Near-Infrared Transflectance Spectroscopy Discriminates Solutions Containing Two Commercial Formulations of Botulinum Toxin Type A Diluted at Recommended Volumes for Clinical Reconstitution

: Botulinum neurotoxin type A (BoNT-A) is the active substance in pharmaceutical preparations widely used worldwide for the highly effective treatment of various disorders. Among the three commercial formulations of BoNT-A currently available in Italy for neurological indications, abobotulinum A toxin (Dysport\uae, Ipsen SpA, Milano, Italy) and incobotulinum A toxin (Xeomin\uae, Merz Pharma Italia srl, Milano, Italy) differ in the content of neurotoxin, non-toxic protein, and excipients. Clinical applications of BoNT-A adopt extremely diluted solutions (10-6 mg/mL) for injection in the target body district. Near-infrared spectroscopy (NIRS) and chemometrics allow rapid, non-invasive, and non-destructive methods for qualitative and quantitative analysis. No data are available to date on the chemometric analysis of the spectral fingerprints acquired from the diluted commercial formulations of BoNT-A. In this proof-of-concept study, we tested whether NIRS can categorize solutions of incobotulinum A toxin (lacking non-toxic proteins) and abobotulinum A toxin (containing non-toxic proteins). Distinct excipients in the two formulations were also analyzed. We acquired transmittance spectra in the visible and short-wave infrared regions (350-2500 nm) by an ASD FieldSpec 4\u2122 Standard-Res Spectrophotoradiometer, using a submerged dip probe designed to read spectra in transflectance mode from liquid samples. After preliminary spectra pre-processing, principal component analysis was applied to characterize the spectral features of the two BoNT-A solutions and those of the various excipients diluted according to clinical standards. Partial least squares-discriminant analysis was used to implement a classification model able to discriminate the BoNT-A solutions and excipients. NIRS distinguished solutions containing distinct BoNT-A commercial formulations (abobotulinum A toxin vs. incobotulinum A toxin) diluted at recommended volumes for clinical reconstitution, distinct proteins (HSA vs. incobotulinum A toxin), very diluted solutions of simple sugars (lactose vs. sucrose), and saline or water. Predictive models of botulinum toxin formulations were also performed with the highest precision and accuracy

The Ventricular System Enlarges Abnormally in the Seventies, Earlier in Men, and First in the Frontal Horn: A Study Based on More Than 3,000 Scans

Objectives: To detect on computed tomography (CT) brain scans the trajectories of normal and abnormal ventricular enlargement during aging. Methods: For each 1-year age cohort, we assessed in 3,193 axial CT scans the Evans' index (EI) in the anterior frontal horns and the parieto-occipital (POR) and temporal ratio (TR) in the posterior and inferior horns. Cut-off values for abnormal enlargement were based on previous clinical studies. Results: The mean age associated with normal linear measures was 71 years. Values for all three measures increased with age, showing a linear relationship below-but not above-each cut-off value. The mean age of participants with abnormal enlargement on CT progressed from 79 years for EI to 83 years for POR to 87 years for TR. These results suggested that ventricular dilatation progresses in an age-location relationship. First comes enlargement of the frontal horns (13.8% of scans), followed by the parieto-occipital horns (15.1% of scans) and then temporal horn enlargement (6.8% of scans). Scans from men displayed abnormal values earlier than scans from women (on average 6 years). Risk increased 5.1% annually for abnormal EI, 9.0% for abnormal POR, and 11% for abnormal TR (all p < 0.001). The most frequent agreement between categories (normal-abnormal) for values of neuroimaging measures was identified for POR-TR. Conclusion: The results of this large radiological study suggest that the ventricular system enlarges progressively during aging, and in a subset of patients follows an abnormal consecutive geometric dilatation, influenced by age and sex

A randomised controlled cross-over double-blind pilot study protocol on THC:CBD oromucosal spray efficacy as an add-on therapy for post-stroke spasticity

