An analysis of ideal and actual time to surgery after traumatic spinal cord injury in Canada.

STUDY DESIGN: Retrospective analysis of a prospective registry and surgeon survey. OBJECTIVES: To identify surgeon opinion on ideal practice regarding the timing of decompression/stabilization for spinal cord injury and actual practice. Discrepancies in surgical timing and barriers to ideal timing of surgery were explored. SETTING: Canada. METHODS: Patients from the Rick Hansen Spinal Cord Registry (RHSCIR, 2004-2014) were reviewed to determine actual timing of surgical management. Following data collection, a survey was distributed to Canadian surgeons, asking for perceived to be the optimal and actual timings of surgery. Discrepancies between actual data and surgeon survey responses were then compared using χ2 tests and logistic regression. RESULTS: The majority of injury patterns identified in the registry were treated operatively. ASIA Impairment Scale (AIS) C/D injuries were treated surgically less frequently in the RHSCIR data and surgeon survey (odds ratio (OR)= 0.39 and 0.26). Significant disparities between what surgeons identified as ideal, actual current practice and RHSCIR data were demonstrated. A great majority of surgeons (93.0%) believed surgery under 24 h was ideal for cervical AIS A/B injuries and 91.0% for thoracic AIS A/B/C/D injuries. Definitive surgical management within 24 h was actually accomplished in 39.0% of cervical and 45.0% of thoracic cases. CONCLUSION: Ideal surgical timing for traumatic spinal cord injury (tSCI) within 24 h of injury was identified, but not accomplished. Discrepancies between the opinions on the optimal and actual timing of surgery in tSCI patients suggest the need for strategies for knowledge translation and reduction of administrative barriers to early surgery.

Understanding crossovers and potential ways to mitigate the problem: Lessons from influential trials on lumbar microdiscectomy.

BACKGROUND: Lumbar microdiscectomy is the most frequent surgical intervention used in the treatment of sciatica from herniated lumbar discs. Many discectomy trials have been plagued with an excessive number of crossovers that have rendered results inconclusive. METHODS: We review the design and results of influential lumbar microdiscectomy trials. We also discuss the various strategies that have been used to decrease the number of crossovers or to mitigate the effects of crossovers on analyses. RESULTS: Randomized trials on lumbar discectomy were affected by crossover rates of 8% to 42%. Various strategies that have been used to decrease that number or to mitigate the effects on results include: patient selection, blinding (placebo-controlled trials), an immediate access to surgery for the surgical group (but limited access to surgery for the conservative group), shortening the follow-up period necessary to reach the primary outcome measure, postponing crossovers to surgery after determination of the primary outcome, and modifying the primary outcome measure to include treatment failures. Crossovers should be anticipated and compensated for by increasing the number of participants. CONCLUSION: Non-adherence to randomly allocated management options can deprive trials of the statistical power needed to inform clinical care. Crossovers and ways to mitigate related problems should be anticipated at the time of trial design.

Excessive calcium ingestion leading to milk-alkali syndrome.

This report describes the presentation and clinical course of a 40-year-old woman who had an emergency admission for eclampsia. During routine investigations, she was found to have profound hypercalcaemia, the cause of which was identified as milk-alkali syndrome, caused by self-medication with antacid tablets for dyspepsia. Treatment with aggressive rehydration, bisphosphonates and discontinuation of antacid tablets restored normocalcaemia. The patient made a full recovery with no long-term side-effects. Her male infant was safely delivered with no deleterious effects of exposure to high calcium concentrations in utero.

A clinical approach to managing the mare with placentitis.

Placental infections in the mare are a diagnostic and therapeutic challenge. The following article will review techniques for identifying placental infections, approaches for treating placentitis, and methods for managing these mares after foaling.

Expression of bovine myf5 induces ectopic skeletal muscle formation in transgenic mice.

myf5 is one of a family of four myogenic determination genes that control skeletal muscle differentiation. To study the role of myf5 in vivo, we generated transgenic mice harboring the bovine homolog, bmyf, under control of the murine sarcoma virus promoter. Ectopic expression of the full-length bmyf transgene was detected in brain and heart tissue samples of F1 progeny from transgenic founder mice. Ectopic bmyf expression activated endogenous skeletal myogenic determination genes in the hearts and brains of transgenic animals. Incomplete skeletal myogenesis in most hearts gave rise to cardiomegaly and focal areas of cardiomyopathy. In brains in which ectopic expression led to a more complete myogenesis, focal areas of multinucleated, striated myotubes containing actin, desmin, and myosin were observed. These unexpected results show that myf5 can initiate myogenic differentiation in vivo, supporting the hypothesis that myf5 is responsible for determination of cells to the myogenic lineage in normal embryogenesis.

