Nerve conduction study on the split-hand plus index in Amyotrophic lateral sclerosis: correlations with lower motor neuron impairment.

INTRODUCTION: In the arms of patients with Amyotrophic lateral sclerosis (ALS) two peculiar patterns of dissociated muscular atrophy have been described: the split-hand sign (with predominant atrophy of the lateral aspect of the hand, compared to hypothenar eminence) and the split-hand-plus sign (SHPS), a predominant abductor pollicis brevis (ABP) atrophy with sparing of flexor pollicis longus (FPL). AIMS: In this case-control study, we evaluated the diagnostic utility of a neurophysiological indicator of SHPS and assessed its association with clinical features. METHODS: We prospectively studied 59 incident ALS patients, 61 patients with ALS-mimic disorders (OND) and 61 non-neurological controls (NNCs). ABP and FPL compound muscle action potentials (CMAP) amplitudes were obtained by supramaximal stimulation of median nerve at elbow. Split-hand plus index (SHPI) was calculated according to the formula: APB-CMAP/FPL-CMAP. RESULTS: SHPI was significantly lower in ALS compared to OND patients and NNCs (p < 0.0001). SHPI value < 1 was observed in 2% of NNCs and 9% of OND patients and demonstrated an accuracy of 71% in differentiating ALS from OND and an accuracy of 74% in differentiating ALS from NNC. SHPI was associated with higher LMN score, and higher disease severity as quantified by the ALSFRS-r. CONCLUSION: Our results indicate that SHPI is a reliable indicator to distinguish ALS patients from ONDs and NNCs. SHPI was significantly associated to the degree of lower motor neuron impairment but showed no association with upper motoneuron impairment.

Comparing Essential Tremor with and without Soft Dystonic Signs and Tremor Combined with Dystonia: The TITAN Study.

BACKGROUND: Tremor disorders remain as clinical diagnoses and the rate of misdiagnosis between the commonest non-parkinsonian tremors is relatively high. OBJECTIVES: To compare the clinical features of Essential Tremor without other features (pure ET), ET plus soft dystonic signs (ET + DS), and tremor combined with dystonia (TwD). METHODS: We compared the clinical features of patients with pure ET, ET + DS, and TwD enrolled in The ITAlian tremor Network (TITAN). Linear regression models were performed to determine factors associated with health status and quality of life. RESULTS: Three-hundred-eighty-three patients were included. Sex distribution was significantly different between the groups with males being more represented in pure ET and females in TwD. The initial site of tremor was different between the groups with about 40% of TwD having head tremor and ET + DS unilateral upper limb tremor at onset. This pattern mirrored the distribution of overt dystonia and soft dystonic signs at examination. Sensory trick, task-specificity, and position-dependence were more common, but not exclusive, to TwD. Pure ET patients showed the lowest degree of alcohol responsiveness and ET + DS the highest. Midline tremor was more commonly encountered and more severe in TwD than in the other groups. Regression analyses demonstrated that tremor severity, sex, age, and to a lesser degree the variable "group", independently predicted health status and quality of life, suggesting the existence of other determinants beyond tremor. CONCLUSIONS: Pure ET and TwD manifest with a phenotypic overlap, which calls for the identification of diagnostic biomarkers. ET + DS shared features with both syndromes, suggesting intra-group heterogeneity.

Neurophysiological indices for split phenomena: correlation with age and sex and potential implications in amyotrophic lateral sclerosis.

Background: Split phenomena (SP) are characterized by patterns of differential muscle wasting and atrophy, which are highly prevalent in amyotrophic lateral sclerosis (ALS) patients. Several neurophysiological indicators, including the split-hand index (SHI), split-leg index (SLI), and split-elbow index (SEI), have been proposed to assess SP. Nevertheless, their cutoff values and the impact of age and sex on these measures remain unclear. Methods: We prospectively collected neurophysiological data from 300 healthy adult subjects. The following indices were measured from compound muscle action potentials (CMAPs): SHI [abductor pollicis brevis (APBcmap) x first dorsal interosseous (FDI)cmap/adductor digiti minimi (ADMcmap)], SEI (BICEPScmap/TRICEPScmap), SLI (extensor digit brevis (EDB)cmap/abductor Hallucis (AH)cmap), and the neurophysiological ratios APBcmap /ADMcmap and FDIcmap/ADMcmap. Multiple linear regression analysis was used to investigate the association between age, sex, CMAPs, and neurophysiological indicators. Results: The median SHI was 10.4, with a median APBcmap/ADMcmap ratio of 0.9 and a median FDIcmap/ADMcmap ratio of 1.2. The median SEI was 1.6 (IQR:1.1-2.4) and the median SLI was 0.7 (IQR:0.5-1.0). Negative associations were observed between age, most of the CMAPs, and all the neurophysiological indices, except for SLI. The male subjects exhibited significantly higher CMAP values for the first dorsal interosseous (FDI), biceps, and SHI compared to the female participants. Conclusion: Our findings highlight the importance of age- and sex-adjusted normative data for SP indices, which could enhance their diagnostic accuracy and clinical utility in patients with ALS. The SL index appears to be the most reliable indicator, as it showed no significant association with age or sex.