Stroke is the most disabling neurological disorder and often causes spasticity. Transmucosal cannabinoids (tetrahydrocannabinol and cannabidiol (THC:CBD), Sativex) is currently available to treat spasticity-associated symptoms in patients with multiple sclerosis. Cannabinoids are being considered useful also in the treatment of pain, nausea and epilepsy, but may bear and increased risk for cardiovascular events. Spasticity is often assessed with subjective and clinical rating scales, which are unable to measure the increased excitability of the monosynaptic reflex, considered the hallmark of spasticity. The neurophysiological assessment of the stretch reflex provides a precise and objective method to measure spasticity. We propose a novel study to understand if Sativex could be useful in reducing spasticity in stroke survivors and investigating tolerability and safety by accurate cardiovascular monitoring

"Spastic dystonia" or "Inability to voluntary silence EMG activity"? Time for clarifying the nomenclature

We thank Lumsden and colleagues for their comments on ourpaper ‘‘Spastic dystonia in stroke subjects: prevalence and featuresof the neglected phenomenon of the upper motor neuron syn-drome” (Trompetto et al., 2019). We agree with them that preciseterminology is essential for unambiguous communication andsharing of knowledge. Since this goal is far from being achievedin the field of the positive phenomena of the upper motor neuronsyndrome (UMNS), we agree that the time has come to find anomenclature able to capture the essential and unique featuresof the phenomenon so far reported as ‘‘spastic dystonia”, therebyeliminating eventual confusion. Realistically, this should be matterof dedicated reflections, but we welcome the opportunity offeredby Lumsden and colleagues (Lumsden et al., 2019).The main points of the subject (and debate) are the following.First, the currently used term ‘‘spastic dystonia” refers to theinability of patients with UMNS to voluntary silence muscle activ-ity on command (Gracies, 2005; Sheean and McGuire, 2009;Trompetto et al., 2014). This inability leads to spontaneous tonicmuscle contractions, which prove stretch-sensitive (Gracies,2005), and ultimately amplify the velocity-dependent hypertonia(Marinelli et al., 2017; Trompetto et al., 2019Trompetto et al., 2019).Second, as an inability to relax muscles at will, the phenomenonfalls in the most recent definition of dystonia, ‘‘a movement disor-der characterized by sustained or intermittent muscles contrac-tions causing abnormal, often repetitive, movements, postures, orboth” (Albanese et al., 2013).Third, since ‘‘spastic dystonia” may occur in the absence ofvelocity-dependent hypertonia (Denny-Brown, 1966), which isthe hallmark of spasticity, why qualifying this phenomenon as‘‘spastic”? But: if this is not ‘‘spastic”, should it be simply ‘‘dysto-nia”, ‘‘secondary dystonia”, or ‘‘dystonia in the context of theUMNS”?As delineated above, the debate prompts comments that movefrom the phenomenological to the pathophysiological level. Weshortly review strengths and weaknesses for each point, and post-pone eventual solution to more thorough review.From a phenomenological point of view, we consider as undis-puted that dystonia and ‘‘spastic dystonia” manifest similarly,therefore the involuntary muscle activity we are dealing with isdystonic in nature. But it is only one nature of the abnormal move-ment, the second one being its exquisite sensitivity to musclelengthening.Equally undisputed is the clearly distinct pathophysiologybetween ‘‘dystonia” and ‘‘spastic dystonia”. The overwhelmingmajority of papers using the term ‘‘dystonia” refers to clinical con-ditions stemming from structural or functional diseases of thebasal ganglia, unrelated to the activity of the stretch reflex. Onthe contrary, ‘‘spastic dystonia” is found in patients having lesionsoutside the basal ganglia, exhibiting clear abnormality in theexcitability of the stretch reflex circuitry. Because definitely