Visualisation of the medial longitudinal fasciculus using fibre tractography in multiple sclerosis patients with internuclear ophthalmoplegia.

BACKGROUND: This study investigates the use of fibre tractography to facilitate visualisation of the medial longitudinal fasciculus (MLF) and the impact of internuclear ophthalmoplegia (INO) causing lesions on these reconstructions of the tract. Improved visualisation of such tracts may improve knowledge, understanding and confidence related to neurological conditions. AIMS: To explore the use of fibre tractography for the visualisation of the MLF in patients with INO. METHODS: Twelve MS subjects with clinical evidence of INO and 12 matched controls underwent magnetic resonance imaging (MRI), including diffusion tensor imaging (DTI), of the brain. Fibre tractography reconstructions were then evaluated and validated by an experienced neuroanatomist. RESULTS: The evaluating neuroanatomist confirmed that the MLF had been reproduced in all of the reconstructed cases (fibre tractography was unsuccessful in five cases). The sensitivity of fibre tractography to MLF pathology was 58.3 % while the specificity was much higher at 85.7 % with a positive predictive value of 87.5 % and a negative predictive value of 54.6 %, with excellent intra-reader reliability. CONCLUSION: This study demonstrates that fibre tractography of the MLF can potentially be performed with a view to facilitating improved visualisation of the tract and associated pathology in cases of INO. This may help explain the association between lesion type and location with clinical symptomatology and may assist in monitoring disease progression. These reconstructions may provide a valuable addition to the teaching and understanding of clinical signs related to subtle pathology.

Diagnostic Efficacy of Conventional MRI Pulse Sequences in the Detection of Lesions Causing Internuclear Ophthalmoplegia in Multiple Sclerosis Patients.

PURPOSE: The purpose of this study was to investigate the diagnostic efficacy of a range of conventional magnetic resonance imaging (MRI) pulse sequences in the identification of internuclear ophthalmoplegia (INO) caused by medial longitudinal fasciculus (MLF) lesions in multiple sclerosis patients using a receiver-operating characteristic (ROC) methodology. METHODS: A total of 15 clinically confirmed INO and 15 control subjects underwent conventional MRI at 1.5 T consisting of T2-weighted, proton density (PD)-weighted, and fluid-attenuated inversion recovery (FLAIR) sequences, following full institutional approval. A free-response, multiple-reader multiple-case design ROC study was used to evaluate the diagnostic efficacy of each sequence. All imaging sequences were evaluated by 10 board-certified neuroradiologists. Area under the curve (AUC), sensitivity, and specificity were analysed statistically for all three pulse sequences using repeated-measures analyses of variance and post-test analysis using Bonferroni's multiple comparison test of differences. RESULTS: No significant AUC differences were found between the three sequences (p = 0.0697), with T2 recording the highest AUC (0.8346). Sensitivity differences between PD (0.7927) and FLAIR (0.6329) were significant (p < 0.05). Non-significant differences were also evident between T2 and FLAIR (p = 0.0511). The specificity analysis revealed an overall difference (p = 0.0005), with specific inter-sequence differences shown between T2 and PD (p < 0.05) and PD and FLAIR (p < 0.001) with the PD values being lower than those provided with the other two sequences. CONCLUSION: T2-weighted axial imaging through the MLF region resulted in the greatest overall diagnostic efficacy when viewing a combination of mean AUC, sensitivity, and specificity, in terms of the identification of INO-causing lesions.

Assessment and management of transient ischaemic attack--the role of the TIA clinic.

BACKGROUND: As the risk of early stroke following transient ischaemic attack (TIA) is increasingly recognised, the management of patients presenting with symptoms suggestive of TIA presents a clinical challenge. METHODS: Analysis of prospectively collected data on patients referred to a TIA clinic in St. Vincent's University Hospital, between January 2003 and July 2004. RESULTS: One-hundred-and-seventeen (117) patients (mean age 75.5 years) were assessed. The majority (79%) were referred from Accident and Emergency and 61% were seen within one week of referral. Seventy-two patients (62%) had a final diagnosis of cerebrovascular disease (56 TIA, 16 completed strokes), of whom five (7%) and four (5.5%) had severe (> 70%) and moderate (> 50%) symptomatic carotid artery stenosis, respectively, whilst seven patients (10%) had newly diagnosed atrial fibrillation, five of whom were anticoagulated. Non-cerebrovascular diagnoses were made in twenty-seven patients (24%). CONCLUSION: A TIA clinic, in co-ordination with Accident and Emergency Services, provides a safe and efficient alternative to hospital admission for patients with TIA symptoms and a low early stroke risk.