Does thyroid diseases contribute to the natural history of idiopathic adult-onset dystonia? Data from the Italian Dystonia Registry.

A few earlier observations and recent controlled studies pointed to the possible contribution of thyroid diseases in idiopathic adult-onset dystonia (IAOD). The aim of this study was to investigate the association between thyroid status and clinical characteristics of IAOD, focusing on dystonia localization, spread, and associated features such as tremors and sensory tricks. Patients were identified from those included in the Italian Dystonia Registry, a multicentre dataset of patients with adult-onset dystonia. The study population included 1518 IAOD patients. Patients with hypothyroidism and hyperthyroidism were compared with those without any thyroid disease. In the 1518 IAOD patients, 167 patients (11%; 95% CI 9.5-12.6%) were diagnosed with hypothyroidism and 42 (2.8%; 95% CI 1.99-3.74) with hyperthyroidism. The three groups were comparable in age at dystonia onset, but there were more women than men in the groups with thyroid disease. Analysing the anatomical distribution of dystonia, more patients with blepharospasm were present in the hyperthyroidism group, but the difference did not reach statistical significance after the Bonferroni correction. The remaining dystonia-affected body sites were similarly distributed in the three groups, as did dystonia-associated features and spread. Our findings provided novel information indicating that the high rate of thyroid diseases is not specific for any specific dystonia subpopulation and does not appear to influence the natural history of the disease.

Do cerebrovascular risk factors impact the clinical expression of idiopathic isolated adult-onset dystonia?

BACKGROUND: Although acquired dystonia may develop following ischaemic/haemorrhagic stroke, the relationship between cerebrovascular disease and idiopathic dystonia has been poorly investigated. This cross sectional study aimed at evaluating the impact of cerebrovascular risk factors on the clinical expression of idiopathic adult onset dystonia (IAOD), with reference to dystonia localization and dystonia-associated features. METHODS: Data were obtained from the Italian Dystonia Registry. Patients with IAOD were stratified into two groups according to the presence of diabetes mellitus and/or arterial hypertension and/or dyslipidemia and/or heart disease. The two groups were compared for demographic features, dystonia phenotype, and dystonia-associated features (sensory trick, tremor, eye symptoms in blepharospasm, and neck pain in cervical dystonia). RESULTS: A total of 1108 patients participated into the study. Patients who reported one cerebrovascular factor or more (n = 555) had higher age and longer disease duration than patients who did not. On multivariable logistic regression analysis, blepharospasm was the only localization, and sensory trick was the only dystonia-associated feature that was significantly associated with cerebrovascular risk factors. Linear regression analysis showed that the strength of the association between cerebrovascular factors and blepharospasm/sensory trick increased with increasing the number of cerebrovascular factors per patient. CONCLUSIONS: Results of the present study showed that cerebrovascular risk factors may be associated with specific features of IAOD that is development of blepharospasm and sensory trick. Further studies are needed to better understand the meaning and the mechanisms underlying this association.

A Clinical Scale for Rating the Severity of Bulbar Lower Motor Neuron Dysfunction in Amyotrophic Lateral Sclerosis.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is characterized by the progressive loss of upper (UMN) and lower motor neurons (LMN) in four different body regions (bulbar, cervical, thoracic, and lumbosacral). Over the past decades, several clinical scoring systems have been developed to assess the UMN and LMN burden in ALS. However, concerning the bulbar LMN burden, the available scoring systems solely assess the presence/absence of bulbar LMN signs without providing a degree of impairment. Therefore, in this study, we proposed a novel scale to stratify subjects with ALS according to the bulbar LMN involvement and assessed its prognostic value. METHODS: We developed a four-item scale based on the LMN signs according to the El Escorial criteria. Ten raters, specializing in ALS or neurocognitive disorders, retrospectively applied the scale to the first evaluation of 195 patients with ALS. Cohen's kappa (Cohen's k) and an intra-class correlation coefficient (ICC) were used to assess the inter-rater reliability. The Kaplan-Mayer estimator was used to estimate survival distribution according to the bulbar scale scores. RESULTS: The raters showed a substantial to excellent agreement with Cohen's k, ranging from 0.834 to 0.975, with an overall ICC of 0.922 (95% CI = 0.906-0.936). The survival distribution was statistically different across the three bulbar scale scores (χ2(2) = 9.50, p < 0.01). CONCLUSIONS: Our bulbar LMN scale represents a reliable measure of the bulbar LMN signs in ALS. This easy-to-administer clinical scale could provide unique information in phenotyping and predicting survival in ALS.