dis-tinct pathological mechanisms give rise to muscle overactivitysharing similar phenomenology, the term ‘‘dystonia” seems inade-quate for describing the involuntary muscle contraction we aredealing with.Even from a nosological perspective, the term ‘‘dystonia”appears inappropriate. By definition, ‘‘dystonia” is amovement dis-order, whereas ‘‘spastic dystonia” is not. Indeed, amovement disor-der(meaning to indicate a disease of the basal ganglia) is definedas a ‘‘neurological syndrome in which there is either an excess ofmovement or a paucity of voluntary and automatic movements,unrelated to weakness or spasticity” (Fahn et al., 2011). It is apod-ictic how much ‘‘spastic dystonia” can be related to both weaknessand spasticity. Corollary is that spastic dystonia can neither beconsideredtout-court‘‘a subset of dystonia” (Lorentzen et al.,2018).For old-fashioned ‘‘motorist” neurologists, the term ‘‘spasticdystonia” reflects perfectly the double nature of the stretch-sensi-tive (although not stretch-induced), spontaneous, tonic musclecontraction that can be observed in the absence of movement (assole inability to relax) or during movement (as associated posturalreactions) in patients affected by UMNS. None of the semanticnuances, such as ‘‘dystonic spasticity” (Lorentzen et al., 2018), or‘‘dystonia with spasticity” or ‘‘dystonia accompanying the UpperMotor Neuron Complex” (as suggested by these respected authors)is likely to improve the understanding or the clarity of this simi-larly old-fashioned concept. But as time goes on, the audience ofphysicians dealing with UMNS patients grows, and we see the needfor changing the term ‘‘spastic dystonia”. Nevertheless, we mustacknowledge the difficulty to find an equally efficacious two-worddescriptor, probably reflecting the peculiarity and complexity ofthis motor phenomenon (sensitivity to - but not dependency fromperipheral input; occurrence both in the absence and during move-ment; ability to cause or not abnormal postures).The letter by Lumdsen et al. (2019) proves that ‘‘spastic dysto-nia” seems no more conducive to the recognition of the phe-nomenon that it wants to identify, probably explaining why it is‘‘the neglected phenomenon of the UMNS” (Trompetto et al.,2019). A newly proposed definition as a ‘‘stretch- and effort-unre-lated sustained involuntary muscle activity following centralmotor lesions” (Lorentzen et al., 2018) certainly avoids confusionin terms of dystonia, but it fails to convey the inability to relaxmuscles, it overestimates the ‘‘un-relation” to muscle stretch, anduncouples this involuntary muscle activity from velocity-depen-dent hypertonia, which is the more evident clinical sign in thesepatients (Marinelli et al., 2017; Trompetto et al., 2019). Aside from shading dystonia vs. spasticity andvice versa,weconsider that ‘‘inability to voluntary silence EMG activity”describes well both the phenomenological and pathophysiologicallevel, the positive phenomenon of the UMNS currently referred toas ‘‘spastic dystonia”. The ensuing stretch-sensitive spontaneoustonic muscle contractions favor/promote velocity-dependenthypertonia, and may produce abnormal postures. This physiologi-cal construct would bring the concept to the clinicians that two arethe causes of velocity-dependent hypertonia: spasticity (Lance,1980) and ‘‘inability to voluntary silence EMG activity”. Such a dis-tinction would help prevent the overdiagnosis of ‘‘spasticity”whenever the clinical examination reveals the presence of veloc-ity-dependent hypertonia, and will strengthen the idea that onlythe use of surface-EMG can discriminate between muscles thatare relaxed prior to passive stretch (i.e., muscles affected by spas-ticity), and those showing stretch-sensitive spontaneous tonic con-tractions (i.e., muscles affected by ‘‘inability to voluntary silenceEMG activity”)

The Cerebellum Modulates Attention Network Functioning: Evidence from a Cerebellar Transcranial Direct Current Stimulation and Attention Network Test Study