Vaginal prolapse in a pregnant Maine coon cat: a case report.

Vaginal prolapse is a condition characterised by excessive accumulation of mucosal oedema and protrusion of hyperplastic tissue through the vulva. It has been reported in ruminants and canines, but has not been characterised in felines. This report describes the history, clinical signs and treatment of a pregnant Maine coon cat with a Type III vaginal prolapse diagnosed approximately 54 days after the first day of mating. Prior to queening, the prolapse was reduced and retained using a vulvar cruciate suture. Due to the risk of dystocia and recurrence, a caesarean section with ovariohysterectomy was performed. Postoperatively, a stay suture was maintained in the vulva for 2 weeks, resulting in permanent reduction of the vaginal prolapse. To the authors' knowledge, this case represents the first report of the successful management of vaginal prolapse in a pregnant cat.

Intracellular analysis of effects of phencyclidine on rat neostriatal neurons recorded in vitro.

The effects of phencyclidine (PCP) on the synaptic and direct membrane properties of neostriatal neurons were assessed using intracellular recordings from 62 neurons in rat neostriatal slices. Electrophysiological measurements were obtained before, during and after bath application of PCP. At all concentrations (1-300 microM) PCP raised current thresholds for evoking synaptic potentials and reduced excitability (the firing rate of directly evoked action potentials). In a smaller number of cells PCP (50-300 microM) increased input resistance. These effects were long-lasting and neurons did not show reversal with washes as long as 75 min. Some neurons were injected with biocytin for identification. All were medium-sized spiny type I neurons typical of rodent neostriatum.

Use of internal controls to increase quantitative capabilities of the ribonuclease protection assay.

Through the use of two internal controls, we have developed an improved method of quantitating ribonuclease protection assay (RPA) results. A truncated sense RNA fragment and an antisense RNA fragment for the gene of interest were transcribed from PCR fragments containing T7 bacterial promoters. An 18S ribosomal RNA fragment was also used. When radiolabeled antisense and 18S probes, along with sense fragment and sample RNA, were hybridized, digested with RNase A/T1 and gel-electrophoresed, three distinct bands resulted. The antisense RNA fragment bound to the sense RNA fragment confirmed the integrity of the reaction. The antisense RNA fragment bound to endogenous mRNA measured the amount of specific gene expression in the sample. The 18S RNA fragment bound to endogenous mRNA determined the actual amount of sample added to the gel. Using the specific activities of the antisense and 18S transcripts, and scintillation counts of the protected fragments, we calculated the amounts of message and total RNA on the gel, determining picogram of message per microgram of total RNA. Final results were not based on assumed original amounts of RNA placed in the assay nor were they biased by lane-to-lane variations. Through the described adaptations, we have developed a well-controlled RPA that accurately and reproducibly quantifies gene expression.

Surgical management of essential blepharospasm.

We have reviewed the surgical management of essential blepharospasm over the last 15 years, comparing the results from facial nerve avulsion with those from orbicularis muscle stripping. After facial nerve avulsion 50% of patients remained free of troublesome spasm for 15 months after surgery, but only 25% remained so for more than two years. Following orbicularis oculi myectomy 50% of patients were free of troublesome spasms for 30 months after surgery and 55% of patients had relief from spasm for more than two years. Secondary effects of the two procedures are compared and are found to be fewer after orbicularis myectomy. There were no major complications after either form of surgery. Botulinum toxin is the treatment of first choice for this condition. If this becomes ineffective or inconvenient, surgical treatment is warranted and should not be deferred for fear of severe side effects of treatment, since these are rare. Protractor myectomy gives longer relief from blepharospasm than facial nerve avulsion and has fewer complications. However, it is technically difficult, time consuming, and has greater peroperative morbidity. Facial nerve avulsion may therefore still have a role in selected patients.

Hedonic reactivity to sucrose in rats: modification by pimozide.

