Does sex influence the natural history of idiopathic adult-onset dystonia?

BACKGROUND: Several earlier studies showed a female predominance in idiopathic adult-onset dystonia (IAOD) affecting the craniocervical area and a male preponderance in limb dystonia. However, sex-related differences may result from bias inherent to study design. Moreover, information is lacking on whether sex-related differences exist in expressing other dystonia-associated features and dystonia spread. OBJECTIVE: To provide accurate information on the relationship between sex differences, motor phenomenology, dystonia-associated features and the natural history of IAOD. METHODS: Data of 1701 patients with IAOD from the Italian Dystonia Registry were analysed. RESULTS: Women predominated over men in blepharospasm, oromandibular, laryngeal and cervical dystonia; the sex ratio was reversed in task-specific upper limb dystonia; and no clear sex difference emerged in non-task-specific upper limb dystonia and lower limb dystonia. This pattern was present at disease onset and the last examination. Women and men did not significantly differ for several dystonia-associated features and tendency to spread. In women and men, the absolute number of individuals who developed dystonia tended to increase from 20 to 60 years and then declined. However, when we stratified by site of dystonia onset, different patterns of female-to-male ratio over time could be observed in the various forms of dystonia. CONCLUSIONS: Our findings provide novel evidence on sex as a key mediator of IAOD phenotype at disease onset. Age-related sexual dimorphism may result from the varying exposures to specific age-related and sex-related environmental risk factors interacting in a complex manner with biological factors such as hormonal sex factors.

The value of routine blood work-up in clinical stratification and prognosis of patients with amyotrophic lateral sclerosis.

BACKGROUND: There is an unmet need in amyotrophic lateral sclerosis (ALS) to provide specific biomarkers for the disease. Due to their easy availability, we aimed to investigate whether routine blood parameters provide useful clues for phenotypic classification and disease prognosis. METHODS: We analyzed a large inpatient cohort of 836 ALS patients who underwent deep phenotyping with evaluation of the clinical and neurophysiological burden of upper (UMN) and lower (LMN) motor neuron signs. Disability and progression rate were measured through the revised ALS Functional Rating Scale (ALSFRS-R) and its changes during time. Cox regression analysis was performed to assess survival associations. RESULTS: Creatinine significantly correlated with LMN damage (r = 0.38), active (r = 0.18) and chronic (r = 0.24) denervation and baseline ALSFRS-R (r = 0.33). Creatine kinase (CK), alanine (ALT) and aspartate (AST) transaminases correlated with active (r = 0.35, r = 0.27, r = 0.24) and chronic (r = 0.37, r = 0.20, r = 0.19) denervation, while albumin and C-reactive protein significantly correlated with LMN score (r = 0.20 and r = 0.17). Disease progression rate showed correlations with chloride (r = -0.19) and potassium levels (r = -0.16). After adjustment for known prognostic factors, total protein [HR 0.70 (95% CI 0.57-0.86)], creatinine [HR 0.86 (95% CI 0.81-0.92)], chloride [HR 0.95 (95% CI 0.92-0.99)], lactate dehydrogenase [HR 0.99 (95% CI 0.99-0.99)], and AST [HR 1.02 (95% CI 1.01-1.02)] were independently associated with survival. CONCLUSIONS: Creatinine is a reliable biomarker for ALS, associated with clinical features, disability and survival. Markers of nutrition/inflammation may offer additional prognostic information and partially correlate with clinical features. AST and chloride could further assist in predicting progression rate and survival.

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.

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.

Phosphorylated tau in plasma could be a biomarker of lower motor neuron impairment in amyotrophic lateral sclerosis.

