Co-registration of structural T1-weighted (T1w) scans and diffusion tensor imaging (DTI)-derived fractional anisotropy (FA) maps to a common space is of particular interest in neuroimaging, as T1w scans can be used for b...Co-registration of structural T1-weighted (T1w) scans and diffusion tensor imaging (DTI)-derived fractional anisotropy (FA) maps to a common space is of particular interest in neuroimaging, as T1w scans can be used for brain segmentation while DTI can provide microstructural tissue information. While the effect of lesions on registration has been tackled and solutions are available, the issue of atrophy is still open to discussion. Multi-channel (MC) registration algorithms have the advantage of maintaining anatomical correspondence between different contrast images after registration to any target space. In this work, we test the performance of an MC registration approach applied to T1w and FA data using simulated brain atrophy images. Experimental results are compared with a standard single-channel registration approach. Multi-channel registration of fractional anisotropy and T1-weighted images in the presence of atrophy: application to multiple sclerosis Both qualitative and quantitative evaluations are presented, showing that the MC approach provides better alignment with the target while maintaining better T1w and FA co-alignment.
The aim of this study was to assess residual cognitive function and perform outcome evaluation in vegetative state (VS) and minimally conscious state (MCS) patients, using Neurowave, a system able to monitor event-relate...The aim of this study was to assess residual cognitive function and perform outcome evaluation in vegetative state (VS) and minimally conscious state (MCS) patients, using Neurowave, a system able to monitor event-related potentials (ERPs) induced by neurosensory stimulation. Eleven VS and five MCS patients underwent neurological examination and clinical evaluation performed using validated clinical and behavioral scales; they also underwent neurosensory stimulation, which consisted of administration of target images (rare stimuli), relevant to the patient's personal history and having emotional significance, alternated with nontarget images ("standard" stimuli), which had no emotional significance. All simultaneous ERP responses at baseline (T0) and at three months from T0 (T1) were recorded. At T0 we found significant differences between the VS and MCS patients for the N200 (p=0.02) and P300 (p=0.04) waves. The neurophysiological analysis at T1 showed a significant difference only for P300 (p=0.02), probably due to the improvements observed in the VS subjects for the N100 (p=0.009) and N200 (p=0.02) sensory components. Neurophysiological assessment for evaluating residual cognition in vegetative and minimally conscious state patients: a pilot study Our findings seem to show the value of ERP monitoring in VS and MCS patients as a means of investigating residual cognitive function. This approach could guide early therapeutic and rehabilitation interventions, and contribute to identifying better diagnostic and prognostic markers for use in unresponsive or low-responsive patients.
Nociception is an important protective mechanism. The Hargreaves method, which involves measuring withdrawal latency following thermal stimulation to Thermal nociception using a modified Hargreaves method in primates and...Nociception is an important protective mechanism. The Hargreaves method, which involves measuring withdrawal latency following thermal stimulation to Thermal nociception using a modified Hargreaves method in primates and humans the paw, is commonly used to measure pain thresholds in rodents. We modified this technique to measure pain thresholds in monkeys and humans. The modified Hargreaves method was used to quantitate pain sensitivity in eight normal rhesus monkeys, 55 human volunteers, and 12 patients with spinal cord or cauda equina lesions. Thermal stimulation was delivered at 80% of maximum output, and the duration of the stimulation was set at a maximum of 10 seconds to avoid skin injury. The following withdrawal latencies were recorded: 2.7 ± 0.12 seconds in volunteers and 3.4 ± 0.35 seconds in neurologically intact monkeys (p>0.05). Patients with spinal cord or cauda equina lesions showed significantly increased latencies (p<0.001). The modified Hargreaves technique is a safe and reliable method that can provide a validated measure of physiological pain sensation.
Idiopathic normal pressure hydrocephalus (iNPH) is a complex and still underestimated pathology. In the early stages, the cognitive profile is characterized mainly by impairments of attention, psychomotor speed and memor...Idiopathic normal pressure hydrocephalus (iNPH) is a complex and still underestimated pathology. In the early stages, the cognitive profile is characterized mainly by impairments of attention, psychomotor speed and memory, suggesting frontal involvement; patients with more advanced iNPH show overall cognitive deterioration. The memory impairment, however, seems to be milder than that seen in Alzheimer's disease (AD). Clinical and neuroimaging data are crucial for the diagnosis of iNPH, but the presence of different variables, such as comorbidities, and the possible overlapping with other neurodegenerative diseases, AD in particular, make the differential diagnosis difficult. To date studies seeking to identify possible biological markers have provided inconclusive results; moreover reliable indices predictive of a good response to surgery are still lacking. There is a need for further studies with longer follow-ups and for closer interaction among the different professionals involved.
