophy and, in a few instances, ocular tremor and head bobbing. The outward signs are often observed by 2–3 months of age but clinical testing can reveal patellar areflexia at 1 month of age. After an initial progression, the signs may stabilize and dogs are alive at 4 years of age having shown no deterioration over the previous 2 years. The electrophysiology shows reduced motor nerve conduction velocities and evoked potential amplitudes after about 4 months of age. The F‐wave latency is considerably increased. Sensory nerves also show a marked reduction in the amplitude of their evoked potentials and eventually cease to conduct. Abnormal spontaneous activity is not a feature on electromyography. The conduction defects probably reflect to some degree the reduced nerve fibre diameters and myelin sheath changes found in PA although other factors may also be operating. The study shows that PA can be diagnosed with reasonable confidence by routine clinical testing at an early age.

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Stimulation techniques and response characteristics of the M and F waves and H reflex in dogs

Cited by 16 publications

References 5 publications

Neospora caninurn Infectionin English Springer Spaniel Littermates

Neospora caninurn Infectionin English Springer Spaniel Littermates

A new method for recording H‐reflexes from the plantar muscles of dogs

Progressive axonopathy: an inherited neuropathy of Boxer dogs. 1. Further studies of the clinical and electrophysiological features

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