Fanny Duval

Bent spine syndrome as the initial symptom of late-onset Pompe disease

Introduction: Late‐onset Pompe disease (LOPD) is a rare disorder characterized by progressive proximal muscle weakness and early respiratory insufficiency, for which enzyme replacement therapy (ERT) is available. Methods: Having diagnosed a case of LOPD presenting with bent spine syndrome, we conducted a brief survey in the French centers involved in management of Pompe disease, from which we collected data on 3 other cases. Results: The patients (3 women and 1 man) had a mean age of 64 years (range 51–77 years) and a delay in diagnosis of approximately 10 years (range 8–42 years). At diagnosis, 3 patients already had respiratory symptoms. All had normal or very mildly raised creatine kinase levels and magnetic resonance imaging abnormalities in the paraspinal muscles. They exhibited the most frequent mutation in Pompe disease (c.‐32‐13 T>G). Conclusion: Clinicians should be aware of this atypical presentation of LOPD to enable earlier diagnosis and treatment. Muscle Nerve 56: 167–170, 2017

Focal neurogenic muscle hypertrophy and fasciculations In: Noteworthy Cases

DISCUSSION HCV infects approximately 170 million people worldwide. HCV is associated with extrahepatic manifestations, including neurological complications. About 10% of patients infected with HCV have peripheral neuropathies, which are usually chronic axonal, sensory dominant. Most of peripheral neuropathies are associated with essential mixed cryoglobulinemia. Neuropathies without cryoglobulinemia are very rare and are predominantly cranial neuropathies and mononeuropathy multiplex. Authier et al. examined 30 patients with neuropathy associated with HCV, showing that demyelinating polyneuropathy without cryoglobulinemia is very rare. One case has been published on acute inflammatory demyelinating polyneuropathy associated with subclinical HCV infection during the preconvalescent phase. Only a few reports of CIDP during the course of HCV infection have been published. CIDP was also reported as a rare side effect in patients treated with IFN-α. Two case reports documenting that CIDP has improved after the treatment of HCV have been published. A report by Corcia et al. described the treatment of a 57-year-old man with a combination of PEGylated IFN-α-2b and ribavirin, and Harada et al. reported on a 36-year-old man treated with IFN-α. In both reports, the authors speculated that an improvement in CIDP could be achieved by IFN-α. Although a spontaneous remission of CIDP cannot be excluded, we suggest 2 alternative explanations for the remission of long-standing CIDP after SOF/LDV treatment and, thereby, achieving SVR. First, SOF/LDV therapy alone may be effective in CIDP, and, second, HCV has significant influences on the pathogenesis of CIDP. Therefore, SOF/LDV treatment could be curative for CIDP occurring in patients with HCV.

Chronic inflammatory demyelinating polyradiculoneuropathy-causing myelopathy

A 52-year-old man presented with a 17-year history of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) that had been treated successfully with intravenous immunoglobulin (IVIg) and corticosteroids for a relapsing–remitting course. For 1 year prior to presentation, his walking worsened despite ongoing treatment with plasma exchanges and cyclophosphamide, and he developed urinary retention. Examination revealed predominantly distal quadriparesis, absent deep tendon reflexes, distal loss of vibratory sensation in all 4 limbs, superficial hypoesthesia (below the first thoracic dermatome), and mild spasticity of the lower limbs, resulting in an ataxic and spastic gait. Cervical MRI revealed spinal cord FIGURE 1. Cervical MRI: sagittal T1-weighted (A,B), coronal multiplanar T2-weighted (C), and axial multiplanar T2-weighted (D). On sagittal cervical T1-weighted MRI, the signal from the CSF was lost (A,B; arrows), with hyperintense and enlarged cervical roots on multiplanar T2-weighted (C; arrows). Hypertrophic roots compressed the cervical spine at C6–C7 (D; 1), with high T2-signal within the spinal cord (D; 2). CSF, cerebrospinal fluid.

History and current difficulties in classifying inherited myopathies and muscular dystrophies

The wide spectrum of hereditary muscular disorders leads to unavoidable difficulties in their classification, even for specialists. For this reason, new proposals are required that would ultimately replace our current rather complex classifications by a simpler structure. Our proposal will be limited to dystrophic and non-dystrophic myopathies (excluding metabolic disorders, mitochondriopathies, and channelopathies) for which similar proposals would also be relevant. Various genes (encoding structural proteins associated with the sarcolemma, nuclear membrane proteins, and proteins involved in myofiber metabolism have now been sequenced and mutations ascribed to specific forms of inherited muscular disorders. Based on our observations and our recent proposals in other neurogenetic conditions and informal discussions with specialists of neuromuscular disorders, the prerequisite for a simple and sound classification for inherited muscular disorders should encompass the clinical and pathological phenotypes (described in a simple and clear manner), the mode of inheritance, and the mutated gene. We think that the denomination of the different subtypes could be simplified considerably, although any new proposal of classification of muscular disorders will need to be discussed in the neurological and genetic communities.

Some new proposals for the classification of inherited myopathies

Dear Editor, In a recent publication in the Journal of the Neurological Sciences, we highlighted the current difficulties in classifying the various forms of inherited myopathies [1]. These suggestions were based on our initial proposals for Charcot-Marie-Tooth disease (CMT) and other neurogenetic disorders) [2]. Recently, we conducted an internet survey to evaluate the interest of the scientific community: 65% of the people consulted considered that changes are needed and that our proposals constitute an improvement over the historical classification of CMT [3, 4]. There have also been recent attempts to solve such problems in other neurogenetic disorders such as hereditary ataxias [5]. We are aware that any new classification of neuromuscular disorders will need to be discussed in the neurological and genetic communities, but we have proposed simplifying the classification of inherited muscular disorders by using the same three successive steps: clinical phenotype, mode of inheritance, then the name of the causative gene (Fig. 1A) [1]....

Value of nerve biopsy in the management of peripheral neuropathies

ABSTRACT Introduction: Peripheral neuropathy is a common symptom throughout the population, with numerous possible etiologies. The diagnosis of peripheral neuropathies (and their causes) is mainly based on clinical, electrophysiological, biological, and imaging features. Areas covered: This paper reviews the main causes of neuropathy and discusses the usefulness of nerve biopsy (NB) in such cases. Expert commentary: In most cases, NB is not mandatory in the diagnostic work-up of a peripheral neuropathy. However, NB is clearly an indication in cases of vasculitis. It is also valuable in peripheral neuropathies with severe and rapid worsening (without clear cause) in order to uncover a pathological hallmark (amyloid deposits). Although NB is considered an invasive method, it may be useful in the management of peripheral neuropathy, especially to guide treatment in certain cases. In summary, although NB is not a systematic procedure, it is a useful tool that should be discussed on a case-by-case basis within the clinical context.