CT-guided catheter drainage of loculated thoracic air collections in mechanically ventilated patients with acute respiratory distress syndrome.

OBJECTIVE: We report our experience with CT-guided percutaneous catheter drainage of loculated thoracic air collections in mechanically ventilated patients with acute lung injury or acute respiratory distress syndrome. MATERIALS AND METHODS: Nine critically ill patients had 17 air collections (13 pneumothoraces, three pneumatoceles, one tension pneumomediastinum) that either developed despite the presence of standard surgical chest tubes or were in loculated sites that were difficult to access. All nine patients were ventilated mechanically for a clinical diagnosis of acute respiratory distress syndrome. Catheter size ranged from 7- to 28-French. Response was measured by imaging follow-up, ventilatory parameters, and clinical outcome. RESULTS: On follow-up imaging studies, all 17 air collections were shown to have been evacuated successfully. Catheters remained in place for a mean of 11 days (range, 4-28 days). No major complications occurred. Sixteen air collections were treated successfully with CT-guided catheter placement alone; the remaining air collection, a pneumothorax, was treated with subsequent placement of a chest tube by the surgeon at the patient's bedside. No surgery was undertaken for the air collections. Improvement in gas exchange was documented by increase in the hypoxemia ratio (arterial oxygen pressure divided by the inspired fraction of oxygen) in seven of 12 drainages; the other drainages were accompanied either by no improvement or by deterioration. Eight (89%) of the nine patients eventually were extubated and discharged from the hospital. The ninth patient died. CONCLUSION: CT-guided percutaneous catheter drainage provided effective treatment for loculated thoracic air collections and obviated surgical intervention in these critically ill, high-surgical-risk patients.

Drainage efficiency of double-lumen sump catheters and single-lumen catheters: an in vitro comparison.

PURPOSE: To compare the drainage efficiency of double-lumen sump catheters and single-lumen catheters in an in vitro model. MATERIALS AND METHODS: Four 12-F, 27.5-cm catheters were used in the study. Three of these had a double lumen with a 7-F internal diameter drainage lumen and one had a single lumen with an 8-F internal diameter drainage lumen. The sump hole opened internally to the drainage lumen in one catheter, opened externally in one catheter, and was occluded in one catheter. Catheters were connected to continuous low-wall suction and were immersed in water, viscous fluid, and viscous fluid with particles. The volume of fluid drained by each catheter was measured and compared. RESULTS: The single-lumen catheter with an 8-F internal diameter drainage lumen drained a volume equal to or larger than that for double-lumen catheters with a 7-F internal diameter drainage lumen for each type of fluid. The open sump of the double-lumen catheters may have decreased the catheter's drainage efficiency by allowing air to be suctioned into the catheter. CONCLUSION: Single-lumen catheters performed as well as or more efficiently than double-lumen catheters of the same outer diameter in this in vitro model.

Drainage catheters: in vitro comparison of internal retention mechanisms.

In five drainage catheters, internal retention mechanisms (locking pigtail [14 and 8 F], inflatable balloon [14 F], or wings [14 and 24 F]) were evaluated for resistance to and distortion from dislodgment. Catheters were inserted into simulated tissue, and weight was added until dislodgment occurred. Resistance to dislodgment increased when the mechanisms were locked; the locking pigtail supported the most weight. Distortion caused by dislodgment was minimal.

High resolution computed tomography in cystic fibrosis: correlation with pulmonary function and assessment of prognostic value.

OBJECTIVE: To assess the correlation between HRCT and pulmonary function in patients with CF. Further, to assess the prognostic value of HRCT in these patients. SUBJECTS AND METHODS: Clinical examination, chest radiographs and HRCT scans on 30 CF patients with an average age of 17 were scored using established scoring systems. The results were correlated with FEV1 and FVC both at time of CT scanning and after 30 months. Results were also correlated with the clinical progress of the patients over the follow-up period. RESULTS: HRCT, chest radiograph and clinical examination demonstrated similar correlation (p < 0.001) with FEV1 and FVC at the time of scanning. HRCT demonstrated the closest correlation with the clinical progress of the patients over the follow-up period and with follow-up pulmonary function. A maximum combined score for bronchiectasis and emphysema on HRCT seemed to indicate a poor prognosis. CONCLUSION: HRCT in CF patients correlates well with pulmonary function at time of scanning and at follow-up, and with clinical progress. There may be a role for CT in the identification of adolescent/adult patients who can be expected to need aggressive therapy in the future.

Treatment of postbiopsy pneumothorax with a self-contained pneumothorax treatment device.

