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The Pain in Neuropathy Study (PiNS): a cross-sectional observational study determining the somatosensory phenotype of painful and painless diabetic neuropathy.

Themistocleous AC, Ramirez JD, Shillo PR, Lees JG, Selvarajah D, Orengo C, Tesfaye S, Rice AS, Bennett DL - Pain (2016)

Bottom Line: The DN4 questionnaire demonstrated excellent sensitivity (88%) and specificity (93%) in screening for NeuP.Brush-evoked allodynia was present in only those with NeuP (15%); the paradoxical heat sensation did not discriminate between those with (40%) and without (41.3%) NeuP.The "irritable nociceptor" subgroup could only be applied to a minority of patients (6.3%) with NeuP.

View Article: PubMed Central - PubMed

Affiliation: aNuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United KingdombDiabetes Research Unit, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United KingdomcStructural & Molecular Biology, Division of Biosciences, University College London, London, United KingdomdPain Research Group, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea and Westminster Hospital Campus, London, United KingdomePain Medicine, Chelsea and Westminster Hospital NHS Foundation Trust, London, United Kingdom.

ABSTRACT
Disabling neuropathic pain (NeuP) is a common sequel of diabetic peripheral neuropathy (DPN). We aimed to characterise the sensory phenotype of patients with and without NeuP, assess screening tools for NeuP, and relate DPN severity to NeuP. The Pain in Neuropathy Study (PiNS) is an observational cross-sectional multicentre study. A total of 191 patients with DPN underwent neurological examination, quantitative sensory testing, nerve conduction studies, and skin biopsy for intraepidermal nerve fibre density assessment. A set of questionnaires assessed the presence of pain, pain intensity, pain distribution, and the psychological and functional impact of pain. Patients were divided according to the presence of DPN, and thereafter according to the presence and severity of NeuP. The DN4 questionnaire demonstrated excellent sensitivity (88%) and specificity (93%) in screening for NeuP. There was a positive correlation between greater neuropathy severity (r = 0.39, P < 0.01), higher HbA1c (r = 0.21, P < 0.01), and the presence (and severity) of NeuP. Diabetic peripheral neuropathy sensory phenotype is characterised by hyposensitivity to applied stimuli that was more marked in the moderate/severe NeuP group than in the mild NeuP or no NeuP groups. Brush-evoked allodynia was present in only those with NeuP (15%); the paradoxical heat sensation did not discriminate between those with (40%) and without (41.3%) NeuP. The "irritable nociceptor" subgroup could only be applied to a minority of patients (6.3%) with NeuP. This study provides a firm basis to rationalise further phenotyping of painful DPN, for instance, stratification of patients with DPN for analgesic drug trials.

No MeSH data available.


Related in: MedlinePlus

Scatter plot of (A) DN4 scores, (B) painDETECT scores, against 7-day pain intensity diary mean. All screening scores were highly correlated with the 7-day pain dairy mean (Spearman correlation).
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Figure 2: Scatter plot of (A) DN4 scores, (B) painDETECT scores, against 7-day pain intensity diary mean. All screening scores were highly correlated with the 7-day pain dairy mean (Spearman correlation).

Mentions: Study participants with painful DPN scored higher on screening tools, the DN4 and painDETECT, designed to detect pain with neuropathic characteristics (Table 3). Our gold standard for the definition of NeuP was the IASP/NeuPSIG grading system.48 Using this as a reference, the sensitivity of DN4 and painDETECT was 88.3% and 61.3%, respectively, and the specificity of DN4 and painDETECT was 92.5% and 91.7%, respectively. The DN4 and painDETECT, correlated well with the mean score obtained from the 7-day pain intensity diary (Fig. 2). Some study participants with DPN and no NeuP still experienced pain in their feet or legs, such as musculoskeletal pain of the ankle or leg cramps, that was unrelated to their DPN. The DN4 and painDETECT quantified the NeuP characteristics of this nonneuropathic lower limb pain (Table 3)


The Pain in Neuropathy Study (PiNS): a cross-sectional observational study determining the somatosensory phenotype of painful and painless diabetic neuropathy.