INTRODUCTION: Plasma levels of phosphorylated tau (P-tau181) have been recently reported to be increased in amyotrophic lateral sclerosis (ALS) and associated with lower motor neuron (LMN) impairment. PATIENTS AND METHODS: We quantified plasma P-tau181 (pP-tau181) in a cohort of 29 deeply phenotyped ALS patients using the new fully automated Lumipulse assay and analysed phenotype-biomarker correlations. RESULTS: pP-tau181 levels correlated positively with a clinical LMN score (r = 0.3803) and negatively, albeit not significantly, with a composite index of muscle strength (r = - 0.3416; p = 0.0811), but not with Penn Upper Motor Neuron (UMN) Score. Accordingly, pP-tau181 correlated with electromyographic indices of spinal active and chronic denervation (r = 0.4507 and r = 0.3864, respectively) but not with transcranial magnetic stimulation parameters of UMN dysfunction. pP-tau181 levels did not correlate with those in the cerebrospinal fluid (CSF), serum NFL, serum GFAP, CSF/serum albumin ratio, or estimated glomerular filtration rate, but correlated with plasma creatine kinase levels (r = 0.4661). Finally, while not being associated with neuropsychological phenotype, pP-tau181 correlated negatively with pH (r = - 0.5632) and positively with partial pressure of carbon dioxide (PaCO2; r = 0.7092), bicarbonate (sHCO3-; r = 0.6667) and base excess (r = 0.6611) on arterial blood gas analysis. DISCUSSION: pP-tau181 has potential as ALS biomarker and could be associated with LMN impairment. Its raised levels might reflect pathophysiological processes (tau hyperphosphorylation and/or release) occurring in the axons of LMNs distantly from the CNS and the CSF. pP-tau181 could also be associated with respiratory dysfunction.

Phenotypic correlates of serum neurofilament light chain levels in amyotrophic lateral sclerosis.

Objective: To investigate the relationship between serum levels of the neuroaxonal degeneration biomarker neurofilament light chain (NFL) and phenotype in ALS. Materials and methods: Serum NFL (sNFL) concentration was quantified in 209 ALS patients and 46 neurologically healthy controls (NHCs). Results: sNFL was clearly increased in ALS patients and discriminated them from NHCs with AUC = 0.9694. Among ALS patients, females had higher sNFL levels, especially in case of bulbar onset. sNFL was more increased in phenotypes with both upper (UMN) and lower motor neuron (LMN) signs, and particularly in those with UMN predominance, compared to LMN forms. At the same time, primary lateral sclerosis (PLS) had significantly lower levels compared to UMN-predominant ALS (AUC = 0.7667). sNFL correlated negatively with disease duration at sampling and ALSFRS-R score, positively with disease progression rate, differed among King's stages, and was negatively associated with survival. It also correlated with clinical/neurophysiological indices of UMN and LMN dysfunction (Penn UMN Score, LMN score, MRC composite score, active spinal denervation score). On the contrary, sNFL was not associated with cognitive deficits nor with respiratory parameters. Notably, we found a negative correlation between sNFL and estimated glomerular filtration rate (eGFR). Interpretation: We confirm that ALS is characterized by increased sNFL levels, whose main determinant is the rate of degeneration of both UMNs and LMNs. sNFL is a biomarker of only motor, not of extra-motor, disease. The negative correlation with kidney function might reflect varying renal clearance of the molecule and deserves further investigation before introducing sNFL measurement as routine test in clinical care of ALS patients.

Regional spreading pattern is associated with clinical phenotype in amyotrophic lateral sclerosis.

