Trends in risk of recurrence after the first ischemic stroke in adults younger than 55 years of age in Sweden.

BACKGROUND: Previous studies on stroke recurrence in younger adults often contain small sample size which makes it difficult to study trends in stroke recurrence over a long period of time. AIMS: The aim of the present study was to investigate temporal trends in the risk of recurrence in younger patients with a first ischemic stroke. METHODS: All men and women aged 18-54 years who had survived at least 28 days after a first ischemic stroke from 1987 to 2006 were identified in the Swedish Inpatient Register. The patients were stratified into four 5-year periods according to their admission period and were followed up for a total of four years after the index event with regard to recurrent ischemic stroke. A Cox regression model was used to analyze the risk of recurrent ischemic stroke. RESULTS: Of the 17,149 ischemic stroke patients who were identified, 2432 (14.2%) had a recurrent ischemic stroke event within four years. From the first to the last periods (1987-1991 versus 2002-2006), the four-year risk of recurrent ischemic stroke decreased by 55% (hazard ratio 0.45, 95% confidence interval 0.39-0.53) in men and 59% (hazard ratio 0.41, 95% confidence interval, 0.33-0.50) in women. The cumulative four-year risk was 11.8% (95% CI 10.55-13.25) in men and 9.8% (95% CI 8.40-11.46) in women during the last five-year period (2002-2006). CONCLUSIONS: The risk of recurrence among younger ischemic stroke patients has decreased over the past 20 years. Despite these improvements, younger patients are still at a high risk for recurrent ischemic stroke.

Biomechanical Evaluation of the Stabilizing Function of Three Atlantoaxial Implants Under Shear Loading: A Canine Cadaveric Study.

OBJECTIVE: To compare the biomechanical properties of a ventral transarticular lag screw fixation technique, a new dorsal atlantoaxial instability (AAI) clamp, and a new ventral AAI hook plate under sagittal shear loading after transection of the ligaments of the atlantoaxial joint. STUDY DESIGN: Cadaveric biomechanical study. ANIMALS: Canine cadavers (n = 10). MATERIALS AND METHODS: The occipitoatlantoaxial region of Beagles euthanatized for reasons unrelated to the study was prepared leaving only ligamentous structures and the joint capsules between the first 2 cervical vertebrae (C1 and C2). The atlanto-occipital joints were stabilized with 2 transarticular diverging positive threaded K-wires. The occipital bone and the caudal end of C2 were embedded in polymethylmethacrylate and loaded in shear to a force of 50 Newtons. The range of motion (ROM) and neutral zone (NZ) of the atlantoaxial joint were determined after 3 loading cycles with atlantoaxial ligaments intact, after ligament transection, and after fixation with each implant. The testing order of implants was randomly assigned. The implants tested last were subjected to failure testing. RESULTS: All stabilization procedures decreased the ROM and NZ of the atlantoaxial joint compared to transected ligament specimens. Only stabilization with transarticular lag screws and ventral plates produced a significant reduction of ROM compare to intact specimens. CONCLUSION: Fixation with transarticular lag screws and a ventral hook plate was biomechanically similar and provided more rigidity compared to dorsal clamp fixation. Further load cycling to failure tests and clinical studies are required before making clinical recommendations.

Feasibility of using EMG for early detection of the facial nerve during robotic direct cochlear access.

HYPOTHESIS: Facial nerve monitoring can be used synchronous with a high-precision robotic tool as a functional warning to prevent of a collision of the drill bit with the facial nerve during direct cochlear access (DCA). BACKGROUND: Minimally invasive direct cochlear access (DCA) aims to eliminate the need for a mastoidectomy by drilling a small tunnel through the facial recess to the cochlea with the aid of stereotactic tool guidance. Because the procedure is performed in a blind manner, structures such as the facial nerve are at risk. Neuromonitoring is a commonly used tool to help surgeons identify the facial nerve (FN) during routine surgical procedures in the mastoid. Recently, neuromonitoring technology was integrated into a commercially available drill system enabling real-time monitoring of the FN. The objective of this study was to determine if this drilling system could be used to warn of an impending collision with the FN during robot-assisted DCA. MATERIALS AND METHODS: The sheep was chosen as a suitable model for this study because of its similarity to the human ear anatomy. The same surgical workflow applicable to human patients was performed in the animal model. Bone screws, serving as reference fiducials, were placed in the skull near the ear canal. The sheep head was imaged using a computed tomographic scanner and segmentation of FN, mastoid, and other relevant structures as well as planning of drilling trajectories was carried out using a dedicated software tool. During the actual procedure, a surgical drill system was connected to a nerve monitor and guided by a custom built robot system. As the planned trajectories were drilled, stimulation and EMG response signals were recorded. A postoperative analysis was achieved after each surgery to determine the actual drilled positions. RESULTS: Using the calibrated pose synchronized with the EMG signals, the precise relationship between distance to FN and EMG with 3 different stimulation intensities could be determined for 11 different tunnels drilled in 3 different subjects. CONCLUSION: From the results, it was determined that the current implementation of the neuromonitoring system lacks sensitivity and repeatability necessary to be used as a warning device in robotic DCA. We hypothesize that this is primarily because of the stimulation pattern achieved using a noninsulated drill as a stimulating probe. Further work is necessary to determine whether specific changes to the design can improve the sensitivity and specificity.