Themistocleous AC, Ramirez JD, Shillo PR, Lees JG, Selvarajah D, Orengo C, Tesfaye S, Rice AS, Bennett DL - Pain (2016)

Scatter plot of (A) DN4 scores, (B) painDETECT scores, against 7-day pain intensity diary mean. All screening scores were highly correlated with the 7-day pain dairy mean (Spearman correlation).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4834814&req=5

Figure 2: Scatter plot of (A) DN4 scores, (B) painDETECT scores, against 7-day pain intensity diary mean. All screening scores were highly correlated with the 7-day pain dairy mean (Spearman correlation).
Mentions: Study participants with painful DPN scored higher on screening tools, the DN4 and painDETECT, designed to detect pain with neuropathic characteristics (Table 3). Our gold standard for the definition of NeuP was the IASP/NeuPSIG grading system.48 Using this as a reference, the sensitivity of DN4 and painDETECT was 88.3% and 61.3%, respectively, and the specificity of DN4 and painDETECT was 92.5% and 91.7%, respectively. The DN4 and painDETECT, correlated well with the mean score obtained from the 7-day pain intensity diary (Fig. 2). Some study participants with DPN and no NeuP still experienced pain in their feet or legs, such as musculoskeletal pain of the ankle or leg cramps, that was unrelated to their DPN. The DN4 and painDETECT quantified the NeuP characteristics of this nonneuropathic lower limb pain (Table 3)

Bottom Line: The DN4 questionnaire demonstrated excellent sensitivity (88%) and specificity (93%) in screening for NeuP.Brush-evoked allodynia was present in only those with NeuP (15%); the paradoxical heat sensation did not discriminate between those with (40%) and without (41.3%) NeuP.The "irritable nociceptor" subgroup could only be applied to a minority of patients (6.3%) with NeuP.

View Article: PubMed Central - PubMed

Affiliation: aNuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United KingdombDiabetes Research Unit, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United KingdomcStructural & Molecular Biology, Division of Biosciences, University College London, London, United KingdomdPain Research Group, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea and Westminster Hospital Campus, London, United KingdomePain Medicine, Chelsea and Westminster Hospital NHS Foundation Trust, London, United Kingdom.

ABSTRACT
Disabling neuropathic pain (NeuP) is a common sequel of diabetic peripheral neuropathy (DPN). We aimed to characterise the sensory phenotype of patients with and without NeuP, assess screening tools for NeuP, and relate DPN severity to NeuP. The Pain in Neuropathy Study (PiNS) is an observational cross-sectional multicentre study. A total of 191 patients with DPN underwent neurological examination, quantitative sensory testing, nerve conduction studies, and skin biopsy for intraepidermal nerve fibre density assessment. A set of questionnaires assessed the presence of pain, pain intensity, pain distribution, and the psychological and functional impact of pain. Patients were divided according to the presence of DPN, and thereafter according to the presence and severity of NeuP. The DN4 questionnaire demonstrated excellent sensitivity (88%) and specificity (93%) in screening for NeuP. There was a positive correlation between greater neuropathy severity (r = 0.39, P < 0.01), higher HbA1c (r = 0.21, P < 0.01), and the presence (and severity) of NeuP. Diabetic peripheral neuropathy sensory phenotype is characterised by hyposensitivity to applied stimuli that was more marked in the moderate/severe NeuP group than in the mild NeuP or no NeuP groups. Brush-evoked allodynia was present in only those with NeuP (15%); the paradoxical heat sensation did not discriminate between those with (40%) and without (41.3%) NeuP. The "irritable nociceptor" subgroup could only be applied to a minority of patients (6.3%) with NeuP. This study provides a firm basis to rationalise further phenotyping of painful DPN, for instance, stratification of patients with DPN for analgesic drug trials.

No MeSH data available.


Related in: MedlinePlus