Age matters: Impact of data-driven CSF protein upper reference limits in Guillain-Barré syndrome

Prognostic Implications of Early Albuminocytological Dissociation in Guillain-Barré Syndrome

BACKGROUND

Half of Guillain-Barré syndrome (GBS) present elevated cerebrospinal fluid (CSF) protein levels within 1 week since symptom onset and 80% within 2 weeks. Our objective was to determine the clinical and prognostic implication of albuminocytological dissociation in early GBS.

METHODS

An ambispective cohort study was conducted. Good outcome was considered if the patient was able to walk unaided (Guillain-Barré disability score [GDS] ≤ 2 points) at 3-month follow-up. Patients were classified into two groups: with and without albuminocytological dissociation; we compared clinical and paraclinic characteristics between the groups. We analyzed clinical and electrophysiological factors related to presenting early dissociation through a multivariate model.

RESULTS

We included 240 patients who fulfilled Asbury criteria for GBS. On further selection, only 94 patients fulfilled inclusion. Mean age was 45.94 ± 17.1 years and 67% were male. Median time from symptom onset to admission was 5 days (IQR 3-6). Regarding albuminocytological dissociation and electrophysiological variants, we found a significant difference: acute inflammatory demyelinating polyneuropathy (AIDP) [60.6% vs 26.2%, p = 0.002], acute motor axonal neuropathy (AMAN) [21.2% vs 49.1%, p = 0.009] and acute motor sensory axonal neuropathy (AMSAN) [12.1% vs 1.6%, p = 0.05]. We did not observe significant differences in recovery of independent walking in short term between both groups. The presence of conduction block in any variant (OR 3.21, 95% CI 1.12-9.16, p = 0.02) and absence of sural registration (OR 5.69, 95% CI 1.48-21.83, p = 0.011) were independent factors related to early dissociation.

CONCLUSIONS

Early dissociation (<7 days) is not associated with any particular clinical feature or unfavorable outcome. It is more common to see in AIDP rather than axonal variants.

CSF Findings in Relation to Clinical Characteristics, Subtype, and Disease Course in Patients With Guillain-Barré Syndrome

BACKGROUND AND OBJECTIVES

To investigate CSF findings in relation to clinical and electrodiagnostic subtypes, severity, and outcome of Guillain-Barré syndrome (GBS) based on 1,500 patients in the International GBS Outcome Study.

METHODS

Albuminocytologic dissociation (ACD) was defined as an increased protein level (>0.45 g/L) in the absence of elevated white cell count (<50 cells/μL). We excluded 124 (8%) patients because of other diagnoses, protocol violation, or insufficient data. The CSF was examined in 1,231 patients (89%).

RESULTS

In 846 (70%) patients, CSF examination showed ACD, which increased with time from weakness onset: ≤4 days 57%, >4 days 84%. High CSF protein levels were associated with a demyelinating subtype, proximal or global muscle weakness, and a reduced likelihood of being able to run at week 2 (odds ratio [OR] 0.42, 95% CI 0.25-0.70; p = 0.001) and week 4 (OR 0.44, 95% CI 0.27-0.72; p = 0.001). Patients with the Miller Fisher syndrome, distal predominant weakness, and normal or equivocal nerve conduction studies were more likely to have lower CSF protein levels. CSF cell count was <5 cells/μL in 1,005 patients (83%), 5-49 cells/μL in 200 patients (16%), and ≥50 cells/μL in 13 patients (1%).

DISCUSSION

ACD is a common finding in GBS, but normal protein levels do not exclude this diagnosis. High CSF protein level is associated with an early severe disease course and a demyelinating subtype. Elevated CSF cell count, rarely ≥50 cells/μL, is compatible with GBS after a thorough exclusion of alternative diagnoses.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that CSF ACD (defined by the Brighton Collaboration) is common in patients with GBS.

Looks Like Neurosyphilis, Feels Like Guillain-Barre: At the Confluence of Infection and Immunology

We present a 51-year-old male, with a past medical history of type 2 insulin-dependent diabetes mellitus (T2IDDM) without neuropathy, coronavirus disease 2019 (COVID-19) in April 2020 without residual symptoms, Raynaud's, and recent occupational outdoor exposure to insects as a construction manager who came to the emergency room complaining of a three-week history of bilateral progressive numbness and weakness beginning in his lower extremities and ascending toward his pelvis. Notably, he received the second dose of his Moderna COVID-19 vaccine one week prior to symptom onset and four weeks prior to admission. He also reported a recent appearance of a maculopapular rash on his upper extremities and flanks. Physical exam was remarkable for bilateral distal motor weakness in the upper and lower extremities with associated paresthesia and decreased reflexes in the lower extremities. The patient had slight ataxia and difficulty with heel walk and toe walk. Notably, the cranial nerve exam was normal, and the patient was afebrile. Intravenous immune globulin (IVIG) was started empirically for the treatment of Guillain-Barre syndrome (GBS), and doxycycline 100mg intravenous twice a day and ceftriaxone 2g intravenous daily were started for possible tick-borne disease. Subsequently, rapid plasma reagin (RPR) returned reactive at 1:64, and cerebral spinal fluid (CSF) venereal disease research laboratory (VDRL) test was reactive at 1:2 with markedly elevated protein and pleocytosis. Human immunodeficiency virus (HIV) testing was negative. Lyme disease testing was negative. Nerve conduction studies (NCS) and electromyography (EMG) showed a sensorimotor polyneuropathy with mixed demyelinating and axonal features. IVIG was continued for a total of five days, and antibiotics were changed to penicillin G (PCN G) for a total of 14 days for definitive treatment of early neurosyphilis (NS). While both clinical and laboratory findings confirm a positive diagnosis of NS, the patient’s CSF composition showed very elevated total protein levels and pleocytosis. Additionally, his early peripheral neuropathy and EMG findings are not characteristics of a single disease and, instead, suggested a mixed pathology. We postulate that this patient had confirmed secondary syphilis with early NS associated with, and possibly correlated with, a simultaneous episode of acute inflammatory demyelinating polyneuropathy (AIDP) and/or a vaccine-related phenomenon.

