Brain metal concentrations in chronic liver failure patients with pallidal T1 MRI hyperintensity

BACKGROUND

Chronic liver failure may be associated with pallidal MRI T1 hyperintensity and heterogeneous neurologic syndromes, including parkinsonism, cognitive impairment, and others. Manganese accumulation may be responsible for the imaging and clinical findings.

OBJECTIVE

To measure manganese plus other metal concentrations in pallidum and additional brain regions and to examine the corresponding neuropathology in cases of chronic liver failure.

METHODS

Regional brain metal concentrations were measured in seven chronic liver failure cases, four with pallidal T1 hyperintensity and three with normal MRI, plus five controls. Neuropathologic examination employed alpha-synuclein and tau immunohistochemistry.

RESULTS

In patients with pallidal T1 hyperintensity, pallidal manganese concentrations were increased sevenfold over controls and over fourfold vs liver patients with normal MRI; manganese concentrations were also significantly elevated in all other brain regions. Copper was additionally increased in all brain regions, whereas other metal concentrations were similar to control values. Neuropathology revealed mild to moderate Alzheimer type II gliosis in the liver failure groups and negative alpha-synuclein and tau immunostaining except for one case (intermediate Alzheimer disease pathology).

CONCLUSION

In chronic liver failure, manganese accumulation is responsible for the pallidal MRI T1 hyperintensity. Pallidal copper was also elevated in affected cases, but copper does not have the paramagnetic properties to generate isolated T1 hyperintensity. Basal ganglia manganese or copper accumulation may be responsible for the parkinsonism sometimes seen in chronic liver failure. Pallidal MRI T1 hyperintensity is a biomarker of manganese overload.

Neurologic manifestations in welders with pallidal MRI T1 hyperintensity

BACKGROUND

Neurologic symptoms have been attributed to manganese fumes generated during welding. Increased T1 MRI signal in the basal ganglia is a biologic marker of manganese accumulation. Recent studies have associated welding and parkinsonism, but generally without MRI corroboration.

OBJECTIVE

To characterize the clinical and neuropsychological features of patients with MRI basal ganglia T1 hyperintensity, who were ultimately diagnosed with neurotoxicity from welding fumes.

METHODS

The medical records of welders referred to the Department of Neurology with neurologic problems and basal ganglia T1 hyperintensity were reviewed.

RESULTS

All eight patients were male career welders with increased T1 basal ganglia signal on MRI of the brain. Several different clinical syndromes were recognized: a parkinsonian syndrome (three patients), a syndrome of multifocal myoclonus and limited cognitive impairment (two patients), a mixed syndrome with vestibular-auditory dysfunction (two patients), and minor subjective cognitive impairment, anxiety, and sleep apnea (one patient). Neuropsychometric testing suggested subcortical or frontal involvement. Inadequate ventilation or lack of personal respiratory protection during welding was a common theme.

CONCLUSIONS

Welding without proper protection was associated with syndromes of parkinsonism, multifocal myoclonus, mild cognitive impairment, and vestibular-auditory dysfunction. The MRI T1 hyperintensity in the basal ganglia suggests that these may have been caused by manganese neurotoxicity.

A guide to the diagnosis and treatment of occupational asthma

Occupational asthma is the most prevalent form of occupational lung disease in industrialized nations. As increasing numbers of new chemicals are produced and new manufacturing processes are introduced, the variety of environments in which individuals may become exposed to respiratory sensitizers and irritants makes diagnosing and treating this illness even more challenging. In addition to adverse pulmonary effects, the diagnosis of occupational asthma may bring with it negative social and financial implications that may ultimately affect the patient's quality of life. For this reason, it is important for clinicians to recognize work-related respiratory symptoms early on in their course, maintain a high clinical suspicion for an occupational cause in the diagnostic work-up of asthma, and have a high degree of certainty in the diagnosis. While a number of classification schemes have been proposed to simplify the diagnostic approach to occupational asthma, the inciting factors typically involve sensitization (often by an IgE mechanism), direct airway inflammation, various pharmacologic responses, or irritant reflex pathways. Clinicians must first document the presence of asthma, then establish a relationship between asthma and the work-place. The occupational history is the key diagnostic tool, and clinical suspicions may be evaluated further by serial peak expiratory flow measurements, nonspecific hypersensitivity challenges with histamine or methacholine, collaboration with industrial/occupational hygienists to obtain workplace exposure measurements, and specific challenge testing at tertiary referral centers providing specialized laboratories. Removal from the inciting exposure is the mainstay of therapy, and pharmacologic treatment of patients with occupational asthma is similar to the treatment of patients with other forms of asthma.