Although the knee jerk reflex is mediated by the L3 and L4 nerve roots, evidence exists that altered knee jerk expression may occur with exclusively L5 radiculopathy. The present study set out to identify the factors res...Although the knee jerk reflex is mediated by the L3 and L4 nerve roots, evidence exists that altered knee jerk expression may occur with exclusively L5 radiculopathy. The present study set out to identify the factors responsible for knee jerk reflex abnormalities in L5 monoradiculopathy. We analyzed clinical and electrophysiological data in 56 subjects affected by L5 monoradiculopathy. Seventeen patients (30.3%) showed an abnormal knee reflex. L5 patients with an abnormal knee reflex differed significantly, in severity of pretibial muscle damage, from those with a normal knee reflex. On the basis of evidence, in humans, of a specific spinal pathway linking the pretibial and quadriceps muscles, we infer that an impairment of the proprioceptive drive from the pretibial muscles to spinal premotor excitatory interneurons contacting quadriceps motor neurons is the main causative factor responsible for reducing knee jerk expression. This mechanism should be considered to avoid misinterpretation of knee jerk reflex changes in lumbar radiculopathies.
In recent years, the use of brain diffusion MRI has led to the hypothesis that children with autism spectrum disorder (ASD) show abnormally connected brains. We used the model of disease-discordant identical twins to tes...In recent years, the use of brain diffusion MRI has led to the hypothesis that children with autism spectrum disorder (ASD) show abnormally connected brains. We used the model of disease-discordant identical twins to test the hypothesis that higher-order diffusion MRI protocols are able to detect abnormal connectivity in a single subject. We studied the structural connectivity of the brain of a child with ASD, and of that of his unaffected identical twin, using high angular resolution diffusion imaging (HARDI) probabilistic tractography. Cortical regions were automatically parcellated from high-resolution structural images, and HARDI-based connection matrices were produced for statistical comparison. Differences in diffusion indexes between subjects were tested by Wilcoxon signed rank test. Tracts were defined as discordant when they showed a between-subject difference of 10 percent or more. Around 11 percent of the discordant intra-hemispheric tracts showed lower fractional anisotropy (FA) values in the ASD twin, while only 1 percent showed higher values. This difference was significant. Our findings in a disease-discordant identical twin pair confirm previous literature consistently reporting lower FA values in children with ASD.
The intentional activation of autonomic dysreflexia (AD, also called "boosting"), a practice sometimes used by athletes affected by spinal cord injury (SCI), is banned by the International Paralympic Committee (IPC). Alt...The intentional activation of autonomic dysreflexia (AD, also called "boosting"), a practice sometimes used by athletes affected by spinal cord injury (SCI), is banned by the International Paralympic Committee (IPC). Although various studies have addressed doping and AD as separate issues, studies evaluating AD as a doping method are lacking. The aim of this brief review is to contribute to better understanding of the relationship between doping and AD. We conducted a literature search of the PubMed database (from 1994 onwards). The key search terms "autonomic dysreflexia" and "boosting" were crossreferenced with "sport performance". The official Paralympic website was also viewed. AD is a potent sympathetic reflex, due to a massive release of noradrenaline, that results in marked vasoconstriction distal to the level of the lesion. Athletes with SCI often self-inflict physical suffering in order to induce this phenomenon, which carries high health risks (i.e., hypertension, cerebral hemorrhage, stroke and sudden death). Boosting is a practice that can be compared to doping methods and the IPC expressly prohibits it. Any deliberate attempt to induce AD, if detected, will lead to disqualification from the sporting event and subsequent investigation by the IPC Legal and Ethics Committee.
Encephalopathy with status epilepticus during sleep (ESES) is an age-related disorder characterized by neuropsychological regression, epilepsy and a typical EEG pattern of continuous epileptiform activity (> 85%) during...Encephalopathy with status epilepticus during sleep (ESES) is an age-related disorder characterized by neuropsychological regression, epilepsy and a typical EEG pattern of continuous epileptiform activity (> 85%) during NREM sleep. Cases of worsening or induction of ESES with phenytoin, carbamazepine and phenobarbital have been reported. We describe a child with benign epilepsy with centrotemporal spikes (BECTS) in whom treatment with oxcarbazepine (OXC) induced ESES. The patient was studied through repeated clinical-neuropsychological evaluations and 24-hour EEG recordings. He was treated with OXC two months after epilepsy onset. One month after starting OXC, he developed an abrupt and severe cognitive deterioration. A 24-hour EEG and neuropsychological tests showed an electroclinical picture compatible with ESES. Withdrawal of OXC and introduction of other drugs were followed by a prompt improvement. Five months after ESES onset, a 24-hour EEG was normal. Our report indicates that OXC can induce ESES in BECTS.