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.

Cerebrospinal fluid analysis in Guillain-Barré syndrome: value of albumin quotients

Background

Albuminocytologic dissociation in cerebrospinal fluid (CSF) is a diagnostic hallmark of Guillain–Barré syndrome (GBS). Compared to CSF total protein (TP), the CSF/serum albumin quotient (Qalb) has the advantage of method-independent reference ranges. Whether the diagnostic yield differs between Qalb and CSF-TP is currently unknown.

Methods

We retrospectively analyzed the diagnostic yield (i.e., a value above the URL indicating blood–nerve barrier dysfunction) of Qalb and CSF-TP levels in patients with GBS. We evaluated two different equations (Reiber’s and Hegen’s) for age-adjusted URLs of Qalb and compared results to CSF-TP using the standard URL of 0.45 g/L as well as age-adjusted URLs (by decade of age). Additionally, multivariable logistic regression analysis was used to assess the effect of clinical factors on the diagnostic yield.

Results

We analyzed 110 patients [62% males; median age 48 (IQR 35–58)] with sensorimotor (68), motor (16), sensory (12) and localized (8) GBS as well as Miller Fisher syndrome (6).

Qalb and CSF-TP were highly correlated (r = 0.95, p < 0.001). The diagnostic yield of Qalb was 65% with Reiber’s and 47% with Hegen’s age-adjusted URLs compared to 66% with the fixed CSF-TP URL of 0.45 g/L and 49% with age-adjusted CSF-TP URLs. A longer duration from clinical onset to lumbar puncture was associated with a higher diagnostic yield.

Conclusion

Qalb strongly correlates with CSF-TP in patients with GBS with a similar diagnostic yield for the detection of a blood–nerve barrier dysfunction. However, the diagnostic yield of both values is lower when using more recent age-adjusted URLs and at earlier timepoints.

Cerebrospinal fluid protein in Guillain-Barré syndrome: Need for age-dependent interpretation

BACKGROUND AND PURPOSE

Elevated cerebrospinal fluid (CSF) total protein in patients with acute ascending paresis is indicative of Guillain-Barré syndrome (GBS). Recent studies showed that the outdated, but still widely used upper reference limit (URL) for CSF total protein of 0.45 g/L leads to false-positive results, mainly as a result of lack of age-adjustment. The objective of this study was to assess the frequency of increased CSF total protein in adult GBS patients according to a new age-dependent URL.

METHODS

Patients with GBS treated at the Medical University of Innsbruck between 2000 and 2018 were included in this study. Demographic, clinical, electrophysiological and CSF data were obtained from patients' medical charts. Frequency of increased CSF total protein depending on disease duration was compared using the conventional URL of 0.45 g/L and the age-dependent URL.

RESULTS

Ninety-seven patients with GBS aged 57 ± 18 years, comprising 38% women, underwent CSF sampling within a median of 6 days after symptom onset. The median CSF total protein concentration was 0.65 g/L and correlated with disease duration. Overall, 74% of patients had elevated CSF total protein levels using the conventional URL, as opposed to 52% applying the age-dependent URL. At 0-3, 4-7, 8-14 and >14 days after disease onset, elevated CSF total protein was found in 46%, 84%, 78% and 100% of patients using the conventional URL, and in 32%, 53%, 65% and 64% of patients using the age-dependent URL. In multivariate analysis, significant predictors of elevated CSF total protein were disease duration and the demyelinating GBS variant. Similar results were obtained for CSF/serum albumin quotient (Q_alb ).

CONCLUSION

Fewer true-positives for CSF total protein and Q_alb must be considered in suspected GBS, especially in the early disease course.

Cerebrospinal fluid total protein in Guillain-Barré syndrome variants: correlations with clinical category, severity, and electrophysiology

The discriminative value of CSF total protein (CSF-TP) in subtypes of Guillain-Barré syndrome has not been well documented in North-American patients. We reviewed 173 cases from a single institution, comprising the following clinical categories of neuropathy: 134 Sensorimotor (SM) GBS, 13 Motor (M) GBS, 8 Localized (L) GBS, and 18 Miller Fisher syndrome (MFS). We grouped the electrophysiological interpretation in primarily demyelinating, primarily axonal and normal / equivocal categories. Mean CSF-TP were substantially higher for SM and L-GBS, as well as cases classified as Acute-onset chronic inflammatory demyelinating polyneuropathy. They were lower for M-GBS and L-GBS. The most statistically significant correlation was found for elevated CSF-TP in GBS cases showing an electrophysiologic pattern classified as demyelinating (1.56 g/L) compared with axonal (0.68 g/L) or normal/ equivocal patterns (0.65 g/L). There was a correlation between CSF-TP and time interval between symptom onset and lumbar puncture. There was a weak correlation between CSF-TP and maximal overall-clinical severity grade, which was likely mostly determined by the electorphysiological pattern. Though CSF-TP is a sensitive test for GBS in the second week after onset, it may not be a reliable predictor of clinical severity. There is a robust association of CSF-TP elevation and a demyelinative electrophysiologic pattern and a suggestion that lower mean CSF-TP values can be expected in GBS-spectrum disorders thought to represent nodo-paranodopathies.