Clinical correlates of fatigue in chronic inflammatory demyelinating polyneuropathy

Symptom and Treatment Satisfaction in Members of the US and Canadian GBS/CIDP Foundations with a Diagnosis of Chronic Inflammatory Demyelinating Polyneuropathy

INTRODUCTION

Current guidelines for defining good outcomes in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) are predominately defined by experts. At present, we do not have a patient-anchored definition of what constitutes a "good" outcome. Our study aimed to assess the symptom burden of people living with CIDP, as well as satisfaction with treatments and clinical outcomes.

METHODS

We conducted an online-survey in CIDP patients registered with the US and Canadian GBS/CIDP foundations. Respondents answered general demographic and clinical questions, as well as satisfaction with current symptom burden and treatments, plus validated outcome measures.

RESULTS

A total of 318 individuals with self-reported CIDP completed the online survey, of whom 128 (40%) considered their current disease burden as satisfactory while 190 (60%) did not. Of 305 patients who answered the treatment satisfaction question, 222(74%) were satisfied with their treatments. Patients who were satisfied with their current symptoms had, on average, better scores in quality of life and disease severity scales, although regression modeling showed that only ability to walk, stable symptoms, and health utility scores were associated with symptom satisfaction. Treatment satisfaction was associated with stable symptoms, use of IVIG, and use of one versus no medication.

CONCLUSIONS

A high proportion of members of the US and Canadian GBS/CIDP Foundations reporting a diagnosis of CIDP were unsatisfied with current symptoms, despite a high level of overall satisfaction with treatments. There is an unmet need for improving long-term outcomes in people with a diagnosis of CIDP, and for studying patient-centered long-term treatment goals.

Impact of social-functioning and sleep on quality of life in chronic inflammatory demyelinating polyneuropathy

INTRODUCTION/AIMS

The impact of impairment of social functioning and sleep on health-related quality of life (HR-QoL), is unknown in chronic inflammatory demyelinating polyneuropathy (CIDP). The value of the Chronic Acquired Polyneuropathy Patient-Reported Index (CAP-PRI) to identify potential social functioning and sleep issues is equally unknown.

METHODS

We performed a cross-sectional evaluation of social functioning and sleep using the "Scales for Outcomes in Parkinson's Disease" (SCOPA) in 40 subjects with clinically-stable CIDP through a structured questionnaire. We assessed HR-QoL through the CAP-PRI. Disability was evaluated through the Overall Neuropathy Limitation Score (ONLS).

RESULTS

SCOPA social functioning scores were impaired at least "a little" per averaged item in > 50 % of subjects, and at least "quite a bit" per averaged item in > 20 %. Most affected items were (i) difficulty with work/household/other chores (ii) difficulties with hobbies/sport/leisure activities. SCOPA sleep sub-scores indicated at least "a little concern" for night-time sleep in nearly 50 % of subjects. Abnormal sleep timing was rare. Associations were found between both SCOPA social-functioning and SCOPA sleep scores and the CAP-PRI. Linear regression demonstrated the SCOPA social-functioning score was independently associated with the CAP-PRI. The CAP-PRI showed high association with disability scores, good internal consistency, absence of ceiling effect, absence of significant floor-effect, and good criteria-related as well as construct-related validity.

DISCUSSION

Social functioning and night-time sleep are frequently affected in CIDP and impact on HR-QoL. In contrast to traditional disability scales, the CAP-PRI additionally allows adequately capturing these impairments and may represent an adequate holistic outcome measure.

Fatigue, depression, and product tolerability during long-term treatment with intravenous immunoglobulin (Gamunex® 10%) in patients with chronic inflammatory demyelinating polyneuropathy

INTRODUCTION/AIMS

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is characterized by progressive weakness and sensory loss, often affecting patient's ability to walk and perform activities of daily living independently. Furthermore, patients often report fatigue and depression which can affect their quality of life. These symptoms were assessed in CIDP patients receiving long-term intravenous immunoglobulin (IVIG) treatment.

