Saccadic adaptation in Chiari type II malformation

BACKGROUND: Saccadic adaptation corrects errors in saccadic amplitude. Experimentally-induced saccadic adaptation provides a method for studying motor learning. The cerebellum is a major participant in saccadic adaptation. Chiari type II malformation (CII) is a developmental deformity of the cerebellum and brainstem that is associated with spina bifida. We investigated the effects of CII on saccadic adaptation. METHOD: We measured eye movements using an infrared eye tracker in 21 subjects with CII (CII group) and 39 typically developing children (control group), aged 8-19 years. Saccadic adaptation was induced experimentally using targets that stepped horizontally 120 to the right and then stepped backward 3 degrees during saccades. RESULTS: Saccadic adaptation was achieved at the end of the adaptation phase in participants in each group. Saccadic amplitude gain decreased by 6.9% in the CII group and 9.3% in the control group. The groups did not differ significantly (p = 0.27). Amplitude gain reduction was significantly less in the CII participants who had multiple shunt revisions. Regression analyses revealed no effects of spinal lesion level, presence of nystagmus, or cerebellar vermis dysmorphology on saccadic adaptation. CONCLUSION: The neural circuits involved in saccadic adaptation appear to be functionally intact in CII.     

Clinical aspects of ballistic peripheral nerve injury: shrapnel versus gunshot

Objectives

Ballistic injuries to peripheral nerves pose special challenges in terms of indications, timing and type of surgical intervention. The aim of the present work was to analyze our experience in the surgical treatment of peripheral nerve ballistic injuries with respect to the mechanism of injury (gunshot versus shrapnel), and identify common and dissimilar prognostic factors in both types of injury.

Methods

This study was conducted on 42 patients totaling 58 nerves. Twenty-two patients (32 nerves) were injured by gunshot and 20 patients (26 nerves) by shrapnel. Median postoperative follow-up was 33 months (range 12 months to 14 years).

Results

Overall postoperative outcome appears to be more favorable for gunshot-wound (GSW) patients than shrapnel-injured patients, especially in terms of neuropathic pain relief (75 % vs. 58 % respectively, p < 0.05). Presence of foreign particles in shrapnel injured patients has a negative impact on the surgical outcome in terms of rate of pain improvement (28 % compared to 67 % in patients with and without foreign particles, respectively). Nerve graft reconstruction, rather than neurolysis, seems to be the more beneficial treatment for shrapnel-induced neuropathic pain (100 % vs. 47 % in improvement rate, respectively). Early surgical intervention (median 2 months after injury) significantly relieved neuropathic pain in 83 % of shrapnel-injured patients compared to 58 % in patients operated later.

Conclusions

This study suggests that shrapnel injury is more destructive for nerve tissue than gunshot injury. Our impression is that early surgical intervention in shrapnel injuries and split nerve grafting (especially when small fragments are recognized in the nerve) significantly improve the patient’s functional activity and quality of life.     

Surgical Myocardial Revascularization versus Percutaneous Coronary Intervention with Drug-Eluting Stents in Octogenarian Patients

Objective: Our goal was to compare the clinical outcomes of octogenarian (or older) patients who are referred for either surgical or percutaneous coronary revascularization.Methods: We retrospectively evaluated the outcomes of all patients 80 years of age who had undergone coronary artery bypass grafting (CABG) with an internal mammary artery or had undergone a percutaneous coronary intervention (PCI) with a sirolimus-eluting stent to the left anterior descending artery in our center between May 2002 and December 2006.Results: Of the 301 patients, 120 underwent a PCI, and 181 underwent CABG. Surgical patients had higher rates of left main disease, triple-vessel disease, peripheral vascular disease, emergent procedures, and previous myocardial infarctions (39.7% versus 3.3% [P = .001], 76.1% versus 28.3% [P = .0001], 19.6% versus 7.5% [P = .004], 15.8% versus 2.5% [P = .0001], and 35.9% versus 25% [P = .04], respectively). CABG patients had a higher early mortality rate (9.9% versus 2.5%, P = .01). There were no differences in 1- and 4-year actuarial survival rates, with rates of 90% and 68%, respectively, for the PCI group and 85% and 71% for the CABG group (P = .85). The rates of actuarial freedom from major adverse cardiac events (MACEs) at 1 and 4 years were 83% and 75%, respectively, for the PCI group, and 86% and 78% for the CABG group (P = .33). The respective rates of freedom from reintervention were 87% and 83% for the PCI group, versus 99% and 97% for the CABG group (P < .001). The 4-year rate of freedom from recurring angina was 58% for the PCI group, versus 88% for CABG patients (P < .001). Revascularization strategy was not a predictor of adverse outcome in a multivariable analysis.Conclusion: Octogenarian CABG patients were sicker and experienced a higher rate of early mortality. The 2 strategies had similar rates of late mortality and MACEs, with fewer reinterventions and recurring angina occurring following surgery.     

The effect of growth hormone on the development of diabetic kidney disease in rats.

