I. S. J. Merkies

Intravenous immune globulin (10% caprylate-chromatography purified) for the treatment of chronic inflammatory demyelinating polyradiculoneuropathy (ICE study): a randomised placebo-controlled trial

BACKGROUNDnShort-term studies suggest that intravenous immunoglobulin might reduce disability caused by chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) but long-term effects have not been shown. We aimed to establish whether 10% caprylate-chromatography purified immune globulin intravenous (IGIV-C) has short-term and long-term benefit in patients with CIDP.nnnMETHODSn117 patients with CIDP who met specific neurophysiological inflammatory neuropathy cause and treatment (INCAT) criteria participated in a randomised, double-blind, placebo-controlled, response-conditional crossover trial. IGIV-C (Gamunex) or placebo was given every 3 weeks for up to 24 weeks in an initial treatment period, and patients who did not show an improvement in INCAT disability score of 1 point or more received the alternate treatment in a crossover period. The primary outcome was the percentage of patients who had maintained an improvement from baseline in adjusted INCAT disability score of 1 point or more through to week 24. Patients who showed an improvement and completed 24 weeks of treatment were eligible to be randomly re-assigned in a blinded 24-week extension phase. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00220740.nnnFINDINGSnDuring the first period, 32 of 59 (54%) patients treated with IGIV-C and 12 of 58 (21%) patients who received placebo had an improvement in adjusted INCAT disability score that was maintained through to week 24 (treatment difference 33.5%, 95% CI 15.4-51.7; p=0.0002). Improvements from baseline to endpoint were also recorded for grip strength in the dominant hand (treatment difference 10.9 kPa, 4.6-17.2; p=0.0008) and the non-dominant hand (8.6 kPa, 2.6-14.6; p=0.005). Results were similar during the crossover period. During the extension phase, participants who continued to receive IGIV-C had a longer time to relapse than did patients treated with placebo (p=0.011). The incidence of serious adverse events per infusion was 0.8% (9/1096) with IGIV-C versus 1.9% (11/575) with placebo. The most common adverse events with IGIV-C were headache, pyrexia, and hypertension.nnnINTERPRETATIONnThis study, the largest reported trial of any CIDP treatment, shows the short-term and long-term efficacy and safety of IGIV-C and supports use of IGIV-C as a therapy for CIDP.

Fatigue in immune-mediated polyneuropathies

Objectives: To determine the prevalence and severity of ongoing fatigue and to investigate the internal consistency, reliability, and validity of the Fatigue Severity Scale (FSS) in patients with immune-mediated polyneuropathies. Methods: The FSS was assessed in 113 patients who either experienced Guillain-Barré syndrome in the past or currently have a stable, chronic, inflammatory demyelinating polyradiculoneuropathy or a polyneuropathy associated with a monoclonal gammopathy of undetermined significance, and in 113 age- and sex-matched healthy controls. Data on four additional scales (Medical Research Council sumscore, functional grading scale [f-score], INCAT sensory sumscore, medical outcome study 36-items health survey [SF-36]) were obtained in all patients. SF-36 also was assessed in 59 controls. Results: “Severe” fatigue (FSS scores ≥95th percentile values in controls) was present in 80% of the patients. Fatigue was not significantly related to general strength, sensory deficits, f-score, and duration of symptoms. Severe fatigue was reported in 81% to 86% of patients with normal strength or sensation. Eighty percent of the patients (controls, 12%) reported their fatigue being among the three most disabling symptoms. SF-36 health status scores in the patient group were significantly lower than the obtained values of the controls and partially related to the FSS scores. Good internal consistency, significant reliability, and validity were obtained for the FSS. Conclusions: Fatigue is a major symptom in patients with immune-mediated polyneuropathies and may persist for years after apparent recovery. The Fatigue Severity Scale seems appropriate for assessing fatigue in these patients because good internal consistency, reliability, and validity were demonstrated.

