1362572403 diagnosing dpn
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This document discusses the process of diagnosing diabetic neuropathy through various techniques. It outlines several methods including: - Assessing neuropathic symptoms through a neuropathic symptom score questionnaire - Evaluating the severity and change of neuropathic symptoms using a visual analogue pain scale - Using a neuropathic impairment score which indicates the presence of neuropathy based on lower limb measurements - Performing quantitative sensory testing and sural nerve morphometry to analyze nerve fibers It notes that accurately diagnosing diabetic neuropathy is complex as patients may not report symptoms and various testing methods have limitations and difficulties in comparison. Understanding the limitations of techniques is important.
1362572403 diagnosing dpn
- 1. • Process of Diagnosis of diabetic neuropathy Sanjeev Kelkar Secretary DFSI
- 2. Process of Diagnosis • DIAGNOSING DIABETIC NEUROPATHY • ISSUES, VEXATIONS AND LIMITATIONS • TECHNIQUES
- 3. Process of Diagnosis • Volunteered symptoms – unreliable, insensate feet will have no complaints • Tallying from case records – likely to have been missed / may not have been asked • NSS - Neuropathic Symptom Score – Should be asked from a check list – 1 point given to each either present or absent, severity of symptoms does not count
- 4. Process of Diagnosis • Profiling Neuropathic Symptoms Not useful in DPN, the technique is at variance with other techniques • Assessing severity of and change in the neuropathic symptoms Done on visual analogue pain scale
- 5. Assessing Severity • Descriptive terms are used, symptoms cluster around descriptive terms, eg; Pain, burning parasthesias, numbness, these terms need to be explained to the patients; • Intensity - absent, slight, moderate, severe, • Frequency – occasional, frequent, continuous,
- 6. Assessing Severity • Interpretation of symptoms subjective, mixed, hence unreliable • Maximum points 0 to 14.64 • Descriptive terms are given visual analogue scale giving rise to graphic rating
- 7. Assessing Severity • Neuropathic Symptom Change (NSC) – recommended by Dyke and Thomas • NSC – change and severity – better measures to detect worsening or improvement • NIS, NC, VPT, CASE IV – if changes are large, all of them move in the same direction, if changes are small discrepancies occur • What is NIS?
- 8. Neuropathic Impairment Score • It is a single value provided as cut off • Indicates presence of neuropathy • Only lower limbs are measured • Eliminates noise from or dilution of other normal neurological studies in diabetes eg upper limbs
- 9. Neuropathic Impairment Score • Scoring is NIS LL + 7 • 99th percentile - 1 point • 99 to 99.9 percentile - 2 points • > or = to 99.9 - 3 points
- 10. Neuropathic Impairment Score Scoring on QST, Quantitative Sensory Testing • < 95 percentile 0 points, • 95 to 99 percentile 1 point, • > or = to 99th to 99.9 percentile 2 points, • > or = to 99.9 percentile 3 points
- 11. Sural Nerve Morphometry Cut sections – quantitative , allows statistical analysis of even large data sets Reduces observer bias Can assess myelinated, unmyelinated fibers, blood vessels Adaptable to computerization of image processing and analysis
- 12. Sural Nerve Morphometry On teased fiber technique – Could be normal, Detects – Excessive myelin irregularities Segmental, nodal demyelination Thinly myelinated internodes indicating remyelination Focal myelin thickening
- 13. Sural Nerve Morphometry On teased fiber technique – Normally myelinated internodes with superimposed myelin ovoids indicating fiber regenration Several normal proximal internodes adjacent to arow of myelin ovoids indicating Wallerian degenration
- 14. Sural Nerve Morphometry Objections: Ovoids mistaken as normal fibers Myelinated fibers may be non functional Benefits are not outweighed by the morbidity and cost o procedure
- 15. Nerve Endings in Punch Skin Biopsies Questionable – how well does it detect all nerve fibers? Counted nerve fibers may not be functional Difficult to correlate what degree of change is meaningful for a clinical change
- 16. Conclusion Neuropathy research is complex, Choice of method to record data important Calls for meticulous questioning from well trained staff Variable methods, difficulties in comparing with other studies limitations of various techniques be known