Uncovering auditory evoked potentials from cochlear implant users with independent component analysis

Auditory evoked potentials (AEPs) provide an objective measure of auditory cortical function, but AEPs from cochlear implant (CI) users are contaminated by an electrical artifact. Here, we investigated the effects of electrical artifact attenuation on AEP quality. The ability of independent component analysis (ICA) in attenuating the CI artifact while preserving the AEPs was evaluated. AEPs recovered from CI users were systematically correlated with age, demonstrating that individual differences were well preserved. CI users with high-quality AEPs were characterized by a significantly shorter duration of deafness. Finally, a simulation study revealed very high spatial correlations between original and recovered normal hearing AEPs (r>.95) that were previously contaminated with CI artifacts. The results confirm that after ICA, good quality AEPs can be recovered, facilitating the objective, noninvasive study of auditory cortex function in CI users.     

Perioperative management of acute ischemic stroke: a case report

Interrupting anticoagulation in patients at high risk for thromboembolism, even for critically important surgery, may lead to devastating outcomes. The patient described developed "Locked-in Syndrome" from basilar arterial thrombosis within 24 hours of withholding anticoagulation for urgent airway surgery. Emergency thrombolysis partially restored arterial flow, with recovery of some function. The dangers of hemorrhage during surgery must be balanced against the potentially devastating consequences of withholding anticoagulation in patients at high risk for thrombosis.     

Intraoperative cerebral high-intensity transient signals and postoperative cognitive function: a systematic review

Background

Much attention in the literature has focused on the relationship between perioperative microemboli during cardiac and vascular surgery and postoperative cognitive decline. Transcranial Doppler ultrasonography (TCD) has been used to measure high-intensity transient signals (HITS), which represent microemboli during cardiac, vascular, and orthopedic surgery. The purpose of this study was to systematically examine the literature with respect to HITS and postoperative cognitive function.

Methods

Systematic PubMed searches identified articles related to the use of TCD and cognitive function in the surgical setting.

Results

The literature remains largely undecided on the role of HITS and cognitive impairment after surgery, with most studies being underpowered to show a relationship. Although the cognitive effects of HITS may be difficult to detect, subclinical microemboli present potential harm, which may be modifiable.

Conclusions

TCD represents a tool for intraoperative cerebral monitoring to reduce the number of HITS during surgery.     

Spindle epithelial tumor with thymus-like elements of the thyroid: a multi-institutional case series and review of the literature

Background/Purpose

Spindle epithelial tumor with thymus-like elements (SETTLE) is a rare tumor of the thyroid observed in children and adolescents. We present a case series of 3 patients with SETTLE, focusing on the clinical and pathologic features of this rare tumor.

Methods

Three male patients presented at ages 4.5, 6.5, and 7 years with a right thyroid mass. All were treated by standard hemithyroidectomy. None had evidence of distant metastases at presentation. The diagnosis of SETTLE was confirmed at the time of the initial operation in 2 of the 3 patients.

Results

All patients had uneventful postoperative courses. Two patients remain disease-free 4 and 7 years postresection, respectively. One patient presented 10 years after resection with shortness of breath and hemoptysis secondary to multiple bilateral parenchymal lung metastases. This patient received chemotherapy against the epithelial components of the tumor with a 25% response based on imaging studies.

Conclusion

Spindle epithelial tumor with thymus-like elements is rare tumor that should be suspected if spindle elements are observed in the resected thyroid specimen. Because these patients may present with delayed metastases, follow-up is recommended. However, chemotherapy against specific tumor elements is only marginally effective.     

Complications of recombinant activated human coagulation factor VII

Background

Recombinant factor VIIa (rFVIIa) frequently is used for treatment of life-threatening hemorrhage in trauma.

Methods

A retrospective review of injured patients receiving rFVIIa at an American College of Surgeons-verified Level 1 trauma center was performed. Controls were matched for age, sex, Injury Severity Score, and traumatic brain injury. Thrombotic complications in patients administered rFVIIa, including deep venous thrombosis (DVT), pulmonary embolus, acute myocardial infarction, ischemic stroke, mesenteric ischemia, arterial thromboembolism, and death, were determined.

Results

Thirty-six patients were given rFVIIa, of whom 5 (13.8%) had thrombotic complications. Indications for rFVIIa were life-threatening intracranial bleeding in the presence of pre-injury anticoagulation or hemorrhage. The incidences of DVT (n = 4) and acute myocardial infarction (n = 1) were noted. In the control group, there were fewer thrombotic complications (DVT, 1; pulmonary embolus, 1). The mortality rate (52.8%) was higher in patients receiving rFVIIa compared with the control group (22.2%; P = .014). Pre-injury anticoagulation was common in the treatment group.