Intraepidermal nerve fiber density and its application in sarcoidosis

Background: Intraepidermal nerve fiber density (IENFD) is considered a good diagnostic tool for small fiber neuropathy (SFN). Objectives: To assess stratified normative values for IENFD and determine the reliability and validity of IENFD in sarcoidosis. Methods: IENFD was assessed in 188 healthy volunteers and 72 patients with sarcoidosis (n = 58 with SFN symptoms, n = 14 without SFN symptoms). Healthy controls were stratified (for age and sex), resulting in 6 age groups (20–29, 30–39, … up to ≥70 years) containing at least 15 men and 15 women. A skin biopsy was taken in each participant 10 cm above the lateral malleolus and analyzed in accordance with the international guidelines using bright-field microscopy. Interobserver/intraobserver reliability of IENFD was examined. In the patients, a symptoms inventory questionnaire (SIQ; assessing SFN symptoms) and the Vickrey Peripheral Neuropathy Quality-of-Life Instrument-97 (PNQoL-97) were assessed to examine the discriminative ability of normative IENFD values. Results: There was a significant age-dependent decrease of IENFD values in healthy controls, with lower densities in men compared with women. Good interobserver/intraobserver reliability scores were obtained (κ values ≥0.90). A total of 21 patients with sarcoidosis had a reduced IENFD score (<5th percentile; 19 [32.8%] in patients with SFN symptoms, 2 [14.3%] in patients without SFN symptoms). The validity of the normative IENFD values was demonstrated by distinguishing between the SIQ scores and various PNQoL-97 values for the different patient groups. Conclusion: This study provides clinically applicable distal intraepidermal nerve fiber density normative values, showing age- and sex-related differences.

Physical training and fatigue, fitness, and quality of life in Guillain–Barré syndrome and CIDP

Many patients with Guillain–Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP) experience excessive fatigue, which may persist for years and reduce quality of life. The authors performed a 12-week study of bicycle exercise training in 20 patients with severe fatigue, 16 with relatively good recovery from GBS, and 4 with stable CIDP. Training seemed well tolerated, and self-reported fatigue scores decreased 20% (p = 0.001). Physical fitness, functional outcome, and quality of life were improved.

Psychometric evaluation of a new sensory scale in immune-mediated polyneuropathies

Objective: To perform a psychometric evaluation of the inflammatory neuropathy cause and treatment (INCAT) sensory sumscore (ISS) in sensory–motor immune-mediated polyneuropathies. This new sensory scale was evaluated to strive for uniformity in assessing sensory deficit in these disorders. Methods: The ISS comprises vibration and pinprick sense plus a two-point discrimination value and ranges from 0 (normal sensation) to 20 (maximum sensory deficit). Before its clinical use, a panel of expert neurologists concluded that the ISS has face and content validity. The construct validity of the ISS was investigated by correlation and regression studies with additional scales (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–Barré syndrome [GBS] in the past, 22 with chronic inflammatory demyelinating polyneuropathy [CIDP], 8 patients with a monoclonal gammopathy associated polyneuropathy), and 10 patients with recently diagnosed GBS or CIDP with changing clinical conditions. Reliability of the ISS was evaluated in the stable patients. Its responsiveness was investigated 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 ≤ 0.006; longitudinal group: R = 0.60 to 0.82, p ≤ 0.007, except for the association with the 10-Meter Walking Test [p = 0.08]). Acceptable internal consistency, and inter- and intraobserver reliability were demonstrated for the ISS (α = 0.68 to 0.87; R = 0.85 to 0.89, p < 0.0001). Standardized response mean scores for the ISS were high (≥0.8), indicating good responsiveness. Conclusions: All psychometric requirements are provided for the the inflammatory neuropathy cause and treatment sensory sumscore. The use of this scale is therefore suggested for bedside evaluation of sensory deficit in the individual patient with a sensory–motor immune-mediated polyneuropathy as well as in clinical trials.

Assessing grip strength in healthy individuals and patients with immune-mediated polyneuropathies.

Grip strength reference values for a portable dynamometer, the hand‐held Vigorimeter, were calculated, and its validity, reliability, and responsiveness were examined in patients with immune‐mediated polyneuropathies. We studied 530 healthy controls (age 5–93 years), 113 patients with stable polyneuropathy (83 with Guillain‐Barré syndrome [GBS], 22 with chronic inflammatory demyelinating polyneuropathy [CIDP], and 8 with a gammopathy‐associated polyneuropathy), and 20 patients with GBS or CIDP and changing clinical conditions (longitudinal group). An arm‐disability scale was also assessed. Grip‐strength reference values were calculated depending primarily on age and gender. Significant association was obtained between the Vigorimeter and the arm scale (in stable group, Spearman rank: r = −0.52 to −0.62; P ≤ 0.0005; in longitudinal group, linear regressions: r = 0.62–0.64, P < 0.0001). Good interobserver and intra‐observer agreements (analysis of variance, r = 0.95–0.97) and high responsiveness (standardized response mean scores ≥ 0.8) were demonstrated for the Vigorimeter. These results emphasize the clinical usefulness of the Vigorimeter, particularly in patients with immune‐mediated polyneuropathies.

