Severe Unilateral Proprioceptive Loss in Medullary- Rostral Spinal Cord Infarction. A Posterior Spinal Artery Syndrome.

We draw attention to a unique presentation, severe unilateral loss of limb proprioception, in patients with medullary and rostral spinal cord infarction. Two patients developed acute severe proprioceptive loss in the limbs ipsilateral to infarcts that involved the caudal medulla and rostral spinal cord. They also had symptoms and signs often found in lateral medullary infarction. The proprioceptive loss is attributable to injury to the gracile and cuneate nuclei and/or their projections to the medial lemniscus. The infarct territory is supplied by the posterior spinal branches of the vertebral artery near its penetration into the posterior fossa. The presence of severe ipsilateral proprioceptive loss in a patient with features of lateral medullary infarction indicates involvement of the rostral spinal cord.

Nociplastic pain: towards an understanding of prevalent pain conditions.

Nociplastic pain is the semantic term suggested by the international community of pain researchers to describe a third category of pain that is mechanistically distinct from nociceptive pain, which is caused by ongoing inflammation and damage of tissues, and neuropathic pain, which is caused by nerve damage. The mechanisms that underlie this type of pain are not entirely understood, but it is thought that augmented CNS pain and sensory processing and altered pain modulation play prominent roles. The symptoms observed in nociplastic pain include multifocal pain that is more widespread or intense, or both, than would be expected given the amount of identifiable tissue or nerve damage, as well as other CNS-derived symptoms, such as fatigue, sleep, memory, and mood problems. This type of pain can occur in isolation, as often occurs in conditions such as fibromyalgia or tension-type headache, or as part of a mixed-pain state in combination with ongoing nociceptive or neuropathic pain, as might occur in chronic low back pain. It is important to recognise this type of pain, since it will respond to different therapies than nociceptive pain, with a decreased responsiveness to peripherally directed therapies such as anti-inflammatory drugs and opioids, surgery, or injections.

Developing additional competition classes for athletes with intellectual impairments: Conceptual approach and efficacy of an ICF derived measure.

The purpose of para sport classification systems is to minimize the impact of impairment on competition outcome. Currently, athletes with intellectual impairment (II) compete in one class, regardless of the extent of activity limitation resulting from their impairment. Consequently, athletes with II that cause relatively minor difficulty in sport have a competitive advantage over athletes who have intellectual impairments that cause more significant advantage. This research investigated the efficacy of a measure of health-related functional impairment, derived from the World Health Organization International Classification of Functioning, Disability, and Health (ICF), as a tool to classify athletes with intellectual impairments (II) into groups with impairments that cause similar activity limitation. The first study used a Delphi technique to identify the most relevant codes within the ICF from which a measure of impairment presence and severity was derived. The second study investigated whether the measure could discriminate between groups of II athletes organized into three competition groups, and whether these groups could be predicted by ICF score. The ICF-based questionnaire shows promise as a conceptual approach and as a tool in this context, but this is a preliminary step before establishing a sport-specific approach to classification.

Sensory Processing in People With and Without Tendinopathy: A Systematic Review With Meta-analysis of Local, Regional, and Remote Sites in Upper- and Lower-Limb Conditions.

OBJECTIVE: To synthesize results of somatosensory processing tests in people with upper- and lower-limb tendinopathy, compared to controls. DESIGN: Systematic review with meta-analysis. LITERATURE SEARCH: Four electronic databases (MEDLINE, CINAHL Plus, SPORTDiscus, and Embase) were searched. STUDY SELECTION CRITERIA: Included studies measured a domain of sensory processing and compared a tendinopathy group to a healthy control group. DATA SYNTHESIS: Meta-analysis was conducted for outcomes with homogeneous data from at least 2 studies. Upper- and lower-limb conditions were compared and outcomes were examined by measurement site (local, regional, or remote to location of pain). RESULTS: Of the 30 studies included, 18 investigated lateral elbow tendinopathy. The most commonly assessed outcome measures were pressure pain threshold (PPT) and thermal pain threshold. There was moderate evidence for local and regional reduction of PPT in upper-limb tendinopathies, but not at remote sites. In lower-limb tendinopathies, there was conflicting evidence regarding reduced PPT at local sites and limited evidence of normal PPT at remote sites. There was moderate evidence of sensitization of thermal pain threshold at local sites in upper-limb tendinopathies and limited evidence of no difference in thermal pain threshold in lower-limb tendinopathies. Findings across other domains were variable. CONCLUSION: Sensory processing was different between upper-limb tendinopathy and lower-limb tendinopathy. Upper-limb tendinopathies showed signs consistent with primary and secondary hyperalgesia, but lower-limb tendinopathies did not. There was mixed evidence for primary hyperalgesia and limited evidence against secondary hyperalgesia. J Orthop Sports Phys Ther 2021;51(1):12-26. doi:10.2519/jospt.2021.9417.

