Clinical, paraclinical and outcome features of 166 patients with acute anti-GQ1b antibody syndrome

BACKGROUND & PURPOSE

In this retrospective study, we aimed at defining the clinical, paraclinical and outcome features of acute neurological syndromes associated with anti-GQ1b antibodies.

RESULTS

We identified 166 patients with neurological symptoms appearing in less than 1 month and anti-GQ1b antibodies in serum between 2012 and 2022. Half were female (51%), mean age was 50 years (4-90), and the most frequent clinical features were areflexia (80% of patients), distal upper and lower limbs sensory symptoms (78%), ophthalmoplegia (68%), sensory ataxia (67%), limb muscle weakness (45%) and bulbar weakness (45%). Fifty-three patients (32%) presented with complete (21%) and incomplete (11%) Miller Fisher syndrome (MFS), thirty-six (22%) with Guillain-Barre syndrome (GBS), one (0.6%) with Bickerstaff encephalitis (BE), and seventy-three (44%) with mixed MFS, GBS & BE clinical features. Nerve conduction studies were normal in 46% of cases, showed demyelination in 28%, and axonal loss in 23%. Anti-GT1a antibodies were found in 56% of cases, increased cerebrospinal fluid protein content in 24%, and Campylobacter jejuni infection in 7%. Most patients (83%) were treated with intravenous immunoglobulins, and neurological recovery was complete in 69% of cases at 1 year follow-up. One patient died, and 15% of patients relapsed. Age > 70 years, initial Intensive Care Unit (ICU) admission, and absent anti-GQ1b IgG antibodies were predictors of incomplete recovery at 12 months. No predictors of relapse were identified.

CONCLUSION

This study from Western Europe shows acute anti-GQ1b antibody syndrome presents with a large clinical phenotype, a good outcome in 2/3 of cases, and frequent relapses.

Rate and characteristics of inflammatory neuropathies associated with brentuximab vedotin therapy

BACKGROUND AND PURPOSE

Peripheral neuropathy is a frequent complication of brentuximab vedotin (BV), used in CD30+ lymphoma treatment. Classic BV-induced neuropathy (BV-CN) is a mild distal sensory axonal polyneuropathy. Severe BV-induced inflammatory neuropathies (BV-IN) have been described. BV-IN contribute to lymphoma-associated morbidity but might be immunotherapy-responsive. Our primary objective was to evaluate the rate of BV-IN. Our secondary objectives were to determine risk factors and warning signs.

METHODS

We conducted a retrospective cohort study on all patients treated with BV at our center between April 2014 and September 2021. Clinical, biological, and electrophysiological data were collected. BV-induced neuropathy was defined as the occurrence of neuropathy up to 3 months after BV discontinuation. BV-IN was defined with criteria adapted from European Academy of Neurology/Peripheral Nerve Society 2021 electrodiagnostic criteria for chronic inflammatory demyelinating polyradiculoneuropathy. Other neuropathies were classified as BV-CN.

RESULTS

Among 83 patients, 41 (49%) developed neuropathy: 35 BV-CN and 6 BV-IN. Thus, the rate of BV-IN was 7.2%. Compared to patients with BV-CN, no predisposing factor was identified. However, patients with BV-IN more frequently presented muscle weakness (67% vs. 5.7%, p < 0.05), gait disorders (83% vs. 20%, p < 0.05), or acute or subacute onset (67% vs. 14%, p < 0.05). BV-IN was frequently more severe (Common Terminology Criteria for Adverse Events grade ≥3; 50% vs. 0%, p < 0.05). Four patients were treated with immunotherapy.

CONCLUSIONS

Brentuximab vedotin-induced neuropathy is an overlooked complication. Based on four easily identifiable "red flags", we provide an algorithm to help non-neurologist physicians that care for BV-treated patients to detect BV-IN. The aim of the algorithm is to decrease the diagnostic and management delay of this disabling neuropathy.

Characterizing Acute-Onset Small Fiber Neuropathy

BACKGROUND AND OBJECTIVES

Immune-mediated small fiber neuropathy (SFN) is increasingly recognized. Acute-onset SFN (AOSFN) remains poorly described. Herein, we report a series of AOSFN cases in which immune origins are debatable.

