Definitions of the ratings of recommendations (A, B, C, U) and the classification scheme for a diagnostic article (Class I-IV) are provided at the end of the "Major Recommendations" field.
Diabetic Neuropathy
- Based on Class II evidence, quantitative sensory testing (QST) measuring vibration and thermal perception thresholds is probably an effective tool in the documentation of sensory abnormalities in patients with diabetic neuropathy (Level B recommendation).
- Based on several Class II studies, QST is probably useful in documenting changes in sensory thresholds in longitudinal evaluation of patients with diabetic neuropathy (Level B recommendation).
- Although there is data to suggest that QST abnormalities may be detectable in the absence of clinical evidence of neuropathy in diabetic patients, there is no credible prospective evidence that patients with these abnormalities will ultimately go on to develop clinical neuropathy. Thus, whether QST is useful in the detection of preclinical neuropathy is unproven (Level U recommendation).
Small Fiber Sensory Neuropathy
- Based on limited Class II and Class III evidence, QST is possibly useful in demonstrating thermal threshold abnormalities in patients with small fiber neuropathy (Level C recommendation). The clinical utility of demonstrating such abnormalities has yet to be fully defined.
Pain Syndromes
- Although there is limited Class II evidence to suggest that QST may be useful in demonstrating altered thresholds for pain perception in patients with various pain syndromes, the sensitivity and specificity of QST in the diagnosis of such disorders are unclear (Level U recommendation).
Toxic Neuropathies
- Based on limited Class II evidence, QST is possibly useful in demonstrating sensory abnormalities that result from chemotherapy-induced neuropathy (Level C recommendation).
- There is insufficient evidence to support the use of QST in monitoring the development of neuropathy secondary to workplace exposures (Level U recommendation).
Uremic Neuropathy
- QST is possibly useful in identifying large sensory fiber dysfunction in uremic patients on the basis of limited Class II and Class III evidence (Level C recommendation).
Acquired and Inherited Demyelinating Neuropathies
- The usefulness of QST in the diagnosis or prognosis of patients with acquired or inherited demyelinating neuropathy is unproven due to the limited Class III evidence available (Level U recommendation).
Malingering
- There is insufficient evidence to support the use of QST in the diagnosis of psychogenic sensory loss or malingering (Level U recommendation)
Legal Proceedings
- Malingering and other nonorganic factors can influence the testing results, and there is currently no reliable means to account for these factors. At this time, QST is not sufficiently established to justify utilization of this technique for the purpose of resolving medicolegal matters (Level U recommendation). Therefore, it should not be used in legal proceedings.
General Clinical Recommendations. QST has contributed and has the potential to further contribute to research of sensory dysfunction. However, its role is only established when it is used as one of several tools in the evaluation of neurologic disorders. In addition to the recommendations made earlier for specific neurologic disorders, the following general recommendations are warranted.
- QST results should not be the sole criterion utilized to diagnose structural pathology, of either a peripheral or central nervous system (CNS) origin.
- Abnormalities on QST must be interpreted in the context of a thorough neurologic examination and other appropriate testing, such as electromyography (EMG), nerve biopsy, skin biopsy, or appropriate imaging studies.
- Laboratories engaged in QST should demonstrate reproducible results on both controls and patients and only allow adequately trained personnel to perform such testing. Testing should be preceded by standardized instructions to subjects and be performed in a designated, quiet room with no distractions.
Definitions:
Rating of Recommendation
A = established as effective, ineffective, or harmful for the given condition in the specified population.
B = probably effective, ineffective, or harmful for the given condition in the specified population.
C = possibly effective, ineffective, or harmful for the given condition in the specified population.
U = data inadequate or conflicting. Given current knowledge, treatment is unproven.
Classification of Evidence
Class I: Evidence provided by a prospective study in a broad spectrum of persons with the suspected condition, using a "gold standard" for case definition, where test is applied in a blinded evaluation, and enabling the assessment of appropriate tests of diagnostic accuracy.
Class II: Evidence provided by a prospective study of a narrow spectrum of persons with the suspected condition, or a well-designed retrospective study of a broad spectrum of persons with an established condition (by "gold standard") compared to a broad spectrum of controls, where test is applied in a blinded evaluation, enabling the assessment of appropriate tests of diagnostic accuracy.
Class III: Evidence provided by a retrospective study where either persons with the established condition or controls are of a narrow spectrum, and where test is applied in a blinded evaluation.
Class IV: Any design where test is not applied in blinded evaluation OR evidence provided by expert opinion alone or in descriptive case series (without controls).
