The role of intraoperative extensor digitorum brevis muscle MEPs in spinal surgery

PURPOSE

Intraoperative muscle motor evoked potentials (m-MEPs) are widely used in spinal surgery with the aim of identifying a damage to spinal cord at a reversible stage. Generally, lower limb m-MEPs are recorded from abductor hallucis [AH] and the tibialis anterior [TA]. The purpose of this work is to study an unselected population by recording the m-MEPs from TA, AH and extensor digitorum brevis (EDB), with the aim of identifying the most adjustable and stable muscles responses intraoperatively.

METHODS

Transcranially electrically induced m-MEPs were intraoperative recorded in a total of 107 surgical procedures. m-MEPs were recorded by a needle electrode placed in the muscle from TA, AH and EDB muscles in the lower extremities.

RESULTS

Overall monitorability (i.e., at least 1 Lower Limb m-MEP recordable) was 100/107 (93.5%). In the remaining 100 surgeries in 3 cases, the only muscle that could be recorded at baseline was one AH, and in other 2 the EDB. Persistence (i.e., the recordability of m-MEP from baseline to the end of surgery) was 88.7% for TA, 89.8% for AH and 93.8% for EDB.

CONCLUSION

In our series, EDB m-MEPs have demonstrated a recordability superior to TA and a stability similar to AH. The explanations may be different and range from changes in the excitability of the cortical motor neuron to the different sensitivity to ischemia of the spinal motor neuron. EDB can be used alternatively or can be added to TA and AH as a target muscle of the lower limb in spinal surgery.

Magnetoencephalography reveals differences in brain activations for fast and slow responses to simple multiplications

Despite decades of studies, it is still an open question on how and where simple multiplications are solved by the brain. This fragmented picture is mostly related to the different tasks employed. While in neuropsychological studies patients are asked to perform and report simple oral calculations, neuroimaging and neurophysiological studies often use verification tasks, in which the result is shown, and the participant must verify the correctness. This MEG study aims to unify the sources of evidence, investigating how brain activation unfolds in time using a single-digit multiplication production task. We compared the participants' brain activity-focusing on the parietal lobes-based on response efficiency, dividing their responses in fast and slow. Results showed higher activation for fast, as compared to slow, responses in the left angular gyrus starting after the first operand, and in the right supramarginal gyrus only after the second operand. A whole-brain analysis showed that fast responses had higher activation in the right dorsolateral prefrontal cortex. We show a timing difference of both hemispheres during simple multiplications. Results suggest that while the left parietal lobe may allow an initial retrieval of several possible solutions, the right one may be engaged later, helping to identify the solution based on magnitude checking.

Intra-operative fluorescence angiography is reproducible and reduces the rate of anastomotic leak after colorectal resection for cancer: a prospective case-matched study

AIM

Intra-operative fluorescence angiography (IOFA) with indocyanine green provides information on tissue perfusion that may help prevent an anastomotic leak (AL). The aim of this study was to assess the impact of IOFA on outcomes after left-sided colonic or low anterior resection with anastomosis for colorectal cancer.

METHODS

All patients with left-sided colonic or rectal cancer, operated between June 2017 and December 2018, were prospectively included. IOFA has been routinely implemented since May 2018. Reproducibility of IOFA, after a 1:1 matching for relevant clinical risk factors of AL, was studied in patients with IOFA (IOFA+) and without IOFA (IOFA-). Outcomes were compared in terms of postoperative events such as clinically relevant AL as the primary end-point.

RESULTS

In the IOFA+ group, changing of the initially planned colon transection due to inadequate perfusion occurred in five out of 46 patients (10.9%). Agreement between intra-operative assessment and postoperative blind review of IOFA was deemed strong (Cohen's kappa index 0.893, 95% CI 0.788-0.998, P < 0.001). Among 111 patients, 42 matched patients were included in each group. There was significantly more clinically relevant AL in the IOFA- group compared to the IOFA+ group (16.7% vs 2.4%, P = 0.026) involving significantly more anastomotic dehiscence which required re-intervention (19% vs 2.4%, P = 0.014). Additionally, more descending colon ischaemia/necrosis was observed in the IOFA- group compared with the IOFA+ group (9.5% vs 0%, P = 0.040).

CONCLUSION

In this prospective case-matched study, IOFA decreased the occurrence of clinically relevant AL due to necrosis of the descending colon or anastomosis. Upon blind review, perfusion assessment using IOFA was reproducible.

