Altered TDP-43-dependent splicing in HSPB8-related distal hereditary motor neuropathy and myofibrillar myopathy.

BACKGROUND AND PURPOSE: Mutations in the small heat-shock protein 22 gene (HSPB8) have been associated with Charcot-Marie-Tooth disease type 2L, distal hereditary motor neuropathy (dHMN) type IIa and, more recently, distal myopathy/myofibrillar myopathy (MFM) with protein aggregates and TDP-43 inclusions. The aim was to report a novel family with HSPB8K141E -related dHMN/MFM and to investigate, in a patient muscle biopsy, whether the presence of protein aggregates was paralleled by altered TDP-43 function. METHODS: We reviewed clinical and genetic data. We assessed TDP-43 expression by qPCR and alternative splicing of four previously validated direct TDP-43 target exons in four genes by reverse transcriptase-polymerase chain reaction. RESULTS: The triplets and their mother presented in the second to third decade of life with progressive weakness affecting distal and proximal lower limb and truncal muscles. Nerve conduction study showed a motor axonal neuropathy. The clinical features, moderately raised creatin kinase levels, selective pattern of muscle involvement on magnetic resonance imaging and pathological changes on muscle biopsy, including the presence of protein aggregates, supported the diagnosis of a contemporary primary muscle involvement. In affected muscle tissue we observed a consistent alteration of TDP-43-dependent splicing in three out of four TDP-43-target transcripts (POLDIP3, FNIP1 and BRD8), as well as a significant decrease of TDP-43 mRNA levels. CONCLUSIONS: Our study confirmed the role of mutated HSPB8 as a cause of a combined neuromuscular disorder encompassing dHMN and MFM with protein aggregates. We identified impaired RNA metabolism, secondary to TDP-43 loss of function, as a possible pathological mechanism of HSPB8K141E toxicity, leading to muscle and nerve degeneration.

No effect of AR polyG polymorphism on spinal and bulbar muscular atrophy phenotype.

BACKGROUND AND PURPOSE: Disease severity varies considerably among patients with Spinal and Bulbar Muscular Atrophy (SBMA). Our aim was to investigate the role of androgen receptor (AR) polymorphic repeats in SBMA phenotype. METHODS: We analyzed the length of AR polyQ and polyG tracts in 159 SBMA patients. RESULTS: No relationship between polyG size or polyG/polyQ haplotypes and clinical phenotype was found. An independent negative correlation between polyQ-length and onset of weakness was confirmed (P < 0.001). CONCLUSIONS: The negative results of our study prompt to continue the search for potential disease modifiers in SBMA outside the AR gene.

Tauroursodeoxycholic acid in the treatment of patients with amyotrophic lateral sclerosis.

BACKGROUND AND PURPOSE: Tauroursodeoxycholic acid (TUDCA) is a hydrophilic bile acid that is produced in the liver and used for treatment of chronic cholestatic liver diseases. Experimental studies suggest that TUDCA may have cytoprotective and anti-apoptotic action, with potential neuroprotective activity. A proof of principle approach was adopted to provide preliminary data regarding the efficacy and tolerability of TUDCA in a series of patients with amyotrophic lateral sclerosis (ALS). METHODS: As a proof of principle, using a double-blind placebo controlled design, 34 ALS patients under treatment with riluzole who were randomized to placebo or TUDCA (1 g twice daily for 54 weeks) were evaluated after a lead-in period of 3 months. The patients were examined every 6 weeks. The primary outcome was the proportion of responders [those subjects with improvement of at least 15% in the Amyotrophic Lateral Sclerosis Functional Rating Scale Revised (ALSFRS-R) slope during the treatment period compared to the lead-in phase]. Secondary outcomes included between-treatment comparison of ALSFRS-R at study end, comparison of the linear regression slopes for ALSFFRS-R mean scores and the occurrence of adverse events. RESULTS: Tauroursodeoxycholic acid was well tolerated; there were no between-group differences for adverse events. The proportion of responders was higher under TUDCA (87%) than under placebo (P = 0.021; 43%). At study end baseline-adjusted ALSFRS-R was significantly higher (P = 0.007) in TUDCA than in placebo groups. Comparison of the slopes of regression analysis showed slower progression in the TUDCA than in the placebo group (P < 0.01). CONCLUSIONS: This pilot study provides preliminary clinical data indicating that TUDCA is safe and may be effective in ALS.

Adult polyglucosan body disease in a patient originally diagnosed with Fabry's disease.

