Corticospinal Tract Involvement in MRI of Neuromelioidosis: Report of Three Cases with a Review of Clinicoradiological Features.

Melioidosis is gram-negative bacterial infection endemic in parts of Australia and Asia with significant morbidity and mortality. It is acquired in wet rainy seasons through occupational and recreational activities. Although central nervous system (CNS) involvement is seen in less than 10%, it can have severe sequelae. MRI (magnetic resonance imaging) findings in reported cases have shown predominant brain stem and frontoparietal involvement. We present three pediatric cases of neuromelioidosis in which corticospinal tract involvement was a characteristic finding.

Reevaluating the true diagnostic accuracy of dipstick tests to diagnose urinary tract infection using Bayesian latent class analysis.

OBJECTIVE: Previous studies on diagnostic accuracy of dipstick testing for leukocyte esterase (LE) and nitrite to diagnose urinary tract infection (UTI) had used urine culture, which is an imperfect gold standard. Estimates of diagnostic accuracy obtained using the classical gold standard framework might not reflect the true diagnostic accuracy of dipstick tests. METHODS: We used the dataset from a prospective, observational study conducted in the emergency department of a teaching hospital in southern India. Patients with a clinical suspicion of UTI underwent dipstick testing for LE and nitrite, urine microscopy, and urine culture. Based on the results of urine microscopy and culture, UTI was classified into definite, probable, and possible. Patients with microscopic pyuria and a positive urine culture were adjudicated as definite UTI. Unequivocal imaging evidence of emphysematous pyelonephritis or perinephric collections was also considered definite UTI. We estimated the diagnostic accuracy of LE and nitrite tests using the classical analysis (assuming definite UTI as gold standard) and two different Bayesian latent class models (LCMs; 3-tests in 1-population and 2-tests in 2-populations models). RESULTS: We studied 149 patients. Overall, 64 (43%) patients had definite, 76 (51%) had probable, and 2 (1.3%) had possible UTI; 7 (4.6%) had alternate diagnoses. In classical analysis, LE was more sensitive than nitrite (87.5% versus 70.5%), while nitrite was more specific (24% versus 58%). The 3-tests in 1-population Bayesian LCM indicated a substantially better sensitivity and specificity for LE (98.1% and 47.6%) and nitrite (88.2% and 97.7%). True sensitivity and specificity of urine culture as estimated by the model was 48.7% and 73.0%. Estimates of the 2-tests in 2-populations model were in agreement with the 3-tests in 1-population model. CONCLUSIONS: Bayesian LCMs indicate a clinically important improvement in the true diagnostic accuracy of urine dipstick testing for LE and nitrite. Given this, a negative dipstick LE would rule-out UTI, while a positive dipstick nitrite would rule-in UTI in our study setting. True diagnostic accuracy of urine dipstick testing for UTI in various practice settings needs reevaluation using Bayesian LCMs.

Cutaneous polyarteritis nodosa: A rare isolated cutaneous vasculitis.

Cutaneous polyarteritis nodosa (CPAN) is a rare form of cutaneous vasculitis that involves small and medium sized arteries of the dermis and subcutaneous tissue without systemic involvement. It presents with tender subcutaneous nodules, digital gangrene, livedo reticularis and subcutaneous ulcerations. The diagnosis is by skin biopsy and characteristic pathologic feature is a leukocytoclastic vasculitis in the small to medium-sized arterioles of the dermis. We report a rare case of benign cutaneous PAN in a 14-year-old girl who presented with history of fever, subcutaneous nodules with cutaneous ulcer and digital gangrene. The skin biopsy showed leukocytoclastic vasculitis with fibrinoid necrosis in the dermal vessels. She received treatment with steroids and lesions resolved completely over a period of month.

Asymptomatic right atrial thrombus in a case of nephrotic syndrome.

Hypercoagulable state in nephrotic syndrome can be complicated by thrombosis in unusual sites. We describe the case of a steroid-responsive nephrotic syndrome in an adult patient complicated by isolated thrombus in the right atrium which was completely asymptomatic. The patient was treated with steroids, anticoagulation and excision of the intracardiac thrombus with complete resolution. The case is presented in view of its rarity and to highlight the importance of routine echocardiography in all cases of nephrotic syndrome.