Outcome predictors in the management of spinal cord ependymoma

The aim of this study was to determine predictors of functional outcome and survival in a retrospective cohort of spinal cord ependymomas treated at a single institution. Twenty-six patients who underwent treatment of spinal cord ependymoma at a single institution were retrospectively analysed. The clinicopathological features were reviewed and correlated with functional outcome (measured using the Frankel grade), recurrence (clinical or radiological), progression-free survival (PFS) and overall survival (OS). Seventy-nine percent of patients with complete excision had maintained or improved functional outcome, compared to 75% in the incomplete resection plus radiotherapy group. Patients with a good pre-operative Frankel grade tended to maintain their functional status, though this did not reach statistical significance (Fisher’s Exact test, P = 0.090). Univariate analysis revealed that longer symptom duration prior to treatment was associated with poorer functional outcome (P = 0.006). Extent of resection and the use of adjuvant radiotherapy did not influence PFS or OS; however, early diagnosis and treatment are paramount in the management of spinal ependymoma if a good functional outcome is to be achieved.     

Musculoskeletal modelling in determining the effect of botulinum toxin on the hamstrings of patients with crouch gait

This study aimed to determine the effect of hamstring botulinum toxin A (Btx-A) injection in 10 children with crouch gait in terms of changes in muscle length and lower-limb kinematics. Before Btx-A injection limb kinematics were recorded. Maximum hamstring lengths and excursions were calculated by computer modelling of the lower limb. Data were compared with the averaged hamstring lengths of 10 control children. Hamstrings were denned as short if their length was shorter than the average maximum length minus one standard deviation. Gait analysis was repeated 2 weeks after isolated hamstring Btx-A injection. Pre- and postinjection kinematic data and muscle lengths were then compared. Four of 18 injected limbs in three subjects had short medial hamstring before injection, none of the subjects had short lateral hamstrings. Muscle excursion was significantly reduced in the short and adequate maximum muscle length groups. A significant increase in the semimembranosus and semitendinosus length in all of the injected limbs was noted. Only in the short muscle group was a significant increase in muscle excursion observed. Knee extension improved by 13° in the adequate muscle length group and by 15.6° in the short muscle length group. Pelvic tilt and hip flexion increased in both groups non-significantly. Average walking speed postinjection increased from 0.60 ms^-1 to 0.71 ms^-1. Short hamstrings are over-diagnosed in crouch gait. Hamstring Btx-A injection in patients with crouch gait produces significant, repeatable muscle lengthening and improved ambulatory function.     

The angiomatous polyp and the angiofibroma: two different lesions

Five cases of angiomatous polyps that were initially interpreted as angiofibromas are presented. Although they are similar to angiofibromas, angiomatous polyps have a distinctly different pattern of growth on computed tomography and a different angiographic appearance. In addition, they are more easily extirpated at surgery than are angiofibromas.     

Comparing outcomes in renal replacement therapy: how should we correct for case mix?

The need to evaluate the effectiveness of clinical practice to justify expensive therapy in the face of financial constraints in all areas of health care delivery makes it necessary to identify groups of patients who are likely to benefit most from treatment. Various risk stratification methods have been used for analyzing survival probabilities for patients receiving renal replacement therapy. Complicated risk stratification methods produce large numbers of risk groups of small sizes, which makes comparison between individual centers difficult. We compared three simple methods of risk stratification, that divided patients into low-, medium-, and high-risk groups, in a cohort of 1,407 patients who commenced renal replacement therapy in five European countries during a 7-year period. Method 1 considered age (>55 years) and diabetes alone; method 2 used a higher age limit (>70 years) and comorbid illnesses, including those other than diabetes; and method 3 used only the number of comorbidities (none, 1, or > or =2) for stratification. Kaplan-Meier survival curves were constructed for comparison between risk groups and Cox's regression model used to assess strength of relationship with mortality. Although patient survival was significantly different between the low-, medium-, and high-risk groups using all three methods, Cox's regression analysis showed that method 2 provided the greatest discrimination between risk groups. In predicting mortality, method 2 (based on comorbidities and age) showed the highest sensitivity and specificity (84% and 80%, respectively) compared with method 1 (80% and 74%) and method 3 (64% and 82%). Validation of this approach in other populations in a prospective study is required before this method, which takes into account the influences of both age and comorbidity for risk stratification, can be used for comparing survival data and for presenting results of renal replacement therapy.     

The utility of cytodiagnostic urinalysis as a tool to diagnose kidney allograft dysfunction in the era lymphocyte-depleting induction therapy

Cytodiagnostic urinalysis (CDU) has been used to evaluate causes of kidney allograft dysfunction, such as an acute rejection episode (ARE), calcineurin inhibitor (CNI) toxicity, or polyoma virus infection. We examined the concordance between CDU and allograft biopsy in patients with allograft dysfunction. Between 2002 and 2006, 201 patients had CDU performed within 7 days of a biopsy. The cohort was black (73%) with, male preponderance (59.2%), and an overall mean age of 48 ± 13 years with 46% having received a deceased donor kidney. The induction regimen consisted of either antithymocyte globulin or alemtuzumab. CDU results that demonstrated 5 to 10 lymphocytes per high-power field (HPF) and >20 lymphocytes/HPF had 2.5 increased odds of predicting acute rejection (AR) on biopsy (odds ratio [OR] 2.5; 95% confidence interval [CI] 1.12–5.79; P = .025). In the era of antithymocyte globulin induction, a CDU result demonstrating >5 lymphocytes/HPF had a 4.3 increased odds of predicting AR (CI 1.76–10.50; P = .001). This association was lost with alemtuzumab induction. A positive CDU result for calcineurin inhibitor (CNI) toxicity did not predict CNI nephrotoxcity on biopsy, but a positive CDU for polyoma virus infection predicted polyoma virus nephropathy (OR 22.18; CI: 4.41–111.63; P < .001). In conclusion, CDU is an adjunctive diagnostic tool for kidney transplantation.