Increasing evidence shows that disease spreading in amyotrophic lateral sclerosis (ALS) follows a preferential pattern with more frequent involvement of contiguous regions from the site of symptom onset. The aim of our study was to assess if: (i) the burden of upper (UMN) and lower motor neuron (LMN) involvement influences directionality of disease spreading; (ii) specific patterns of disease progression are associated with motor and neuropsychological features of different ALS subtypes (classic, bulbar, primary lateral sclerosis, UMN-predominant, progressive muscular atrophy, flail arm, flail leg); and (iii) specific clinical features may help identify ALS subtypes, which remain localized to the site of onset for a prolonged time (regionally entrenching ALS). A single-centre, retrospective cohort of 913 Italian ALS patients was evaluated to assess correlations between directionality of the disease process after symptom onset and motor/neuropsychological phenotype. All patients underwent an extensive evaluation including the following clinical scales: Penn Upper Motor Neuron Score (PUMNS), MRC Scale for Muscle Strength and the Edinburgh Cognitive and Behavioural ALS Screen (ECAS). The most frequent initial spreading pattern was that towards adjacent horizontal regions (77.3%), which occurred preferentially in patients with lower MRC scores (P = 0.038), while vertical diffusion (21.1%) was associated with higher PUMNS (P < 0.001) and with reduced survival (P < 0.001). Non-contiguous disease spreading was associated with more severe UMN impairment (P = 0.003), while contiguous disease pattern with lower MRC scores. Furthermore, non-contiguous disease spreading was associated with more severe cognitive impairment in both executive and visuospatial ECAS domains. Individuals with regionally entrenching ALS were more frequently female (45.6% versus 36.9%; P = 0.028) and had higher frequencies of symmetric disease onset (40.3% versus 19.7%; P < 0.001) and bulbar phenotype (38.5% versus 16.4%; P < 0.001). Our study suggests that motor phenotypes characterized by a predominant UMN involvement are associated with a vertical pattern of disease progression reflecting ipsilateral spreading within the motor cortex, while those with predominant LMN involvement display more frequently a horizontal spreading from one side of the spinal cord to the other. These observations raise the hypothesis that one of the mechanisms underlying disease spreading in ALS pathology is represented by diffusion of toxic factors in the neuron microenvironment. Finally, it is possible that in our cohort, regionally entrenching ALS forms are mainly observed in patients with atypical bulbar phenotypes, characterized by a slowly progressive course and relatively benign prognosis.

Clinimetrics and feasibility of the Italian version of the Frontal Assessment Battery (FAB) in non-demented Parkinson's disease patients.

BACKGROUND: This study aimed at assessing the cross-sectional and longitudinal clinimetrics and feasibility of the Frontal Assessment Battery (FAB) in non-demented Parkinson's disease (PD) patients. METHODS: N = 109 PD patients underwent the FAB and the Montreal Cognitive Assessment (MoCA). A subsample of patients further underwent a thorough motor, functional and behavioral evaluation (the last including measures of anxiety, depression and apathy). A further subsample was administered a second-level cognitive battery tapping on attention, executive functioning, language, memory, praxis and visuo-spatial abilities. The following properties of the FAB were tested: (1) concurrent validity and diagnostics against the MoCA; (2) convergent validity against the second-level cognitive battery; (4) association with motor, functional and behavioral measures; (5) capability to discriminate patients from healthy controls (HCs; N = 96); (6) assessing its test-retest reliability, susceptibility to practice effects and predictive validity against the MoCA, as well as deriving reliable change indices (RCIs) for it, at a ≈ 6-month interval, within a subsample of patients (N = 33). RESULTS: The FAB predicted MoCA scores at both T0 and T1, converged with the vast majority of second-level cognitive measures and was associated with functional independence and apathy. It accurately identified cognitive impairment (i.e., a below-cut-off MoCA score) in patients, also discriminating patients from HCs. The FAB was reliable at retest and free of practice effects; RCIs were derived according to a standardized regression-based approach. DISCUSSION: The FAB is a clinimetrically sound and feasible screener for detecting dysexecutive-based cognitive impairment in non-demented PD patients.

Relationship between cerebrospinal fluid/serum albumin quotient and phenotype in amyotrophic lateral sclerosis: a retrospective study on 328 patients.

BACKGROUND: We analysed the relationship between cerebrospinal fluid (CSF)/serum albumin quotient (Q-Alb) and phenotype in a large cohort of patients with amyotrophic lateral sclerosis (ALS). METHODS: Three hundred twenty-eight single-centre consecutive patients with ALS were evaluated for Q-Alb, basic epidemiological and clinical data, motor phenotype, cognitive/behavioural impairment, clinical staging, clinical and neurophysiological indexes of upper (UMN) and lower motor neuron (LMN) dysfunction, and presence of ALS gene mutations. RESULTS: Q-Alb did not correlate with age but was independently associated with sex, with male patients having higher levels than female ones; the site of onset was not independently associated with Q-Alb. Q-Alb was not associated with motor phenotype, cognitive/behavioural impairment, disease stage, progression rate, survival, or genetic mutations. Among measures of UMN and LMN dysfunction, Q-Alb only had a weak positive correlation with an electromyography-based index of active limb denervation. CONCLUSION: Previous work has documented increased Q-Alb in ALS compared to unaffected individuals. This, together with the absence of associations with nearly all ALS phenotypic features in our cohort, suggests dysfunction of the blood-CSF barrier as a shared, phenotype-independent element in ALS pathophysiology. However, correlation with the active denervation index could point to barrier dysfunction as a local driver of LMN degeneration.