Recent evidence demonstrates that female subjects show exaggerated responses to 3,4-methylenedioxymethamphetamine (MDMA) compared with males. The aim of our study was to evaluate sex differences and the role of endogenou...Recent evidence demonstrates that female subjects show exaggerated responses to 3,4-methylenedioxymethamphetamine (MDMA) compared with males. The aim of our study was to evaluate sex differences and the role of endogenous gonadal hormones on the effects of MDMA. Fifty-six intact and gonadectomized male and female Sprague-Dawley rats were randomly assigned to either MDMA (5 mg/kg) or saline treatment. Learning and memory were assessed using the Morris water maze (MWM). The expression of Bax and Bcl-2 in the hippocampus was detected by Western blotting. Behavioral analysis showed that MDMA led to memory impairment in both male and female rats. The female rats showed more sensitivity to impairment than the males, as assessed using all the memory parameters in the MWM. Ovariectomy attenuated the MDMA-induced memory impairment. By contrast, orchiectomized rats showed more impairment than MDMA-treated intact male rats. Bcl-2 and Bax were down-regulated and up-regulated in MDMA-treated male and female rats, respectively. MDMA treatment in the orchiectomized rats led to upregulation of Bax and down-regulation of Bcl-2. Ovariectomy attenuated the MDMA-induced up-regulation of Bax and caused more expression of Bcl-2 compared with what was observed in the MDMA-treated intact female rats. In summary, female rats showed exaggerated responses to the effects of MDMA and this may be explained by endogenous gonadal hormones.
Rehabilitation programs, to be efficiently tailored, need clear prognostic markers. In acute stroke, neurophysiological measures, such as motor evoked potentials (MEPs), have been proposed, although with discordant resul...Rehabilitation programs, to be efficiently tailored, need clear prognostic markers. In acute stroke, neurophysiological measures, such as motor evoked potentials (MEPs), have been proposed, although with discordant results. The aim of this study was to identify a reliable neurophysiological measure of recovery in acute post-stroke individuals by combining MEPs and the N100 component of transcranial magnetic stimulation-evoked potentials (TEPs). Nine acute post-stroke subjects were included. Clinical evaluation performed in the first week after the event included administration of the European Stroke Scale and Barthel Index and recording of MEPs and TEPs; administration of the clinical scales was repeated after one and three months. The presence/absence of MEPs and TEPs showed correlations with motor outcome. Individuals with a poorer outcome showed absence of both MEPs and TEPs; absence of MEPs alone was related to a partial recovery. Given the results of this exploratory study, further investigation is needed to define the accuracy of combined use of MEPs and TEPs as an approach for predicting motor recovery after acute stroke.
It is well known that migraine attacks can preferentially occur during night sleep and/or upon awakening, however the possible implications of this timing on migraine clinical presentation remain unclear. The aim of this...It is well known that migraine attacks can preferentially occur during night sleep and/or upon awakening, however the possible implications of this timing on migraine clinical presentation remain unclear. The aim of this study was to assess the possible consequences of sleep-related migraine (defined as ≥ 75% of migraine attacks occurring during night sleep and/or upon awakening) on the migraine clinical picture (i.e. migraine-related disability, attack severity, use of symptomatic drugs), subjective sleep quality, excessive daytime sleepiness and fatigue. Two hundred consecutive migraine without aura patients were enrolled; patients with comorbid disorders or chronic medication use were excluded. 39% of the migraineurs included in the study received a diagnosis of sleep-related migraine. The mean frequency of migraine attacks (days per month) did not significantly differ between the patients with and those without sleep-related migraine, whereas migraine-related disability (p<0.0001), mean attack severity (p<0.0001), and monthly intake of symptomatic drugs (p<0.0001) were significantly higher in patients with migraine preferentially occurring at night-time and/or upon awakening. Subjective sleep quality and excessive daytime sleepiness did not differ significantly between the two groups, whereas fatigue was significantly more present in the patients with sleep-related migraine (p=0.0001). These data seem to support the hypothesis that patients with sleep-related migraine represent a subset of individuals with a more severe and disabling clinical presentation of migraine and greater impairment of daily functioning, as suggested by the higher degree of fatigue. Migraineurs with night-time attacks Preferential occurrence of attacks during night sleep and/or upon awakening negatively affects migraine clinical presentation also showed a greater use of symptomatic drugs, possibly related to delayed use of symptomatic treatment. The identification of subtypes of patients with a higher disability risk profile could have crucial implications for individually tailored management of migraine patients.