Complications and cost associated with parenteral nutrition delivered to hospitalized patients through either subclavian or peripherally-inserted central catheters

BACKGROUND AND AIMS

Total parenteral nutrition (TPN) is typically delivered through catheters inserted into the superior vena cava (SVC) via a subclavian or internal jugular vein approach. A peripherally-inserted central venous catheter (PICC), utilizing a cephalic or basilic venous approach, may provide a safe alternative to the standard catheter approach and, because non-physician providers can insert the PICC, may introduce a potential cost-savings to health care institutions. We sought to determine if PICC lines are safer and more cost-effective than the standard central venous catheter approach for hospitalized patients who require TPN.

METHODS

One hundred and two hospitalized patients (age range, 18-88 years) who required TPN were prospectively randomized to receive therapy via a centrally-inserted subclavian catheter (n=51) or a peripherally-inserted PICC line (n=51). The primary end-point was the development of a complication requiring catheter removal. Other end-points included catheter infection and thrombophlebitis. Cost associated with insertion and maintenance of each catheter was also studied.

RESULTS

Complication-free delivery rate (without the need to remove or replace the catheter) was 67% for subclavian catheters and 46% for PICC lines (P<0.05). The overall infection rate was 4.9 per 1000 catheter days and was similar for each catheter type (P=0.68). PICC lines were associated with higher rates of clinically-evident thrombophlebitis (P<0.01), difficult insertion attempts (P<0.05), and malposition on insertion (P<0.05). No catheter complications resulted in significant long-term morbity or mortality. No significant difference was noted between the two catheter types in terms of aborted insertion attempts (P=0.18), dislodgement (P=0.12), or line occlusion (P=0.25). After standardizing costs for each hospital, the direct institutional costs for insertion and maintenance of PICC lines (US$22.32+/-2.74 per day) was greater than that for subclavian lines (US$16.20+/-2.96 per day;P<0.05).

CONCLUSION

PICC catheters have higher thrombophlebitis rates and are more difficult to insert into certain patients when compared to the standard subclavian approach for central venous access in hospitalized patients who require TPN. Because of this, PICCs may be less cost-effective than currently believed because of the difficulty in inserting and maintaining the catheter.

Varicella-zoster virus detection by polymerase chain reaction using bronchoalveolar lavage specimens

We report the use of polymerase chain reaction (PCR) techniques from a bronchoalveolar lavage (BAL) specimen for the successful early diagnosis in a case of atypical but severe varicella-zoster virus (VZV) pneumonitis. Atypical presentations of disseminated VZV frequently prolong the time required for accurate diagnosis, resulting in increased morbidity, or mortality. Although further investigation is necessary to determine the sensitivity and positive predictive value of this test, PCR analysis of bronchoscopic specimens may expedite the diagnosis of disseminated VZV.

The role of anticholinergics in bronchoscopy. A randomized clinical trial

BACKGROUND

Anticholinergic medications have been utilized frequently prior to bronchoscopy and are thought to facilitate the drying of secretions to limit the amount of required topical anesthetic on the airway mucosa, prevent cardiac arrhythmias during the procedure, and increase patient comfort.

OBJECTIVE

To determine if atropine or glycopyrrolate, two anticholinergic agents utilized most frequently in this setting, have any significant role for this purpose.

DESIGN

Double-blind, placebo-controlled study, in which patients were randomly selected to receive atropine (0.01 mg/kg body weight, IM injection), glycopyrrolate (0.005 mg/kg, IM injection), or saline solution placebo (approximately 2 mL, IM injection) 15 to 45 min prior to being sedated with midazolam until judged to be lightly sedated.

SETTING

A large academic teaching hospital in the midwestern United States.

PARTICIPANTS

Two hundred seventeen outpatients referred for bronchoscopy who satisfied inclusion and exclusion criteria.