A Structured Approach to the Diagnosis of Peripheral Nervous System Disorders.

PURPOSE OF REVIEW: Neuroanatomic localization and pattern recognition can be used to diagnose both focal lesions and generalized disorders of the peripheral nervous system. This article describes the nature and pattern of sensory and motor deficits associated with lesions of specific spinal nerve roots, plexus, or peripheral nerves. It also describes the patterns of sensory and motor deficits that suggest multifocal or generalized disorders of the motor neurons, sensory neurons, and peripheral nerves. RECENT FINDINGS: The pattern of sensory and motor deficits may be used to distinguish lesions of the peripheral nervous system from those of the central nervous system. The spinal roots, nerve plexus, and peripheral nerves supply specific muscles and receive sensory input from distinctive cutaneous regions. Focal lesions of these structures therefore produce characteristic patterns of sensory and motor deficits. Multifocal or generalized disorders of the peripheral nervous system may be distinguished by categorizing their sensory and motor involvement, proximal and distal predominance, and degree of symmetry. Serum tests, CSF analysis, electrodiagnostic studies, MRI, ultrasound, nerve biopsy, and skin biopsy have unique roles in the diagnosis of suspected neuromuscular disorders. SUMMARY: A structured approach to the diagnosis of nerve and motor neuron disorders can lead to hypothesis-driven diagnostic testing. Ancillary tests should be reserved for cases in which confirming or refuting a diagnosis will change patient management.

Diagnosis of Transient Ischemic Attack: Sex-Specific Differences From a Retrospective Cohort Study.

BACKGROUND AND PURPOSE: Research suggests that women and men may present with different transient ischemic attack (TIA) and stroke symptoms. We aimed to explore symptoms and features associated with a definite TIA/stroke diagnosis and whether those associations differed by sex. METHODS: We completed a retrospective cohort study of patients referred to The Ottawa Hospital Stroke Prevention Clinic in 2015. Exploratory multinomial logistic regression was used to evaluate candidate variables associated with diagnosis and patient sex. Backwards elimination of the interaction terms with a significance level for staying in the model of 0.25 was used to arrive at a more parsimonious model. RESULTS: Based on 1770 complete patient records, sex-specific differences were noted in TIA/stroke diagnosis based on features such as duration of event, suddenness of symptom onset, unilateral sensory loss, and pain. CONCLUSIONS: This preliminary work identified sex-specific differences in the final diagnosis of TIA/stroke based on common presenting symptoms/features. More research is needed to understand if there are biases or sex-based differences in TIA/stroke manifestations and diagnosis.

Reorganization of motor modules for standing reactive balance recovery following pyridoxine-induced large-fiber peripheral sensory neuropathy in cats.

