Utility of P300 auditory event related potential latency in detecting cognitive dysfunction in growth hormone (GH) deficient patients with Sheehan's syndrome and effects of GH replacement therapy

OBJECTIVE: Impaired cognitive function has been demonstrated in adults with growth hormone (GH) deficiency (GHD) by using different neuropsychological tests. Despite several studies, present knowledge about the impact of GHD and GH replacement therapy (GHRT) on cognitive function is limited. P300 event-related potential (ERP) application is a well-established neurophysiological approach in the assessment of cognitive functions including the updating of working memory content and the speed of stimulus evaluation. GHD is a well-known feature of Sheehan's syndrome and cognitive changes due to GHD and the effects of GHRT remain to be clarified. The present study was designed to investigate the effects of GHD and 6 months of GHRT on cognitive function in patients with Sheehan's syndrome by using P300 latency. DESIGN AND METHODS: The study comprised 14 patients with Sheehan's syndrome (mean age, 49.5+/-7.8 years) and 10 age-, education- and sex-matched healthy controls. With hormone replacement therapy, basal hormone levels other than GH were stable before enrollment and throughout the GHRT. The diagnosis of GH deficiency was established by insulin-tolerance test (ITT), and mean peak level of GH in response to insulin hypoglycemia was 0.77+/-0.35 mIU/l. Treatment with GH was started at a dose of 0.45 IU (0.15 mg)/day in month 1, was increased to 0.9 IU (0.30 mg)/day in month 2 and was maintained at 2 IU (0.66 mg)/day. Initially baseline auditory ERPs in patients and controls were recorded at frontal (Fz), central (Cz), and parietal (P3 and P4) electrode sites. In the patient group, ERPs were re-evaluated after 6 months of GH replacement therapy. During each session P300 amplitude and latency were measured. RESULTS: Mean serum insulin-like growth factor-I (IGF-I) concentration in the patient group before GHRT was 23+/-13 ng/ml. After 6 months of GH therapy mean IGF-I significantly increased to an acceptable level, 234+/-71 ng/ml (P<0.05). The mean latencies (at all electrode sites) of the patients before GHRT were found to be significantly prolonged when compared with those of normal controls (P<0.05). After 6 months of GHRT mean P300 latencies (at all electrode sites) were decreased significantly when compared with latencies before treatment (P<0.05). CONCLUSIONS: The present study, using P300 ERP latencies, therefore suggests an impairment of cognitive abilities due to severe GHD in patients with Sheehan's syndrome and an improvement of cognitive function after 6 months of physiological GHRT. Moreover, this was a novel application of P300 ERP latencies in cognitive function detection in patients with GHD. Further studies with different patient groups need to be done to assess the clinical use of this electrophysiological method in the diagnosis of cognitive dysfunction due to GHD.     

A contemporary overview of peripheral nerve research from the Cleveland Clinic microsurgery laboratory

Despite our better understanding of the pathophysiology of peripheral nervous system and advancements in microsurgical repair techniques, peripheral nerve injuries are still considered as a reconstructive challenge for all surgeons. For achieving a better nerve regeneration and better end organ reinnervation, advanced microsurgical manipulations are parallel with molecular biological discoveries. The field of peripheral nerve research is still developing and includes more sophisticated approach at the basic science level. In our Microsurgery Research Laboratory we have been working on different nerve repair techniques, including sleeve neurorrhaphy, sleeve grafts, single and polyfascicular nerve grafting techniques and studies on nerves in diabetic rats, in addition to the roles of different growth factors and pharmacological agents on peripheral nerve regeneration. New approaches for filling nerve gaps with nerve allografts and tolerance inducing strategies with their effect on nerve regeneration are included into our research armamentarium. In this overview we will summarize our 15-year experience in peripheral nerve research.     

Primary renal lymphoma of mucosa-associated lymphoid tissue

Mucosa-associated lymphoid tissue-type lymphomas have recently been recognized as a distinctive form of B-cell malignant lymphoma. In contrast to other types of low-grade lymphomas, these tumors have a tendency to be localized at diagnosis and to be curable with local therapy. We report an unusual case of primary localized low-grade lymphoma of mucosa-associated lymphoid tissue arising in the kidney. The patient underwent radical nephrectomy and was free of disease at 28 months of follow-up without additional treatment. Once properly staged and classified, lymphoma of mucosa-associated lymphoid tissue involving the kidney can be managed by radical nephrectomy and follow-up.     

Epiglottic tuberculosis in a patient treated with steroids for Addison's disease

Isolated epiglottic tuberculosis (TBC) is uncommon and has rarely been described. We report the case of a 40-year-old man with tuberculous involvement of the epiglottis and primary adrenal insufficiency. Endoscopic examination showed a severely swollen epiglottis with granulomatous and partially necrotic mucosa. The patient has been treated with glucocorticoids for four years due to primary adrenocortical insufficiency. We therefore assume that tuferculous involvement of epiglottis is due to the reactivation of pulmonary TBC. We also discuss differential diagnosis and management of epiglottic TBC and Addison's disease.     