Adult polyglucosan body disease is a rare autosomal recessive disease, caused by glycogen branching enzyme gene mutations, characterised by urinary dysfunction, spastic paraplegia with vibration sense loss, peripheral neuropathy, and cognitive impairment. Fabry's disease is an X-linked lysosomal storage disorder caused by α-galactosidase A gene mutations; neurological manifestations include cerebrovascular accidents, small-fibre neuropathy and autonomic dysfunction. Here, we report the case of a 44-year-old Sicilian male with stroke-like episodes, hypohidrosis and mild proteinuria, which led to the diagnosis of Fabry's disease after a hemizygous mutation (p.Ala143Thr) in α-galactosidase A gene was detected. Subsequently, he developed progressive walking difficulties and dementia, which were considered atypical for Fabry's disease. Therefore, we performed additional investigations that eventually led to the diagnosis of adult polyglucosan body disease caused by two novel missense mutations (p.Asp413His and p.Gly534Val) in the glycogen branching enzyme gene. Recently, the pathogenic role of the p.Ala143Thr mutation in causing Fabry's disease has been questioned. This case underlines the importance of performing further investigations when facing with atypical features even in the presence of a genetic diagnosis of a rare disease.

Widespread microstructural white matter involvement in amyotrophic lateral sclerosis: a whole-brain DTI study.

BACKGROUND AND PURPOSE: The extensive application of advanced MR imaging techniques to the study of ALS has undoubtedly improved our knowledge of disease pathophysiology, even if the actual spread of the neurodegenerative process throughout the central nervous system is not fully understood. The present study aimed to detect WM patterns of microstructural abnormalities to better investigate the pathologic process in ALS, within but also beyond CSTs, in a whole-brain analysis. MATERIALS AND METHODS: DTI was performed in 19 patients with ALS and 20 matched healthy controls, by using whole-brain TBSS and VOI analyses. RESULTS: We observed a significant decrease of FA in the body of CC of the ALS group (P < .05). At the VOI level, both FA decrease and RD increase in the body of CC significantly correlated with the UMN score (P = .003 and P = .02). Additionally, significant voxelwise positive correlations between FA and the ALSFRS-R were detected in the WM tracts underneath the left premotor cortex (P < .05). CONCLUSIONS: The correlations between reduction of FA and increase of RD in the body of CC with the UMN score indicate that the WM degeneration in the CC is strictly related to the ALS pyramidal impairment, while the correlation between FA and ALSFRS-R in the associative tracts underneath the left premotor cortex might reflect the progressive spread of the disease from the motor toward the extramotor areas.

Search for compensation postures with videofluoromanometric investigation in dysphagic patients affected by amyotrophic lateral sclerosis.

PURPOSE: This study was undertaken to verify the effectiveness of compensatory postures, suggested on the basis of the type of dysphagia identified at videofluoromanometric (VFM) investigation to ensure safe oropharyngeal transit. MATERIALS AND METHODS: Eighty-one patients with amyotrophic lateral sclerosis (ALS) underwent speech therapy assessment and VFM investigation of the swallowing process. In the event of altered transit, penetration or aspiration of contrast material into the airways, compensation postures for correction of the swallowing disorder were suggested and verified during VFM examination. RESULTS: In 37 patients, contrast agent transport was preserved and safe; in 19, we observed penetration of the contrast agent into the laryngeal inlet without aspiration; in 24, there was aspiration (four preswallowing, eight intraswallowing, nine postswallowing, three mixed), whereas in one patient no transit was seen. Penetration without aspiration was resolved by coughing or throat clearing; aspiration was resolved in 13 patients by assuming the chin-tuck posture and in six by rotating the head; in five patients, it was not resolved. A hyperextended head posture proved to be effective to resolve lack of transit. CONCLUSIONS: By correlating morphological with functional data, VFM enables one not only to precisely characterise the dysphagic disorder but also to identify the most appropriate compensation posture for each patient and verify its effectiveness.

Amyotrophic lateral sclerosis: sonographic evaluation of dysphagia.

PURPOSE: The authors sought to determine the role of video ultrasonography (VUS) in the diagnostic assessment of dysphagia in patients with amyotrophic lateral sclerosis (ALS). MATERIALS AND METHODS: Nine patients underwent simultaneous static and dynamic VUS examination and videofluoroscopy (VFS) of swallowing. RESULTS: At the static phase, VUS showed 5/9 patients had lingual atrophy. Abnormal bolus position was observed in 6/9 patients at VUS and 3/9 at VFS. Both techniques identified an inability to keep the bolus in the oral cavity in 4/9 patients. At the dynamic phase, reduced lingual movement was observed in 5/9 patients at VUS and 2/9 at VFS. Disorganised tongue movement was seen in 3/9 patients at VUS and in 2/9 at VFS. Fragmented swallowing was only visualised at VUS. Stagnation of ingested material was never visualised at VUS, whereas it was clearly depicted in 2/9 patients at VFS. CONCLUSIONS: VUS can be integrated into the diagnostic protocol for evaluating swallowing in patients with ALS, as it has higher sensitivity than VFS in assessing the dynamic factors that represent the early signs of dysphagia.