Long-term success of low-frequency subthalamic nucleus stimulation for Parkinson's disease depends on tremor severity and symptom duration

Patients with Parkinson's disease can develop axial symptoms, including speech, gait and balance difficulties. Chronic high-frequency (>100 Hz) deep brain stimulation can contribute to these impairments while low-frequency stimulation (<100 Hz) may improve symptoms but only in some individuals. Factors predicting which patients benefit from low-frequency stimulation in the long term remain unclear. This study aims to confirm that low-frequency stimulation improves axial symptoms, and to go further to also explore which factors predict the durability of its effects. We recruited patients who developed axial motor symptoms while using high-frequency stimulation and objectively assessed the short-term impact of low-frequency stimulation on axial symptoms, other aspects of motor function and quality of life. A retrospective chart review was then conducted on a larger cohort to identify which patient characteristics were associated with not only the need to trial low-frequency stimulation, but also those which predicted its sustained use. Among 20 prospective patients, low-frequency stimulation objectively improved mean motor and axial symptom severity and quality of life in the short term. Among a retrospective cohort of 168 patients, those with less severe tremor and those in whom axial symptoms had emerged sooner after subthalamic nucleus deep brain stimulation were more likely to be switched to and remain on long-term low-frequency stimulation. These data suggest that low-frequency stimulation results in objective mean improvements in overall motor function and axial symptoms among a group of patients, while individual patient characteristics can predict sustained long-term benefits. Longer follow-up in the context of a larger, controlled, double-blinded study would be required to provide definitive evidence of the role of low-frequency deep brain stimulation

Transcutaneous spinal direct current stimulation

In the past 10\u2009years renewed interest has centered on non-invasive transcutaneous weak direct currents applied over the scalp to modulate cortical excitability ("brain polarization" or transcranial direct current stimulation, tDCS). Extensive literature shows that tDCS induces marked changes in cortical excitability that outlast stimulation. Aiming at developing a new, non-invasive, approach to spinal cord neuromodulation we assessed the after-effects of thoracic transcutaneous spinal DC stimulation (tsDCS) on somatosensory potentials (SEPs) evoked in healthy subjects by posterior tibial nerve (PTN) stimulation. Our findings showed that thoracic anodal tsDCS depresses the cervico-medullary PTN-SEP component (P30) without eliciting adverse effects. tsDCS also modulates post-activation H-reflex dynamics. Later works further confirmed that transcutaneous electric fields modulate spinal cord function. Subsequent studies in our laboratory showed that tsDCS modulates the flexion reflex in the human lower limb. Besides influencing the laser evoked potentials (LEPs), tsDCS increases pain tolerance in healthy subjects. Hence, though the underlying mechanisms remain speculative, tsDCS modulates activity in lemniscal, spinothalamic, and segmental motor systems. Here we review currently available experimental evidence that non-invasive spinal cord stimulation (SCS) influences spinal function in humans and argue that, by focally modulating spinal excitability, tsDCS could provide a novel therapeutic tool complementary to drugs and invasive SCS in managing various pathologic conditions, including pain

Imaging of Hereditary Hemorrhagic Telangiectasia

This pictorial review is based on our experience of the follow-up of 120 patients at our multidisciplinary center for hereditary hemorrhagic telangiectasia (HHT). Rendu-Osler-Weber disease or HHT is a multiorgan autosomal dominant disorder with high penetrance, characterized by epistaxis, mucocutaneous telangiectasis, and visceral arteriovenous malformations (AVMs). The research on gene mutations is fundamental and family screening by clinical examination, chest X-ray, research of pulmonary shunting, and abdominal color Doppler sonography is absolutely necessary. The angioarchitecture of pulmonary AVMs can be studied by unenhanced multidetector computed tomography; however, all other explorations of liver, digestive bowels, or brain require administration of contrast media. Magnetic resonance angiography is helpful for central nervous system screening, in particular for the spinal cord, but also for pulmonary, hepatic, and pelvic AVMs. Knowledge of the multiorgan involvement of HHT, mechanism of complications, and radiologic findings is fundamental for the correct management of these patients

Sentinel lymph node mapping in endometrial cancer: A literature review and state of the art