The temporal and the prefrontal cortices have different roles in semantic information processing: the temporal lobe is where knowledge is stored (Graham and Hodges, 1997), whereas the prefrontal cortex is more specifical...The temporal and the prefrontal cortices have different roles in semantic information processing: the temporal lobe is where knowledge is stored (Graham and Hodges, 1997), whereas the prefrontal cortex is more specifically involved in executive aspects of semantic processing. Relatively little is known about the semantic profiles of mild cognitive impairment (MCI) in Alzheimer's disease (AD) and Parkinson's disease (PD). This observational study investigated naming and semantic questionnaire performances in three groups of subjects: 10 patients with the amnestic-type MCI prodrome of AD (aMCI), 10 patients with early-stage executive-type MCI in PD (MCI-PD), and 10 normal subjects. The MCI-PD subjects demonstrated inferior performances on a semantic questionnaire, whereas the aMCI group displayed modest difficulties in a naming task. These differences may be explained by topographical differences in pathological involvement. Since the frontal areas are more functionally impaired in PD, we hypothesize that the semantic deficit may be a consequence of a deficiency in control of semantic processing. On the other hand, the semantic deficit in aMCI may be related to a lexical-semantic storage dysfunction resulting from pathological involvement of the temporal lobe.
This study was performed with the aim of assessing dispositional optimism (DO) in a sample of Parkinson's disease (PD) patients, in order to evaluate its association with clinical outcomes and its impact on rehabilitatio...This study was performed with the aim of assessing dispositional optimism (DO) in a sample of Parkinson's disease (PD) patients, in order to evaluate its association with clinical outcomes and its impact on rehabilitation. Before entering an outpatient rehabilitation program, 58 participants suffering from idiopathic PD completed the Life Orientation Test-Revised (LOT-R) to evaluate their level of DO, the WHO-5 scale to evaluate their health-related quality of life (HR-QoL), the Hospital Anxiety and Depression Scale (HADS) to identify emotional distress, and the Barthel Index to evaluate their level of disability. All the measures were repeated four months later, at their discharge from the program. Disease stage and severity measures (Unified Parkinson's Disease Rating Scale) were also taken into consideration. Correlations and multivariate regression analyses compared DO with the health-related variables. On admission a high level of DO was found to be associated with less severe disease, a better quality of life (QoL) and lower emotional distress, but not with level of disability (Barthel Index). Consistent results were found at discharge. The level of DO di not change after rehabilitation, while anxiety was significantly reduced, especially in subjects with low LOT-R and high HADS scores. The Barthel Index values significantly improved. At discharge, participants with high DO showed the best improvements in disability and in QoL. Effects of dispositional optimism on quality of life, emotional distress and disability in Parkinson's disease outpatients under rehabilitation In conclusion, a high level of DO was associated with QoL, HADS and UPDRS both on admission and at discharge. The level of DO remained stable after rehabilitation, while disability and anxiety were reduced. Participants with high DO generally had better QoL, and better clinical and psychological performances.
The purpose of this study was to establish the selfmotion perception threshold, in roll, in the visualvestibular interaction (VVI) state, creating an oculogyral illusion, and to compare this threshold to the self-motion...The purpose of this study was to establish the selfmotion perception threshold, in roll, in the visualvestibular interaction (VVI) state, creating an oculogyral illusion, and to compare this threshold to the self-motion perception threshold in darkness. A further aim was to investigate the dynamics of the threshold at a low frequency range (0.1-1 Hz) of sinusoidal rotation. Seven healthy subjects were tested. A motion platform was used to generate motion. Single cycles of sinusoidal acceleration at four frequencies (0.1, 0.2, 0.5 and 1 Hz) were used as motion stimuli. To avoid otolith stimulation, subjects were rotated about a vertical axis in supine position. To evoke an oculogyral illusion subjects were instructed to fixate their gaze on a cross-shaped object aligned with their head, which rotated with them. The results show a lowering of the self-motion perception threshold in the VVI state, significant for the frequencies 0.1 and 0.2 Hz (p<0.05). In all the subjects, visual fixation on the cross evoked an oculogyral illusion. The threshold in both tested conditions was frequency dependent: it decreased with increasing frequency values. However, this effect was consistently stronger in darkness across all frequencies (p<0.05). In conclusion, the application of sinusoidal rotation during roll at low frequencies in the VVI condition evokes oculogyral illusion. This interaction lowers the self-motion perception threshold compared to that measured during rotation in darkness. This testing method could be of practical benefit in clinical application for revealing brain dysfunction involving integrative mechanisms of perception.