METHODS

We included consecutive patients with probable or definite AOSFN. Diagnosis of SFN was based on the NEURODIAB criteria. Acute onset was considered when the maximum intensity and extension of both symptoms and signs were reached within 28 days. We performed the following investigations: clinical examination, neurophysiologic assessment encompassing a nerve conduction study to rule out large fiber neuropathy, laser-evoked potentials (LEPs), warm detection thresholds (WDTs), electrochemical skin conductance (ESC), epidermal nerve fiber density (ENF), and patient serum reactivity against mouse sciatic nerve teased fibers, mouse dorsal root ganglion (DRG) sections, and cultured DRG. The serum reactivity of healthy subjects (n = 10) and diseased controls (n = 12) was also analyzed. Data on baseline characteristics, biological investigations, and disease course were collected.

RESULTS

Twenty patients presenting AOSFN were identified (60% women; median age: 44.2 years [interquartile range: 35.7-56.2]). SFN was definite in 18 patients (90%) and probable in 2 patients. A precipitating event was present in 16 patients (80%). The median duration of the progression phase was 14 days [5-28]. Pain was present in 17 patients (85%). Twelve patients (60%) reported autonomic involvement. The clinical pattern was predominantly non-length-dependent (85%). Diagnosis was confirmed by abnormal LEPs (60%), ENF (55%), WDT (39%), or ESC (31%). CSF analysis was normal in 5 of 5 patients. Antifibroblast growth factor 3 antibodies were positive in 4 of 18 patients (22%) and anticontactin-associated protein-2 antibodies in one patient. In vitro studies showed IgG immunoreactivity against nerve tissue in 14 patients (70%), but not in healthy subjects or diseased controls. Patient serum antibodies bound to unmyelinated fibers, Schwann cells, juxtaparanodes, paranodes, or DRG. Patients' condition improved after a short course of oral corticosteroids (3/3). Thirteen patients (65%) showed partial or complete recovery. Others displayed relapses or a chronic course.

DISCUSSION

AOSFN primarily presents as an acute, non-length-dependent, symmetric painful neuropathy with a variable disease course. An immune-mediated origin has been suggested based on in vitro immunohistochemical studies.

Changes in amyloidosis phenotype over 11 years in a cardiac amyloidosis referral centre cohort in France

BACKGROUND

Early cardiac amyloidosis (CA) diagnosis enables patients to access effective treatments for better long-term outcomes, yet it remains under-recognised, misdiagnosed and inadequately managed.

AIM

To reduce diagnostic delays, we aimed to describe the epidemiological and clinical characteristics and changes over an 11-year period.

METHODS

This was a retrospective, observational cohort study of all patients referred to the Henri-Mondor Hospital for suspected CA.

RESULTS

Overall, 3194 patients were identified and 3022 were included and analysed. Our patients came from varied ethnic backgrounds, and more than half (55.2%) had confirmed CA. Over 11 years, referrals increased 4.4-fold, mostly from cardiologists. Notably, wild-type transthyretin amyloidosis (ATTRwt) became the predominant diagnosis, with referrals increasing 15-fold from 20 in 2010-2012 to 308 in 2019-2020. The number of amyloid light chain (AL) diagnoses increased, whilst variant transthyretin amyloidosis (ATTRv) numbers remained relatively stable. Concerning disease severity, AL patients presented more frequently with severe cardiac involvement whereas an increasing number of ATTRwt patients presented with National Amyloid Centre stage I (22.0% in 2013-2014 to 45.9% in 2019-2020). Lastly, among patients diagnosed with ATTRv in 2019-2020, 83.9% had ATTR Val122Ile cardiac phenotype.

CONCLUSIONS

This study shows that increasing cardiologist awareness and referrals have increased CA diagnoses. With improved awareness and non-invasive diagnostic techniques, more patients with ATTRwt with milder disease and more ATTRv Val122Ile mutations are being referred and diagnosed. Although more AL cases are being recognised, patients are diagnosed with severe cardiac involvement.