The functional domain of the cerebellum extends beyond its traditional role in motor control. In recent years, this structure has increasingly been considered to play a crucial role even in cognitive performance and attentional processes. Attention is defined as the ability to appropriately allocate processing resources to relevant stimuli. According to the Posnerian model, three interacting networks modulate attentive processes: the alerting, orienting, and executive networks. The aim of this study was to investigate the role played by the cerebellum in the functioning of the attentive networks using the Attention Network Test (ANT). We studied the effects of transcranial direct current stimulation (tDCS), delivered over the cerebellum in cathodal, anodal, and sham sessions, on ANT parameters in healthy subjects. After anodal and sham tDCS, the efficiency of the three attention networks remained stable, and a significant reduction in reaction time (RT) following the task repetition was observed for both congruent and incongruent targets, indicating a learning effect. After cathodal stimulation, instead, while the efficiency of the alerting and orienting networks remained stable, the efficiency of the executive network was significantly reduced. Moreover, a significant reduction in RT was observed for the congruent target alone, with no difference being detected for the incongruent target, indicating that cerebellar inhibition caused an attentive executive dysfunction specifically related to the ability to process complex stimuli in which conflict signals or errors are present. These results point to a role of the cerebellum, a subcortical structure that is thought to affect error processing both directly, by making predictions of errors or behaviors related to errors, and indirectly, by managing the functioning of brain cortical areas involved in the perception of conflicting signals, in the functioning of the attentional networks, particularly the executive network

Pathophysiology of Spasticity: Implications for Neurorehabilitation

Spasticity is the velocity-dependent increase in muscle tone due to the exaggeration of stretch reflex. It is only one of the several components of the upper motor neuron syndrome (UMNS). The central lesion causing the UMNS disrupts the balance of supraspinal inhibitory and excitatory inputs directed to the spinal cord, leading to a state of disinhibition of the stretch reflex. However, the delay between the acute neurological insult (trauma or stroke) and the appearance of spasticity argues against it simply being a release phenomenon and suggests some sort of plastic changes, occurring in the spinal cord and also in the brain. An important plastic change in the spinal cord could be the progressive reduction of postactivation depression due to limb immobilization. As well as hyperexcitable stretch reflexes, secondary soft tissue changes in the paretic limbs enhance muscle resistance to passive displacements. Therefore, in patients with UMNS, hypertonia can be divided into two components: hypertonia mediated by the stretch reflex, which corresponds to spasticity, and hypertonia due to soft tissue changes, which is often referred as nonreflex hypertonia or intrinsic hypertonia. Compelling evidences state that limb mobilisation in patients with UMNS is essential to prevent and treat both spasticity and intrinsic hypertonia

Spastic dystonia in stroke subjects: prevalence and features of the neglected phenomenon of the upper motor neuron syndrome

Objective Spastic dystonia is one of the positive phenomena of the upper motor neuron syndrome (UMNS). It is characterised by the inability to relax a muscle leading to a spontaneous, although stretch-sensitive, tonic contraction. Although spastic dystonia is a recognized cause of muscle hypertonia, its prevalence among hypertonic muscles of stroke subjects has never been investigated. Differently from spasticity, which is an exaggerated stretch reflex, spastic dystonia is viewed as an efferent phenomenon, due to an abnormal central drive to motoneurons. Methods In 23 hemiparetic stroke subjects showing increased muscle tone of wrist flexors, surface EMG was used to investigate the presence of spontaneous, stretch-sensitive EMG activity in flexor carpi radialis. Results Spontaneous, stretch-sensitive EMG activity was found in 17 subjects. In the remaining 6 subjects, no spontaneous EMG activity was found. Conclusions The majority of stroke subjects is affected by spastic dystonia in their hypertonic wrist flexor muscles. Only a minority of subjects is affected by spasticity. Significance To stop spastic dystonia from being the neglected aspect of UMNS, it is essential to link its definition to increased muscle tone, as occurred for spasticity. Recognizing the real phenomena underling muscle hypertonia could improve its management

