Patients with chronic autoimmune demyelinating polyneuropathies exhibit cognitive deficits which might be associated with CSF evidence of blood-brain barrier disturbance

Patient Experience of Chronic Inflammatory Demyelinating Polyneuropathy (CIDP): A Qualitative Exploration of Signs, Symptoms, and Health-Related Quality of Life Impacts

INTRODUCTION

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare type of autoimmune neuropathy, characterized by signs of distal and proximal weakness of the upper and lower limbs, sensory dysfunction, absent or diminished tendon reflexes, and symptoms of numbness, tingling, pain, and fatigue. These signs/symptoms can lead to difficulty walking, climbing stairs, and reduced manual dexterity. Detailed qualitative exploration of the patient experience of CIDP, notably signs/symptoms, its impacts on health-related quality of life, and treatment experience is limited. Qualitative patient experience data is recommended by regulatory bodies to inform patient-focused drug development. This study aimed to qualitatively explore the experience of CIDP from the patient and clinician perspectives.

METHODS

Qualitative concept elicitation telephone interviews were conducted with adult patients with a confirmed diagnosis of CIDP and with neurologists experienced in diagnosing and treating patients with CIDP from the USA. Interview transcripts were analyzed using thematic analysis methods, and findings informed development of a conceptual model.

RESULTS

Overall, 15 patients with CIDP and 10 neurologists were interviewed. A total of 19 signs/symptoms were identified as important and relevant, of which weakness, fatigue, loss of balance, tingling, numbness, pain, and loss of coordination were most frequently reported by patients and neurologists. Except for loss of coordination, these signs/symptoms were also considered most salient to patients. Patients identified fatigue as the most bothersome symptom and weakness and fatigue as the most important to treat. CIDP impacted health-related quality-of-life (HRQoL), including physical functioning (e.g., walking difficulties), activities of daily living (e.g., difficulty with personal care), work (e.g., being unable to work), emotional wellbeing (e.g., depression), social wellbeing (e.g., participation in social/leisure activities), sleep (e.g., difficulty falling asleep), and cognition (e.g., brain fog). Patients reported that current CIDP treatments lacked effectiveness in treating specific symptoms, caused unwanted side effects, and impacted their independence.

CONCLUSIONS

Findings contribute novel and detailed qualitative insights into the key signs/symptoms of CIDP and the profound impact of these on patients' HRQoL from both the patient and clinician perspectives. Findings can be used to identify treatment targets and support selection of appropriate clinical outcome assessments for the evaluation of CIDP symptoms and HRQoL impacts in future CIDP clinical trials.

Comparative analysis of albumin quotient and total CSF protein in immune-mediated neuropathies: a multicenter study on diagnostic implications

Introduction

Blood-cerebrospinal fluid (CSF) barrier dysfunction is pivotal for diagnosing immune-mediated neuropathies, especially in spinal nerve root inflammation. Typically, either total CSF protein or the CSF to serum albumin ratio (QAlb) is measured. Total CSF protein measurements have limitations, notably its fixed reference value regardless of age, in contrast to the age-dependent reference for QAlb. Our goal was to evaluate both markers in patients with immune-mediated neuropathies.

Methods

In our multicenter research, we collected retrospective CSF data from patients suffering from immune-mediated neuropathies across four German research centers. These parameters were analyzed in relation to their clinical characteristics.

Results

Out of 419 samples, 36 (8.6%) displayed a notable variation between total CSF protein and QAlb values. A detailed analysis revealed that patients displaying elevated QAlb but normal total CSF protein levels were significantly younger at disease onset (p = 0.01), at the time of diagnosis (p = 0.005), and when undergoing lumbar puncture (p = 0.001) compared to patients with elevated CSF protein and normal QAlb levels. These effects were especially evident for the subgroup of samples derived by female patients.

Discussion

Our work confirms the crucial role of QAlb in diagnosing immune-mediated neuropathies and particularly its efficacy as a marker for evaluating the blood-CSF barrier in patients with an earlier disease onset. Considering the significance of the albumin quotient, its assessment is especially advisable in younger patients of female sex to avoid missing a potential barrier dysfunction that might be falsely negative when using total protein.

