The Diagnostic Dilemma in Delayed Subarachnoid Hemorrhage: A Case Report.

Introduction: Radiologically negative subarachnoid hemorrhage (SAH) has a low incidence and is associated with good clinical outcomes.

Case Report: We present the case of a 44-year-old male with new-onset headaches, which began one week prior while bike riding. At an outside hospital, he had normal computed tomography head and angiogram.

Powassan Encephalitis: A Case Report from New York, USA.

Background: Powassan is a positive-sense, single-stranded, enveloped RNA virus that is a tick-borne transmitted by species, with groundhogs being the usual mammalian host. The virus is endemic to North America, with peak transmission during the summer and fall. The incubation period is 7-34 days, followed by a prodrome of flu-like symptoms.

Post craniotomy extra-ventricular drain (EVD) associated nosocomial meningitis: CSF diagnostic criteria.

Because external ventricular drains (EVDs) provide access to cerebrospinal fluid (CSF), there is potential for EVD associated acute bacterial meningitis (EVD-AM). Post-craniotomy, in patients with EVDs, one or more CSF abnormalities are commonly present making the diagnosis of EVD-AM problematic. EVD-AM was defined as elevated CSF lactic acid (>6 nmol/L), plus CSF marked pleocytosis (>50 WBCs/mm(3)), plus a positive Gram stain (same morphology as CSF isolate), plus a positive CSF culture of neuropathogen (same morphology as Gram stained organism).

Demonstration of natriuretic activity in urine of neurosurgical patients with renal salt wasting.

Unlabelled: We have utilized the persistent elevation of fractional excretion (FE) of urate, > 10%, to differentiate cerebral/renal salt wasting (RSW) from the syndrome of inappropriate antidiuretic hormone secretion (SIADH), in which a normalization of FEurate occurs after correction of hyponatremia.  Previous studies suggest as well  that an elevated FEurate with normonatremia, without pre-existing hyponatremia, is also consistent with RSW, including studies demonstrating induction of RSW in rats infused with plasma from normonatremic neurosurgical and Alzheimer's disease patients.  The present studies were designed to test whether precipitates from the urine of normonatremic neurosurgical patients, with either normal or elevated FEurate, and patients with SIADH, display natriuretic activity.

Changes in QT dispersion after thrombolysis for stroke.

Background: QT dispersion (QTD) reflects heterogeneity of myocardial repolarization, which is modulated by the central nervous system. Although largely studied in patients with cardiovascular disease, QTD is increased in acute stroke and this finding is an independent predictor of functional outcome and mortality following acute neurological events.

Hypothesis: The hypothesis of this study was to determine whether changes in QTD in patients presenting with ischemic stroke parallel changes in neurologic function.