Reward summation functions (RSFs) are an important way to dissociate and quantify hedonic and motor effects of neuroleptics. Previously used only with brain stimulation reinforcement, we demonstrate they will also work using sucrose solution reinforcement. Eighteen male rats were trained to lever press on a CRF schedule for 0.01 ml sucrose solution reinforcers of varying concentration (0.025, 0.05, 0.1, 0.3, 0.5, 0.7, 0.9, 1.1, 1.7, 2.3 M). Making the lever harder to press caused an increase in the asymptote of the function, demonstrating a motor effect. Quinine added to the solutions (0.05%) caused the function to shift right, demonstrating an hedonic effect. Rats injected with 0.2 mg/kg pimozide, a dopamine antagonist, then tested four hours later, showed a right shift in the function with no change in asymptote. Thus, at this dose pimozide affects hedonic and not motor substrates of the CNS. These data demonstrate the generalizability of the RSF method to reinforcers other than brain self-stimulation.

A review of relative risks associated with four types of contact lenses.

This paper reviews the data of Frank et al. in the light of increasing concern over the safety of contact lenses used for extended wear. Relative risks were calculated for four types of contact lenses (CLs): extended wear soft, daily wear soft, rigid gas-permeable (RGP), and polymethylmethacrylate (PMMA) lenses--worn by a group of patients who presented themselves for emergency ocular treatment. The cases comprised 329 CL wearers who were found to have lens related metabolic disorders, toxic or hypersensitivity reactions, cornea abrasions, microbial keratitis, or some other lens-induced problem. Controls comprised 64 CL wearers whose ocular problems were unrelated to lens use. It was found that extended wear soft lenses were nearly 7 times more likely to be associated with an ocular disorder than PMMA hard lenses, and approximately 3.4 times more likely than daily wear soft lenses. Furthermore, extended wear soft lenses were nearly 5 times more likely to be linked with microbial keratitis than daily wear soft lenses, and approximately 7.5 times more likely than RGP lenses. Metabolic disorders were also more common with extended wear lenses (relatively risk: 3.3) than with either RGP (1.8) or daily wear soft lenses (2.0) or PMMA lenses (1.0). If the association between extended wear soft lenses and ocular complications is borne out in large population studies, eye-care professionals may need to reconsider the wisdom of prescribing these lenses for the cosmetic correction of vision.

MPTP-induced Parkinson-like disease in sheep: clinical and pathologic findings.

Eight ewes, divided into two groups based on age, with group 1 7-8 and group 2 1-3 years old, respectively, were administered 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intravenously (IV) at cumulative doses of 2.0 to 34.6 mg/kg body weight. Two group 1 sheep, given cumulative doses of 2 and 8.5 mg/kg, developed persistent severe neurologic signs of body stiffness and rigidity, paucity of movement, intention body tremors, and abnormal body posture and stance similar to those signs in MPTP-induced disease in people and primates. After their acute onset, these persistent signs were nonprogressive up to the observation period of 32 days post infusion. None of the younger ewes had persistent neurologic symptoms at equivalent cumulative doses (9.0 mg/kg). The only pathologic changes were microscopic lesions in the central nervous system, consisting of bilaterally symmetrical neuronal chromatolysis and necrosis limited to the substantia nigra and locus ceruleus. These lesions were found in two persistently affected and two younger sheep, suggesting age-based differences in dose response and the threshold of clinical expression of disease. Serum MPTP half-life was 11 days. Thus sheep exposed to MPTP could be an alternative model to the primate for the comparative study of clinical, pathologic, and biochemical mechanisms in MPTP neurotoxicity and Parkinson's disease in people.

Outcome of plate fixation of olecranon fractures.

