F. Madia

Pure motor chronic inflammatory demyelinating polyneuropathy.

Abstract We describe four patients affected by chronic inflammatory demyelinating polyneuropathy (CIDP) in a pure motor form. Selective involvement of motor fibers was suggested by the absence of sensory symptoms, normal sensation at neurological examination and normal findings on electrophysiological testing of sensory fibres and sural nerve biopsy. The onset of the disease occurred at a young age (3–29 years) and the clinical course was relapsing-remitting. Over a follow-up periode of 1.5–14 years, periodical clinical and electrophysiological examinations showed that selective involvement of motor fibers remained a constant feature. Electromyography and nerve conduction studies continued to show a purely demyelinating neuropathy without signs of axonal impairment. All patients were steroid-unresponsive, whereas they considerably improved after being treated with immunoglobulins. Two patients were treated with interferon alpha and showed a good response. In conclusion, the occurrence in our four patients of pure motor involvement over a long period of time during which several relapses occurred, suggests that pure motor CIDP may represent the result of a specific immunological process rather than of a random distribution of inflammation throughout peripheral nerves.

Natural history of young-adult amyotrophic lateral sclerosis

Background: Amyotrophic lateral sclerosis (ALS) affects people of all ages, but whether the wide range of age at onset is due to distinct diseases or merely reflects phenotypic variability of the same disorder is still unknown. The purpose of this study is to describe clinical and prognostic features of young-adult ALS, with onset before age 40 years, and to compare them with features of the common adult-onset type. Methods: We analyzed clinical features and long-term follow-up of 57 young-adult ALS patients, with disease onset between 20 and 40 years, and compared them with 450 patients affected by adult-onset ALS. Results: We found that the majority of young-adult patients showed a predominant upper motor neuron (p-UMN) ALS, characterized by marked spastic paraparesis, with lower motor neuron signs confined to the upper limbs. The proportion of patients with p-UMN ALS phenotype was 59.6% in the young-adult patients and 17.4% in the adult-onset form (p < 0.0001). Young-adult ALS with p-UMN phenotype had longer survival than did the classic phenotype: median survival was 74 months (range 10–226, 95% CI 60.61–87.38) in the former and 56 months (range 6–106, 95% CI 48.65–63.34) in the latter (p = 0.03). In the young-adult patients, a marked male excess was observed in the p-UMN ALS group (5.8:1), whereas the ratio of men to women was 1.1:1 in the classic phenotype (p = 0.01). Conclusions: Our findings show that young-adult amyotrophic lateral sclerosis with the predominant upper motor neuron phenotype represents a distinctive clinical variant characterized by a unique clinical pattern, longer survival, and male prevalence.

Rare Missense Variants of Neuronal Nicotinic Acetylcholine Receptor Altering Receptor Function Are Associated with Sporadic Amyotrophic Lateral Sclerosis

Sporadic amyotrophic lateral sclerosis (SALS) is a motor neuron degenerative disease of unknown etiology. Current thinking on SALS is that multiple genetic and environmental factors contribute to disease liability. Since neuronal acetylcholine receptors (nAChRs) are part of the glutamatergic pathway, we searched for sequence variants in CHRNA3, CHRNA4 and CHRNB4 genes, encoding neuronal nicotinic AChR subunits, in 245 SALS patients and in 450 controls. We characterized missense variants by in vitro mutagenesis, cell transfection and electrophysiology. Sequencing the regions encoding the intracellular loop of AChRs subunits disclosed 15 missense variants (6.1%) in 14 patients compared with only six variants (1.3%) in controls (P = 0.001; OR 4.48, 95% CI 1.7-11.8). The frequency of variants in exons encoding extracellular and transmembrane domains and in intronic regions did not differ. NAChRs formed by mutant alpha3 and alpha4 and wild-type (WT) beta4 subunits exhibited altered affinity for nicotine (Nic), reduced use-dependent rundown of Nic-activated currents (I(Nic)) and reduced desensitization leading to sustained intracellular Ca(2+) concentration, in comparison with WT-nAChR. The cellular loop has a crucial importance for receptor trafficking and regulating ion channel properties. Missense variants in this domain are significantly over-represented in SALS patients and alter functional properties of nAChR in vitro, resulting in increased Ca(2+) entry into the cells. We suggest that these gain-of-function variants might contribute to disease liability in a subset of SALS because Ca(2+) signals mediate nAChRs neuromodulatory effects, including regulation of glutamate release and control of cell survival.