Serum levels of glial fibrillary acidic protein in patients with amyotrophic lateral sclerosis.

OBJECTIVE: To compare serum levels of the astrocyte biomarker glial fibrillary acidic protein (GFAP) in patients with amyotrophic lateral sclerosis (ALS) and neurologically healthy controls and to analyze the relations between serum GFAP (sGFAP) and phenotype in ALS. METHODS: We studied 114 ALS patients and 38 controls. sGFAP was quantified with single molecule array (Simoa) technology. RESULTS: In both ALS patients and controls, sGFAP moderately correlated with age. ALS patients had higher sGFAP levels compared to controls, but this yielded a weak discriminative performance (AUC = 0.6198). In ALS, sGFAP was not associated with most of the motor phenotypic features, including site of onset, functional status, disease progression rate, disease stage, and indices of upper (UMN) and lower motor neuron (LMN) impairment. However, sGFAP negatively correlated with cognitive scores regarding ALS-nonspecific functions, particularly memory (r = -0.2082) and tended to be higher in ALS patients with eye movement abnormalities (p = 0.0628). sGFAP also correlated with polysomnographic indices of oxygen desaturation (ODI; r = 0.2639) and apnea-hypopnea (AHI; r = 0.2858). In a multivariate analysis, sGFAP was negatively associated with survival (HR = 1.005). Relevantly, we found a negative correlation between sGFAP and estimated glomerular filtration rate (eGFR; r = -0.3500). INTERPRETATION: Our work provides neurochemical evidence of astrocyte involvement in ALS pathophysiology and particularly in the development of extra-motor manifestations (namely, cognitive - memory - impairment) and respiratory dysfunction. The negative correlation between sGFAP and eGFR has practical relevance and should not be disregarded in future investigations.

Correlation between clinical phenotype and electromyographic parameters in amyotrophic lateral sclerosis.

INTRODUCTION: Even if electromyography (EMG) is routinely used to confirm the diagnosis of amyotrophic lateral sclerosis (ALS), few studies have analysed the correlation between electrophysiological parameters and clinical characteristics of ALS. We assessed if the quantification of active denervation (AD) and chronic denervation (CD) provides clinicians with information about phenotype, disease progression and survival in ALS patients. METHODS: We studied a cohort of 689 ALS patients recording the following parameters: age and site of onset, survival, MRC scale for muscle strength evaluation, burden of upper and lower motor signs as measured with specific scales (PUMNS and LMNS, respectively), ALSFRS-R, progression rate (ΔFS), MITOS and King's Staging systems (KSS). We performed EMG on 11 muscles, and calculated semiquantitative AD and CD scores for each limb, as well as for the bulbar and spinal regions. RESULTS: We found a positive correlation between AD and CD scores with LMNS (respectively p = 4.4 × 10-37 and p = 2.8 × 10-45) and a negative correlation with MRC (respectively p = 4.5 × 10-35 and p = 3.0 × 10-35). Furthermore, patients with higher spinal AD and CD scores had significantly lower ALSFRS-R scores, and higher KSS and MITOS stages. Conversely, only AD was associated to higher ΔFS (p = 1.0 × 10-6) and shorter survival (p = 1.1 × 10-5). CONCLUSION: Our results confirmed that EMG examination represents not only a diagnostic instrument, but also a prognostic tool. In this context, AD seems to be a reliable predictor of disease's progression and survival while CD better describes functional disability.

Progressive motor neuron syndromes with single CNS lesions and CSF oligoclonal bands: never forget solitary sclerosis!