METHODS

GAMEDIS was a multi-center, prospective, non-interventional study in adult CIDP patients treated with IVIG (10%) and followed for two years. Inflammatory Neuropathy Cause and Treatment (INCAT) disability score, Hughes Disability Scale (HDS), Fatigue Severity Scale (FSS), Beck Depression Inventory II (BDI), Short Form-36 health survey (SF-36) and Work Productivity and Activity Impairment Score Attributable to General Health (WPAI-GH) were assessed at baseline and quarterly. Dosing and treatment intervals, changes in outcome parameters, and adverse events (AEs) were analyzed.

RESULTS

148 evaluable patients were followed for a mean of 83.3 weeks. The mean maintenance IVIG dose was 0.9 g/kg/cycle (mean cycle interval 38 days). Disability and fatigue remained stable throughout the study. Mean INCAT score: 2.4 ± 1.8 at baseline and 2.5 ± 1.9 at study end. HDS: 74.3% healthy/minor symptoms at baseline and 71.6% at study end. Mean FSS: 4.2 ± 1.6 at baseline and 4.1 ± 1.7 at study end. All patients reported minimal/no depression at baseline and throughout. SF-36 and WPAI-GH scores remained stable. Fifteen patients (9.5%) experienced potentially treatment-related AEs. There were no AEs in 99.3% of infusions.

DISCUSSION

Long-term treatment of CIDP patients with IVIG 10% in real-world conditions maintained clinical stability on fatigue and depression over 96 weeks. This treatment was well-tolerated and safe.

Contemporary challenges in the diagnosis and management of chronic inflammatory demyelinating polyneuropathy

INTRODUCTION

Despite extensive research, multiple inter-related diagnostic and management challenges remain for chronic inflammatory demyelinating polyneuropathy (CIDP).

AREAS COVERED

A literature review was performed on diagnosis and treatment in CIDP. The clinical features and disease course were evaluated. Investigative techniques, including electrophysiology, cerebrospinal fluid examination, neuropathology, imaging and neuroimmunology, were considered in relation to technical aspects, sensitivity, specificity, availability and cost. Available evidenced-based treatments and those with possible efficacy despite lack of evidence, were considered, as well as current methods for evaluation of treatment effects.

EXPERT OPINION

CIDP remains a clinical diagnosis, supported first and foremost by electrophysiology. Other investigative techniques have limited impact. Most patients with CIDP respond to available first-line treatments and immunosuppression may be efficacious in those who do not. Consideration of the natural history and of the high reported remission rate, of under-recognised associated disabling features, of treatment administration modalities and assessment methods, require enhanced attention.

What is in the Literature

This edition of What is in the Literature focuses on chronic immune neuropathies as they represent treatable conditions. There are formal criteria to solidify the diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), but patients are encountered who have clinical and electrodiagnostic features of CIDP but do not fulfill diagnostic criteria. These patients are addressed in recent publications. CIDP (and variants) and other forms of immune-mediated neuropathies (multifocal motor neuropathy) are responsive early on to treatment, but long-term factors are less well described, and a number of publications focus on extended consequences. Acute immune neuropathies have been described in the setting of viral illness, and recent publications look at the question as to whether they are associated with the COVID-19 pandemic. Finally, idiopathic sensory neuropathies are the most common polyneuropathy, and consensus efforts to codify features into subtypes can be used clinically for a more precise diagnosis.

Patient perceptions of outcome measures in chronic inflammatory demyelinating polyneuropathy: A study of the Inflammatory Rasch-built Overall Disability Scale

BACKGROUND

Patients' perceptions of outcome measures used in chronic inflammatory demyelinating polyneuropathy (CIDP) are unknown.

METHODS

We performed a cross-sectional evaluation of patient perceptions of the Inflammatory Rasch-built Overall Disability Scale (I-RODS) from 41 subjects with CIDP through a structured questionnaire. We assessed perceived hesitation to provide a response, item importance and relevance, understanding of specific items and factors affecting responses.