EEG to Identify Attempted Movement in Unresponsive Wakefulness Syndrome

Assessment of consciousness following severe brain-injury is challenging. Our hypothesis is that electroencephalography (EEG) can provide information on awareness, in terms of oscillatory activity and network task-related modifications, in people with disorders of consciousness. Similar results were obtained with neuroimaging techniques; we aim at demonstrating the use of EEG, which is low cost and routinely implemented, to the same goal. Nineteen-channel EEG was recorded in 7 persons with unresponsive wakefulness syndrome (UWS) and in 10 healthy subjects during the execution of active (attempted movement) and passive motor tasks as well as 2 mental imagery tasks. Event-related synchronization/desynchronization (ERS/ERD), coherence and network parameters were calculated in delta (1-4 Hz), theta (4-8 Hz), alpha1 (8-10 Hz), alpha2 (10-12 Hz), and beta (13-30 Hz) ranges. In UWS subjects, passive movement induced a weak alpha2 ERD over contralateral sensorimotor area. During motor imagery, ERD was detected over the frontal and motor contralateral brain areas; during spatial imagery, ERS in lower alpha band over the right temporo-parietal regions was missing. In UWS, functional connectivity provided evidence of network disruption and isolation of the motor areas, which cannot dialog with adjacent network nodes, likely suggesting a diffuse structural alteration. Our findings suggest that people with a clinical diagnosis of UWS were able to modulate their brain activity when prompted to perform movement tasks and thus suggest EEG as a potential tool to support diagnosis of disorders of consciousness.

Transcranial direct current stimulation over the sensory-motor regions inhibits gamma synchrony

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique able to induce plasticity phenomena. Although tDCS application has been spreading over a variety of neuroscience domains, the mechanisms by which the stimulation acts are largely unknown. We investigated tDCS effects on cortical gamma synchrony, which is a crucial player in cortical function. We performed a randomized, sham-controlled, double-blind study on healthy subjects, combining tDCS and magnetoencephalography. By driving brain activity via 40 Hz auditory stimulation during magnetoencephalography, we experimentally tuned cortical gamma synchrony and measured it before and after bilateral tDCS of the primary sensory-motor hand regions (anode left, cathode right). We demonstrated that the stimulation induces a remarkable decrease of gamma synchrony (13 out of 15 subjects), as measured by gamma phase at 40 Hz. tDCS has strong remote effects, as the cortical region mostly affected was located far away from the stimulation site and covered a large area of the right centro-temporal cortex. No significant differences between stimulations were found for baseline gamma synchrony, as well as early transient auditory responses. This suggests a specific tDCS effect on externally driven gamma synchronization. This study sheds new light on the effect of tDCS on cortical function showing that the net effect of the stimulation on cortical gamma synchronization is an inhibition.

Magnetoencephalography in Stroke Recovery and Rehabilitation

Magnetoencephalography (MEG) is a non-invasive neurophysiological technique used to study the cerebral cortex. Currently, MEG is mainly used clinically to localize epileptic foci and eloquent brain areas in order to avoid damage during neurosurgery. MEG might, however, also be of help in monitoring stroke recovery and rehabilitation. This review focuses on experimental use of MEG in neurorehabilitation. MEG has been employed to detect early modifications in neuroplasticity and connectivity, but there is insufficient evidence as to whether these methods are sensitive enough to be used as a clinical diagnostic test. MEG has also been exploited to derive the relationship between brain activity and movement kinematics for a motor-based brain–computer interface. In the current body of experimental research, MEG appears to be a powerful tool in neurorehabilitation, but it is necessary to produce new data to confirm its clinical utility.

Activity and safety of RAD001 (everolimus) in patients affected by biliary tract cancer progressing after prior chemotherapy: a phase II ITMO study

BACKGROUND

Biliary tract cancer (BTC) is a highly lethal disease for which the best available therapy remains undetermined. The mammalian target of rapamycin (mTOR) pathway is up-regulated in several cancers, including BTC, and preclinical evidence indicates that mTOR inhibition may be effective in the treatment of BTC. We sought to evaluate the activity and tolerability of the mTOR inhibitor RAD001-everolimus-in patients with BTC progressing after prior chemotherapy.

PATIENTS AND METHODS

This was an open-label, single-arm, phase II study (EUDRACT 2008-007152-94) conducted in eight sites in Italy. Patients with locally advanced, metastatic or recurrent BTC progressing despite previous chemotherapy received a daily oral dose of everolimus 10 mg administered continuously in 28-day cycles. The two primary end points were disease control rate (DCR) and objective response rate (ORR). Secondary end points were progression-free survival (PFS), overall survival (OS) and time-to-progression (TTP).

RESULTS

Thirty-nine patients were enrolled. The DCR was 44.7%, and the ORR was 5.1%. One patient showed a partial response at 2 months and one patient showed a complete response sustained up to 8 months. The median (95% confidence interval) PFS was 3.2 (1.8-4.0) months, and the median OS was 7.7 (5.5-13.2) months. The median TTP was 2.0 (1.7-3.7) months. Most common toxicities were asthenia (43.6%), thrombocytopenia (35.9%), pyrexia (30.8%) and erythema, mainly of mild-to-moderate severity. Two patients required dose reduction due to adverse events.

CONCLUSION

Everolimus demonstrated a favourable toxicity profile and encouraging anti-tumour activity. Further trials are needed to establish the role of everolimus in the treatment of BTC. EUDRACT 2008-007152-94.