Phenotypic Variability in Acquired and Idiopathic Dystonia.

Background: To date, a few studies have systematically investigated differences in the clinical spectrum between acquired and idiopathic dystonias. Objectives: To compare demographic data and clinical features in patients with adult-onset acquired and idiopathic dystonias. Methods: Patients were identified from among those included in the Italian Dystonia Registry, a multicenter Italian dataset of patients with adult-onset dystonia. Study population included 116 patients with adult-onset acquired dystonia and 651 patients with isolated adult-onset idiopathic dystonia. Results: Comparison of acquired and idiopathic dystonia revealed differences in the body distribution of dystonia, with oromandibular dystonia, limb and trunk dystonia being more frequent in patients with acquired dystonia. The acquired dystonia group was also characterized by lower age at dystonia onset, greater tendency to spread, lower frequency of head tremor, sensory trick and eye symptoms, and similar frequency of neck pain associated with CD and family history of dystonia/tremor. Conclusions: The clinical phenomenology of dystonia may differ between acquired and idiopathic dystonia, particularly with regard to the body localization of dystonia and the tendency to spread. This dissimilarity raises the possibility of pathophysiological differences between etiologic categories.

AChR+ Ocular Myasthenia and Facial Hemispasm: A Case Report of Unusual Association and Botulinum Toxic Type A Safety and Efficacy.

INTRODUCTION: Hemifacial spasm represents segmental myoclonus of muscles innervated by the facial nerve, which is usually and successfully treated with botulinum toxin. Botulinum toxin (BTX) acts as an acetylcholine release inhibitor at presynaptic cholinergic junctions and therefore is considered contraindicated (or administrable with caution) in patients with neuromuscular disorders like Myasthenia Gravis (MG). Moreover, to date, the association of hemifacial spasm and ocular MG is extremely rare and only a few cases have been described. CASE PRESENTATION: We report the case of a 73 years old man with a 3-year history of ocular MG who developed a left hemifacial spasm. The patient underwent hemispasm, treatment with BTX type A (abobotulinum toxin-A, total dose of 50 IU) that resulted in safe and successful 6 months re-evaluation. CONCLUSION: Our results suggest that in selected cases with concomitant MG and conditions characterized by orbicularis oculi spasms or hemispasm, BTX therapy may not be contraindicated and could be given at longer intervals due to prolonged effects.

The Italian tremor Network (TITAN): rationale, design and preliminary findings.

INTRODUCTION: The recently released classification has revised the nosology of tremor, defining essential tremor (ET) as a syndrome and fueling an enlightened debate about some newly conceptualized entities such as ET-plus. As a result, precise information of demographics, clinical features, and about the natural history of these conditions are lacking. METHODS: The ITAlian tremor Network (TITAN) is a multicenter data collection platform, the aim of which is to prospectively assess, according to a standardized protocol, the phenomenology and natural history of tremor syndromes. RESULTS: In the first year of activity, 679 patients have been recruited. The frequency of tremor syndromes varied from 32% of ET and 41% of ET-plus to less than 3% of rare forms, including focal tremors (2.30%), task-specific tremors (1.38%), isolated rest tremor (0.61%), and orthostatic tremor (0.61%). Patients with ET-plus were older and had a higher age at onset than ET, but a shorter disease duration, which might suggest that ET-plus is not a disease stage of ET. Familial aggregation of tremor and movement disorders was present in up to 60% of ET cases and in about 40% of patients with tremor combined with dystonia. The body site of tremor onset was different between tremor syndromes, with head tremor being most commonly, but not uniquely, associated with dystonia. CONCLUSIONS: The TITAN study is anticipated to provide clinically relevant prospective information about the clinical correlates of different tremor syndromes and their specific outcomes and might serve as a basis for future etiological, pathophysiological, and therapeutic research.

Spread of segmental/multifocal idiopathic adult-onset dystonia to a third body site.