Attention in Parkinson\u2019s disease with fatigue: evidence from the attention network test

Fatigue is a non-specific symptom that is common in chronic diseases and represents one of the most disabling symptoms in Parkinson\u2019s disease. PD patients often experience cognitive deficits related above all to executive functions. The relationship between cognitive changes and fatigue in PD patients has not been explored in depth. The Attention Network Test (ANT) is a rapid, widely used test to measure the efficiency of three attentional networks, i.e., alerting, orienting, and executive, by evaluating reaction times (RTs) in response to visual stimuli. To assess the association between fatigue and the efficiency of the attentional networks, according to the Posnerian view, ANT was administered to 15 parkinsonian patients with fatigue (PFS-16 > 2.95), 17 parkinsonian patients without fatigue, and 37 age- and sex-matched healthy controls. Anxiety, depression, quality of sleep, and quality of life were also assessed. Parkinsonian patients displayed significantly longer RTs and lower executive network efficiency than controls. Patients with fatigue displayed significantly lower executive network efficiency than patients without fatigue. Moreover, patients with fatigue exhibited a lower accuracy than either patients without fatigue or controls. Finally, patients without fatigue displayed a more efficient alerting network than either patients with fatigue or controls. Although the pathogenesis of fatigue is multifactorial, our results indicate that fatigue may be closely related to an alteration of the striato-thalamo-cortical loop connecting the neostriatum to the prefrontal cortex, which is also responsible for the executive dysfunction that is typical of Parkinson\u2019s disease

Stance postural strategies in patients with chronic inflammatory demyelinating polyradiculoneuropathy

Introduction: Polyneuropathy leads to postural instability and an increased risk of falling. We investigated how impaired motor impairment and proprioceptive input due to neuropathy influences postural strategies. Methods: Platformless bisegmental posturography data were recorded in healthy subjects and patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Each subject stood on the floor, wore a head and a hip electromagnetic tracker. Sway amplitude and velocity were recorded and the mean direction difference (MDD) in the velocity vector between trackers was calculated as a flexibility index. Results: Head and hip postural sway increased more in patients with CIDP than in healthy controls. MDD values reflecting hip strategies also increased more in patients than in controls. In the eyes closed condition MDD values in healthy subjects decreased but in patients remained unchanged. Discussion: Sensori-motor impairment changes the balance between postural strategies that patients adopt to maintain upright quiet stance. Motor impairment leads to hip postural strategy overweight (eyes open), and prevents strategy re-balancing when the sensory context predominantly relies on proprioceptive input (eyes closed)

Effect of radial shock wave therapy on pain and muscle hypertonia: a double-blind study in patients with multiple sclerosis.

BACKGROUND: Radial shock wave therapy (RSWT) has been extensively used in rehabilitative medicine to treat pain, and more recently muscle hypertonia, in patients with cerebral palsy and stroke. OBJECTIVES: To assess the long-term effects of RSWT in a cohort of subjects affected by multiple sclerosis (MS) who were suffering from painful hypertonia of ankle extensor muscles. METHODS: In this randomised, double blind, placebo-controlled study, we treated 34 patients with four sessions of RSWT (once weekly) and treated 34 patients with placebo. Participants were assessed at baseline, 1 week after the first session, and 1 week and 4 weeks after the last session. We measured pain using the visual analogue scale for pain, while we assessed muscle tone using the modified Ashworth scale and evaluated spinal excitability using the H-reflex. RESULTS: After RSWT, muscle tone decreased 1 week after the last session and pain decreased at all the follow-up evaluations, while spinal excitability was unaffected. No significant changes were found after the placebo treatment. CONCLUSIONS: RSWT can reduce pain and muscle tone in MS patients without adverse effects. The lack of RSWT effects on spinal excitability supports the idea that RSWT is likely to act on non-reflex hypertonia, for example reducing muscle fibrosis