Effect of Revascularization on Headache Associated with Moyamoya Disease in Pediatric Patients

Episodic headache is common in childhood moyamoya disease (MMD). The onset, mechanism, cause of headache and the effect of revascularization surgery on headache are not yet clear. We studied 10 cases of children (7 boys and 3 girls) younger than 18 years who underwent revascularization for MMD between 2009 and 2013. We evaluated frequency of headache and cerebral blood flow changes by single photon emission computed tomography brain imaging with [I123]-labeled iofetamine (IMP­SPECT) before and after surgery. Patients’ ages ranged from 0 to 15 years at onset and 2 to 17 years at the time of surgery, mean age being 6.7 and 8.0 years respectively. 9 of 10 patients presented with ischemic symptoms and 8 had headache. 5 patients underwent indirect bypass and 5 underwent combined direct and indirect bypass. Cerebral blood flow improvement was obtained in 14 of the 15 cerebral hemispheres revascularized mean follow-up duration was 32.9 months. All the patients had good outcomes with improvement of ischemic neurological deficits. Headache improved in 7 (87.5%) of 8 patients. Headache in pediatric moyamoya disease is associated with change in cerebral hemodynamics. Revascularization including combined direct bypass and indirect techniques may be required to reduce headache in patients with MMD

Long-term potentiation-like cortical plasticity is disrupted in Alzheimer's disease patients independently from age of onset

OBJECTIVE Alzheimer's disease (AD) is considered an age-related disorder. However, it is unclear whether AD induces the same pathological and neurophysiological modifications in synaptic functions independently from age of disease onset. We used transcranial magnetic stimulation tools to investigate the mechanisms of cortical plasticity and sensory-motor integration in AD patients with a wide range of disease onset. METHODS We evaluated newly diagnosed sporadic AD (n = 54) in comparison with healthy age-matched controls (HS; n = 24). Cortical plasticity mechanisms of long-term potentiation (LTP) or of long-term depression (LTD) were assessed using respectively intermittent (iTBS) or continuous theta burst stimulation (cTBS) protocols. Sensory-motor integration was evaluated by means of short afferent inhibition (SAI) protocol. RESULTS AD patients show after iTBS an impairment of LTP-like cortical plasticity forming a paradoxical LTD in comparison to HS. LTD-like cortical plasticity is similar between AD and HS. LTP-like cortical plasticity is not associated with age, but AD patients presenting with more altered LTP-like cortical plasticity have more-severe cognitive decline at 18 months. SAI is impaired in AD and shows a strong association with the individual age of subjects rather than with disease age of onset. INTERPRETATION Cortical LTP disruption is a central mechanism of AD that is independent from age of onset. AD can be described primarily as a disorder of LTP-like cortical plasticity not influenced by physiological aging and associated with a more-severe cognitive decline. Ann Neurol 2016;80:202-210

Intracranial Vertebral Artery Aneurysms : Clinical Features and Outcome of 190 Patients

BACKGROUND: Vertebral artery (VA) aneurysms comprise approximately one-third of posterior circulation aneurysms. They are morphologically variable, and located critically close to the cranial nerves and the brainstem. We aim to represent the characteristics of these aneurysms and their treatment, and to analyze the outcome. METHODS: We reviewed retrospectively 9709 patients with intracranial aneurysms. Of these, we included 190 with aneurysms at the VA or VA posterior inferior cerebellar artery junction. The patients were treated in the Department of Neurosurgery, Helsinki, Finland, between 1934 and 2011. RESULTS: The 190 patients had 193 VA aneurysms, among which 131 (68%) were ruptured, The VA aneurysm caused a mass effect in 7 and ischemia in 2 patients. Compared to 4387 patients with a ruptured aneurysm in other locations, those with a VA aneurysm were older, their aneurysms were more often fusiform, and more often caused intraventricular hemorrhages. Among surgically treated aneurysms, clipping was the treatment in 91 (88%) saccular and 11 (50%) fusiform aneurysms. Treatment was endovascular in 13 (9%), and multimodal in 6 (4%) aneurysms, Within a year after aneurysm diagnosis, 53 (28%) patients died. Among the survivors, 104 (93%) returned to an independent or to their previous state of life; only 2 (2%) were unable to return home. CONCLUSIONS: Microsurgery is a feasible treatment for VA aneurysms, although cranial nerve deficits are more common than in endovascular surgery. Despite the challenge of an often severe hemorrhage, of challenging morphology, and risk for laryngeal palsy, most patients surviving the initial stage return to normalcy.Peer reviewe