BACKGROUND: Nephropathy is the most severe complication of diabetes mellitus. We investigated the effect of exogenous growth hormone (GH) administration on renal function and matrix deposition in the streptozotocin (STZ) model of type I-diabetic rat. METHODS: Adult female STZ-diabetic rats (D), non-diabetic control rats injected with saline (C) and control and diabetic rats injected with bovine GH for 3 months (CGH and DGH, respectively) were used. RESULTS: The usual renal hypertrophy seen in D animals was more pronounced in the DGH group. Creatinine clearance increased only in the D rats, but not in the other groups, including DGH. Albuminuria was observed in the D animals but was significantly elevated in the DGH group. Glomeruli from DGH animals showed more extensive matrix accumulation (manifested as an increase in mesangial/glomerular area ratio). Renal extractable insulin-like growth factor (IGF-I) mRNA was decreased in the D and DGH groups, but renal IGF-I protein was not significantly increased. Renal IGF binding protein-1 was increased in the D groups and further increased in the DGH group, at both the mRNA and protein levels. CONCLUSIONS: GH-treated diabetic rats had less hyperfiltration and more albuminuria, concomitant with more glomerular matrix deposition, when compared with regular diabetic animals. This was associated with a significant increase in renal IGFBP-1, and dissociated from IGF-I changes. Thus, in this model, GH exacerbates the course of diabetic kidney disease.     

Laparoscopic Management of Lap-Band<Superscript>®</Superscript> Slippage

Background. The Lap-Band^? is generally associated with a low morbidity rate. Although gastric slippage through the band remains a concern, the rate has diminished with new band placement techniques. Methods. Between November 2000 and June 2002, 198 Lap-Band? Systems were inserted in patients in the Houston, Texas, area. 4 of these patients, plus an additional patient whose Lap-Band^? had been inserted by another surgeon, developed slippages, and in each case the gastric slip was corrected and the band was salvaged and repositioned laparoscopically. To facilitate dissection and repositioning of the band in 3 of these patients, the band had to be unlocked using a simple laparoscopic technique. Results. All patients were discharged the morning following surgery with no complications and good position of the band as evidenced by esophagogram study and resolution of symptoms. After 2 to 12 months follow-up, all 5 patients remain symptom-free and continue to lose weight. Conclusions. Gastric slippage with the Lap-Band^? can be managed by laparoscopic salvage and repositioning of the slipped band.     

Breast Conservation After Neoadjuvant Chemotherapy

Background Tumor downstaging by preoperative neoadjuvant chemotherapy in patients with locally advanced breast tumors allows breast conservation in women who were previously candidates for mastectomy. Nevertheless, lumpectomy success in such cases cannot be fully achieved. The aim of this study was to create a quantitative tool for preoperative evaluation of the success of breast conservation in such patients.Methods The study population included 100 consecutive patients with stage II and III breast cancer who were designated for lumpectomy and 19 patients who were designated for mastectomy. All patients received neoadjuvant therapy. Breast-conserving surgery was offered in accordance with clinical and esthetic criteria. Demographic details and clinical, imaging, and pathologic information were collected from medical files. A decision protocol for classifying patients to lumpectomy or mastectomy was built by using the Classification and Regression Trees procedure based on preoperative characteristics.Results Three factors were found to be the main predictors for successful breast conservation: absence of diffuse microcalcifications as seen in the pretreatment mammogram, a postchemotherapy tumor size of < 25 mm, and the existence of a circumscribed lesion on mammography.Conclusions The use of these criteria as a basis for decision on the type of surgery may decrease the performance of unnecessary procedures.     

Laparoscopic colectomy is associated with decreased postoperative gastrointestinal dysfunction

Background  Major abdominal surgery is associated with early postoperative gastrointestinal dysfunction, which may lead to abdominal distention and vomiting, requiring nasogastric (NGT) tube insertion. This study aimed to compare the rates of early postoperative NGT insertion after open and laparoscopic colorectal surgery. Methods  A retrospective chart review was performed for patients who underwent colorectal surgery with removal of the NGT at completion of surgery. Patients who required reinsertion of the NGT in the early postoperative course were identified. The reinsertion rate for patients who underwent laparoscopic surgery was compared with that for the open group. Results  There were 103 patients in the open group and 227 in the laparoscopic group. In the laparoscopic group, 42 patients underwent conversion to open surgery. Reinsertion of the NGT was required for 18.4% of the patients in the open group, compared with 8.6% of the patients for whom the procedure was completed laparoscopically (p = 0.02). Conversion to open surgery resulted in a reinsertion rate of 17%. Conclusion  Laparoscopic colorectal surgery is associated with decreased postoperative gastrointestinal dysfunction, resulting in a significantly lower NGT reinsertion rate. Presented as a poster at the annual meeting of the Society of American Gastrointestinal and Endoscopic Surgeons, (SAGES), Dallas, Texas, 26–29 April 2006, and at the annual meeting of the European Society for Endoscopic Surgeons (EAES), Berlin, Germany, 13–16 September 2006.