Revised normative values for grip strength with the Jamar dynamometer

The Jamar dynamometer has been widely used in various chronic illnesses and has demonstrated its strength as a potential prognostic indicator. Various stratified normative values have been published using different methodologies, leading to conflicting results. No study used statistical techniques considering the non‐Gaussian distribution of the obtained grip strength (GS) values. Jamar GS was assessed in 720 healthy participants, subdivided into seven age decade groups consisting of at least 50 men and 50 women each. Normative values (median and fifth values) were calculated using quantile regressions with restricted cubic spline functions on age. Possible confounding personal factors (hand dominance, length, weight, hobby, and job categorization) were examined. Clinically applicable revised normative values for the Jamar dynamometer, stratified for age and gender, are presented. Hand dominance had no influence. Other personal factors only minimally influenced final values. This study provides revised normative GS values for the Jamar dynamometer.

Timing and Course of Clinical Response to Intravenous Immunoglobulin in Chronic Inflammatory Demyelinating Polyradiculoneuropathy

OBJECTIVEnTo investigate the timing, course, and clinical characteristics of the response to intravenous immunoglobulin in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).nnnDESIGNnData were extracted from the ICE trial, a randomized, double-blind, placebo-controlled trial of immune globulin intravenous, 10% caprylate/chromatography purified (IGIV-C).nnnSETTINGnMultiple international centers.nnnPARTICIPANTSnOne hundred seventeen individuals with CIDP. Intervention Treatment with IGIV-C (Gamunex, n = 59) or placebo (n = 58), with IGIV-C administered as a 2-g/kg loading dose followed by a 1-g/kg maintenance dose every 3 weeks, for up to 24 weeks.nnnMAIN OUTCOME MEASURESnThe primary efficacy parameter was an improvement of 1 or more points in adjusted Inflammatory Neuropathy Cause and Treatment (INCAT) disability score. Participants treated with IGIV-C were divided into subgroups based on meeting responder vs nonresponder definitions and by time to first improvement.nnnRESULTSnAmong 30 responders to IGIV-C, 14 (47%) patients had improved adjusted INCAT scores by week 3, and 16 (53%) patients improved at week 6 after a second infusion. Participants who improved by week 3 were more severely disabled at baseline than those who improved at 6 weeks. In patients who improved, the number of individuals reaching maximal improvement continued to increase during maintenance therapy for up to 24 weeks. For patients with first improvement by week 3, the change in dominant-hand grip strength over time tended to parallel the INCAT score. In patients with first improvement by week 6, however, the improvement in dominant-hand grip strength preceded initial improvement in INCAT score.nnnCONCLUSIONSnData suggest that treatment with 2 courses of IGIV-C administered 3 weeks apart may be required for initial improvement, and continued maintenance therapy may be necessary to achieve a maximal therapeutic response. Trial Registration clinicaltrials.gov Identifier: NCT00220740.

Quality of life complements traditional outcome measures in immune-mediated polyneuropathies

ObjectivesTo determine whether quality of life complements traditional outcome measures in immune-mediated polyneuropathies using the Medical Outcome Study 36-item short-form health status scale (SF-36). The validity, reliability, and responsiveness of the SF-36 were also analyzed. MethodsSF-36 and three other measures (Medical Research Council sumscore, sensory sumscore, and Hughes functional scale) were assessed in 114 stable patients (83 with Guillain–Barré syndrome (GBS), 23 with chronic inflammatory demyelinating polyneuropathy (CIDP), eight with a gammopathy-related polyneuropathy) and serially in 20 patients with recently diagnosed GBS (n = 7) or CIDP (n = 13) with changing conditions. The SF-36 values were compared with reported healthy Dutch community scores (controls). The SF-36 validity and reliability were examined by correlation and regression studies with the other measures and by calculating its internal consistency. The standardized response mean and effect size techniques were applied to determine its responsiveness. ResultsIn the stable group, all SF-36 scores were substantially lower (indicating worse clinical condition) compared with control subjects (p < 0.0001). Improvement in the longitudinal group resulted in a gradual shift of all SF-36 scores toward normal values. Acceptable validity and internal consistency values and moderate to good standardized response mean and effect size scores were demonstrated for the SF-36. The Medical Research Council sumscore and sensory sumscore explained SF-36 values only partially. ConclusionThe SF-36 as a generic health status complemented traditional strength and sensory measures in patients with immune-mediated polyneuropathies and appears to be a potentially valuable instrument for measuring quality of life in these conditions.

Treatment of multifocal motor neuropathy with interferon-β1A

Article abstract Nine patients with multifocal motor neuropathy who had previously responded favorably to IV immunoglobulins (IVIg) were treated with interferon-β1a. Muscle strength and disability were evaluated. In six patients there was no effect of treatment. Four patients deteriorated in such a way that IVIg had to be restarted during the study. Three patients showed an improvement that was more pronounced than on IVIg. These patients had a shorter disease duration and were less affected clinically and electrophysiologically than those who did not respond.