Describing mode of death in three major cardiac amyloidosis subtypes to improve management and survival

BACKGROUND

The three main cardiac amyloidosis (CA) types have different progression and prognosis. Little is known about the mode of death (MOD) which is commonly attributed to cardiovascular causes in CA. Improving MOD's knowledge could allow to adapt patient care.

OBJECTIVE

This retrospective study describes the MOD that occurred during long-term follow-up in CA patients in light-chain (AL), transthyretin hereditary (ATTRv) or wild-type (ATTRwt).

MATERIAL AND METHODS

Patients referred to and cared for, at the French referral centre for CA, Henri Mondor Hospital, Créteil between 2010 and 2016 were included. Clinical information surrounding patient deaths were investigated and centrally evaluated by two blinded clinical committees which classified MOD as cardiovascular, non-cardiovascular or unknown and sub-classified it depending on its subtype.

RESULTS

From the 566 patients included, 187 had AL, 206 ATTRv and 173 ATTRwt. During the 864 patient-year follow-up, 160 (28%) deaths occurred, with median survival time of 17.3 months (interquartile range 5.1-35.4). The most frequent MOD was cardiovascular (64%) of which worsening heart failure occurred most frequently and for which, 69% were of AL subtype, 79% ATTRv and 76% ATTRwt. Sudden death also occurred more frequently in AL subtype accounting for 29% of AL deaths. Non-cardiovascular MOD occurred in 26% of patients overall. Among these, infection was the most common non-cardiovascular MOD in any type of CA (80%).

CONCLUSIONS

Mortality is high during natural course of CA and differs between subtypes. The main MOD were worsening heart failure, sudden death and infection, opening room to optimise management.

Broadening the spectrum of the neurological complications in systemic lupus erythematosus: A patient with meningoradiculitis

BACKGROUND

Neurological complications of systemic lupus erythematosus (SLE) are wide and may rarely involve the peripheral nervous system. However, no case of meningoradiculitis has been well-detailed.

METHODS

We report a patient with lupus-associated meningoradiculitis.

RESULTS

A 57-year-old woman had SLE without neurological involvement, treated with hydroxychloroquine, methotrexate, and prednisone for 10 years. Six months after the drug discontinuation for SLE, she acutely developed gait instability, paresthesia, and neuropathic pain of the four limbs. The neurological examination and nerve conduction studies were consistent with radiculopathies. Cerebrospinal fluid (CSF) analysis showed lymphocytic meningitis. The spinal magnetic resonance imaging (MRI) revealed thickening and an enhancement of the lumbosacral roots consistent with meningoradiculitis. The extensive investigations did not argue for a differential diagnosis of SLE. The patient dramatically improved upon corticosteroids. At the last follow-up, the patient still reported mild paresthesia but the clinical examination, the CSF, and the spinal MRI were normal.

CONCLUSION

This well-detailed case of meningoradiculitis broadens the spectrum of neurological complications in SLE. Early recognition of such complications might lead to efficient immunotherapy.

Charcot-Marie-Tooth disease misdiagnosed as chronic inflammatory demyelinating polyradiculoneuropathy: An international multicentric retrospective study

BACKGROUND AND PURPOSE

Charcot-Marie-Tooth (CMT) disease, an untreatable hereditary polyneuropathy, may mimic chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), a treatable neuropathy.

METHODS

In this retrospective study, we analyzed the characteristics of CMT patients misdiagnosed as CIDP at 16 university hospitals in three countries, compared these patients with a reference group of CIDP patients, and estimated the cost of misdiagnosis.

RESULTS

Among 1104 CIDP cases, we identified 35 CMT patients misdiagnosed as CIDP (3.2%). All were initially diagnosed with definite or probable CIDP (European Federation of Neurological Societies/Peripheral Nerve Society criteria), and mutations in PMP22, MPZ, and 10 other CMT genes were found in 34%, 31%, and 35% of cases, respectively. In comparison with a reference group of 35 CIDP patients, CMT patients were younger (median age at disease onset = 39 vs. 56 years) and more frequently had motor weakness at disease onset (80% vs. 29%), hearing loss (14% vs. 0%), normal brachial plexus imaging (70% vs. 40%), lower cerebrospinal fluid protein content (median = 0.5 vs. 0.8 g/L), and lower treatment response (20% vs. 69%). Treatment cost in these 35 misdiagnosed patients was estimated at 4.6 million euros (M€), whereas the cost of CMT genetic analysis in 1104 patients was estimated at 2.7 M€.