MEASUREMENTS AND RESULTS

Using a modified visual analog scale (0 to 100 mm), the bronchoscopist and the nurse anesthetist estimated the antisialagogic effect, effectiveness in cough suppression, and overall patient comfort during the procedure. The patients completed a similar questionnaire after recovering from the procedure. Patients were also monitored for complications (cardiac arrhythmias, oxygen desaturation, hypertension, wheezing, or coughing severe enough to curtail the procedure). There was no significant difference found among atropine, glycopyrrolate, and placebo for the primary end point of secretion control. In addition, there was no difference found between either medication and placebo for effectiveness of cough suppression, amount of topical anesthetic used, complication rates, or overall patient comfort.

CONCLUSION

The use of anticholinergic agents prior to bronchoscopy did not affect performance of bronchoscopy or complication rates, and there was no appreciable benefit from the resultant reduction in airway secretions in a population of patients receiving concurrent sedation with benzodiazepines.

Visualization of diaphragmatic fenestration associated with catamenial pneumothorax

Catamenial pneumothorax is a rare entity of unknown etiology characterized by recurrent accumulation of air in the thoracic space during or preceding menstruation. We documented the presence of a diaphragmatic fenestration during thoracoscopy, lending support for hypotheses involving diaphragmatic defects as possible avenues of air collection in the thorax.

Factors associated with fatalities and injuries from hot-air balloon crashes

CONTEXT

Despite the increased popularity of hot-air balloon flight, data on injuries and fatalities associated with hot-air balloon crashes are limited.

OBJECTIVE

To determine factors associated with injury and death in hot-air balloon crashes.

DESIGN

Retrospective review of data collected from reports and investigations by the Civil Aeronautics Board and the National Transportation Safety Board.

STUDY SUBJECTS

Individuals involved in US hot-air balloon crashes from 1964 to 1995.

MAIN OUTCOME MEASURES

Total number of crashes and factors associated with fatality or serious injury.

RESULTS

From 1964 to 1995, a total of 495 hot-air balloon crashes involving 1533 persons were reported and included 92 fatalities and 384 serious injuries. Pilot error or incapacitation was determined subjectively by crash investigators to contribute to 85.1% of the crashes. In univariate analysis, collision with the ground was the most significant predictor of a fatality or serious injury (P<.001), and power-line contact was the most significant predictor of fatality (P<.001). In multiple logistic regression, only the type of object struck by a balloon predicted a fatal crash or a fatality or serious injury.

CONCLUSIONS

Although a number of factors likely contribute to increased severity of hot-air balloon crashes, the object struck during a crash is most predictive of fatality or serious injury. Preventive efforts are needed to decrease future injuries.

The opinion of current and recent internal medicine residents regarding a fourth year of training and the future of general internal medicine. American College of Physicians National Council of Associates

OBJECTIVE

To determine the opinion of current residents and recent graduates of internal medicine training programs regarding an additional mandatory year of residency training.

METHODS

A survey was made of 2,000 associate members of the American College of Physicians from five geographic regions.

RESULTS

Of 917 respondents, 70.3% thought a fourth year of training would impact negatively on their choice of a career in internal medicine, and 82.9% believed a mandatory fourth year should not be required of residents choosing a subspecialty career. Furthermore, 58.1% of physicians surveyed thought a mandatory fourth year would discourage individuals from pursuing subspecialty careers. If a mandatory fourth year of training were required, 50.7% respondents indicated that it should consist of ambulatory training in a number of general fields, while 49.6% physicians believed the training should focus on one or two subspecialty fields.

CONCLUSIONS

A mandatory fourth year of training is not supported by residents and recent graduates of the programs surveyed.

Resection of lymphatic malformation of the scrotum

It is important for clinicians to consider lymphatic malformations in the differential diagnosis of chronic skin lesions, no matter where they appear anatomically. We report a case of deep surgical excision of an extensive lymphatic malformation of the scrotum using regional flaps from uninvolved scrotal tissue. Removal of the lesion not only allowed the patient more comfort but also may have ultimately cured his symptomatology.

Ceftazidime-related nonconvulsive status epilepticus

The third-generation cephalosporin, ceftazidime, is widely used for the treatment of serious gram-negative infections. As is true of cephalosporins in general, reported adverse effects have been few. We report a case of ceftazidime-induced status epilepticus in a patient with Pseudomonas aeruginosa meningitis and compare the clinical manifestations of this case with those of two previously described cases of ceftazidime-related encephalopathy. This diagnosis should be entertained and an electroencephalogram should be obtained in all patients with myoclonus and/or altered mental status while they are receiving ceftazidime therapy.