Neuropathic complications after 157 procedures of continuous popliteal nerve block for hallux valgus surgery. A retrospective study

BACKGROUND

Continuous peripheral nerve block (CPNB), in particular at the popliteal fossa, is widely used in orthopedic surgery, allowing good postoperative analgesia. Possible neuropathic complications, however, remain poorly known.

OBJECTIVE

To review the characteristics of peripheral neuropathy (PN) after sciatic CPNB at the popliteal fossa, estimating prevalence, severity, evolution and possible risk factors, especially those relating to the procedure.

METHODS

Retrospective study of PN associated with popliteal fossa CPNB for hallux valgus surgery, between November 1st, 2005 and November 1st, 2009. All procedures were analyzed (type of anesthesia, approach, nerve location technique, number of procedures by operator) with, for each case of PN, analysis of clinical and electromyographic data.

RESULTS

One hundred and fifty seven sciatic CPNBs were performed (92% women; mean age, 55 years). The approach was lateral (n=62), posterior (n=74) or unknown (n=21). Ultrasound guidance was combined to neurostimulation for 69 patients (44%). Three women (prevalence=1.91%), aged 19, 24 and 65 years respectively, developed associated common superficial peroneal and sural nerve injury (2), axonal on electromyography, with motor (n=1) and/or sensory (n=3) residual dysfunction.

DISCUSSION

The higher prevalence found in the present study than in the literature (0 to 0.5%) raises questions of methodological bias or technical problems. The common peroneal and sural nerves seem to be exposed, unlike the tibial. Several mechanisms can be suggested: anesthetic neurotoxicity, direct mechanical lesion, or tourniquet-related ischemia and conduction block. Further studies are necessary to determine the ideal anesthetic procedure.

CONCLUSION

Patients should be informed of the potential risk, however rare, even during mild surgery. The best possible technique should be implemented, with reinforced surveillance.

Acute delirium, delusion, and depression during IFN-beta-1a therapy for multiple sclerosis: a case report

Adverse effects of interferon (IFN) treatment are common, and efforts to minimize these reactions are of considerable importance. IFN-beta-1a is an established therapy for patients with relapsing-remitting multiple sclerosis (MS). Its psychiatric side effects are debated and not yet fully established. The authors report here the case of a patient on IFN-beta-1a therapy for MS who developed acute delirium, delusion, and depression that ceased with treatment discontinuation. Although he had a history of recurrent major depressive disorder, his prior psychiatric illness had followed a course that was clinically independent of other signs of MS. This observation points out psychiatric vulnerability of patients taking IFN-beta-1a therapy for MS and suggests that IFN-beta-1a may induce or exacerbate preexisting psychotic symptoms.

Nitrogen storage and remobilization in Brassica napus L. during the growth cycle: nitrogen fluxes within the plant and changes in soluble protein patterns

Oilseed rape (Brassica napus L.) is commonly grown for oil or bio-fuel production, while the seed residues can be used for animal feed. It can also be grown as a catch crop because of its efficiency in extracting mineral N from the soil profile. However, the N harvest index is usually low, due in part to a low ability to remobilize N from leaves and to the fall of N-rich leaves which allows a significant amount of N to return to the environment. In order to understand how N filling of pods occurs, experiments were undertaken to quantify N flows within the plant by (15)N labelling and to follow the changes in soluble protein profiles of tissues presumed to store and subsequently to remobilize N. Whereas N uptake increased as a function of growth, N uptake capacity decreased at flowering to a non-significant level during pod filling. However, large amounts of endogenous N were transferred from the leaves to the stems and to taproots which acted as a buffering storage compartment later used to supply the reproductive tissue. About 15% of the total N cycling through the plant were lost through leaf fall and 48%, nearly all of which had been remobilized from vegetative tissues, were finally recovered in the mature pods. SDS-PAGE analysis revealed that large amounts of a 23 kDa polypeptide accumulated in the taproots during flowering and was later fully hydrolysed. Its putative function of storage protein is further supported by the fact that when plants were grown at lower temperature, both flowering, its accumulation and further mobilization were delayed. The overall results are discussed in relation to plant strategies which optimize N cycling to reproductive sinks by means of buffering vegetative tissues such as stems and taproots.