We describe 3 cases of solitary sclerosis (SS), a rare condition characterized by a single inflammatory demyelinating lesion in the white matter of the brain or spinal cord. All patients had progressive limb motor impairment (patient 1, 66-year-old female: left spastic hemiparesis; patient 2, 39-year-old male: right spastic hemiparesis; patient 3, 42-year-old female: proximally predominant left upper limb weakness with amyotrophy and fasciculations). In all patients, MRI disclosed a single small T2-hyperintense demyelinating lesion: in the right anterior paramedian upper medulla, in the median-left paramedian anterior lower medulla, and in the left paramedian anterior cervical spinal cord at C4 level, respectively. In patients 1 and 2, transcranial magnetic stimulation (TMS) demonstrated altered motor evoked potentials (MEPs) and increased central motor conduction time (CMCT) in the affected limbs; in patient 3, needle EMG revealed chronic neurogenic changes in C5-C7 muscles of left upper limb. Patients 1 and 2 had normal brain 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET). CSF analysis demonstrated IgG oligoclonal bands in all patients. In patients 2 and 3, levels of neurofilament light chain (NFL) in CSF and serum, respectively, were within normal limits. The three cases were consistent with the diagnosis of SS. Notably, while the first two cases mimicked Mills' syndrome (the hemiparetic variant of primary lateral sclerosis, PLS), the third one was rather reminiscent of amyotrophic lateral sclerosis (ALS). This suggests including SS in the differential diagnosis not only of PLS, but also of ALS. We also report the first quantification of NFL levels in SS.

Ecological Validity of the Montreal Cognitive Assessment in Non-Demented Parkinson's Disease Patients.

BACKGROUND: The ecological validity of performance-based cognitive screeners needs to be tested in order for them to be fully recommended for use within clinical practice and research. OBJECTIVES: The objective of this study was to examine, within an Italian cohort of non-demented Parkinson's disease (PD) patients, the ecological validity of the Montreal Cognitive Assessment (MoCA) by assessing its association with (1) functional independence (FI), (2) quality of life (QoL), and (3) behavioural-psychological (BP) outcomes. METHODS: Seventy-four non-demented PD patients were administered the MoCA and underwent motor functional - i.e., Unified Parkinson's Disease Rating Scale (UPDRS), Modified Hoehn-Yahr Scale (HY), and Schwab and England Scale (SES) -, behavioural and psychological - i.e., State- and Trait-Anxiety Inventory-Form Y (STAI-Y1/-Y2), Beck Depression Inventory (BDI), and Dimensional Apathy Scale (DAS) - and QoL evaluations - i.e., MOS 36-Item Short Form Health Survey (SF-36). Associations of interest against FI, QoL, and BP outcomes were tested via Bonferroni-corrected Pearson's/Spearman's correlations while covarying for demographics, disease duration as well as UPDRS-III, UPDRS-IV, and HY scores. Intake of psychotropic drugs was also covaried when assessing the association between the MoCA and BP/QoL measures. RESULTS: MoCA scores were significantly associated with the SES (rs(73) = 0.34; p = 0.005) and the DAS-Executive (r(67) = -0.47; p < 0.001), while not to other FI/BP outcomes and QoL measures. CONCLUSIONS: The MoCA is a valid estimate of daily life functional autonomy in non-demented PD patients, also reflecting apathetic features of a dysexecutive nature.

Sudden Onset, Fixed Dystonia and Acute Peripheral Trauma as Diagnostic Clues for Functional Dystonia.

BACKGROUND: The differentiation of functional dystonia from idiopathic dystonia may be clinically challenging. OBJECTIVE: To identify clinical features suggestive of functional dystonia to guide physicians to distinguish functional dystonia from idiopathic dystonia. METHODS: Patient data were extracted from the Italian Registry of Functional Motor Disorders and the Italian Registry of Adult Dystonia. Patients with functional and idiopathic dystonia were followed up at the same clinical sites, and they were similar in age and sex. RESULTS: We identified 113 patients with functional dystonia and 125 with idiopathic dystonia. Sudden onset of dystonia, evidence of fixed dystonia, and acute peripheral trauma before dystonia onset were more frequent in the functional dystonia group. No study variable alone achieved satisfactory sensitivity and specificity, whereas a combination of variables yielded 85% sensitivity and 98% specificity. A diagnostic algorithm was developed to reduce the risk of misclassifying functional dystonia. CONCLUSION: Our findings extend the current diagnostic approach to functional dystonia by showing that clinical information about symptom onset, fixed dystonia, and history of peripheral trauma may provide key clues in the diagnosis of functional dystonia.

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.