Objective: Sentinel lymph node biopsy has proven safe and feasible in a number of gynecologic cancers such as vulvar cancer, cervical cancer, and endometrial cancer. The aim of sentinel node mapping is to decrease the morbidity associated with a complete lymphadenectomy, while also increasing the detection rate of small lymph node metastases. The scope of this review is to critically appraise the published literature on (Sentinel Lymph Node) SLN procedure in endometrial cancer (EC). Methods: We run a PubMed search for publications in English using “endometrial cancer” and “sentinel node” as key words. All abstracts from 2005 to December 2015 were reviewed. We excluded studies aimed to determine the risk of metastasis in the remaining non-SLNs when the SLN is positive, studies that only reported on successfully mapped patients, those where different types of gynecological cancers other than EC and/ or atypical endometrial hyperplasia were included and those studies with less than 30 cases. Results: 23 studies met the inclusion criteria. The overall detection rate of sentinel nodes after cervical injection ranged from 62% to 100%, while it was 73% to 95% after corporeal injection. All studies with n of cases ≥ 100 had overall detection rates of &gt;80%. In terms of product/tracer used, Technetium colloid, blue dye and ICG were used either alone or in combination. Detection rates were good for all three products, however, detection rates were higher when blue dye was combined with Technetium (Tc) or Indocyanine Green (ICG). The injection site influenced the pattern of sentinel mapping with para-aortic SLNs being found more often using corporeal and deeper (3–4 cm) cervical injection techniques. Studies in which the protocol included a systematic para-aortic lymphadenectomy had higher detection of para-aortic SLNs, as well as isolated para-aortic metastases. Conclusion: Sentinel lymph node mapping for endometrial cancer balances the need to assess nodal disease with the low likelihood of nodal metastasis for most patients. It is a technique with minimal morbidity, sparing the need for a full lymphadenectomy and its associated higher morbidity potentially leading to a greater utilization by gynecologic surgeons in the future. Achieving high bilateral SLN detection rates and low false-negative rates is mandatory to implement the SLN mapping as a routine component of clinical practice

ProBiota | Serie Documentos | El Instituto de Biología Marina de Mar del Plata, Argentina (1960-1977) : Aportes para su historia

Se reseña la creación del Instituto Interuniversitario de Biología Marina, Mar del Plata (IBM), Argentina, dependiente de la Universidad de Buenos Aires (UBA), la Universidad Nacional de La Plata (UNLP), la Universidad Nacional del Sur (UNS) y del Poder Ejecutivo de la provincia de Buenos Aires. Se destaca su funcionamiento durante el período 1960-1976 hasta su desaparición en 1977 y las numerosas actividades desarrolladas en el plano de la biología marina argentina. También se mencionan los diversos cursos nacionales, congresos nacionales e internacionales realizados en dicha institución. Se destaca asimismo el rol del IBM con el Proyecto de Desarrollo Pesquero (FAO/PNUD) por haber sido asiento de expertos internacionales y de los científicos argentinos que actuaron como contraparte dentro de ese proyecto. Como resultado de su accionar, el IBM editó 21 publicaciones científicas denominadas Boletines, productos de monografías originales, y 342 contribuciones científicas. Se señala el impacto de la intervención a las universidades con el golpe de Estado de 1966, de la persecución a los investigadores, los eventos durante el 1974-1976 y de la implantación de la dictadura militar en 1976 como factores desencadenantes de la emigración de sus investigadores y de la clausura del mismo instituto.The creation of the Institute of Marine Biology (Instituto de Biología Marina, IBM) from Mar del Plata, Argentina, under the dependence of the Buenos Aires University, La Plata National University, South National University and the Executive Power of Buenos Aires Province is described. It is remarkable its development during 1960 to 1976 period until it extinction in the year 1977 and the different activities carried on in the area of the Argentine marine biology and fisheries. The development of different national courses, national and international congress carried in the institution is reported. It is also mentioned the relationship between the IBM and the Fishery Development Project (FAO/PNUD) as a place of international experts and the Argentinean scientists who acted as a counterpart inside the Project. As a result of their action, the IBM published 21 scientific publications named Bulletins as a product of original monographs and 342 scientific contributions. It is outlined the impact of the attempted coup of the year 1966 and the persecution to the resident scientists and the implantation of the military dictatorship of the year 1976 as a trigger factors for the emigration of their researchers and closure of the institution.Facultad de Ciencias Naturales y Muse