Posterior reversible encephalopathy syndrome associated with Guillain-Barré syndrome: Case report and clinical management considerations

Around half of the patients with Guillain-Barré syndrome (GBS) present autonomic dysfunction requiring admission to intensive care unit in up to a quarter of patients. Treatment of GBS consists of plasma exchange (PE) and intravenous immunoglobulins (IVIG). Posterior reversible encephalopathy syndrome (PRES) consists in a reversible subcortical vasogenic brain edema caused by endothelial damage triggered by abrupt blood pressure changes. We report on a woman who presented with PRES in the course of GBS treated first with IVIG, and then with PE. The present report underlines the challenge that the clinicians face when these two rare syndromes concur. The literature is not helpful considering that both blood pressure fluctuations and IVIG are reported to be involved in the pathogenesis of PRES. In the present letter, both pathogenic mechanisms and clinical management considerations are discussed.     

Sporadic hereditary neuropathies misdiagnosed as chronic inflammatory demyelinating polyradiculoneuropathy: Pitfalls and red flags

Hereditary neuropathies may be misdiagnosed with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). A correct diagnosis is crucial for avoiding unnecessary therapies and access genetic counseling. We report on nine patients (seven men, mean age 49.2 ± 16.1) diagnosed with and treated as CIDP, in whom mutations or variants of unknown significance (VUS) in genes associated with hereditary neuropathies were reported. All underwent neurological and neurophysiological examination, eight also cerebrospinal fluid (CSF) analysis. In 4/9, nerve ultrasound and/or MR‐neurography were performed. All the patients complained of progressive upper or lower limbs sensory‐motor symptoms, with heterogeneous disease duration (1‐34 years, mean 8.6 ± 10.8). Neurophysiology showed demyelinating signs in seven patients, mixed findings with predominant axonal damage in two patients. Neuroimaging disclosed diffuse abnormalities at proximal and distal segments. Molecular screening showed PMP22 duplication in two patients, mutations in the MPZ, EGR2, and GJB1 genes were reported in each of the remaining patients. The two patients with mixed neurophysiological findings had p.Val30Met mutation in the transthyretin gene. Two patients had VUS in the MARS and HSPB1 genes. Four patients had partial response to immunomodulant therapies, and CSF and neurophysiological features suggesting an inflammatory condition concomitant with the hereditary neuropathy. Hereditary neuropathy may be misdiagnosed with CIDP. The most common pitfalls are CSF (high protein levels and oligoclonal bands), incorrect interpretation of neurophysiology, and transient benefit from therapies. Neuroimaging may be helpful in cases with atypical presentations or when severe axonal damage complicate the neurophysiological interpretation.     

Genetic determinants of chronic oxaliplatin‐induced peripheral neurotoxicity: a genome‐wide study replication and meta‐analysis

We aimed at validating the role of genetic variants identified by a recent genome‐wide association study (GWAS) as determinants of chronic oxaliplatin‐induced peripheral neurotoxicity (OXAIPN). Eight polymorphisms (rs10486003, rs2338, rs843748, rs797519, rs4936453, rs12023000, rs17140129, and rs6924717) were genotyped in a total of 150 colorectal cancer patients of Caucasian origin receiving oxaliplatin‐based chemotherapy. The severity grade of chronic OXAIPN was assessed by NCI‐CTC criteria and the clinical version of the Total Neuropathy Score^© (TNSc^©). None of the polymorphisms investigated was found associated with grade ≥ 2 chronic OXAIPN (NCI‐CTC criteria), while a nominal association emerged for ACYP2 rs843748 when using the TNSc^© scale (dominant model: odds ratio [OR]: 0.27, 95% confidence interval [CI]: 0.10–0.75, P = 0.008). In the combined analysis of this results with data of the two previously published studies which assessed chronic OXAIPN by NCI‐CTC criteria, evidence suggestive of association with chronic OXAIPN (NCI‐CTC criteria) was found for ACYP2 rs843748 (dominant model: OR: 2.40, 95%CI: 1.40–5.24, P = 0.027), which, however, did not remain significant after correction for multiple testing (threshold P‐value <0.00625). These findings suggest a minor role of the single nucleotide polymorphisms (SNPs) investigated as genetic determinants of chronic OXAIPN. These results also highlight the importance of replication studies with meta‐analysis for validation of GWAS findings.     