A novel HSPB1 mutation in an Italian patient with CMT2/dHMN phenotype.

Mutations in the gene encoding 27-kDa small heat-shock protein B1 (HSPB1) have been reported in association with Charcot-Marie-Tooth disease type 2F or dHMN type II. We describe an Italian patient with wasting and weakness of distal muscles, involving primarily and mostly the lower limbs and later the upper limbs, in which a novel mutation of HSPB1, T180I, was detected. Electrophysiological evaluation disclosed a pure motor axonal neuropathy. Sural nerve biopsy showed a mild reduction of myelinated fibre density. All these findings suggested a CMT2/dHMN phenotype.

Peripheral neuropathy with hypomyelinating features in adult-onset Krabbe's disease

We describe three brothers suffering from Krabbes disease with onset in the fifth decade. The proband showed a complete deficiency of leukocyte enzyme galactocerebrosidase and was found to be heterozygous for two previously described mutations: G > A809 and 502T/del consisting of a 30 kb deletion. In all three brothers the neurological examination showed features of asymmetrical peripheral neuropathy associated with pyramidal signs and the electrophysiological examination showed a generalized slowing of nerve conduction velocities. Two patients died at 59 and 61 years of age due to respiratory failure. Both the proband and his brother underwent a sural nerve biopsy. In the former the most striking finding was the presence of uniformly thin myelin sheaths without evidence of demyelination; a complete absence of fibers was found in the latter. Our findings confirm that peripheral neuropathy may be the presenting feature of late-onset Krabbes disease. Hypomyelination rather than demyelination may represent the distinguishing pathological finding of this condition.

pSTAT1, pSTAT3, and T-bet as markers of disease activity in chronic inflammatory demyelinating polyradiculoneuropathy.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is considered an auto‐immune disorder. We evaluated expression of pSTAT1, T‐bet, and pSTAT3 in circulating T‐cells, B‐cells, and monocytes and spontaneous production of interleukin‐17 (IL17), interferon‐gamma (IFNγ), and interleukin‐10 (IL10) by peripheral blood mononuclear cells (PBMCs) from 14 active CIDP patients compared with 6 patients with long‐lasting remission and 20 controls. Active disease patients showed higher pSTAT1, T‐bet, and pSTAT3 in CD4+ T‐cells than controls (p < 0.001, p = 0.0002, p = 0.0097, respectively) and remission patients (p < 0.001, p = 0.0036, p = 0.0008, respectively). pSTAT1, T‐bet, and pSTAT3 were also higher in monocytes from active CIDP patients than controls (p = 0.0011, p = 0.0041, p = 0.0413, respectively) and remission patients (p = 0.0073, p = 0.0274, p = 0.0251, respectively). Moreover in CD8+ T‐cells, pSTAT3 expression was higher in active CIDP patients than in remission patients (p = 0.0345) and in controls (p = 0.0023). IL17 and IFNγ production were significantly higher in active CIDP patients than in controls (p < 0.0395, p = 0.0010, respectively); IFNγ levels were higher also in remission CIDP patients (p = 0.0073). IL10 levels were higher in active phase patients than in controls (p = 0.0334). Our data suggest that pSTAT1, T‐bet, and pSTAT3 can be considered putative markers of disease activity and potential targets for specific therapies.

