Abnormal sweating and "skin flushing" as possible predictive factor for treatment related fluctuations in Guillain-Barré syndrome: a case series and a review of the literature.

Treatment related fluctuations (TRFs) in Guillain-Barré Syndrome (GBS) are described as one or more episodes of deterioration manifesting within two months after disease onset and following an initial improvement or stabilisation after treatment. They may be encountered in 8% to 16% of patients, but currently predictive factors of TRF occurrence and severity are poorly known. To this end, we evaluated the frequency and clinical features of TRFs in a cohort of GBS patients admitted to the Neurological unit of Sant'Andrea Hospital (La Spezia, Italy) from January 1st, 2003 to December 31st, 2017. Among the 98 GBS collected patients, five (5.1%) developed a TRF during disease course. Consistently with the literature, the majority of our GBS patients who developed a TRF did not report a preceding diarrhoea, had a predominant proximal weakness and all of them had sensory disturbances at the clinical onset. Interestingly, 80% of our TRF patients manifested since GBS onset an autonomic dysfunction with abnormal sweating and a peculiar 'skin flushing' in face, neck and chest. Two patients developed respiratory insufficiency at the TRF time, and they both died. We would advise to pay attention to GBS patients with particular 'skin flushing' in face, neck and chest and abnormal sweating, because these findings could be a red flag for TRF.

Neuromuscular complications following targeted therapy in cancer patients: beyond the immune checkpoint inhibitors. Case reports and review of the literature.

INTRODUCTION: In the last years, many new drugs have been developed targeting different oncology pathways, overall improving both quality of life and survival in several malignancies. However, the increase of those therapies is associated with novel toxicities, mainly immune-related adverse events (irAEs), never observed before. Different irAEs are now well characterized, and, among them, neuromuscular complications, following immune checkpoint inhibitor (ICPi) therapy, are increasingly studied and described. However, there are also neurological complications related to the use of other targeted therapies, less known and probably underestimated. Herein we describe two oncological patients who developed neuromuscular diseases after administration of targeted therapies, different from ICPi. CASE REPORTS: The first patient was treated with the combination of Vemurafenib and Cobimetinib, BRAF and MEK inhibitors, respectively, for a cutaneous melanoma. One year after the beginning of the combined treatment, she developed a sub-acute motor neuropathy with predominant cranial nerve involvement. She was successfully treated with methylprednisolone. The second patient received therapy with Imatinib, tyrosine kinase inhibitor and precursor of the targeted therapy, for a gastrointestinal stromal tumour. Few days after the first administration, he developed generalized myasthenia gravis with respiratory failure. Clinical remission was obtained with plasma-exchange, intravenous immunoglobulins and steroids. DISCUSSION AND CONCLUSION: We strengthen the relevance of neuromuscular complications which may occur long after treatment start or in patients receiving not only the latest ICPi but also "older" and apparently better-known targeted therapies. Also in the latter cases, an immune-mediated "off-target" pathogenic mechanism can be hypothesized, and consequences can be life threatening, if not promptly diagnosed and appropriately managed.

Taxane and epothilone-induced peripheral neurotoxicity: From pathogenesis to treatment.

Taxane-induced peripheral neurotoxicity (TIPN) is the most common non-hematological side effect of taxane-based chemotherapy, and may result in dose reductions and discontinuations, having as such a detrimental effect on patients' overall survival. Epothilones share similar mechanism of action with taxanes. The typical TIPN clinical presentation is mainly comprised of numbness and paresthesia, in a stocking-and-glove distribution and may progress more proximally over time, with paclitaxel being more neurotoxic than docetaxel. Motor and autonomic involvement is less common, whereas an acute taxane-induced acute pain syndrome is frequent. Patient reported outcomes questionnaires, clinical evaluation, and instrumental tools offer complementary information in TIPN. Its electrodiagnostic features include reduced/abolished sensory action potentials, and less prominent motor involvement, in keeping with a length-dependent, axonal dying back predominately sensory neuropathy. TIPN is dose-dependent and may be reversible within months after the end of chemotherapy. The single and cumulative delivered dose of taxanes is considered the main risk factor of TIPN development. Apart from the cumulative dose, other risk factors for TIPN include demographic, clinical, and pharmacogenetic features with several single-nucleotide polymorphisms potentially linked with increased susceptibility of TIPN. There are currently no neuroprotective strategies to reduce the risk of TIPN, and symptomatic treatments are very limited. This review critically examines the pathogenesis, incidence, risk factors (both clinical and pharmacogenetic), clinical phenotype and management of TIPN.