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.     

Prolonged distal motor latency of median nerve does not improve diagnostic accuracy for CIDP

Journal of Neurology - Compression of the median nerve at the carpal tunnel can give demyelinating features and result in distal motor latency (DML) prolongation fulfilling the EFNS/PNS...     

Usefulness of F-18 FDG PET/CT in the follow-up of POEMS syndrome after autologous peripheral blood stem cell transplantation

We report a case of a patient with relapse of POEMS syndrome (peripheral neuropathy, organomegaly, endocrinopathy, monoclonal plasma proliferative disorder, skin changes) that occurred 6 years after an autologous peripheral blood stem cell transplantation. F-18 FDG PET/CT showed several hypermetabolic as well as nonhypermetabolic bone lesions. Based on these findings, the patient was referred for radiotherapy to the hypermetabolic bone lesions. After autologous peripheral blood stem cell transplantation, F-18 FDG PET/CT may play a pivotal role in detecting new bone lesions in patients with POEMS syndrome, which may be treated by a focalized radiotherapy and/or systemic therapy.     

Replication of association of CHRNA4 rare variants with sporadic amyotrophic lateral sclerosis: The Italian multicentre study

Neuronal nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels widely expressed throughout the mammalian brain, including bulbar and spinal motor neurons. They are involved in neuroprotection and in control of release of many neurotransmitters, including glutamate. Previous data raised the hypothesis that rare variants in the region coding the intracellular loop subunits of nAChRs might represent one of several genetic risk factors for SALS. The aim of present study was to replicate the study in an independent cohort of ALS patients. We analysed 718 sporadic ALS patients from five Italian ALS centres and 1300 ethnically matched controls. We focused primarily on CHRNA4, encoding α4 subunit, since most mutations were previously detected in this gene. We observed a significant association between CHRNA4 mutations and ALS (OR 2.91; 95% CI 1.4080-6.0453; p =?0.0056). Most mutations detected in patients were not present in the dbSNP134 and in 3500 ethnically matched control chromosomes and affected evolutionary conserved amino acid residues. In conclusion, the present data confirm that CHRNA4 variants are overrepresented in SALS strengthening the hypothesis can they act as predisposing genetic factors for SALS.     

Nerve ultrasound in hereditary transthyretin amyloidosis: red flags and possible progression biomarkers

Journal of Neurology - Diagnostic delay of hereditary transthyretin amyloidosis (ATTRv, v for variant) prevents timely treatment and, therefore, concurs to the mortality of the disease. The aim of...     

Progressive ascending myelopathy: atypical forms of multiple sclerosis or what else?

The spinal cord can be affected by multiple heterogeneous disorders often difficult to diagnose. We describe ten patients affected by a progressive ascending myelopathy with a poor prognosis. The patients, during the follow-up period, underwent neurological examinations, cerebrospinal fluid analysis, hematological, microbiological, auto-antibodies screening, brain and spinal cord magnetic resonance imaging (MRI) and electroneurophysiological study. At disease onset spinal cord MRI showed ≥1 myelopathic lesions extended for <2 segments and then evidenced a progressive spinal cord atrophy without any new lesion. All patients showed an increase of the visual evoked potential P100 latency. All of them showed two or more clinical recurrences of myelitis and then, after a period ranging from 3 to 5 years from the disease onset, a progressive course. Five patients became unresponsive to intravenous high-dose steroid treatments and/or intravenous immunoglobulins and to any other therapeutic attempts, developed a progressive ascending myelopathy to tetraplegia and died from respiratory failure. The other five patients are in progressive phase of the disease with an initial involvement of the upper limbs and show mild cervical spinal cord atrophy at MRI, configuring the early stage of an ascending progressive myelopathy. In our opinion, the more suitable diagnosis is an atypical form of MS although is not possible to exclude a new nosological entity that could be included in the expanding range of spinal cord diseases.