In addition, we asked whether patients with atypical manifestation show subclinical signs of generalized muscle weakness compared to healthy controls. Methods Patients In this cross-sectional observational study patients who met the diagnostic criteria for typical and atypical CIDP of the EFNS 2010 [9] were included in order to objectively quantify muscular weakness with non-invasive Q-Motor assessment of grip force and involuntary activity. controls (HC). For Q-Motor tests all subjects had to lift a device (250?g and 500?g) equipped with an electromagnetic sensor that measured grip force (GF) and three-dimensional changes in position and orientation. The measures grip force variability (GFV), position index (PI) and orientation index (OI) were provided to assess involuntary movements due to muscular weakness. Results 33 patients with CIDP and 28 HC were included. All measures were significantly elevated in CIDP patients for both devices in the right and left hand compared to healthy controls. Subgroup analysis revealed no differences between typical and atypical CIDP variants. INCAT score only weakly correlated with OI and PI. However, there was a stronger correlation between MRC and QIMA parameters in both hands. Conclusion Q-Motor assessments were capable to objectively assess muscular weakness in CIDP. In particular, QIMA measures detected subclinical generalized muscle weakness even in patients with milder disability. Sensitivity and rater-independence of Q-Motor assessments support a further exploration of QIMA measures as potential endpoints for future clinical trials in CIDP. is often applied in order to measure the muscle strength on the level of [7], whereas BCH the INCAT overall disability scale measures the disability resulting from muscular weakness [8]. However, none of these methods is appropriate to assess muscle weakness objectively and to detect even very small subclinical changes. Here, we hypothesized that muscular weakness in patients with CIDP can be objectively quantified with (1) non-invasive quantitative motor (Q-Motor) assessment of grip force and involuntary activity and (2) that pathological findings correlate BCH with disease severity as measured by the MRC and INCAT disability score. In addition, we asked whether individuals with atypical manifestation display subclinical indications of generalized muscle mass weakness compared to healthy controls. Methods Individuals With this cross-sectional observational study individuals who met the diagnostic criteria for standard and atypical CIDP of the EFNS 2010 [9] were included in order to objectively quantify muscular weakness with non-invasive Q-Motor assessment of hold push and involuntary activity. Individuals were screened consecutively between March and August 2013 in our outpatient medical center of the Division of Neurology, Charit University BCH Medicine, Berlin, Germany. Data of all CIDP individuals was compared to a group BCH of healthy settings (HC) that was related in age and sex (distribution) to the patient group. HC experienced to meet the following criteria: Age??18?years, no other neurological diseases, no other diseases affecting the musculoskeletal system, no cognitive deficits. Overall, 33 individuals with CIDP and 28 HC were included. Unlike recent epidemiological data, numbers of recruited standard and atypical CIDP individuals were nearly identical for statistical reasons [10]. There was no screening for NF155 and CNTN1 antibodies for individuals with atypical CIDP. Clinical assessment Individuals were examined from the treating neurologist (JK). Sociodemographics as well as current medication were documented. We used the modified inflammatory neuropathy cause and treatment (INCAT) disability score [8] and the Medical Study Council (MRC) sum score [7] to assess the medical status within 2?months when clinically stable. For the MRC the following muscles had been tested on both sides: shoulder abduction, elbow flexion, wrist extension, index finger extension, hip flexion, knee extension, ankle dorsiflexion, extension of the big feet. For classification, we used CIDP disease activity status (CDAS) [11], summarizing unstable active and improving status as unstable stage, stabile Rabbit Polyclonal to OR5W2 active status and remission status as stable stage.. Quantitative.