Diagnostic yield by testing small fiber function in patients examined for polyneuropathy

Abstract

We assessed the diagnostic yield of adding quantitative sensory testing to the standard work-up for polyneuropathy in unselected patients. All patients aged 18 to 70 years referred to our department for electrodiagnosis with a tentative diagnosis of polyneuropathy and symptoms complying with predefined criteria were included in the study. We performed near nerve conduction studies in 4 nerves and determined heat and cold detection thresholds on hand and foot with a Thermotest (Somedic AB, Sweden). In order to uncover CNS diseases, somatosensory-evoked potentials were recorded in patients with abnormal quantitative sensory testing and normal nerve conduction studies. A total of 198 patients completed the study and 149 were considered to have polyneuropathy. Twenty-five patients remained undiagnosed and in 24 patients, other diseases were responsible for the symptoms. Of the patients with either polyneuropathy or no other diagnosis, 76% (n = 174) had abnormal nerve conduction. Abnormal cold sensation, heat sensation or abnormality in at least 1 of these and normal nerve conduction were found in 14, 12 and 17 patients. Of the 174 patients, 86% (95% CI 80-90%) had an abnormality in at least 1 of the tests (i.e. abnormal nerve conduction and/or abnormal quantitative testing of temperature sensation). In conclusion, quantitative testing of temperature sensation improves the diagnostic yield in patients examined for chronic polyneuropathy.

Influence of aging on thermal and vibratory thresholds of quantitative sensory testing

“…The results suggest that age is the most single determinant of sensory thresholds among all parameters studied; these are important references for the interpretation of clinical data on sensory thresholds. Quantitative sensory testing is an easily performed, non‐invasive assessment, and these approaches could be applied clinically ( Zaslansky and Yarnitsky, 1998 ; Burns et al, 2002 ; Magda et al, 2002 ; Shy et al, 2003 ) , including screening of sensory disorders ( Dyck et al, 1987 ; 2000 ; Lipton et al, 1987 ; Nurmikko, 1991 ; Gulevich et al, 1992 ; Dyck and O'Brien, 1999 ; Sindrup et al, 2001 ) and monitoring of disease progression or therapeutic effects ( Simovic et al, 2001 ; Wellmer et al, 2001 ; Wallace et al, 2002 ; Hilz et al, 2004 ; Windebank et al, 2004 ; de la Cour and Jakobsen, 2005 ) .…”

Thermal and vibratory thresholds after liposuction in patients with Dercum's disease

“…The subject was instructed to press a switch whenever she felt an onset of a change in temperature (cold or warmth). She was asked to push a button when she felt sensations of warm and cold, respectively, at which moment the temperature of the probe returned to baseline [8,9].…”

Test‐retest and time dependent variation and diagnostic values of vibratory sensation determined by biothesiometer and the Rydel‐Seiffer tuning fork

“…The biothesiometer has previously been compared with nerve conducting studies and quantitative tests of thermal sensation for detection of large and small fiber neuropathies (Sindrup et al, 2001).…”

“…The biothesiometer has previously been compared with nerve conducting studies and quantitative tests of thermal sensation for detection of large and small fiber neuropathies (Sindrup et al., 2001). Diagnostic performance of the biothesiometer when testing on thumb and first toe was found to be slightly better than in our study, except for NPV.…”