CONCLUSIONS

In this study, 35 of 1104 (3.2%) patients initially diagnosed with CIDP had CMT. Importantly, the cost of treating these 35 misdiagnosed patients was significantly higher than the cost of performing CMT genetic analysis in 1104 patients (4.6 M€ vs. 2.7 M€), suggesting that CMT genetic investigations should be more widely used before diagnosing CIDP.

Natural history and impact of treatment with tafamidis on major cardiovascular outcome-free survival time in a cohort of patients with transthyretin amyloidosis

AIMS

Hereditary (ATTRv) and wild-type (ATTRwt) transthyretin amyloidosis are severe and fatal systemic diseases, characterised by amyloid fibrillar accumulation principally in the heart or peripheral nerves (or both). Since 2012, tafamidis has been used in France to treat patients with ATTRv with neuropathy (alone or combined with cardiomyopathy). Recently, the Phase III ATTR-ACT trial showed that tafamidis decreased the relative risk of mortality in ATTR amyloidosis with cardiomyopathy. The aims of this study were to assess the clinical characteristics of ATTR amyloidosis in a real-life population in comparison to the population included in the ATTR-ACT trial and to assess the impact of tafamidis treatment on major cardiovascular outcome (MCO)-free survival time without cardiac decompensation, heart transplant, or death.

METHODS AND RESULTS

From June 2008 to November 2018, 648 patients with ATTR amyloidosis (423 ATTRwt and 225 ATTRv) consecutively referred to the French Referral Center for cardiac amyloidosis were included. A total of 467 (72%) patients matched the inclusion criteria of the ATTR-ACT trial. For the 631 patients with cardiomyopathy, tafamidis treatment was associated with a longer median MCO-free survival time (n = 98): 1565 (1010-2400) days vs. 771 (686-895) days without treatment (log-rank P < 0.001). This association was confirmed after considering confounding factors (age at inclusion, N-terminal pro-B-type natriuretic peptide and amyloidosis type) with a propensity score (hazard ratio 0.546; P = 0.0132).

CONCLUSION

In a large cohort of ATTRwt and ATTRv patients, representative of the inclusion criteria of the ATTR-ACT trial, the present results show an association between tafamidis treatment and a lower occurrence of cardiovascular outcomes in a real-life population.

Quality of life in functional movement disorders is as altered as in organic movement disorders

OBJECTIVE

Patients with functional movement disorders (FMD) often report a disability and psychiatric comorbidities. However, few studies have compared these aspects in FMD and in organic movement disorders (OMD). The objectives were to compare QoL and psychiatric comorbidities of FMD and OMD patients.

METHODS

Twenty-one and 30 FMD patients were compared to 21 and 30 sex- and age-matched dystonia and Parkinson patients respectively. QoL was assessed using the Parkinson's Disease Summary Index (PDSI). Psychiatric comorbidities were screened with the Mini International Neuropsychiatric Interview, the Hospital Anxiety and Depression Scale and the Composite International Diagnostic Interview questionnaire.

RESULTS

QoL was more altered in FMD than in dystonia on PDSI (42.1 vs 25.1; p = .003). No significant difference was observed in QoL in FMD and Parkinson's disease on PDSI (38.3 vs 32.2; p = .61). Moreover, FMD patients were more often unemployed because of their condition than dystonia (61.9% vs 14.3%; p = .01) and Parkinson patients (53.3% vs 13.3%; p = .005). The occurrence of anxiety (p = .58 and > 0.99), depression (p = .77 and 0.77), and traumatic events (p = .58 and 0.75) was not different between groups. FMD patients reported more often sexual abuse than dystonia (28,6% vs 4.8%; p = .13) and Parkinson patients (23.3% vs 0.0%; p = .02).

CONCLUSION

FMD patients presented a significant alteration of QoL and no increased psychiatric comorbidities compared to OMD patients. These results highlight the impact of FMD and suggest that neurologists should be as involved in the management of FMD as they are in OMD.