Chronic autoimmune autonomic neuropathy responsive to immunosuppressive therapy

Autoimmune autonomic neuropathy refers to a group of autoimmune disorders characterized by the failure of both sympathetic and parasympathetic systems,1 related to the presence of autoantibodies against neuronal ganglionic acetylcholine (AChR) receptors.2 These antibodies are detectable in the serum of about 30% of patients with paraneoplastic-acquired autoimmune autonomic neuropathy and in 50% of patients with idiopathic subacute autoimmune autonomic neuropathy.3 We describe a 59-year-old woman who presented 6 months after the gradual development of severe dysautonomia, characterized by recurrent orthostatic syncope, dry mouth, early satiety, constipation, and urinary retention. Family history was negative and she denied any viral illness preceding the onset of the above symptoms. The results of physical examination showed her blood pressure to be 115/70 mm Hg in a supine position, but fell to 80/50 mm Hg in a sitting position; the patient was unable to stand upright for more than a few seconds because of a fainting sensation. Pupillary responses to light were torpid; however, the remaining neurologic examination was normal. Routine blood tests, including glucose determination, were normal. X-ray gastrointestinal transit evaluation after barium ingestion documented markedly delayed gut motility …

Uncovering amyotrophic lateral sclerosis phenotypes: clinical features and long-term follow-up of upper motor neuron-dominant ALS

Abstract The aim of our study was to analyse the natural history and clinical features of upper motor neuron- dominant (UMN-D) ALS. We studied a large series of sporadic ALS patients admitted in a single referral centre over a 23-year period. UMN-D phenotype was compared with other ALS forms, including classic ALS, flail arm and progressive muscular atrophy. Seven hundred and thirty-four sporadic ALS patients were included of which 163 had UMN-D ALS. The mean age of onset in UMN-D ALS (52 years) was 10 years lower than in classic ALS (61.4 years, p < 0.0001); sex ratio by age groups significantly differed with respect to other phenotypes. The pattern of spread of lower motor neuron signs in UMN-D was characterized by early involvement of upper limb muscles and late impairment of respiratory muscles. Duration of the disease was longer in the UMN-D group (56 months) than in classic ALS (33 months, p < 0.001). The UMN-D phenotype was a strong independent predictor of long survival. In summary, UMN-D ALS showed significant differences in age of onset, sex ratio, pattern of spreading and prognosis with respect to other ALS forms, most probably reflecting biological differences.

TTR-related amyloid neuropathy: clinical, electrophysiological and pathological findings in 15 unrelated patients

Familial amyloid polyneuropathy (FAP) is a rare condition caused by mutations of the transthyretin (TTR) gene and it is generally characterized by a length-dependent polyneuropathy affecting prevalently the small fibers. We reviewed clinical, electrophysiological and pathological findings of 15 unrelated patients with genetically confirmed TTR-FAP. All patients presented a progressive sensory-motor polyneuropathy. Pathological findings were negative for amyloid deposits in about half of the cases. Sequence analysis of TTR gene revealed the presence of three different mutations (p.Val30Met, p.Phe64Leu, and p.Ala120Ser). The p.Val30Met was the most frequently identified mutation and it often occurred in apparently sporadic cases. Conversely, the p.Phe64Leu generally presented in a high percentage of familial cases in patients coming from Southern Italy. Clinicians should consider, to avoid misdiagnosis, the screening for TTR mutations in patients presenting with progressive axonal polyneuropathy of undetermined etiology, including apparently sporadic cases with pathological examinations negative for amyloid deposition.

SOD1 G93D mutation presenting as paucisymptomatic amyotrophic lateral sclerosis.

We describe a patient with a familial form of amyotrophic lateral sclerosis (ALS) in which a heterozygous G > A exchange at position 1087 in the SOD1 gene was detected. This mutation results in an amino acid substitution of aspartate for glycine at position 93 (G93D). The patient had a five-year history of fasciculations in all four limbs, with no clear evidence of muscular atrophy or weakness at last follow-up. However, electrophysiological examination revealed lower and upper motor neuron involvement. His mother and a cousin had died of ALS after prolonged disease. This report shows that G93D may cause a form of ALS with slow progression, long-lasting paucisymptomatic phase and both lower and upper motor neuron involvement.