PURPOSE: To evaluate the usefulness of a self-contained pneumothorax treatment device, in which a catheter and a one-way valve compose a single unit, in cases of postbiopsy pneumothorax. MATERIALS AND METHODS: Twenty-one patients underwent placement of the device to drain a postbiopsy pneumothorax. Treatment was considered successful when no therapy other than the device was needed. RESULTS: Treatment was successful in 16 (76%) of the 21 patients. Causes of treatment failure were dislodgment of the device (n = 3), malfunction of the device (n = 1), and a persistent air leak that led to pneumothorax recurrence after removal of the device (n = 1). Eight patients (38%) experienced problems after insertion of the device: The device dislodged in seven patients and malfunctioned in one patient. These problems led to treatment failure in four patients (see above). In the remaining four, further treatment after device dislodgment was not required. CONCLUSION: Treatment with the self-contained pneumothorax treatment device shows promise. Modifications to the device may alleviate technical problems and insertion difficulties.

Malignant ureteral obstruction: treatment with metal stents--technique, results, and observations with percutaneous intraluminal US.

PURPOSE: To test the technical feasibility and results of placement of metal stents into ureters obstructed by extensive tumor. MATERIALS AND METHODS: Six consecutive patients (two men and four women, aged 35-66 years and with incurable malignancies) underwent insertion of metallic endoprostheses in nine obstructed ureters through percutaneous tracts. RESULTS: Metal stents were inserted without technical difficulty in all obstructed ureters. The stents functioned well in four patients. In two patients, the metal were not tolerated and plastic double-J stents were placed through the metal stents; this permitted effective functioning and withdrawal of the protective external catheter. Intraluminal ultrasonography depicted stent clogging and debris, dimensions of stent opening, and tumor level. CONCLUSION: Insertion of metal stents in the ureter is technically straightforward and was well tolerated by patients. However, the efficacy is variable, and a greater beneficial effect than is achieved with plastic stents is not established.

Reasons underlying negative mammography in patients with palpable breast cancer.

It is well recognized that a negative mammogram report does not exclude the presence of breast carcinoma. This study examines the accuracy of mammography in patients with palpable breast cancer. In particular, the study evaluates the reasons underlying negative mammography in breast cancer. All patients with Paget's disease, carcinoma in situ lesions or lesions infiltrating skin were excluded. A total of 291 patients presenting with palpable breast carcinoma underwent mammography prior to biopsy. False negative reports occurred in 16.5% (48). The sensitivity of mammography increased with age, from 70% (14/20) in 31-40-year-olds to 91% (113/124) in women over 60 years. Retrospective review of false negative mammograms showed that 30% of these were deemed normal while 20% were obvious oversights. The remaining 50% showed subtle radiographic abnormalities, consistent with but not diagnostic of malignancy.

Symptomatic hepatic cysts: percutaneous drainage and sclerosis.

PURPOSE: To evaluate the authors' experience with treatment of symptomatic hepatic cysts by means of percutaneous catheterization and sclerosis. MATERIALS AND METHODS: Twenty patients with 24 symptomatic hepatic cysts underwent percutaneous drainage and sclerosis. Ten patients had polycystic disease, and 10 had solitary cysts. Sclerosants used were alcohol, tetracycline, doxycycline, or a combination. RESULTS: Twenty-one of 24 cysts in 17 of 20 patients were treated successfully. Treatment was unsuccessful in three patients: one patient with innumerable medium-size and small cysts, one patient in whom only a needle was inserted (no catheter), and one patient with a cystic metastasis (rather than a simple cyst) that recurred. Complications included pleural effusion in two patients and secondary infection in one patient. The range of blood alcohol levels was 0-0.8 mg%. CONCLUSION: Percutaneous catheter drainage with sclerosis is an effective method of therapy for symptomatic hepatic cysts; careful patient selection is essential for proper therapy.

Ultrasound guided biopsy of nonpalpable and difficult to palpate thyroid masses.

