Diagnostic Value of Assessment Tools for Sciatica in Clinical Practice: A Systematic Review and Narrative Synthesis

BACKGROUND: Sciatica is one of the most common reasons for seeking healthcare for musculoskeletal pain and can be a challenge to healthcare providers to diagnose and treat. In view of the variability of sciatica symptoms, a great range of patient reported outcome measures (PROMs) and performance-based measures (PBOs) have been developed for its assessment and management, with however, often poor or controversial results in their reliability and discriminative ability.  Accurate diagnosis of sciatica is crucial to ensure appropriate intervention is given. However, to date there is no gold standard to diagnose sciatica. There has been no systematic review conducted to compare the diagnostic validity of assessment tools of sciatica. OBJECTIVE: To evaluate the diagnostic value of tools (PROMs and PBOs) used to assess patients presenting with sciatica. METHODS: This review informed and reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis-Protocols. PubMed, Science Direct, Cochrane Library, CINAHL, MEDLINE, EMBASE, key journals and grey literature searched rigorously to find diagnostic accuracy studies investigating patient with sciatica. Two independent reviewers conducted the search, extracted the data and assessed risk of bias for included studies using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. The overall quality of included studies evaluated using Grading of Recommendations, Assessment, Development and Evaluation guidelines.  RESULTS: From 8347 studies, 11 studies were included. Nine studies out of the 11 were at risk of bias. Very low level evidence supports the use of dermatomal patterns and low level evidence supports the use of 7 tools (neurological examination, Βragard test, S-LANSS, ID Pain, PDQ, S-DN4, SQST) for diagnosing sciatica. Moderate level evidence supports a cluster of eight signs (age, duration of disease, paroxysmal pain, pain worse in leg than back, typical dermatomal distribution, worse on coughing/sneezing/straining, finger to floor distance and paresis), twenty items of patient history, self-reported items (pain below knee,  which pain worst, numbness pins and needles), question «worsening of pain during sneezing coughing and straining» and Slump test for diagnosing sciatica. Also, moderate level evidence supports the use of the StEP tool for diagnosing lumbar radicular pain, demonstrating high sensitivity (92%) and specificity (97%) values. SLR showed moderate level evidence in one study and high level evidence in another study in diagnosing sciatica with sensitivity 63.46% and specificity 45.88%. CONCLUSIONS: Overall low-moderate level evidence supports the diagnostic utility of the tools examined in this review in diagnosing sciatica.  The weak evidence base is largely due to methodological flaws and indirectness regarding applicability of the included studies. The most promising diagnostic tools include a cluster of 8 patient history/clinical examination signs, the StEP tool and the SLR test. From these results it is easily understood that history taking has a major role as assessment tool of sciatica in clinical practice. Low risk of bias and high level of evidence diagnostic utility studies are needed, in order for stronger recommendations to be mad

Multiphase Diagenetic Processes and Their Impact on Reservoir Character of the Late Triassic (Rhaetian) Kingriali Formation, Upper Indus Basin, Pakistan

Multiple episodes of dolomitization of the shallow marine carbonates of the Late Kingriali Formation resulted in regional scale mappable dolostone geobodies in the Kohat and Potwar sub-basins. With the exception of few unaltered patches of the host limestone, more than 90% of the carbonates of the studied formation are diagenetically altered by replacive dolomites with associated dolomite cementation. Petrographical and geochemical data interpretation reveals that during the initial stage of dolomitization, the precursor limestone was significantly modified by the fabric-retentive replacive dolomite (RD-I) and produced bulk dolostones with non-planar-a to planar-s crystals. Neomorphic recrystallization (RD-II) was observed as an overgrowth of the already formed RD-I dolomite crystals during progressive dolomitization. The seawater at shallow depths is enriched with Fe-ions due to its interaction with Fe-rich beds within the studied formation. The modified seawater actively participated in the formation of ferroan replacive dolomites (RD-III). Stable isotopic composition of the unaltered Echinoderm plates, calcite cement (CC-I), and RD-I demonstrates signatures of δ18O and δ13C within the limit of late Triassic marine seawater or modified seawater. Depletion in the stable oxygen isotopic composition (from −0.99‰ to −3.75‰ V-PDB) demonstrates that RD-II and RD-III were formed in a sequence with progressively higher temperature fluids than normal seawater. Precipitation of dolomite cements as cavity filling rhombs (DC-I) and crystal overgrowth (DC-II) with highly depleted δ18O values (−5.44‰ to −7.45‰ V-PDB) illustrates dolomite cementation at higher temperatures and greater depths. The highly depleted values of δ18O (up to −9.16‰ V-PDB) and (up to 0.42‰ V-PDB) for δ13C of saddle dolomite (SD-I) indicate the precipitation of SD-I as a cavity filling dolomite at considerable depth. Calcite cementation and calcitization actively participated in the early, middle, and late diagenetic modifications as interpreted from their petrographic and stable isotopic studies. Porosity enhancement is clearly demonstrated by dissolution, stylolization, fracturing, and replacement dolomitization. Dolomite and calcite cementation had a negative impact on the reservoir character and occluded the dolostone porosity to a greater extent. © 2022 by the authors.</p

Eco-biostratigraphic advances in late quaternary geochronology and palaeoclimate : the marginal Gulf of Mexico analogue

This study combines high-resolution planktonic foraminiferal eco-biostratigraphy and palaeoclimatic data from the high-sedimentation-rate core JPC-26 from the northwestern margin of the Gulf of Mexico (GoM). The eco-biozones recognized (GOMPFE1-12) being correlated with published Mg/Ca-based sea surface temperatures. This updated palaeoclimatic and stratigraphic reference record facilitates correlations with the Greenland ice core events and their climatic relationships, and also provides a solid stratigraphic framework for correlations with other palaeoclimatic and palaeoceanographic records in the circum-GOM/Caribbean region. This multidisciplinary approach underlines the utility of supporting conventional dating methodologies with different constraints, and further reveals a powerful tool for reliably correlating marine records between comparable deep-sea marginal settings and coeval sequences of this region