Use of a hand-assisted laparoscopic surgical technique for closure of an extensive mesojejunal rent in a horse.

CASE DESCRIPTION: A 7-year-old 573-kg (1,261 -lb) Swiss Warmblood gelding was evaluated because of signs of acute abdominal pain. CLINICAL FINDINGS: Physical examination revealed a markedly distended abdomen with subjectively reduced borborygmi in all abdominal quadrants. A large, gas-distended viscus was present at the pelvic brim preventing complete palpation of the abdomen per rectum. Ultrasonographic evaluation could not be safely performed in the initial evaluation because of severe signs of abdominal pain. TREATMENT AND OUTCOME: Ventral midline celiotomy was performed, and right dorsal displacement of the ascending colon was corrected. Progressive signs of abdominal pain after surgery prompted repeat ventral midline celiotomy, and small intestinal incarceration in a large, radial mesojejunal rent was detected. The incarceration was reduced, but the defect was not fully accessible for repair via the celiotomy. Repair of the mesenteric defect was not attempted, and conservative management was planned after surgery; however, signs of colic returned. A standard laparoscopic approach was attempted from both flanks in the standing patient, but the small intestine could not be adequately mobilized for full evaluation of the rent. Hand-assisted laparoscopic surgery (HALS) allowed identification and reduction of jejunal incarceration and repair of the mesenteric rent. Although minor ventral midline incisional complications were encountered, the horse recovered fully. CLINICAL RELEVANCE: HALS techniques should be considered for repair of mesenteric rents in horses. In the horse of this report, HALS facilitated identification, evaluation, and repair of a large radial mesenteric rent that was not accessible from a ventral median celiotomy.

Comparison of the biomechanical properties of a ventral cervical intervertebral anchored fusion device with locking plate fixation applied to cadaveric canine cervical spines.

OBJECTIVE: To evaluate fixation properties of a new intervertebral anchored fusion device and compare these with ventral locking plate fixation. STUDY DESIGN: In vitro biomechanical evaluation. ANIMALS: Cadaveric canine C4-C7 cervical spines (n = 9). METHODS: Cervical spines were nondestructively loaded with pure moments in a nonconstraining testing apparatus to induce flexion/extension while angular motion was measured. Range of motion (ROM) and neutral zone (NZ) were calculated for (1) intact specimens, (2) specimens after discectomy and fixation with a purpose-built intervertebral fusion cage with integrated ventral fixation, and (3) after removal of the device and fixation with a ventral locking plate. RESULTS: Both fixation techniques resulted in a decrease in ROM and NZ (P < .001) compared with the intact segments. There were no significant differences between the anchored spacer and locking plate fixation. CONCLUSION: An anchored spacer appears to provide similar biomechanical stability to that of locking plate fixation.

High-normal blood pressure and long-term risk of type 2 diabetes: 35-year prospective population based cohort study of men.

BACKGROUND: The link between type 2 diabetes and hypertension is well established and the conditions often coexist. High normal blood pressure, defined by WHO-ISH as systolic blood pressure (SBP) 130-139 mm Hg or diastolic blood pressure (DBP) 85-89 mm Hg, has been found to be an independent predictor for type 2 diabetes in studies, although with relatively limited follow-up periods of approximately 10 years. The aim of this study was to investigate whether hypertension, including mildly elevated blood pressure within the normal range, predicted subsequent development of type 2 diabetes in men over an extended follow-up of 35 years. METHODS: Data were derived from the Gothenburg Primary Prevention Study where a random sample of 7 494 men aged 47-55 years underwent a baseline screening investigation in the period 1970-1973. A total of 7 333 men were free from previous history of diabetes at baseline. During a 35-year follow-up diabetes was identified through the Swedish hospital discharge and death registries. The cumulative risk of diabetes adjusted for age and competing risk of death was calculated. Using Cox proportional hazard models we calculated the multiple adjusted hazard ratios (HR) (95% confidence interval (CI)) for diabetes at different blood pressure levels. RESULTS: During a 35-year follow-up, 956 men (13%) were identified with diabetes. The 35-year cumulative risk of diabetes after adjusting for age and competing risk of death in men with SBP levels <130 mm Hg, 130-139 mm Hg, 140-159 mm Hg and ≥160 mm Hg were 19%, 30%, 31% and 49%, respectively. The HR for diabetes adjusted for age, body mass index (BMI), cholesterol, antihypertensive treatment, smoking, physical activity and occupation were 1.43 (95% CI 1.12-1.84), 1.43 (95% CI 1.14-1.79) and 1.95 (95% CI 1.55-2.46) for men with SBP 130-139 mm Hg, 140-159 mm Hg, and ≥ 160 mm Hg, respectively (reference; SBP<130 mm Hg). CONCLUSION: In this population, at mid-life, even high-normal SBP levels were shown to be a significant predictor of type 2 diabetes, independently of BMI and other conventional type 2 diabetes risk factors over an extended follow-up.