We reviewed our experience with ultrasound-guided biopsies of masses of the thyroid gland that were either nonpalpable or difficult to localize by palpation to evaluate the technique and correlate the results. Thirty-two biopsies were performed upon 25 patients whose clinical presentations were palpable nodule (six patients), throat discomfort (two patients), postpartial thyroidectomy follow-up evaluation (two patients), incidental discovery of a mass--by ultrasound of the neck (two patients), roentgenogram of the chest (two patients), computed tomography of the chest (one patient) and during tracheostomy placement (one patient). Other presentations were eliminate infection (one patient), odynophagia (one patient), hoarseness (one patient), cold nodule on a nuclear medicine study (one patient), hyperparathyroidism (one patient), rule out metastasis from carcinoma of the colon (one patient), persistent cough (one patient), enlarged thyroid gland (one patient) or family history of carcinoma of the thyroid gland (one patient). Fifteen patients had nuclear medicine studies showing either a cold nodule (ten patients), multinodular goiter (one patient), normal examination (two patients), hot nodule (one patient) or no thyroid gland activity (one patient). The ultrasound examinations showed either a hypoechoic nodule (25 patients), inhomogeneous or mixed echogenic nodule (six patients) or a hyperechoic nodule with hypoechoic rim (one patient). The nodules ranged in size from 3 milliliters to 7 centimeters. Twenty-six lesions were less than 3 centimeters in diameter; of the other six, four were substernal goiters. Six patients had a previous nondiagnostic biopsy directed by palpation only. Biopsy was performed using real-time ultrasound guidance with various needles. One patient had a small hematoma, which was the only complication in the study. The results of the biopsies were diagnostic in 26 of 32 patients. The final diagnosis was benign follicular cells (ten patients), adenomatous nodule (seven patients), follicular neoplasm (three patients), colloid cyst (two patients), aspergillus (two patients), fibrosis (one patient) and papillary carcinoma (one patient). Six of the biopsies yielded unsatisfactory specimens. One of the patients with a diagnosis of benign follicular cells on biopsy had a follicular carcinoma after surgical pathologic factors were obtained; that was the only false-negative result. We conclude that ultrasound-guided biopsy of the thyroid is a safe and useful method of evaluating nonpalpable and difficult to palpate thyroid masses.

A chest radiograph scoring system in adult cystic fibrosis: correlation with pulmonary function.

The Birmingham scoring system for chest radiographs was assessed in 40 adult cystic fibrosis patients, with particular reference to correlation with pulmonary function values. Forty 'initial' and forty 'follow-up' chest radiographs were scored. The mean initial age of the group was 17.5 +/- 5.0 years, and the mean age at follow-up was 23.3 +/- 5.3 years. The cross-sectional radiographic score correlated significantly with the values of three commonly measured, pulmonary function parameters (r = 0.65, 0.67, 0.58, P less than 0.0001). There was a significant correlation (r = 0.64, P less than 0.0001), between the change in radiographic score, and the change in percent predicted forced vital capacity (FVC%). There was a less significant correlation (r = 0.45, P less than 0.006) between the change in radiographic score and the change in per cent predicted forced expiratory volume in one second (FEV1%). We conclude that the Birmingham radiographic scoring system is suitable for quantitative radiological evaluation in adult cystic fibrosis.

Short course chemotherapy for pulmonary tuberculosis. A randomised controlled trial of a six month versus a nine month oral regimen.

We report on the first trial in the Republic of Ireland to look at chemotherapy for TB. This management trial, carried out in single unit, which treats a third of all TB cases in the Republic of Ireland compared to effectiveness of a three drug/nine month regimen (Rifampicin (R), Isoniazed (R), supplemented with Ethambutol (E) for the first two months = RHE9) with a four drug six months regimen (R, H supplemented with E and Pyrazinamide (Z) for the first two months = RHEZ6). Two hundred and eighty eight patients (288) were entered into the study. A total of 143, (76 were in the RHE9 group and 67 in the RHEZ6 group) completed the trial as planned. At the end of the third month, significantly more patients in the RHEZ6 regimen (98%) were culture negative compared to the RHE9 regimen (88%). All were culture negative at the end of chemotherapy. Drug intolerance was seen in 35 (12%) patients with no significant difference in hepatitis between the two regimens. Toxicity from Pyrazinamide was minimal. One hundred and forty five (145) patients were invalid for analysis for the following reason:- bacteriologically negative TB (41), drug intolerance (35), death (23), non-compliance (19), diagnosis not TB (10), drug resistance (7), extrapulmonary disease (4), consent withdrawn (3), Mycobacteria other than tuberculosis (3). All patients are being followed to monitor relapse rates.

Arachidonic acid metabolites and small airways disease in non-smoking sarcoidosis patients.

The present study was designed to assess the occurrence of small airways disease (SAD) in non-smoking sarcoidosis patients by pulmonary function measurement; and to investigate the possible mechanisms of SAD by measuring the in vitro production of arachidonic acid metabolites (PGE2 and LTB4) by peripheral blood mononucleocytes from sarcoidosis patients. SAD did in fact occur in 15 of the 32 sarcoid patients studied. The increase in LTB4 and decrease in PGE2 observed in SAD patients could imply a causative role for these arachidonic acid metabolites in SAD.