RESULTS

Hesitation to provide a categorical answer was reported by 20% of subjects or more, for 5/24 (20.8%) items. Uncertainty was most frequent for "travel by public transport" (22.4%) and "catch an object (e.g., ball)" (24%). Six of 24 (25%) items were perceived as unimportant to their disease by at least a third of participants. Items most commonly perceived as unimportant were "travel by public transport" in 53.7%, "catch an object (e.g., ball)" in 61% and "dance" in 65.9%. Several items were frequently perceived as irrelevant. These included "move a chair" (39%), "do the dishes" (46.3%), "catch an object (e.g., ball)" (61%), "travel by public transport" (68.3%) and "stand for hours" (82.9%). The understanding of multiple items such as "read a book", "sit on a toilet" and "take a shower" was found to be highly variable. Fatigue was perceived more commonly than mood (53.7% vs. 17.1%, p = 0.001), and more commonly in younger subjects (p = 0.037), as influencing responses to the I-RODS.

CONCLUSIONS

Patient-perceived uncertainty, unimportance, irrelevance and poor understanding of items, as well as fatigue and mood, impact on the value of the I-RODS. Greater emphasis on individualized disability assessments requires consideration in future.

Prospective analysis of disability and quality of life in patients with chronic inflammatory demyelinating polyradiculoneuropathy

PURPOSE

Even treated chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) continues to pose a significant burden in patients' everyday functioning and may continuously affect their quality of life (QoL). The aims of our prospective study were to analyze health-related QoL in CIDP patients during a 1-year follow-up period in real-life settings and to compare QoL changes with changes in disability and with patient impression of change.

METHODS

The study comprised 59 patients diagnosed with CIDP. SF-36 questionnaire was applied in order to evaluate patients' QoL. Inflammatory neuropathy cause and treatment (INCAT) disability scale was used to assess patients' functionality. The second question from the SF-36 questionnaire was used as an estimation of the patient impression of change (PIC) after 1 year.

RESULTS

SF-36 scores did not change over time in the group as a whole. According to INCAT disability scores, worsening was registered in 24 (40%) patients and improvement in 8 (14%). Fifteen (25%) patients reported worsening and the same number reported improvement, according to PIC. Concordant results on INCAT and PIC were registered in 49% of patients. Pooled SF-36 scores moderately correlated with pooled INCAT disability scores (rho = - 0.27 to - 0.59, p < 0.01). One-year changes of SF-36 scores did not differ when compared to different INCAT outcomes (worsening, stable, improvement). On the other hand, significant changes of SF-36 scores in different outcome groups according to PIC (worsening, stable, improvement) were noted (p < 0.01).

CONCLUSION

INCAT, PIC, and SF-36 are complementary outcome measures that provide neurologists with useful items of information. We propose complementary use of these scales in CIDP patients in everyday clinical practice in order to detect worsening of the disease and/or of related symptoms on time.

Peripheral nerve electrophysiology studies in relation to fatigue in patients with chronic inflammatory demyelinating polyneuropathy

OBJECTIVE

To explore the relationship between fatigue, standard electrophysiological parameters and number and size of functioning motor units in patients with chronic inflammatory demyelinating polyneuropathy (CIDP).

METHODS

Experienced fatigue was assessed using the linearly-weighted, modified Rasch-built fatigue severity scale (R-FSS) and the multidimensional Checklist of Individual Strength (CIS). Averaged electrophysiology values were calculated from multiple nerves. Motor Unit Number Index (MUNIX) technique was utilised to assess motor unit function. Assessments were repeated in 15 patients receiving regular intravenous immunoglobulin therapy, with changes in parameters calculated.

RESULTS

R-FSS and CIS scores did not correlate MUNIX or MUSIX sum scores from 3 different muscles. Inverse correlation was observed only between distal CMAP area and R-FSS but not CIS scores. However, changes in distal CMAP area and R-FSS scores on repeat assessment were not correlated.

CONCLUSIONS

Experienced fatigue does not appear to correlate with loss of functioning motor units in patients with CIDP. Changes in experienced fatigue on repeat assessment did not correlate with changes in any of the electrophysiological parameters, suggesting fatigue experienced in CIDP is not strongly correlated with peripheral nerve dysfunction.

SIGNIFICANCE

Nerve conduction studies and MUNIX values do not appear to be useful surrogate markers for fatigue in CIDP.