Predicting post-surgical outcomes in idiopathic normal pressure hydrocephalus using clinically important changes from the cerebrospinal fluid tap test.

OBJECTIVE: Patients diagnosed with idiopathic Normal Pressure Hydrocephalus (iNPH) typically experience symptom improvements after undergoing a cerebrospinal fluid-tap test (CSF-TT), These improvements are recognized as indicative of potential improvements following surgical intervention. As gait disturbance is the most common iNPH symptom, gait improvements are of predominant interest. The purpose of this study was to examine if clinically important changes in gait and balance from CSF-TT predict meaningful changes following surgery. METHOD: The study involved analysis of data collected in a prospective observational study for 34 iNPH patients who underwent a CSF-TT and subsequent surgery. Linear regression, logistic regression and classification trees were used for predictive modelling comparing changes from CSF-TT with post-surgical changes in Tinetti, Timed Up and Go (TUG) and Berg Balance Scale (BBS) outcomes. RESULTS: Predictive models for minimal clinically important differences (MCIDs) from CSF-TT to surgery were significant for Tinetti (odds ratio = 1.42, p = 0.02) and BBS (odds ratio = 1.57, p < 0.01). Four items on Tinetti and two items on BBS were identified with a predictive accuracy of 79% and 76% respectively. BBS has the highest sensitivity (85%) and negative predictive value (77%). TUG had a 100% specificity and 100% positive predictive value. The predictive model using MCIDs for TUG was not significant (odds ratio = 1.13, p = 0.06). CONCLUSION: Clinically important changes from CSF-TT are useful in predicting post-surgical outcomes in iNPH patients. Tinetti and BBS, both have predictive value using MCID scores as cut off values, of which BBS is a stronger outcome measure for prediction.

Cognitive and upper limb symptom changes from a tap test in Idiopathic Normal Pressure Hydrocephalus.

OBJECTIVES: To determine which cognitive and upper limb assessments can identify change in patients undergoing a Cerebrospinal fluid (CSF) tap test (TT) diagnosed with idiopathic Normal Pressure Hydrocephalus (iNPH). PATIENTS AND METHODS: Prospective observational study of 74 iNPH patients undergoing a CSF TT for consideration of a ventricular peritoneal shunt. Patients who were offered surgical intervention were classified as responders. Patients were assessed with a battery of cognitive and upper limb assessments prior to and following a CSF TT. The Timed up and go cognition (TUG-C), Montreal Cognitive assessment (MoCA) and 9-hole peg test were utilised. RESULTS: 40 patients were classified responders. Significant differences were identified for responders for the MoCA (0.62 points) and TUG-C (-6.02 s). Only the executive function and orientation sub scores of the MoCA showed significant changes for responders. The 9 hole peg test mean change of 4.33 s for responders was not significant. Non-responder change scores for the MoCA (0.22 points), TUG-C (0.3 s) and 9 hole peg test (2.58 s) were not significant. CONCLUSION: The TUG-C has the potential to identify change in patients resulting from a CSF TT. While statistically significant change was found for the MoCA, a mean change of less than 1 point on this scale is unlikely to be clinically relevant. Similarly, the 9 hole peg test cannot be endorsed as an assessment tool for identifying changed performance in iNPH.

t-PA power-pulse spray with rheolytic mechanical thrombectomy using cross-sectional image-guided portal vein access for single setting treatment of subacute superior mesenteric vein thrombosis.

BACKGROUND: Isolated superior mesenteric vein (SMV) thrombosis is a rare but potentially fatal condition if untreated. Current treatments include transjugular or transhepatic approaches for rheolytic mechanical thrombectomy and subsequent infusions of thrombolytics. Tissue plasminogen activator (t-PA) power-pulse spray can provide benefit in a single setting without thrombolytic infusions. Computed tomography (CT) guidance for portal vein access is underutilized in this setting. MATERIALS AND METHODS: Case 1 discusses acute SMV thrombosis treated with rheolytic mechanical thrombectomy alone using ultrasound guidance for portal vein access. Case 2 discusses subacute SMV thrombosis treated with the addition of t-PA power-pulse spray to the rheolytic mechanical thrombectomy, using CT guidance for portal vein access. RESULTS: With rheolytic mechanical thrombectomy alone, the patient in Case 1 had significant improvement in abdominal pain. Follow-up CT demonstrated no residual SMV thrombosis and the patient continued to do well in long-term follow-up. With the addition of t-PA power-pulse spray to rheolytic mechanical thrombectomy, the patient in Case 2 with subacute SMV thrombosis dramatically improved postprocedure with resolution of abdominal pain. Follow-up imaging demonstrated patency to the SMV and partial resolution of thrombus. The patient continued to do well at 2-year follow-up. CONCLUSIONS: Adding t-PA power-pulse spray to rheolytic mechanical thrombectomy can provide benefit in a single setting versus mechanical thrombectomy alone and prevent the need for subsequent infusions of thrombolytic therapy. CT guidance is a useful alternative of localization for portal vein access via the transhepatic route that is nonoperator-dependent and helpful in the case of obese patients.

Comparison of measured oxyhemoglobin saturation and oxygen content with analyzer-calculated values and hand-calculated values obtained in unsedated healthy dogs.

OBJECTIVE: To compare direct measurements of canine oxyhemoglobin (HbO2) saturation and blood oxygen content (ContO2) in healthy dogs with analyzer-calculated values derived by use of a human HbO2 relationship and with hand-calculated values derived by use of a canine HbO2 relationship. ANIMALS: 17 healthy dogs. PROCEDURE: 3-mL samples of heparinized arterial and jugular venous blood were collected from each dog. The pH, Pco2, Po2, hemoglobin, HbO2, carboxyhemoglobin, methemoglobin, and ContO2 were measured; HbO2 and ContO2 were calculated automatically by analyzers and also hand-calculated. Blood gas analyzer-calculated and hand-calculated HbO2 values were compared with co-oximeter-measured HbO2 values. Analyzer-calculated and hand-calculated ContO2 values were compared with oxygen content analyzer-measured values. RESULTS: Hand-calculated HbO2 values for arterial and jugular venous samples were slightly but significantly lower than those calculated by a blood gas analyzer or obtained from a co-oximeter. Hand-calculated and analyzer-calculated arterial and venous ContO2 were similar to measured values. CONCLUSIONS AND CLINICAL RELEVANCE: Although certain HbO2 and ContO2 values generated by use of the different methods were significantly different, these differences are unlikely to be clinically important in healthy dogs.