Theory of mind and executive dysfunction in chronic inflammatory demyelinating polyneuropathy

BACKGROUND AND PURPOSE

Although chronic inflammatory demyelinating polyneuropathy (CIDP) is understood as a disease affecting the peripheral nervous system, mild cognitive dysfunction, particularly in the executive domain, has been described to form part of the condition. Here our interest lay in CIDP-related theory of mind (ToM) capacities as an aspect of social cognition relevant for many aspects of everyday life.

METHODS

Twenty-nine patients with CIDP and 23 healthy controls participated in this study. They were subjected to overview cognitive testing, different executive function (EF) tasks, as well as to the Faux Pas Recognition Task (FPRT) for assessing cognitive ToM and the Reading the Mind in the Eyes Test (RMET) with respect to affective ToM.

RESULTS

Persons with CIDP and controls did not differ with respect to their overall cognitive state. However, in the German verbal fluency standard, the digit span forward and the digit span backward tests used as EF tasks patients performed significantly worse than controls. Further, performance was abnormally low in the FPRT, whilst the groups did not differ with respect to RMET results. The FPRT and digit span backward results correlated with each other.

CONCLUSIONS

Patients with CIDP showed deficits in cognitive ToM performance together with EF dysfunction, whilst affective ToM was preserved. Altogether, the results suggest that low cognitive ToM capacities in patients with CIDP arise as a particular aspect of disease-related executive dysfunction.

Chronic Inflammatory Demyelinating Polyneuropathy With Reversible Severe Cognitive Impairment and Gastrointestinal Dysfunction

We treated a patient with an unusual case of reversible rapidly progressive cognitive impairment, gastrointestinal dysfunction, and generalized neuromyopathy in chronic inflammatory demyelinating polyneuropathy (CIDP) with optic neuropathy. A man in his 50s presented with a four-month history of rapidly progressive cognitive decline in addition to a six-month history of proximal greater than distal painful muscle weakness, wasting in all extremities, almost complete loss of deep tendon reflexes in his lower extremities, and slow progressive vision loss. Additionally, he had a 90-pound weight loss over the past two years with loss of appetite and ongoing chronic diarrhea. The exam showed muscle weakness and wasting with absent deep tendon reflexes. Initial Saint Louis University Mental Status (SLUMS) exam score was 16/30. Visual acuity was 20/25 with full extraocular movements; optical coherence tomography revealed superior arcuate bundle thinning bilaterally. Gastrointestinal workup proved nonrevealing. Serologic studies for vitamin deficiencies, heavy metals, and autoantibodies were negative. Whipple, Giardia lamblia, and Campylobacter jejuni stool testing were negative. Imaging studies were unremarkable. Nerve conduction studies showed demyelinating sensorimotor peripheral neuropathy. Muscle biopsy was indicative of denervation with scattered myopathic changes; no evidence of inflammatory myopathy nor glycogen or mitochondrial abnormalities was seen. Intravenous immunoglobulin treatment was begun. The patient was started at a dose of 0.75g/kg every three weeks. Following good but incomplete clinical improvement after the first treatment, his dose was increased to 1g/kg every three weeks. He improved remarkably after four months of infusions, scoring 30/30 on SLUMS with a full return of muscle strength and reflexes. Diarrhea remitted. Visual acuity and conduction delay remained unchanged. Symptom timing and dramatic response to immunoglobulins suggest a common immunological mechanism. In light of extensive differential investigations, unremarkable imaging and serology, and no other systemic disease processes, this case plausibly represents a potential new CIDP phenotypic variant.

Chronic inflammatory demyelinating polyneurophaty: assessment of the cognitive function and quality of life

BACKGROUND

Studies were carried out with the objective of evaluating the quality of life (QoL) of patients affected by chronic inflammatory demyelinating polyradiculopathy (CIDP). However, the cognitive issue is still little addressed.

OBJECTIVES

To assess the QoL and cognitive impairment of patients with CIDP and to analyze whether there is a correlation between these parameters.

METHODS

Seven patients with CIDP and seven paired controls were subjected to: mini-mental state examination (MMSE); Montreal cognitive assessment (MoCA); digit symbol replacement/symbol copy test (DSST); fatigue severity scale (FSS); Beck depressive inventory-I (BDI-I), and a short-form of health survey (SF-36).