A rapid and reliable method for NO quantification and 15NO/14NO determination using isotope ratio mass spectrometry: an application for the detection of NO synthesis in propionibacteria

For the last decade, numerous studies have focused on the positive or toxic effects of nitric oxide (NO) in procaryotic and eucaryotic cells. This gas has fundamental roles in neurotransmission, vasodilatation, cytotoxicity, and intestinal motility. The ability to produce NO by intestinal microflora or probiotic bacteria is unknown. In this preliminary study, we present a rapid and reproducible procedure for NO quantification and 15NO/14NO determination (based on the reaction between nitrite and acidic potassium iodide) by isotope ratio mass spectrometry. Using this method, we have demonstrated for the first time in vitro production of NO by a dietary bacterium (Propionibacterium acidipropionici, Pa 1) under anaerobic culture conditions. Using different sources of nitrogen, we have clearly shown that propionibacteria can synthesize NO from reduction of nitrate or nitrite. In our experimental conditions, NO synthase was not involved in NO production by propionibacteria.

[Suicidal impulses in patients with chronic viral hepatitis C during or after therapy with interferon alpha]

We report 5 cases of psychiatric side effects in patients treated with alpha interferon for chronic viral C hepatitis. The first case includes depression with suicidal impulses without a suicide attempt; there was a positive rechallenge of interferon. In the second and third cases, depression occurred during interferon therapy, but has not disappeared after interferon withdrawal. In the 4th and 5th cases, depression occurred after interferon withdrawal. Overall, suicide was attempted in 4 cases after interferon withdrawal and was responsible for 2 deaths. The prevalence of suicide attempts during the 6 to 12 months of interferon therapy was 0% compared to 1.3% during the 6 months after interferon therapy (P < 0.05) in 306 patients with chronic hepatitis C treated by interferon in our local area network during the same period.

IN CONCLUSION

a) depression does not always disappear after interferon is discontinued; b) regular psychiatric follow-up is justified during treatment with interferon; c) psychiatric supervision should be continued, even more frequently after interferon withdrawal; d) the increased risk of psychiatric side-effect due to interferon as well as their severity suggest interferon should be administered with caution; e) the role of interferon can only be evaluated in controlled studies including the incidence and predictive value of emotional disorders.

Characterization of proliferative responses and cytokine mRNA profiles induced by Vespula venom in patients with severe reactions to wasp stings

The reasons why severe allergic reactions to bee and wasp stings develop in only a small portion of exposed individuals are incompletely understood, but differences in T cell responses to venom antigens comparing allergic and non-allergic individuals are likely to be important. To identify such differences, venom-induced proliferative responses and cytokine mRNA production by blood mononuclear cells from Vespula venom-allergic patients and non-allergic individuals were compared. Mononuclear cells from most venom-allergic patients proliferated in response to alkylated Vespula venom (7275 +/- 8387 ct/min, n = 19), and the extent of proliferation was greater for patients with a history of multiple prior stings and those with high levels of venom-specific IgE. Although mononuclear cells from non-allergic subjects showed little or no proliferation in response to venom (926 +/- 711 ct/min, n = 8), production of mRNAs coding for IL-2, IL-4, IL-5, IL-10 and interferon-gamma (IFN-gamma) in response to Vespula venom by cells from non-allergic subjects was detected by reverse transcriptase-polymerase chain reaction (RT-PCR), indicating that these individuals had been previously sensitized to venom antigens. In contrast to the Th0 cytokine mRNA profile observed for non-allergic individuals, venom-allergic patients released a more restricted profile of cytokines following stimulation with venom. Only IFN-gamma mRNA expression was detected in all individuals evaluated, whereas IL-2 mRNA was not detected during the first 48 h of stimulation, and T cells from only one of three venom-allergic individuals produced detectable IL-4 or IL-5 mRNA. The difference in cytokine profiles observed comparing venom-allergic patients and non-allergic controls could not be attributed to intrinsic differences in T cells from these individuals, because polyclonal stimulation with phorbol myristate acetate (PMA) + ionophore induced similar cytokine mRNA profiles in the two groups. These studies demonstrate clear differences in the T cell responses of venom-allergic subjects, that may contribute to the development of severe allergic reactions in these individuals.