Lorenzo Verriello

Correlations between individual clinical manifestations and CTG repeat amplification in myotonic dystrophy.

Myotonic dystrophy (DM) is a multisystemic disease caused by the expansion of a CTG repeat, located in the 3′‐untranslated region of the DMPK gene. The number of CTG repeats broadly correlates with the overall severity of the disease. However, correlations between CTG repeat number and presence/absence or severity of individual clinical manifestations in the same patients are yet scarce. In this study the number of CTG repeats detected in blood cells of 24 DM subjects was correlated with the severity of single clinical manifestations. The presence/absence of muscular atrophy, respiratory insufficiency, cardiac abnormalities, diabetes, cataract, sleep disorders, sterility or hypogonadism is not related to the number of CTG repeats. Muscular atrophy and respiratory insufficiency are present with the highest frequency, occurring in 96 and 92% of the cases, respectively. A significant correlation was found with age of onset (r=−0.57, p<0.01), muscular disability (r=0.46, p<0.05), intellective quotient (r=−0.58, p<0.01) and short‐term memory (r=−0.59, p<0.01). Therefore, the CTG repeat number has a predictive value only in the case of some clinical manifestations, this suggesting that pathogenetic mechanisms of DM may differ depending on the tissue.

The accuracy of discharge diagnosis coding for Amyotrophic Lateral Sclerosis in a large teaching hospital

To evaluate the accuracy of hospital discharge data as a source of Amyotrophic Lateral Sclerosis (ALS) cases for epidemiological studies or disease registries, a validation study was performed. All records of patients discharged in 2005 and 2006 with principal or secondary International Classification of Diseases, 9th rev., Clinical Modification (ICD 9 CM) diagnosis code of ALS (335.20), other anterior horn cell disease (335), spinal cord disease (336), hereditary and idiopathic peripheral neuropathy (356), inflammatory and toxic neuropathy (357), myoneural disorders (358), muscular dystrophies and myopathies (359), were selected from the electronic archive of discharge data of the University Hospital of Udine, Friuli Venezia Giulia Region, North East Italy. Corresponding clinical documentation was reviewed to ascertain the presence of El Escorial criteria, the gold standard. Sensitivity of the ICD 9 CM discharge code 335.20 was 93% (95%CI: 82–99%) and decreased to 91% (95%CI: 77–98%) when suspect ALS was excluded. Specificity was 99% (95%CI: 97–99%). The ICD 9 CM discharge code 335.20 can identify a high percentage of hospitalizations of patients truly affected by ALS and of patients with no ALS, among selected neurological diagnostic codes. To ensure complete ALS case ascertainment, prospective population-based registries or epidemiologic studies require active prospective surveillance and use of multiple sources, among them hospital discharge archives can provide accurate information.

The Incidence of Amyotrophic Lateral Sclerosis in Friuli Venezia Giulia, Italy, from 2002 to 2009: A Retrospective Population-Based Study

Background: We conducted a retrospective population-based study to estimate the incidence of amyotrophic lateral sclerosis (ALS) in Friuli Venezia Giulia, Italy, from 2001 to 2009. Methods: Multiple sources were used for case ascertainment: Health databases, archives of the neurology departments and of the regional chapter of the Italian ALS Association. The diagnosis was validated through clinical documentation review. Crude and standardized incidence rates (IRs) per 100,000 person-years were calculated. Results: We identified 262 incident ALS cases, 50.4% men, 4.2% familial. Half of the patients had spinal onset (56.8% in men) and 25.2% bulbar (29% in women). Bulbar onset had a similar frequency in women (31.7%) and men (31.5%) aged 67 or above at diagnosis. The crude IR was 2.72 (95% confidence interval, 95% CI, 2.39-3.05) and the male:female ratio 1.08. The IR peaked in the 65-74 age group, with a second increase in men 85 years and older. The IR standardized to the 2001 Italian population was 2.38 (95% CI 2.13-2.63) and to the 2000 European population 2.58 (95% CI 2.34-2.81). Conclusions: This retrospective study found IRs of ALS in the range of Italian and European prospective population-based registries, suggesting an almost complete case ascertainment.

Botulinum neurotoxin serotype D is poorly effective in humans: An in vivo electrophysiological study

OBJECTIVE Botulinum neurotoxins act on nerve endings and block neurotransmitter release. Their potency is due to their enzymatic activity and high affinity binding to neurons. Botulinum toxin type A is used in the treatment of human diseases characterized by hyperactivity of peripheral cholinergic nerve terminals, but some patients are or become resistant to it. This can be overcome by using other botulinum toxins, and studies have been performed with different toxin serotypes. Botulinum neurotoxin type D has never been tested in humans in vivo, and, therefore, we investigated the action of this toxin in mouse and human muscles. METHODS Botulinum toxin type D potency was determined on mouse hemidiaphragm and on rat neuronal cultures. From these experiments, doses to be injected in human volunteers were decided. The compound muscle action potential of toxin-injected Extensor Digitorum Brevis muscle was measured at different times points after injection in human volunteers. RESULTS Botulinum toxin type D is poorly effective in inducing human skeletal muscle paralysis. CONCLUSIONS Botulinum toxin type D is very potent in mice and almost ineffective in humans in vivo. SIGNIFICANCE The results shed new light on the mechanism of toxin type D binding to the neuronal surface receptors.