From pathogenesis to personalized treatments of neuropathies in hematological malignancies

The peripheral nervous system may be involved at any stage in the course of several hematological diseases, the most common being monoclonal gammopathies (of undetermined significance or malignant) or lymphomas. The underlying pathogenic mechanisms are different and therapies aim at targeting the dangerous either B‐cell or plasma cell clones. Recently, high‐throughput technologies, and next‐generation sequencing have increased our knowledge of hematological diseases pathogenesis by the identification of somatic mutation affecting pivotal signaling pathways. Accordingly, new target therapies are used that may also be borrowed for treatment of neuropathies in hematological diseases.     

Positive and negative effects of thalidomide on refractory cutaneous lupus erythematosus

Background: Thalidomide is used in cutaneous lupus erythematosus (CLE) refractory to conventional therapies. Peripheral neuropathy (PN) is the most severe side effect, but the incidence of PN and its relation to thalidomide dose are still unclear.

Objective: To prospectively evaluate the efficacy as well as the occurrence of PN in CLE patients treated with thalidomide, and to assess whether PN, when occurs, correlates with thalidomide dose and/or length of treatment.

Methods: Fourteen female patients with CLE in low-dose thalidomide therapy were followed for up to 24 months. Prior to, and regularly during treatment patients underwent rheumatological, dermatological, neurological and electrophysiological evaluations. A decline in sural SNAP of 50% or more from baseline value was considered as criterion of sensory axonal PN.

Results: All patients showed a dramatic improvement of skin manifestations. Ten patients (71.4%) developed a sensory axonal PN. The median time free from this complication was 14 months. No correlations were found between age of the patients nor thalidomide cumulative dose and occurrence of PN (Mann-Whitney U Test; p>0.16). Other adverse effects were: tremor, paresthesias, somnolence, amenhorrea, constipation and thoracic pain.

Conclusions: Low does thalidomide is efficacious in treating CLE, but PN is a common complication whose occurrence does not seem to correlate with total thalidomide dose, whereas with the duration of therapy. A closer electrophysiological follow-up is therefore recommended in the long-term treatment.     

Consistence and discrepancy of neuropathic pain screening tools DN4 and ID-Pain

Pain is a subjective condition that cannot be objectively measured; for this reason, self patient-perspective is crucial. Recently, several screening tools to discriminate between nociceptive and neuropathic pain have been developed. We aimed at assessing the consistence and discrepancy of two widely used screening tools, The Douleur Neuropathique 4 (DN4) and the 6-item questionnaire (ID-Pain), by comparing their ability in discriminating neuropathic from nociceptive pain. DN4 and ID-Pain were administered to 392 Italian patients attending 16 outpatient services for peripheral nerve diseases. Based on medical history, clinical findings and diagnostic tools, patients were divided into two groups (neuropathic and nociceptive). Globally, ID-Pain identified neuropathic pain in 60 % of patients (38 % probable, 22 % likely). Interestingly also DN4 diagnosed neuropathic pain in 60 % of cases. A discrepancy was observed in 16 % of cases. DN4 and ID-Pain resulted to be highly interrelated in the identification of neuropathic pain. Sensitivity of DN4 was 82 % and specificity was 81 %, while ID-Pain (considering both probable and likely groups) showed sensitivity 78 % and specificity 74 %. Reliable screening tools for neuropathic pain are well related between them; hence, they are available for researchers and clinicians who may choose the most appropriate for their activity. Since the gold standard for the diagnosis and treatment of neuropathic pain cannot do without a neurological evaluation, perhaps DN4, that includes physician objective measures, may help reducing the percentage of dubious cases. Conversely, when needing a more agile tool (not needing a physician) ID-Pain may be adopted.     

No major progranulin genetic variability contribution to disease etiopathogenesis in an ALS Italian cohort

To analyze the contribution of progranulin (PGRN) to the etiopathogenesis of amyotrophic lateral sclerosis (ALS), we performed a PGRN gene screening in 146 Italian patients (12 familial cases) and evaluated the association of two common variants with risk of developing ALS in 239 sporadic cases (SALS). Progranulin mRNA and protein levels were measured in peripheral blood mononuclear cells and serum of a subset of these patients and controls. PGRN sequence analysis revealed a heterozygous change (p.S120Y), previously observed in an independent sporadic ALS-FTD patient. Haplotype analysis showed a conserved PGRN region among these two subjects consistent with possible common ancestor allele. Two non-coding polymorphisms were not associated to increased risk to develop ALS; mRNA and serum levels were not significantly different between cases and controls. Overall, our data argue against the hypothesis of progranulin as a major risk factor for motor neuron dysfunction, at least in Italian population. The p.S120Y variant may characterize rare patients with SALS, although its pathogenetic mechanism remains to be elucidated.