RESULTS

The mean age of the participants was 50 years (71.4% male). The MMSE and MoCA had no statistical difference between the groups. Patients showed superior results in the memory domain in the MoCA (5 vs. 2, p = 0.013). In the DSST, we observed a tendency for patients to be slower. There was a strong negative correlation between fatigue levels and vitality domain (SF-36). There was no significant correlation between depression levels and QoL, and there was no correlation between depression and the results obtained in the cognitive tests. The patients presented higher levels of depression (15.28 vs. 3.42, p < 0.001). A total of 57% had severe fatigue, 28.8% self-reported pain, and 57.1% complained of cramps.

CONCLUSION

There was no cognitive impairment in these patients. However, there was a tendency of slower processing speed. To better evaluate the alterations found, a study with a larger number of individuals would be necessary. Chronic inflammatory demyelinating polyradiculopathy affects the QoL of patients in different ways.

Processing speed impairment in chronic inflammatory demyelinating polyneuropathy patients: a cross-sectional study

BACKGROUND

There is a lack of evidence of cognitive involvement in chronic inflammatory demyelinating polyneuropathy (CIDP) and, the reports about the involvement of the brain and central nervous system (CNS) are few and controversial. The Five Digit Test (FDT) evaluates processing speed (PS) and executive functions orally.

OBJECTIVE

To evaluate the performance on the FDT of CIDP patients with and without CNS (brain/cerebellum) alterations observed on brain Magnetic Resonance Imaging (MRI) scans.

METHODS

The Hospital Anxiety and Depression Scale (HADS, to assess neuropsychiatry symptoms), the Rasch-built Overall Disability Scale (R-ODS; to assess disability), and the FDT (to assess cognition) were applied to 14 CIDP patients and 24 age-matched healthy control subjects. The patients were submitted to routine brain MRI and, according to the results, they were divided into two groups: those with abnormalities on the MRI (CIDPabnl) and those with normal parameters on the MRI (CIDPnl). The FDT data of five CIDPnl patients and nine CIDPabnl subjects were analyzed. Comparisons between the groups were performed for each task of the FDT.

RESULTS

We found statistical differences for both groups of CIDP patients in terms of PS, for the patients spent more time performing the PS tasks than the controls. The PS measures were negatively associated with disability scores (reading: r = -0.47; p = 0.003; counting: r = -0.53; p = 0.001).

CONCLUSIONS

Our data suggested the presence of PS impairment in CIDP patients. Disability was associated with slow PS.

Impact of psychiatric distress and physical disability on quality of life in neuromyelitis optica spectrum disorder and chronic autoimmune demyelinating polyneuropathies

BACKGROUND

Determinants of quality of life (QoL) in demyelinating disorders have been investigated predominantly for multiple sclerosis, especially with regard to "soft clinical signs" such as psychiatric distress. In this exploratory study, we aimed to identify common determinants of QoL for both central and peripheral demyelination in the understudied disease entities of neuromyelitis optica spectrum disorder (NMOSD) and chronic autoimmune demyelinating polyneuropathy (CADP).

METHODS

20 NMOSD and 16 CADP patients were evaluated for physical disability (EDSS and INCAT ODSS), cognitive dysfunction (neuropsychological test battery), psychiatric distress (SCL-90-R), depression (BDI), fatigue (FSMC) and quality of life (EQ-5D-3 L). A linear regression with QoL as a dependent variable and clinical parameters and demographic covariates as independent variables was computed. Additionally, a multivariate analysis of variance was computed to investigate whether NMOSD and CADP differed with regard to QoL and clinical parameters.

RESULTS

Physical disability and psychiatric distress affected QoL in both NMOSD and CADP with a stronger effect for psychiatric distress in comparison to physical disability, as indicated by the higher standardized beta coefficient for psychiatric distress (b = -0.540; p = 0.002 vs. b = -0.614; p = 0.028). NMOSD reported higher subjective well-being than CADP patients (F = 6.845, p = 0.015) while having similar physical disability, cognitive dysfunction, psychiatric distress, depression and fatigue and after having accounted for the influence of age, gender, education and disease duration.

CONCLUSIONS

Our findings suggest that physical disability and psychiatric distress above all clinical factors affect QoL in patients with NMOSD and CADP. Addressing adequately this aspect in demyelinating diseases would contribute to a better QoL in these patients. Furthermore, higher subjective well-being scores for NMOSD than CADP might be attributable to the distinct immunomodulatory therapy regimens and course (relapse-driven vs. chronic) of the two diseases.