Influence of partial lateral corpectomy with and without hemilaminectomy on canine thoracolumbar stability: a biomechanical study.

OBJECTIVE: To analyze the biomechanical changes induced by partial lateral corpectomy (PLC) and a combination of PLC and hemilaminectomy in a T13-L3 spinal segment in nonchondrodystrophic dogs. STUDY DESIGN: In vitro biomechanical cadaveric study. SAMPLE POPULATION: T13-L3 spinal segments (n = 10) of nonchondrodystrophic dogs (weighing, 25-38 kg). METHODS: A computed tomography (CT) scan of each T13-L3 spinal segment was performed. A loading simulator for flexibility analysis was used to determine the range of motion (ROM) and neutral zone (NZ) during flexion/extension, lateral bending, and axial rotation. A servohydraulic testing machine was used to determine the changes in stiffness during compression, dorsoventral, and lateral shear. All spines were tested intact, after PLC in the left intervertebral space of L1-L2, and after a combination of PLC and hemilaminectomy. RESULTS: Statistically significant increases in ROM and NZ (P < .05) were detected during flexion/extension and lateral bending when PLC was performed. A significant increase in ROM (P < .001) was noted during axial rotation and flexion after PLC and hemilaminectomy. Stiffness decreased significantly during compression and dorsoventral shear after each procedure. Decreased stiffness during lateral shear was only significant after a combination of both procedures. CONCLUSION: PLC might lead to some spinal instability; these changes are enhanced when a hemilaminectomy is added.

MRI features of gastrocnemius musculotendinopathy in herding dogs.

Pelvic limb lameness that was localized clinically to the lateral gastrocnemius head was observed in dogs without history of trauma. The aim of this retrospective study was to describe magnetic resonance imaging (MRI) findings of this condition. Nine dogs were identified, eight Border Collies and one Australian Shepherd. They all had chronic pelvic limb lameness; no signs of joint effusion or instability were present. In MR images there was high signal intensity in the lateral head of the gastrocnemius muscle around the sesamoid bone in T2-weighted, T2*-weighted, and STIR images and an iso- to mildly hyperintense signal in T1-weighted images with marked contrast enhancement. The abnormal signal intensity most likely represents a myotendinous strain. The breed affiliation to Border Collies is striking, and a relation to biomechanical forces or motion pattern may be possible. Except for the dog with the most extensive lesion all dogs had an excellent outcome.

Lethal toxin of Clostridium sordellii is associated with fatal equine atypical myopathy.

The lethal toxin of Clostridium sordellii (TcsL) evokes severe, mostly fatal disease patterns like toxic shock syndrome in humans and animals. Since this large clostridial toxin-induced severe muscle damaging when injected intramuscularly into mice, we hypothesized that TcsL is also associated with equine atypical myopathy (EAM), a fatal myodystrophy of hitherto unknown etiology. Transmission electron microscopy revealed skeletal and heart muscles of EAM-affected horses to undergo degeneration ultrastructurally similar to the damage found in TcsL-treated mice. Performing immunohistochemistry, myofibers of EAM-affected horses specifically reacted with sera derived from horses with EAM as well as an antibody specific for the N-terminal part of TcsL, while both antibodies failed to bind to the myofibers of either healthy horses or those with other myopathies. The presence of TcsL in myofibers of horses with EAM suggests that it plays a role as trigger or even as lethal factor in this disease.

Immune response of horses to vaccination with the recombinant Hc domain of botulinum neurotoxin types C and D.

Botulinum neurotoxins, predominantly serotypes C and D, cause equine botulism through forage poisoning. The C-terminal part of the heavy chain of botulinum neurotoxin types C and D (HcBoNT/C and D) was expressed in Escherichia coli and evaluated as a recombinant mono- and bivalent vaccine in twelve horses in comparison to a commercially available toxoid vaccine. A three-dose subcutaneous immunization of adult horses elicited robust serum antibody response in an ELISA using the immunogen as a capture antigen. Immune sera showed dose-dependent high potency in neutralizing specifically the active BoNT/C and D in the mouse protection assay. The aluminium hydroxide based mono- and bivalent recombinant HcBoNT/C and D vaccines were characterized by good compatibility and the ability to elicit protective antibody titers similar or superior to the commercially available toxoid vaccine.