Reevaluation of predictive factors for complete recovery in dogs with nonambulatory tetraparesis secondary to cervical disk herniation.

The vast majority of dogs with cervical disk herniation experience cervical pain and only mild motor deficits; therefore, not much is known about the factors that predict recovery in dogs with nonambulatory tetraparesis (NAT) secondary to cervical disk herniation. In this retrospective study, we tested the hypothesis that two previously reported prognostic factors, site of disk herniation and severity of neurological deficits, are useful predictors of complete recovery. Overall, 20 (62%) of 32 dogs with cervical disk herniation-associated NAT had complete recovery. Site of disk herniation was not a significant predictor of complete recovery; dogs with high cervical lesions (C2 to C3, C3 to C4) did not have a higher likelihood of complete recovery than other dogs. Likewise, severity of neurological deficits (i.e., intact voluntary motor function versus absent voluntary motor function) was not a significant predictor of complete recovery. Using stepwise logistic regression, two significant predictors of complete recovery were identified. Small dogs (delta15 kg body weight) were six times more likely to achieve complete recovery than larger dogs. Dogs that regained the ability to walk within 96 hours after surgery were seven times more likely to completely recover than dogs not walking 96 hours after surgery. We conclude that neither the site of disk herniation nor severity of neurological deficits assists the clinician in predicting postoperative outcome in dogs with cervical disk herniation-associated NAT. Reliable preoperative predictors of complete recovery are needed to advance current diagnostic and treatment protocols to improve overall prognosis.

Evaluation of electroacupuncture treatment for thoracolumbar intervertebral disk disease in dogs.

OBJECTIVE: To evaluate use of electroacupuncture combined with standard Western medical treatment versus Western medical treatment alone for treatment of thoracolumbar intervertebral disk disease in dogs. DESIGN: Prospective controlled study. ANIMALS: 50 dogs with signs of thoracolumbar intervertebral disk disease. PROCEDURES: Dogs were randomly allocated to 1 of 2 treatment groups and classified as having grade 1 to 5 neurologic dysfunction. Dogs in group 1 received electroacupuncture stimulation combined with standard Western medical treatment; those in group 2 received only standard Western medical treatment. A numeric score for neurologic function was evaluated at 4 time points to evaluate effects of treatments. RESULTS: Time (mean +/- SD) to recover ambulation in dogs with grade 3 and 4 dysfunction in group 1 (10.10 +/- 6.49 days) was significantly lower than in group 2 (20.83 +/- 11.99 days). Success (able to walk without assistance) rate for dogs with grade 3 and 4 dysfunction in group 1 (10/10 dogs) was significantly higher than that of similarly affected dogs in group 2 (6/9 dogs). Dogs without deep pain perception (grade 5 dysfunction) had a success (recovery of pain sensation) rate of 3 of 6 and 1 of 8 in groups 1 and 2, respectively, but the difference was not significant. Overall success rate (all dysfunction grades) for group 1 (23/26; 88.5%) was significantly higher than for group 2 (14/24; 58.3%). CONCLUSIONS AND CLINICAL RELEVANCE: Electroacupuncture combined with standard Western medical treatment was effective and resulted in shorter time to recover ambulation and deep pain perception than did use of Western treatment alone in dogs with signs of thoracolumbar intervertebral disk disease.

Outcome and prognostic factors in non-ambulatory Hansen Type I intervertebral disc extrusions: 308 cases.

Thoracolumbar intervertebral disc disease is the most common cause of caudal paresis in dogs. Whilst the pathogenesis of the extrusion has been widely studied, treatment protocols and prognostic factors relating to outcome remain controversial. Recent studies have examined a multitude of factors relating to time to regain ambulation after decompressive surgery. Most intervertebral disc herniations occur in the thoracolumbar region, causing upper motor neuron signs in the rear limbs, which are thought to have a more favourable prognosis compared to the lower motor neuron signs created by herniation of an intervertebral disc in the caudal lumbar region. Due to the potential disruption of the lumbar intumescence, lower motor neuron signs have been reported as having a less favourable prognosis. The purpose of this study was to evaluate the intervertebral disc space as a prognostic factor relating to ambulatory outcome and time to ambulation after decompressive surgery. Hansen Type I intervertebral disc extrusions were studied in 308 non-ambulatory dogs. Preoperative and postoperative neurological status, corticosteroid use, signalment, intervertebral disc space, postoperative physical rehabilitation, previous hemilaminectomy surgery, disc fenestration, return to ambulation, and time to ambulation were reviewed.

Hyperresponsiveness to phencyclidine in animals lesioned in the amygdala on day 7 of life. Implications for an animal model of schizophrenia.

Phencyclidine (PCP) has been described to exacerbate psychotic symptoms in patients suffering from schizophrenia. In rats, PCP, dose-dependently, induces hyperactivity, stereotyped behaviour and social isolation, postulated to represent the positive (hyperactivity, stereotypy) and negative (social isolation) symptoms of schizophrenia. Based on previous studies, ibotenic acid lesions in the amygdala on day 7 of life have been proposed as an animal model of psychiatric neurodevelopmental disorders like schizophrenia. The purpose of the present study was to determine whether the responsiveness to PCP on locomotor activity in animals lesioned in the amygdala on day 7 of life is different from the response to this drug in sham-operated animals. The effect of graded doses of PCP on behaviour was assessed in a small open field. Animals lesioned in the amygdala on day 7 of life appeared to be hyperresponsive to PCP compared to sham-operated animals. The hyperresponsiveness to PCP in rats lesioned in the amygdala on day 7 of life further contributes to the validation of this putative animal model of schizophrenia.

Prognostic indicators for time to ambulation after surgical decompression in nonambulatory dogs with acute thoracolumbar disk extrusions: 112 cases.

OBJECTIVES: To determine prognostic indicators for time to ambulation after surgical decompression in nonambulatory dogs with intact pain sensation and acute Hansen type-1 disk extrusions. STUDY DESIGN: Retrospective clinical study. ANIMALS: One-hundred twelve dogs with Hansen type-I disk extrusions that had decompressive hemilaminectomy or dorsal laminectomy. METHODS: All dogs had thoracolumbar disk extrusion and were nonambulatory with intact pain sensation at admission. Variables considered included age, weight, voluntary motor function at time of anesthetic induction, glucocorticoid use, times from onset of nonambulatory status to admission and surgical decompression, time in hospital to surgical decompression, anesthetic time, surgical time, number of contrast injections required to perform a diagnostic myelogram, postoperative pain sensation, and postoperative voluntary motor function. Time to ambulation was defined as the number of days from surgical decompression until the dog was able to stand and take a series of steps without assistance. RESULTS: One-hundred seven dogs (96%) were able to ambulate within 3 months. The mean time to ambulation was 12.9 days and was significantly shorter if dogs had postoperative voluntary motor function (7.9 days v 16.4 days, P <.0001). No other variable had a significant association with time to ambulation. CONCLUSIONS: Few perioperative variables have prognostic value for return to ambulation. Nonambulatory dogs with intact pain sensation and Hansen type-1 disk extrusions in the thoracolumbar spine that are treated with surgical decompression have a favorable prognosis. CLINICAL RELEVANCE: The presence of postoperative voluntary motor function is a favorable prognostic indicator for early return to ambulation.