Mission possible: creating a technology infrastructure to help reduce administrative costs

Controlling administrative costs associated with managed care benefits has traditionally been considered a "mission impossible" in healthcare, with the unreasonably high cost of paperwork and administration pushing past the $420 billion mark. Why administrative costs remain a critical problem in healthcare while other industries have alleviated their administrative burdens must be carefully examined. This article looks at the key factors contributing to high administrative costs and how these costs can be controlled in the future with "mission possible" tools, including business process outsourcing, IT outsourcing, technology that helps to bring "consumerism" to managed care, and an IT infrastructure that improves quality and outcomes.     

Outcome in pediatric tracheotomy

OBJECTIVE: To investigate the outcome and related factors in pediatric tracheotomy. DESIGN: Retrospective chart review. SETTING: Tertiary pediatric academic hospital setting. PATIENTS: The study included 181 children below the age of 18 years who underwent 185 tracheotomies between 1991 and 1995. MAIN OUTCOMES AND MEASURES: Presenting symptoms and signs, indications, duration of follow-up, therapeutic and interval procedures, early and late complications, mortality, time to and success in decannulation. RESULTS: There were 108 (59.7%) male patients and 73 (40.3%) female patients. The average age of the children at the time of tracheotomy was 3.8 +/- 5.3 years. The majority of the children were less than 1 year of age (n = 99, 54.7%). Airway obstruction was the leading indication for tracheotomy (59.6%), followed by ventilatory support (30.4%) and pulmonary toilet (9.9%). The average duration of follow-up was 931 +/- 790 days. There were no perioperative complications. Early postoperative complications were seen in 28 (15.5%) children including 12 (6.8%) major complications and 22 (12.2%) minor complications. Late complications were seen in 115 (63.5%) children, including 8 (4.4%) major complications and 107 (59.1%) minor complications. Overall mortality rate was 13.3%, but only 1 tracheotomy-related death was caused by tube displacement. Therapeutic procedures were performed in 43% of the children, including laryngotracheal reconstruction (13%), laser excision of the lesion (5%), and supraglottoplasty (3.9%). Decannulation was accomplished in 116 (64.1%) of the children with an average of 365 +/- 388 days with tracheotomy. CONCLUSION: Tracheotomy is relatively safe in the pediatric population. Decannulation may be possible relatively quickly with resolution of the underlying problem.     

Friedreich's ataxia

Friedreich’s ataxia, the most common hereditary ataxia, is caused by expansion of a GAA triplet located within the first intron of the frataxin gene on chromosome 9q13. There is a clear correlation between size of the expanded repeat and severity of the phenotype. Frataxin is a mitochondrial protein that plays a role in iron homeostasis. Deficiency of frataxin results in mitochondrial iron accumulation, defects in specific mitochondrial enzymes, enhanced sensitivity to oxidative stress, and eventually free-radical mediated cell death. Friedreich’s ataxia is considered a nuclear encoded mitochondrial disease.

This review discusses the major and rapid progress made in Friedreich’s ataxia from gene mapping and identification of the gene to pathogenesis and encouraging therapeutic implications.     

Intraoperative intravenous ketamine in combination with epidural analgesia: postoperative analgesia after renal surgery

We designed this double-blinded, randomized, controlled study to evaluate the effect of small-dose ketamine IV in combination with epidural morphine and bupivacaine on postoperative pain after renal surgery. An epidural catheter was inserted, and the administration of morphine and bupivacaine was started before surgery. Forty patients were assigned to one of two groups (ketamine or control). The ketamine group was administered a ketamine bolus and infusion during surgery. The median visual analog pain scale (VAS) scores at rest were significantly lower in the ketamine group during the first 6 h (P < 0.01). VAS pain scores on coughing were also significantly lower in the ketamine group (P < 0.01). Cumulative postoperative total analgesic consumption was less in the ketamine group on Days 1 and 2 (P < 0.001). The first analgesic demand time was shorter in the control group (9.2 +/- 11.5 min) than in the ketamine group (22.3 +/- 17.1 min) (P < 0.0001). The incidence of nausea and pruritus was more frequent in the control group (P < 0.05). In conclusion, postoperative analgesia was more effective when spinal cord and brain sensitization were blocked by a combination of epidural morphine/bupivacaine and IV ketamine. IMPLICATIONS: Renal nociception conducted multisegmentally by both the spinal nerves (T10 to L1) and the vagus nerve cannot be blocked by epidural analgesia alone. We demonstrated that IV ketamine had an improved analgesic or opioid-sparing effect when it was combined with epidural bupivacaine and morphine after renal surgery.