No Language-Specific Activation during Linguistic Processing of Observed Actions

It has been suggested that cortical neural systems for language evolved from motor cortical systems, in particular from those fronto-parietal systems responding also to action observation. While previous studies have shown shared cortical systems for action--or action observation--and language, they did not address the question of whether linguistic processing of visual stimuli occurs only within a subset of fronto-parietal areas responding to action observation. If this is true, the hypothesis that language evolved from fronto-parietal systems matching action execution and action observation would be strongly reinforced.We used functional magnetic resonance imaging (fMRI) while subjects watched video stimuli of hand-object-interactions and control photo stimuli of the objects and performed linguistic (conceptual and phonological), and perceptual tasks. Since stimuli were identical for linguistic and perceptual tasks, differential activations had to be related to task demands. The results revealed that the linguistic tasks activated left inferior frontal areas that were subsets of a large bilateral fronto-parietal network activated during action perception. Not a single cortical area demonstrated exclusive--or even simply higher--activation for the linguistic tasks compared to the action perception task.These results show that linguistic tasks do not only share common neural representations but essentially activate a subset of the action observation network if identical stimuli are used. Our findings strongly support the evolutionary hypothesis that fronto-parietal systems matching action execution and observation were co-opted for language, a process known as exaptation

Dissociated Representations of Deceptive Intentions and Kinematic Adaptations in the Observer’s Motor System

Previous studies showed that observing deceptive actions modulates the activity of the observer's motor system. However, it is unclear whether this modulation reflects the coding of deceptive intentions or the mapping of the kinematic adaptations required to attain deceptive actions. Here, we used single-pulse transcranial magnetic stimulation to measure cortico-spinal excitability (CSE) from hand and forearm muscles while participants predicted the weight of cubes lifted by actors who received truthful information on the object weight and provided 1) truthful (truthful actions) or 2) deceptive (deceptive actions) cues to the observers or 3) who received fooling information and were asked to provide truthful cues (deceived actions). This way, we independently manipulated actor's intentions and kinematic adaptations. We found that, as compared to truthful action observation, CSE increased during observation of deceptive actions, but decreased during observation of deceived actions. Importantly, while the CSE enhancement in response to deceptive intentions lacked muscle specificity, perceiving kinematic alterations in the deceived condition affected CSE only for the hand muscle involved in kinematic adaptations to unexpected object weight. This suggests that actor's intentions and movement kinematics may be coded by the observer's motor system at different hierarchical levels of action representation

A Role for the Motor System in Binding Abstract Emotional Meaning

Sensorimotor areas activate to action- and object-related words, but their role in abstract meaning processing is still debated. Abstract emotion words denoting body internal states are a critical test case because they lack referential links to objects. If actions expressing emotion are crucial for learning correspondences between word forms and emotions, emotion word–evoked activity should emerge in motor brain systems controlling the face and arms, which typically express emotions. To test this hypothesis, we recruited 18 native speakers and used event-related functional magnetic resonance imaging to compare brain activation evoked by abstract emotion words to that by face- and arm-related action words. In addition to limbic regions, emotion words indeed sparked precentral cortex, including body-part–specific areas activated somatotopically by face words or arm words. Control items, including hash mark strings and animal words, failed to activate precentral areas. We conclude that, similar to their role in action word processing, activation of frontocentral motor systems in the dorsal stream reflects the semantic binding of sign and meaning of abstract words denoting emotions and possibly other body internal states

Grasp It Loudly! Supporting Actions with Semantically Congruent Spoken Action Words

Evidence for cross-talk between motor and language brain structures has accumulated over the past several years. However, while a significant amount of research has focused on the interaction between language perception and action, little attention has been paid to the potential impact of language production on overt motor behaviour

Influence of task-related ipsilateral hand movement on motor cortex excitability

ObjectiveThe time course of the right motor cortex excitability in relation to a task-related voluntary right thumb twitch was studied using sub-threshold transcranial magnetic stimulation (TMS) to the right motor cortex.MethodsMotor excitability was studied in 8 adult subjects who made a brief right thumb twitch to the predictable omission of every fifth tone in a series of tones 2.5 s apart. This paradigm avoided an overt sensory cue, while allowing experimental control of TMS timing relative to both movement and the cue to move. Motor excitability was characterized by several measures of motor evoked potentials (MEPs) recorded from the left thenar eminence in response to TMS over the right scalp with a 9 cm coil: probability of eliciting MEPs, incidence of MEPs and amplitude of MEPs.ResultsAll subjects showed suppression of motor excitability immediately following a voluntary right thumb twitch (ipsilateral response), and up to 1 s after it. However, two distinctly different effects on motor excitability were observed before the response: two subjects showed excitation, beginning about 500 ms before response until 300 ms after it, followed by the post-movement suppression; 6 subjects displayed pre-movement suppression, beginning about 600 ms before the response and persisting for the duration.ConclusionsThe net effect of an ipsilateral response on motor cortex can be either inhibitory or excitatory, changing with time relative to the response. These findings are compatible with two separate processes, inhibitory and excitatory, which interact to determine motor excitability ipsilateral to the responding hand