This study was conducted to assess the efficacy of oral zinc supplementation in children with intractable epilepsy. Forty-five children aged between three and 12 years and diagnosed with idiopathic intractable epilepsy a...This study was conducted to assess the efficacy of oral zinc supplementation in children with intractable epilepsy. Forty-five children aged between three and 12 years and diagnosed with idiopathic intractable epilepsy at Assiut University Hospital, Assiut, Egypt were recruited. The patients were randomly allocated to two groups: the intervention group received oral zinc supplementation (1 mg/kg/day) while the placebo group received placebo, each for six months. The parents of each child filled in a detailed questionnaire that covered demographic characteristics, type of seizures, frequency, duration of seizures, previous hospital admissions, postictal phenomena and the occurrence of status epilepticus. The primary outcome (frequency of seizures) was compared between the two groups. Zinc supplementation resulted in a significant reduction of seizure frequency in 31% of the treated children. Zinc is an important trace element. Our results suggest that it has mildly beneficial effects in children with intractable epilepsy. We recommend further investigation of oral zinc supplementation as an adjunctive therapy for managing intractable epilepsy in children. Zinc therapy may be an option in treatment protocols for intractable epilepsy in the near future.
The signs of sympathetic and sensory nerve-related disorders are not widely investigated in chronic nonspecific neck pain (NNP) patients. Thus, we performed skin temperature (Tsk), evaporation and touch threshold (TT) me...The signs of sympathetic and sensory nerve-related disorders are not widely investigated in chronic nonspecific neck pain (NNP) patients. Thus, we performed skin temperature (Tsk), evaporation and touch threshold (TT) measurements to reveal possible dysfunctions at the fingertips of NNP patients (n=60) compared with healthy controls (n=11). Neck pain intensity was the main modifier of Tsk, and age the main modifier of TT in a multivariate model. On comparisons of the subgroups of NNP patients with unilateral (n=26) and bilateral (n=34) symptoms and controls, TT differed and Tsk tended to differ, the unilateral pain patients being found to demonstrate higher TT values on both sides. Interrelations between the measured parameters were found in the controls, but not in the patients. The NNP patients exhibited signs of functional impairment of innervation reflected in changes in tactile sensitivity and vasoactive sympathetic function. These changes may be based on both central and peripheral mechanisms, which possibly differ in patients with unilateral and bilateral symptoms.
The hallmark of dementia with Lewy bodies (DLB) is the “Lewy body”, an abnormal aggregation of alpha-synuclein found in some areas of the brain. The brain is the organ/system that is most vulnerable to this oxidative dam...The hallmark of dementia with Lewy bodies (DLB) is the “Lewy body”, an abnormal aggregation of alpha-synuclein found in some areas of the brain. The brain is the organ/system that is most vulnerable to this oxidative damage, and reactive oxygen species can cause neurodegenerative diseases. Different models of mitochondrial deregulation have been compared in DLB. The results are consistent with the hypothesis that alpha-synuclein affects the mitochondria themselves, increasing their sensitivity or leading to cell death through protective (neurosin) and accelerating (cytochrome c) factors. This systematic review suggests that mitochondria play an important role in neurodegeneration and a crucial role in the formation of Lewy bodies. DLB is a disease characterized by abnormal accumulation of alpha-synuclein that could result in the release of cytochrome c and subsequent activation of the apoptotic cascade.
Studies in the literature show that jaw and neck regions are linked anatomically, biomechanically and neurologically. Voluntary clenching has been shown to improve muscle strength and performance of various motor tasks....Studies in the literature show that jaw and neck regions are linked anatomically, biomechanically and neurologically. Voluntary clenching has been shown to improve muscle strength and performance of various motor tasks. Information from the neck sensory-motor system is reported to be important for posture. Hence it is reasonable to believe that activation of the jaw sensory-motor system has the potential to modulate posture. In a sample of 116 healthy subjects, we compared center of gravity (COG) velocity during quiet standing on a foam surface during three test positions: i) resting jaw, ii) open jaw, and iii) clenching; these were tested in two conditions: with eyes open and with eyes closed. The COG velocity decreased significantly during clenching in comparison to both open and resting jaw positions (p<0.0001). This suggests that the jaw sensory-motor system can modulate postural mechanisms. We conclude that jaw clenching can enhance postural stability during standing on an unstable surface in both the presence and absence of visual input in healthy adults and suggest that this should be taken into consideration in treatment and rehabilitation planning for patients with postural instability.