OBJECTIVES: To evaluate the functional outcome of plate fixation for displaced olecranon fractures, both simple and comminuted. DESIGN: Retrospective patient, chart, and radiographic review. SETTING: Academic teaching hospital. PATIENTS: Twenty-five patients who underwent plate fixation of displaced olecranon fractures by two surgeons were independently reviewed at an average follow-up of thirty-four months (range, 15-69 months). MAIN OUTCOME MEASUREMENTS: Physical capability was assessed by measuring range of motion and isometric elbow strength. Patient-rated outcomes were evaluated using the SF-36, DASH, Mayo Elbow Performance Index (MEPI), and visual analogue scales for patient satisfaction and pain. Radiographs were evaluated preoperatively, postoperatively, and at the time of final review. RESULTS: The average patient age was fifty-four years (range, 14-81 years). The Mayo classification of fractures was fourteen Type II and eleven Type III. An adequate reduction was maintained in all elbows until union. Physical capability measures indicated nonsignificant side-to-side differences in motion or strength, except for supination motion, which was reduced in the injured arm (p = 0.003). The MEPI-rated outcome was twenty-two excellent or good. Patient satisfaction was high (9.7/10), with a low pain rating (1/10). The mean DASH score was consistent with almost normal upper extremity function. The SF-36 showed no difference in physical health as compared with the average American population. Twenty percent of patients required plate removal because of prominence of the internal fixation. The outcome was not influenced by fracture pattern. CONCLUSION: Plate fixation is an effective treatment option for displaced olecranon fractures with a good functional outcome and a low incidence of complications.

Clinical forms of acquired myasthenia gravis in dogs: 25 cases (1988-1995).

The purpose of this project was to investigate the clinical forms of acquired myasthenia gravis in dogs. The medical records from 25 dogs with seropositive acquired myasthenia gravis were reviewed, and the following data were recorded for each patient: signalment, history, clinical findings; results of IV edrophonium chloride administration, repetitive nerve stimulation, and presence or absence of muscle membrane staining by immunocytochemical methods; serum acetylcholine receptor antibody concentration; treatment; and outcome. Several clinical forms of acquired myasthenia gravis were identified. Nine of the 25 patients (36%) had no historical or clinical evidence of appendicular muscle weakness, and were designated as focal myasthenics. These dogs exhibited focal weakness in one or more of the following muscle groups: facial (3 of 9), pharyngeal (3 of 9), and laryngeal (3 of 9). The remaining 16 dogs (64%) exhibited appendicular muscle weakness. Four of these 16 dogs had acute onset and rapid development of clinical signs, and were designated as acute fulminating myasthenics. The remaining 12 dogs were classified as generalized myasthenics. All 4 dogs with acute fulminating myasthenia gravis had megaesophagus, 2 had facial muscle weakness, and 1 had pharyngeal muscle weakness. Ten of the 12 dogs with generalized myasthenia gravis had megaesophagus, 4 had facial muscle weakness, 4 had pharyngeal muscle weakness, and 3 had laryngeal muscle weakness. Historical or clinical evidence of exercise-associated appendicular weakness was found in only 6 of the 12 (50%) dogs with generalized myasthenia gravis, and in none of the dogs with acute fulminating myasthenia gravis. Seven of the 12 dogs with generalized myasthenia gravis had weakness primarily (n = 1) or exclusively (n = 6) of the pelvic limbs. Two of the 4 dogs with acute fulminating myasthenia gravis had primarily pelvic limb weakness. Twelve of the 25 dogs (48%) died or were euthanized shortly after admission to the hospital due to aspiration pneumonia. The dogs with acute fulminating myasthenia gravis had a markedly higher 1-year mortality rate in comparison with the other 2 groups. The use of immunosuppressive therapy had a significant positive effect on patient survival, regardless of the type of myasthenia gravis. This investigation demonstrates that acquired myasthenia gravis in dogs is a disorder with a wide spectrum of clinical forms, similar to the analogous disorder in people.

Comparison of total white blood cell count and total protein content of lumbar and cisternal cerebrospinal fluid of healthy dogs.

Lumbar and cisternal CSF from 31 healthy dogs were analyzed and compared statistically. The mean total protein of the lumbar CSF samples was 28.68 mg/dl; the mean total protein of cisternal CSF was 13.97 mg/dl. The mean total WBC count of lumbar CSF was 0.55 cells/microliter; the mean WBC count of cisternal CSF was 1.45 cells/microliter. Statistical analysis indicated that the protein and WBC differences between the 2 types of CSF were significant (P = less than 0.001 and P = less than 0.01, respectively).

Spinal nerve root origins of the cutaneous nerves arising from the canine brachial plexus.

