Objective: To perform a psychometric evaluation of the inflammatory neuropa
thy cause and treatment (INCAT) sensory sumscore (ISS) in sensory-motor imm
une-mediated polyneuropathies. This new sensory scale was evaluated to stri
ve for uniformity in assessing sensory deficit in these disorders. Methods:
The LSS comprises vibration and pinprick sense plus a two-point discrimina
tion value and ranges from 0 (normal sensation) to 20 (maximum sensory defi
cit). Before its clinical use, a panel of expert neurologists concluded tha
t the ISS has face and content validity. The construct validity of the ISS
was investigated by correlation and regression studies with additional scal
es (Nine-Hole Peg Test, 10-Meter Walking Test, a disability sumscore). All
scales were applied in 113 patients with a stable neurologic condition (83
patients who experienced Guillain-Barre syndrome [GBS] in the past, 22 with
chronic inflammatory demyelinating polyneuropathy [CIDP], 8 patients with
a monoclonal gammopathy associated polyneuropathy), and 10 patients with re
cently diagnosed GBS or CIDP with changing clinical conditions. Reliability
of the ISS was evaluated in the stable patients. Its responsiveness was in
vestigated in the patients examined longitudinally. Results: A moderate to
good validity was obtained for the ISS (stable group: r = 0.38 to 0.56, p l
ess than or equal to 0.006; longitudinal group: R = 0.60 to 0.82, p less th
an or equal to 0.007, except fbr the association with the 10-Meter Walking
Test [p = 0.08]). Acceptable internal consistency, and inter- and intraobse
rver reliability were demonstrated for the ISS (alpha = 0.68 to 0.87; R = 0
.85 to 0.89, p < 0.0001). Standardized response mean scores for the ISS wer
e high (greater than or equal to 0.8), indicating good responsiveness. Conc
lusions: All psychometric requirements are provided for the the inflammator
y neuropathy cause and treatment sensory sumscore. The use of this scale is
therefore suggested for bedside evaluation of sensory deficit in the indiv
idual patient with a sensory-motor immune-mediated polyneuropathy as well a
s in clinical trials.