Effects of two different glibenclamide dose-strengths in the fixed combination with metformin in patients with poorly controlled T2DM: a double blind, prospective, randomised, cross-over clinical trial

A double-blind, prospective, randomised, cross-over clinical trial was performed comparing a glibenclamide (G) 5.0 mg/metformin (M) 400 mg combination with a G 2.5 mg/M 400 mg formulation to evaluate whether a higher dose of glibenclamide was able to improve glycaemia in poorly controlled Type 2 diabetic patients. One hundred and ninety-eight patients with poorly controlled Type 2 diabetes mellitus were randomised to receive one of the two trial drugs for a first 3-month period, and were then assigned to the alternative combination for further 3 months. The starting dose (2 tablets/day, 30 min before breakfast and dinner) was to be up-titrated to 3 tablets/day when required. A standard dietary regimen was kept constant for the total trial duration. Fasting plasma glucose, HbA1c, C-peptide, insulin and lactate levels, haematology and blood chemistry were measured at the start/end of each cycle. Patients' self-assessment of the glycaemic profile (at fasting and 2 hr after the main meals) was performed weekly. Patients were constantly monitored for adverse events and episodes of hypoglycaemia, and all events were recorded. Decrease of mean fasting glucose levels measured in the first cycle was more pronounced in the group treated with G 5.0 mg/M 400 (p<0.01) compared to baseline, although the difference was not significant--no changes were observed in the second 3-month period. Results of patients' self-assessment of the glycaemic profile in the overall 6-month period show that the two trial drugs produced similar effects on fasting glucose, but the decrease of post-prandial glycaemic levels was markedly higher with G 5 mg/M 400 mg than with G 2.5 mg/M 400 mg at both main meals. A similar significant decrease (p<0.01) of HbA1c was observed in both sequence groups at the end of the first 3-month treatment period, and mean levels remained unchanged at 6 months. Drug-related adverse events were observed in 2 patients during treatment with G 2.5 mg/M 400 mg and in 5 with G 5 mg/M 400 mg, while 14 and 22 episodes of hypoglycaemia occurred with the two trial drugs, respectively (p=NS between treatments). Metformin-induced increases of lactate levels were similar in the two sequence groups. No differences between groups were found either in the number of up-titrated patients or in all the other laboratory parameters. In conclusion, the new combination containing 5-mg glibenclamide produced a greater improvement in post-prandial glycaemic control compared with the standard fixed doses, and resulted equally safe and well tolerated.

Combined immunodeficiency phenotype associated with inappropriate spontaneous and activation-induced apoptosis

Programmed death of T cells has been proposed as one of the mechanisms by which HIV induces a decline in the number and functions of T cells in advanced AIDS. In this study we report on a patient affected by a congenital form of combined immunodeficiency presenting as a profound T cell activation deficiency. Subsequently, a gradual loss of T cells occurred, eventually resulting in a classical form of severe combined immunodeficiency (SCID). In this patient a sizeable fraction of apoptotic cells was documented in the first phase of the disease by either propidium iodide staining or DNA fragmentation analysis. The presence of anergic T cells of maternal origin and engrafted in the child was excluded by analysis of DNA polymorphic regions. At 4 years of age the patient died of disseminated interstitial pneumopathy, while still awaiting an HLA-matched bone marrow transplantation. On the occasion of a new pregnancy in the mother, the prenatal immunological evaluation of the female fetus revealed a T B+ SCID phenotype. This is the first observation of a primary immunodeficiency associated with inappropriate apoptosis.

[Benign tumors of the mandible. The experience of reconstruction using immediate bone grafts]

The numerous benign pathologies of the mandible are considered, attention being focused on the large neoplasms that require full demolition and appropriate reconstructive surgery. Among the most frequent mandibular tumours, a clear-cut prevalence was noted for odontogenic tumours; on the subject of reconstructive therapy, on the other hand, stress is laid on the need for increasingly frequent use of immediate bone grafts for which the iliac bone provides the most available bone tissue both in terms of quantity and ease of access, modellability and tolerance.

[Osteoma of the frontal sinus. Remarks on a clinical case]

A case of frontal osteoma observed at the Maxillofacial Surgery and Odontostomatology Division of the Miulli di Acquaviva delle Fonti (Ba) Regional Hospital, treated surgically by the creation of a bone passage in correspondence with the anterior wall of the sinus which is then reset and osteosynthesized, is reported. The technique adopted thus makes possible full visualisation of the neoformation and valid morphological and aesthetic recovery.

[Fracture of the orbito-maxillo-zygomatic complex. Follow-up study]

The cases are examined of 82 patients out of 126 surgically treated for OMZ fractures who were followed up years later. The assessment of certain parameters reveals that many patients especially those suffering extensive OMZ injuries continued to complain of problems with the sensitivity of the orbital nerve.