Latitudinal variation of planktonic foraminifera shell masses during Termination I

Unidad de excelencia María de Maeztu MdM-2015-0552The oceans' surface layer holds large amounts of dissolved inorganic carbon that is exchanged rapidly with the atmosphere. Carbon enters the ocean mainly through the dissolution of atmospheric carbon dioxide (CO2), and a part of it is converted into carbonate by marine organisms. Calcifying marine organisms include planktonic foraminifers that contribute to the marine carbon turnover by generating inorganic carbon production (CaCO3 shells). Anthropogenic CO2 acidifies the surface ocean, changes the carbonate chemistry and decreases the saturation state of carbonate minerals in sea water, thus affecting the biological precipitation of carbonate shells. Relative changes in average foraminiferal shell mass can be interpreted as variations in test thickness and the extent of calcification that subsequently impacts the global carbonate budgets. The response of calcifying marine organisms to elevated atmospheric pCO2 is diverse and complex with studies reporting from reduced rates of net calcification to neutral receptivity or even increased calcification intensities. This diverse behavior implies that the concentration of dissolved inorganic carbon may not be the dominant factor controlling the amount of carbonate shell masses. Here we provide further evidence that glacial/interglacial variations of planktonic foraminifera shell masses are invariant to atmospheric pCO2. We identify that differences in shell weights of several planktonic foraminiferal species from narrow size intervals, over the most recent deglaciation (Termination I) vary systematically as a function of latitude. Past intervals of abruptly changing pCO2 and temperatures, such as the terminations, can offer a glimpse into the response of marine calcifying plankton to changes in surface oceans. We have compiled all the available bibliographic data of planktonic foraminifera shell weights from restricted sieve fractions of different species from the Atlantic, Pacific and Indian Oceans and we find that for the same pCO2 conditions planktonic foraminifera from equatorial regions may alter their shell mass only as little as 8.2%, while towards higher latitudes changes in shell mass reach up to 54% during the transition from the last glacial to interglacial conditions. We attribute this low variability in the shell mass of planktonic foraminifera from the equator to the stability of the physical oceanographic conditions that characterize the equatorial zone

Evidence of Stable Foraminifera Biomineralization during the Last Two Climate Cycles in the Tropical Atlantic Ocean

Planktonic foraminiferal biomineralization intensity, reflected by the weight of their shell calcite mass, affects global carbonate deposition and is known to follow climatic cycles by being increased during glacial stages and decreased during interglacial stages. Here, we measure the dissolution state and the mass of the shells of the planktonic foraminifera species Globigerina bulloides from a Tropical Eastern North Atlantic site over the last two glacial–interglacial climatic transitions, and we report no major changes in plankton calcite production with the atmospheric pCO2 variations. We attribute this consistency in foraminifera calcification to the climatic and hydrological stability of the tropical regions. However, we recorded increased shell masses midway through the penultimate deglaciation (Termination II). In order to elucidate the cause of the increased shell weights, we performed δ18O, Mg/Ca, and μCT measurements on the same shells from a number of samples surrounding this event. Compared with the lighter ones, we find that the foraminifera of increased weight are internally contaminated by sediment infilling and that their shell masses respond to local surface seawater density changes.</jats:p

Evidence of stable foraminifera biomineralization during the last two climate cycles in the tropical Atlantic ocean

Unidad de excelencia María de Maeztu CEX2019-000940-MPlanktonic foraminiferal biomineralization intensity, reflected by the weight of their shell calcite mass, affects global carbonate deposition and is known to follow climatic cycles by being increased during glacial stages and decreased during interglacial stages. Here, we measure the dissolution state and the mass of the shells of the planktonic foraminifera species Globigerina bulloides from a Tropical Eastern North Atlantic site over the last two glacial-interglacial climatic transitions, and we report no major changes in plankton calcite production with the atmospheric pCO2 variations. We attribute this consistency in foraminifera calcification to the climatic and hydrological stability of the tropical regions. However, we recorded increased shell masses midway through the penultimate deglaciation (Termination II). In order to elucidate the cause of the increased shell weights, we performed δ18O, Mg/Ca, and μCT measurements on the same shells from a number of samples surrounding this event. Compared with the lighter ones, we find that the foraminifera of increased weight are internally contaminated by sediment infilling and that their shell masses respond to local surface seawater density changes

Calcification, Dissolution and Test Properties of Modern Planktonic Foraminifera From the Central Atlantic Ocean

The mass of well-preserved calcite in planktonic foraminifera shells provides an indication of the calcification potential of the surface ocean. Here we report the shell weight of 8 different abundant planktonic foraminifera species from a set of core-top sediments along the Mid-Atlantic Ridge. The analyses showed that near the equator, foraminifera shells of equivalent size weigh on average 1/3 less than those from the middle latitudes. The carbonate preservation state of the samples was assessed by high resolution X-ray microcomputed tomographic analyses of Globigerinoides ruber and Globorotalia truncatulinoides specimens. The specimen preservation was deemed good and does not overall explain the observed shell mass variations. However, G. ruber shell weights might be to some extent compromised by residual fine debris internal contamination. Deep dwelling species possess heavier tests than their surface-dwelling counterparts, suggesting that the weight of the foraminifera shells changes as a function of the depth habitat. Ambient seawater carbonate chemistry of declining carbonate ion concentration with depth cannot account for this interspecies difference. The results suggest a depth regulating function for plankton calcification, which is not dictated by water column acidity