BACKGROUND: Adult-onset focal dystonia can spread to involve one, or less frequently, two additional body regions. Spread of focal dystonia to a third body site is not fully characterized. MATERIALS AND METHODS: We retrospectively analyzed data from the Italian Dystonia Registry, enrolling patients with segmental/multifocal dystonia involving at least two parts of the body or more. Survival analysis estimated the relationship between dystonia features and spread to a third body part. RESULTS: We identified 340 patients with segmental/multifocal dystonia involving at least two body parts. Spread of dystonia to a third body site occurred in 42/241 patients (17.4%) with focal onset and 10/99 patients (10.1%) with segmental/multifocal dystonia at onset. The former had a greater tendency to spread than patients with segmental/multifocal dystonia at onset. Gender, years of schooling, comorbidity, family history of dystonia/tremor, age at dystonia onset, and disease duration could not predict spread to a third body site. Among patients with focal onset in different body parts (cranial, cervical, and upper limb regions), there was no association between site of focal dystonia onset and risk of spread to a third body site. DISCUSSION AND CONCLUSION: Spread to a third body site occurs in a relative low percentage of patients with idiopathic adult-onset dystonia affecting two body parts. Regardless of the site of dystonia onset and of other demographic/clinical variables, focal onset seems to confer a greater risk of spread to a third body site in comparison to patients with segmental/multifocal dystonia at onset.

Motor and Sensory Features of Cervical Dystonia Subtypes: Data From the Italian Dystonia Registry.

Introduction: Cervical dystonia (CD) is one of the most common forms of adult-onset isolated dystonia. Recently, CD has been classified according to the site of onset and spread, in different clinical subgroups, that may represent different clinical entities or pathophysiologic subtypes. In order to support this hypothesis, in this study we have evaluated whether different subgroups of CD, that clinically differ for site of onset and spread, also imply different sensorimotor features. Methods: Clinical and demographic data from 842 patients with CD from the Italian Dystonia Registry were examined. Motor features (head tremor and tremor elsewhere) and sensory features (sensory trick and neck pain) were investigated. We analyzed possible associations between motor and sensory features in CD subgroups [focal neck onset, no spread (FNO-NS); focal neck onset, segmental spread (FNO-SS); focal onset elsewhere with segmental spread to neck (FOE-SS); segmental neck involvement without spread (SNI)]. Results: In FNO-NS, FOE-SS, and SNI subgroups, head tremor was associated with the presence of tremor elsewhere. Sensory trick was associated with pain in patients with FNO-NS and with head tremor in patients with FNO-SS. Conclusion: The frequent association between head tremor and tremor elsewhere may suggest a common pathophysiological mechanism. Two mechanisms may be hypothesized for sensory trick: a gating mechanism attempting to reduce pain and a sensorimotor mechanism attempting to control tremor.

Demographic and clinical determinants of neck pain in idiopathic cervical dystonia.

Cervical dystonia is associated with neck pain in a significant proportion of cases, but the mechanisms underlying pain are largely unknown. In this exploratory study, we compared demographic and clinical variables in cervical dystonia patients with and without neck pain from the Italian Dystonia Registry. Univariable and multivariable logistic regression analysis indicated a higher frequency of sensory trick and a lower educational level among patients with pain.

Does acute peripheral trauma contribute to idiopathic adult-onset dystonia?

BACKGROUND: Acute peripheral trauma is a controversial risk factor for idiopathic dystonia. MATERIALS AND METHODS: We retrospectively analyzed data from the Italian Dystonia Registry regarding the occurrence of acute peripheral trauma severe enough to require medical attention in 1382 patients with adult-onset idiopathic dystonia and 200 patients with acquired adult-onset dystonia. RESULTS: Patients with idiopathic and acquired dystonia showed a similar burden of peripheral trauma in terms of the number of patients who experienced trauma (115/1382 vs. 12/200, p = 0.3) and the overall number of injuries (145 for the 1382 idiopathic patients and 14 for the 200 patients with secondary dystonia, p = 0.2). Most traumas occurred before the onset of idiopathic or secondary dystonia but only a minority of such injuries (14 in the idiopathic group, 2 in the acquired group, p = 0.6) affected the same body part as that affected by dystonia. In the idiopathic group, the elapsed time between trauma and dystonia onset was 8.1 ±â€¯9.2 years; only six of the 145 traumas (4.1%) experienced by 5/1382 idiopathic patients (0.36%) occurred one year or less before dystonia onset; in the acquired dystonia group, the two patients experienced prior trauma to the dystonic body part 5 and 6 years before dystonia development. DISCUSSION AND CONCLUSION: Our data suggest that the contribution of peripheral acute trauma to idiopathic dystonia is negligible, if anything, and likely involves only a small subset of patients.