Conclusions

Pre-injury anticoagulation is frequently the indication for rFVIIa administration. Thrombotic complications occur with rFVIIa administration. The mortality rate of injured patients who receive rFVIIa is high.     

Friedreich's ataxia impact scale: A new measure striving to provide the flexibility required by today's studies

To develop, using modern techniques of rating scale construction, a new patient reported rating scale for clinical studies of Friedreich's ataxia (FA) that strives to meet the measurement needs of different types of study. Qualitative research methods were used to generate a conceptual framework of the impact of FA, and a pool of items necessary to construct a subscale for each area identified. This item pool was then administered to 492 people with FA. Rasch measurement methods guided scale construction. Eight areas for measurement were identified (speech, upper limb functioning, lower limb functioning, body movement, complex tasks, isolation, mood, self perceptions), and a 126‐item scale constructed (FA Impact Scale; FAIS). In addition, three shorter versions were developed to illustrate how the FAIS can be adapted for observational studies, more disabled, and less disabled samples of people with FA. The FAIS is a psychometrically sound 126‐item measure from which subsets of items can be selected to meet the needs of different studies. Importantly, all versions can be referred back to the original scale. This study shows one of the many clinical advantages of using Rasch measurement methods to construct rating scales. © 2009 Movement Disorder Society     

Development of a brief ataxia rating scale (BARS) based on a modified form of the ICARS

To develop a brief ataxia rating scale (BARS) for use by movement disorder specialists and general neurologists. Current ataxia rating scales are cumbersome and not designed for clinical practice. We first modified the International Cooperative Ataxia Rating Scale (ICARS) by adding seven ataxia tests (modified ICARS, or MICARS), and observed only minimally increased scores. We then used the statistics package R to find a five‐test subset in MICARS that would correlate best with the total MICARS score. This was accomplished first without constraints and then with the clinical constraint requiring one test each of Gait, Kinetic Function‐Arm, Kinetic Function‐Leg, Speech, and Eye Movements. We validated these clinical constraints by factor analysis. We then validated the results in a second cohort of patients; evaluated inter‐rater reliability in a third cohort; and used the same data set to compare BARS with the Scale for the Assessment and Rating of Ataxia (SARA). Correlation of ICARS with the seven additional tests that when added to ICARS form MICARS was 0.88. There were 31,481 five‐test subtests (48% of possible combinations) that had a correlation with total MICARS score of ≥0.90. The strongest correlation of an unconstrained five‐test subset was 0.963. The clinically constrained subtest validated by factor analysis, BARS, had a correlation with MICARS‐minus‐BARS of 0.952. Cronbach alpha for BARS and SARA was 0.90 and 0.92 respectively; and inter‐rater reliability (intraclass correlation coefficient) was 0.91 and 0.93 respectively. BARS is valid, reliable, and sufficiently fast and accurate for clinical purposes. © 2009 Movement Disorder Society     

A virtual clinic for diabetes self-management: pilot study

Background

Internet-based interventions to assist in diabetes management have the potential to provide patients with the information and support they need to become effective self-managers.

Objective

To assess the feasibility, acceptability, and effectiveness of an Internet-based virtual clinic designed to facilitate self-management in patients who used insulin pumps to manage their diabetes.

Methods

For a period of 6 months, 17 patients joined the virtual clinic. The system allowed patients to communicate with health professionals, interact with peers and access information. HbA1c, quality of life, and self-efficacy were monitored at baseline and after 6 months. Questionnaires and qualitative interviews examined patient experiences.

Results

Participants found the virtual clinic easy to use and positively rated its design. Peer support was the most valued aspect and the discussion boards the most used component. All participants highly rated the virtual clinic in terms of improving communication with peers, but few agreed it had improved communication with health care professionals. No significant improvements in physiological and psychological measurements were found. Regarding HbA1c measurements, there was no significant difference found between the pre- and post-test results (P = .53). Mean ADDQoL scores at baseline were -2.1 (SD 1.1, range -3.4 to -0.5) compared to -2.0 (SD 1.2, range, -4.6 to -0.4) post-test (n = 12), (P = .62). Surprisingly, patients’ confidence in their ability to perform self-care tasks was found to be significantly reduced from baseline to follow up (P = .045).

Conclusions

An Internet-based system to aid the management of diabetes appears feasible and well accepted by patients. The pilot study did not identify evidence of an impact on improving quality of life or self-efficacy in patients who used insulin pump therapy.