Surgical treatment of patients with symptomatic Kimmerle's anomaly using video endoscopy

Background: Clinical manifestations of Kimmerle’s anomaly are detected in 5.5 to 20% of patients. The main reason for the development of symptoms is prolonged compression of the V3 (atlantic) segment of the vertebral artery in the bone ring as a result of the atlantooccipital membrane’s exostosis. To date, the final tactics for treating patients with Kimmerle’s anomaly has not been determined. The effectiveness of conservative methods of therapy does not exceed 40%. The aim Of this study was to evaluate the results of a minimally invasive surgical treatment of patients with symptomatic Kimmerle’s anomaly using video endoscopic assistance. Methods: In the period from 2020 to 2022, 15 patients were operated on. The indication for the surgical treatment was the lack of the conservative therapy’s effect for 1 year from the onset of the disease, aggravation of the disease symptoms, a decrease in the blood flow through the vertebral artery at the Kimmerle’s anomaly side when turning the head. The vertebral artery decompression was performed using video endoscopy through a posterior median approach in two (13%) patients and through a paravertebral intermuscular approach (4 cm incision in the occipitocervical region in the projection of the Kimmerle’s anomaly) in thirteen (87%) patients. Results: The outcome of the disease was assessed at the time of discharge from the hospital, as well as in 6 and in 12 months after the operation. Following the surgical treatment, all the patients showed the complete regression of symptoms and restoration of the blood flow velocities in the vertebral artery. There were no complications after the operation. The use of video endoscopy made it possible to reduce the size of the surgical wound from 12 cm to 4 cm, which contributed to a decrease in the intensity of pain in the postoperative period, early activation and a decrease in the duration of the inpatient treatment. Conclusion: With the proper selection of patients with Kimmerle’s anomaly, decompression of the V3 segment of the VA using video endoscopy is a safe and effective method of treatment

Long-term results of microvascular decompression with video endoscopy in the treatment of patients with atypical trigeminal neuralgia

Background: The incidence of atypical trigeminal neuralgia (aNTN) varies from 1 to 7 per 100,000 population per year. The main cause of its development is compression of the trigeminal nerve (TN) root by a vein and/or artery in the cerebellar cistern. To date, the final tactics of treatment for patients with aNTN has not been specified. The effectiveness of conservative methods of therapy does not exceed 50%. The aim of this study was to evaluate the results of microvascular decompression using video endoscopy in the treatment of patients with atypical trigeminal neuralgia. Methods: In the period from 2014 to 2021, 34 patients with aNTN were operated on, of which 18 (53%) patients had neuropathic pain (more than 4 points on the DN4 scale), and 15 (44%) patients had transformation of classical trigeminal neuralgia into atypical neuralgia. The conservative therapy (carbamazepine, gabapentin, pregabalin), administered to all the patients in the preoperative period, was not accompanied by a significant relief of pain syndrome. The maximum intensity of pain upon admission to the hospital was, according to the visual analog scale (VAS), 10 points, according to the BNI (Barrow Neurological Institute) Pain Intensity Scale V (severe, persistent pain). All the patients underwent microvascular decompression of the trigeminal nerve root with the use of Teflon; in 12 (35%) patients, in addition to microscopy, video endoscopy was used. The average follow-up period after the surgery was 3.41.7 years (from 1 to 5 years). Results: In all (100%) patients, the pain was completely eliminated (BNI I) after the surgery. A total five-year excellent and good outcome of the disease on the J. Miller and BNI scale (I -II) was noted in 80% (n=27) of patients with aNTN. The risk of pain recurrence after microvascular decompression was 14% (n=3) in the first three years, and 34% (n=4) after 5 years. The use of video endoscopy made it possible to identify the blood vessels compressing the root of the trigeminal nerve with a minimal displacement of the cerebellum and cranial nerves when visualizing the neurovascular conflict. Conclusion: The microvascular decompression method with video endoscopy is effective in the treatment of patients with aNTN

Chronicles of nature calendar, a long-term and large-scale multitaxon database on phenology

We present an extensive, large-scale, long-term and multitaxon database on phenological and climatic variation, involving 506,186 observation dates acquired in 471 localities in Russian Federation, Ukraine, Uzbekistan, Belarus and Kyrgyzstan. The data cover the period 1890-2018, with 96% of the data being from 1960 onwards. The database is rich in plants, birds and climatic events, but also includes insects, amphibians, reptiles and fungi. The database includes multiple events per species, such as the onset days of leaf unfolding and leaf fall for plants, and the days for first spring and last autumn occurrences for birds. The data were acquired using standardized methods by permanent staff of national parks and nature reserves (87% of the data) and members of a phenological observation network (13% of the data). The database is valuable for exploring how species respond in their phenology to climate change. Large-scale analyses of spatial variation in phenological response can help to better predict the consequences of species and community responses to climate change.Peer reviewe

Phenological shifts of abiotic events, producers and consumers across a continent

Ongoing climate change can shift organism phenology in ways that vary depending on species, habitats and climate factors studied. To probe for large-scale patterns in associated phenological change, we use 70,709 observations from six decades of systematic monitoring across the former Union of Soviet Socialist Republics. Among 110 phenological events related to plants, birds, insects, amphibians and fungi, we find a mosaic of change, defying simple predictions of earlier springs, later autumns and stronger changes at higher latitudes and elevations. Site mean temperature emerged as a strong predictor of local phenology, but the magnitude and direction of change varied with trophic level and the relative timing of an event. Beyond temperature-associated variation, we uncover high variation among both sites and years, with some sites being characterized by disproportionately long seasons and others by short ones. Our findings emphasize concerns regarding ecosystem integrity and highlight the difficulty of predicting climate change outcomes. The authors use systematic monitoring across the former USSR to investigate phenological changes across taxa. The long-term mean temperature of a site emerged as a strong predictor of phenological change, with further imprints of trophic level, event timing, site, year and biotic interactions.Peer reviewe

Differences in spatial versus temporal reaction norms for spring and autumn phenological events

For species to stay temporally tuned to their environment, they use cues such as the accumulation of degree-days. The relationships between the timing of a phenological event in a population and its environmental cue can be described by a population-level reaction norm. Variation in reaction norms along environmental gradients may either intensify the environmental effects on timing (cogradient variation) or attenuate the effects (countergradient variation). To resolve spatial and seasonal variation in species' response, we use a unique dataset of 91 taxa and 178 phenological events observed across a network of 472 monitoring sites, spread across the nations of the former Soviet Union. We show that compared to local rates of advancement of phenological events with the advancement of temperature-related cues (i.e., variation within site over years), spatial variation in reaction norms tend to accentuate responses in spring (cogradient variation) and attenuate them in autumn (countergradient variation). As a result, among-population variation in the timing of events is greater in spring and less in autumn than if all populations followed the same reaction norm regardless of location. Despite such signs of local adaptation, overall phenotypic plasticity was not sufficient for phenological events to keep exact pace with their cues-the earlier the year, the more did the timing of the phenological event lag behind the timing of the cue. Overall, these patterns suggest that differences in the spatial versus temporal reaction norms will affect species' response to climate change in opposite ways in spring and autumn