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Soliman, N.

Publications and source records attributed to Soliman, N..

2 recordsLinked to original sources
bioRxiv2025

A systematic review and meta-analysis of the effect of experimental pain on rat grimace scale scores

The rat grimace scale (RGS) purports to assess behavioural responses related to pain by assessing four facial expressions. To understand how experimental pain affects RGS scores, we conducted a systematic review of studies which reported outcomes using this scale (CRD42022292189). Systematic searches were conducted on 3 databases in January 2022. RGS studies that assessed the effects of disease models relating to pain were included. Risk of bias was assessed by using a modified version of the CAMARADES reporting checklist and SYRCLE Risk of Bias tool. A standardised mean difference effect size was calculated using a random-effects model. Fifty-four studies were included, in which 15 disease model classes and 16 classes of pharmacological interventions were identified. RGS scores were increased in disease models hypothesised to be associated with persistent pain (SMD = -4.44 [95%CI -6.25 to -2.63]) and this response was attenuated by analgesic drugs (SMD = 1.97 [95%CI 1.25 to 2.69]). Post-surgical models (39% of experiments) and opioids (30% of experiments) were the most commonly reported. We could not ascertain the sources of heterogeneity due to insufficient data. Most studies were assessed as having an unclear risk of bias due to poor reporting quality. The relationship between RGS scores and mechanically evoked limb withdrawal was inconsistent. These findings indicate emerging evidence to support the use of RGS in persistent pain research, but additional research is needed to strengthen these findings. Future studies could benefit from using sex-balanced animal populations with diverse genetic backgrounds. To enhance the impact and reproducibility of their findings, studies should prioritise improvements in reporting quality.

neuroscience↗
bioRxiv2023

Spontaneous activity in peripheral sensory nerves - A systematic review

In the peripheral nervous system, spontaneous activity in sensory neurons is considered to be one of the two main drivers of chronic pain states, alongside neuronal sensitization. Despite this, the precise nature and timing of this spontaneous activity in neuropathic pain is not well-established. Here, we have carried out a systematic search and data extraction of existing electrophysiological literature to shed light on which fibre types have been shown to maintain spontaneous activity and over what time frame. We examined both in vivo recordings of pre-clinical models of neuropathic pain, as well as microneurography recordings in humans. Our analyses reveal that there is broad agreement on the presence of spontaneous activity in neuropathic pain conditions, even months after injury or years after onset of neuropathic symptoms in humans. However, due to the highly specialised nature of the electrophysiological methods used to measure spontaneous activity, there is also a high degree of variability and uncertainty around these results. Specifically, there are very few directly controlled experiments, with little directly comparable data between human and animals. Given that spontaneous peripheral neuron activity is considered to be a key mechanistic feature of chronic pain conditions, it may be beneficial to conduct further experiments in this space.

neuroscience↗