The Use of Antidepressant Medication before and after the Diagnosis of Amyotrophic Lateral Sclerosis: A Population-Based Cohort Study

Background: The prevalent use of antidepressants (ATDs) in patients with Amyotrophic Lateral Sclerosis (ALS) varies across cross-sectional and clinic-based published studies. This population-based cohort study assesses the real-world prevalence of the use of ATDs, its trajectory and the association of incident use with clinical characteristics. Methods: All patients with incident ALS in the Friuli Venezia Giulia region, Italy, from 2002 to 2009, were identified through multiple sources including health databases. Diagnosis was validated through clinical documentation review. ATDs prescriptions from 2000 to 2011 were obtained from regional database. The trajectory was estimated through generalized estimating equations for repeated measures logistic regression and the Hazard ratio (HR) of initiating ATDs through multivariate proportional hazard Cox regression. Results: In this cohort of 261 ALS cases, age-, sex-adjusted prevalence of the use of ATDs was 37.3%, higher than in general population. The trajectory increased by 16% in 1-year period across diagnosis. Age ≤67 years at diagnosis (HR 1.28, 95% CI 0.84-1.95) and bulbar onset (1.43, 95% CI 0.90-2.26) were positively associated with initiating ATDs after diagnosis. Conclusions: More than one-third of patients used ATDs. Depression may occur more frequently than previously reported. Depression may precede motor alterations and be related to both ALS diagnosis and progression.

Rhabdomyolysis caused by tocolytic therapy with ritodrine hydrochloride

We report a case of rhabdomyolysis with severe generalized weakness and muscle pain after administration of ritodrine hydrochloride, in a pregnant patient without history of neuromuscular disease. Laboratory tests showed an increase of blood CK value and myoglobinuria. An electromyography was performed, revealing a typical myogenic pattern and diffuse denervation activity. Muscular biopsy allowed to rule out inflammatory and metabolic myopathy. After delivery, the patient underwent intensive rehabilitation with progressive improvement of her clinical situation, until complete recovery. Three months later, both neurological assessment and CK levels were normal. This case highlights that rhabdomyolysis has to be considered even in patient treated with ritodrine alone and without history of neuromuscular disease. Therefore, muscular symptoms and CK levels should be monitored in women treated with ritodrine for premature labour.

Evaluating the SERCA2 and VEGF mRNAs as Potential Molecular Biomarkers of the Onset and Progression in Huntington's Disease

Abnormalities of intracellular Ca2+ homeostasis and signalling as well as the down-regulation of neurotrophic factors in several areas of the central nervous system and in peripheral tissues are hallmarks of Huntington’s disease (HD). As there is no therapy for this hereditary, neurodegenerative fatal disease, further effort should be made to slow the progression of neurodegeneration in patients through the definition of early therapeutic interventions. For this purpose, molecular biomarker(s) for monitoring disease onset and/or progression and response to treatment need to be identified. In the attempt to contribute to the research of peripheral candidate biomarkers in HD, we adopted a multiplex real-time PCR approach to analyse the mRNA level of targeted genes involved in the control of cellular calcium homeostasis and in neuroprotection. For this purpose we recruited a total of 110 subjects possessing the HD mutation at different clinical stages of the disease and 54 sex- and age-matched controls. This study provides evidence of reduced transcript levels of sarco-endoplasmic reticulum-associated ATP2A2 calcium pump (SERCA2) and vascular endothelial growth factor (VEGF) in peripheral blood mononuclear cells (PBMCs) of manifest and pre-manifest HD subjects. Our results provide a potentially new candidate molecular biomarker for monitoring the progression of this disease and contribute to understanding some early events that might have a role in triggering cellular dysfunctions in HD.

Identification and characterization of the novel m.8305C>T MTTK and m.4440G>A MTTM gene mutations causing mitochondrial myopathies

We report on two novel mtDNA mutations in patients affected with mitochondrial myopathy. The first patient, a 44-year-old woman, had bilateral eyelid ptosis and the m.8305C>T mutation in the MTTK gene. The second patient, a 56-year-old man, had four-limb muscle weakness and the MTTM gene m.4440G>A mutation. Muscle biopsies in both patients showed ragged red fibers and numerous COX-negative fibers as well as a combined defect of complex I, III and IV activities. The two mutations were heteroplasmic and detected only in muscle tissue, with a higher mutation load in COX-negative fibers. Additionally, both mutations occurred in highly conserved mt-tRNA sites, and were not found by an in silico search in 30,589 human mtDNA sequences. Our report further expands the mutational and phenotypic spectrum of diseases associated with mutations in mitochondrial tRNA genes and reinforces the notion that mutations in mitochondrial tRNAs represent hot spots for mitochondrial myopathies in adults.

Formal Semantics in the Neurology Clinic: Atypical Understanding of Aspectual Coercion in ALS Patients

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of the motor system with subtle adverse effects on cognition. It is still unclear whether ALS also affects language and semantics, and if so, what aspects and processes exactly. We investigated how ALS patients understand verb phrases modified by temporal preposition phrases, e.g., “To watch TV for half an hour.” Interpretation here requires operations such as aspectual coercion that add or delete elements from event structures, depending on temporal modifiers, and constraints on coercion, which make combinations with certain modifiers not viable. Using a theoretically-motivated experimental design, we observed that acceptance rates for aspectual coercion were abnormally high in ALS patients. The effect was largest for the more complex cases of coercion: not those that involve enrichment of event structures (“To switch on the TV in half an hour,” where a number of failed attempts must be included in the interpretation) but those that, if applied, would result in deletion of event structure elements (“To repair the TV for half an hour”). Our experimental results are consistent with a deficit of constraints on coercion, and not with impaired semantic processes or representations, in line with recent studies suggesting that verb semantics is largely spared in ALS.