The spinal nerve root origins of the cutaneous nerves arising from the brachial plexus were investigated in 10 babiturate-anesthetized dogs by stimulating dorsal roots C5 to T2 and recording from each cutaneous nerve. Upon completion of the experiment, the contributions of the spinal nerve ventral branches to the brachial plexus were verified by anatomic dissection. The brachial plexus was formed by the ventral branches of C6 to T2 in 8 dogs, C6 to T1 in 1 dog, and C5 to T1 in 1 dog. The cutaneous branch of brachiocephalicus nerve was formed primarily by contributions from the C6 dorsal root. The cranial lateral cutaneous brachial nerve, a branch of the axillary nerve, was formed predominantly from C6 to C7. The median nerve received contributions primarily from C7, C8, and T1, and the communicating branch from the musculocutaneous to the median nerve contained fibers primarily from C7 and C8. The medial and lateral branches of the superficial branch of the radial nerve arose from C6, C7, C8, and T1, with the medial branch generally arising 1 segment craniad to the lateral. The palmar and dorsal branches of the ulnar nerve arose predominately from C8 and T1, and the caudal cutaneous antebrachial nerve of the ulnar arose predominately from T1 and T2.

Response of muscle spindle primary endings to static stretch in acute and chronic spinal cats.

To evaluate fusimotor activity, the response of muscle spindle primary endings to static stretch was recorded from group Ia fibers in 8 control cats and in 31 cats at 3, 6, 14, 30, and 60 days after lumbar spinal cord transection. The spindle responses and clinical status of each group were compared with those of the control group. At 3 days after transection, the cats were hypotonic and mildly hyperreflexic. Spindle responses were significantly depressed. By day 6, the cats were mildly hypertonic and significant spindle recovery had occurred, although the responses were still significantly depressed from control levels. Spindle responses, hypertonia, and hyperreflexia continued to increase to day 30. At this time, spindle responses remained significantly depressed, although the cats were markedly hypertonic and hyperreflexic. A significant change in spindle activity or clinical status did not occur from 30 to 60 days after transection.

Spinal nerve root origins of the cutaneous nerves of the canine pelvic limb.

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)

Cutaneous innervation of the thorax and abdomen of the dog.

The anatomy of the cutaneous nerves innervating the canine thorax and abdomen was investigated by gross dissection of 38 dogs. Additionally, the cutaneous areas innervated by the thoracic and abdominal cutaneous nerves were mapped in a 2nd group of 33 barbiturate-anesthetized male dogs, using electrophysiologic techniques. The skin of the thorax was innervated by dorsal cutaneous branches, lateral cutaneous branches, and ventral cutaneous branches of the spinal nerves. The dorsal cutaneous branches were branches of the dorsal primary branches of spinal nerves C6 and T2 through T11. The lateral cutaneous branches were branches of the ventral primary branches of spinal nerves T2 through T12. The ventral cutaneous branches were branches of the ventral primary branches of spinal nerves T2 through T10. The skin of the abdomen was innervated by dorsal and lateral cutaneous branches of spinal nerves T12 through L3 (and occasionally L4). The cutaneous areas of the dorsal cutaneous branches occupied the dorsal half of the scapular and thoracic regions and the dorsal 2/5 of the abdominal region. The cutaneous areas of the lateral cutaneous branches covered the major portion of the ventral half of the thorax and the ventral 3/5 of the abdomen. The cutaneous areas of the ventral cutaneous branches occupied the axilla and the ventral part of the thoracic wall.

Electrophysiologic studies of cutaneous nerves of the thoracic limb of the dog.

The cutaneous innervation of the thoracic limb was investigated in 36 barbiturate-anesthetized dogs, using electrophysiologic techniques. The cutaneous area (CA) innervated by each cutaneous nerve was delineated in at least five dogs by stroking the hair in the area with a small watercolor brush while recording from the nerve. Mapping of adjacent CA revealed areas of considerable overlapping. The part of the CA of a given nerve supplied by only that nerve is referred to as its autonomous zone. Of all nerves arising from the brachial plexus, only the suprascapular, subscapular, lateral thoracic, thoracodorsal, and cranial and caudal pectoral nerves lacked cutaneous afferents. The dorsal cutaneous branch of C6 had a CA, but no grossly demonstrable dorsal cutaneous branches for C7 C8, or T1 were found. The cervical nerves had ventral cutaneous branches, but no lateral cutaneous branches. Thoracic nerves T2-T4 had dorsal, ventral, and lateral cutaneous branches. The cutaneous branches of the brachiocephalic, axillary, musculocutaneous, radial, median, and ulnar nerves all had CA which were overlapped by adjacent CA, thus their autonomous zones were much smaller than the cutaneous areas usually depicted for these nerves in anatomy and neurology textbooks.