Task-level goals such as maintaining standing balance are achieved through coordinated muscle activity. Consistent and individualized groupings of synchronously activated muscles can be estimated from muscle recordings in terms of motor modules or muscle synergies, independent of their temporal activation. The structure of motor modules can change with motor training, neurological disorders, and rehabilitation, but the central and peripheral mechanisms underlying motor module structure remain unclear. To assess the role of peripheral somatosensory input on motor module structure, we evaluated changes in the structure of motor modules for reactive balance recovery following pyridoxine-induced large-fiber peripheral somatosensory neuropathy in previously collected data in four adult cats. Somatosensory fiber loss, quantified by postmortem histology, varied from mild to severe across cats. Reactive balance recovery was assessed using multidirectional translational support-surface perturbations over days to weeks throughout initial impairment and subsequent recovery of balance ability. Motor modules within each cat were quantified by non-negative matrix factorization and compared in structure over time. All cats exhibited changes in the structure of motor modules for reactive balance recovery after somatosensory loss, providing evidence that somatosensory inputs influence motor module structure. The impact of the somatosensory disturbance on the structure of motor modules in well-trained adult cats indicates that somatosensory mechanisms contribute to motor module structure, and therefore may contribute to some of the pathological changes in motor module structure in neurological disorders. These results further suggest that somatosensory nerves could be targeted during rehabilitation to influence pathological motor modules for rehabilitation.NEW & NOTEWORTHY Stable motor modules for reactive balance recovery in well-trained adult cats were disrupted following pyridoxine-induced peripheral somatosensory neuropathy, suggesting somatosensory inputs contribute to motor module structure. Furthermore, the motor module structure continued to change as the animals regained the ability to maintain standing balance, but the modules generally did not recover pre-pyridoxine patterns. These results suggest changes in somatosensory input and subsequent learning may contribute to changes in motor module structure in pathological conditions.

Impairment of intermediate somatosensory function in corticobasal syndrome.

Corticobasal syndrome (CBS) is characterized by unilateral atrophy of the brain. New diagnostic criteria for CBS include intermediate somatosensory dysfunction. Here, we aimed to carefully examine intermediate somatosensory function to identify tests which can assess impairment in CBS patients. Using voxel-based morphometry (VBM), we also aimed to show the anatomical bases of these impairments. Subjects included 14 patients diagnosed with CBS and 14 patients with Parkinson's disease (PD). Patients were evaluated using intermediate somatosensory tests and neuropsychological assessments. VBM was used to analyze differences in gray matter volumes between CBS and PD patients. In the PD group, no tests showed a significant difference between the dominant-side onset and the non-dominant-side onset. In the CBS group, all tests showed worse scores on the affected side. For detecting intermediate somatosensory dysfunction in CBS, two tests are recommended: tactile object naming and 2-point discrimination. VBM analysis showed that the volume of the left post- and pre-central gyrus, and both sides of the supplementary motor area were significantly decreased in the CBS group compared to the PD group. Although CBS remains untreatable, early and correct diagnosis is possible by performing close examination of intermediate somatosensory function.

Blood pressure-related hypoalgesia: a systematic review and meta-analysis.

OBJECTIVE: Spontaneous or experimentally induced high blood pressure (BP) is associated with reduced pain perception, known as BP-related hypoalgesia. Despite its clinical implications, such as the interference with early detection of myocardial infarction in 'at risk' groups, the size of the association between high BP and pain has not yet been quantified. Moreover, the distinct association between high BP and physiological or psychological components of pain has not yet been considered so far. The aim of this study was to overcome this gap by performing separate meta-analyses on nociceptive response versus quantifiable perceptual measures of pain in relation to high BP. METHODS: PubMed and Web of Knowledge databases were searched for English language studies conducted in humans. Fifty-nine studies were eligible for the analyses. Pooled effect sizes (Hedges' g) were compared. Random effect models were used. Results show that higher BP is significantly associated with lower nociceptive response (g = 0.38; k = 6) and reduced pain perception, assessed by quantifiable measures (g = 0.48; k = 59). RESULTS: The association between BP and pain perception, derived from highly heterogeneous studies, was characterized by significant publication bias. BP assessment, pain assessment, site of pain stimulation, percentage of female participants in the sample, and control for potential confounders were significant moderators. CONCLUSION: Current meta-analytic results confirm the presence of BP-related hypoalgesia and point towards the need for a better understanding of its underlying mechanisms.

Is Recovery of Somatosensory Impairment Conditional for Upper-Limb Motor Recovery Early After Stroke?

Background. Spontaneous recovery early after stroke is most evident during a time-sensitive window of heightened neuroplasticity, known as spontaneous neurobiological recovery. It is unknown whether poststroke upper-limb motor and somatosensory impairment both reflect spontaneous neurobiological recovery or if somatosensory impairment and/or recovery influences motor recovery. Methods. Motor (Fugl-Meyer upper-extremity [FM-UE]) and somatosensory impairments (Erasmus modification of the Nottingham Sensory Assessment [EmNSA-UE]) were measured in 215 patients within 3 weeks and at 5, 12, and 26 weeks after a first-ever ischemic stroke. The longitudinal association between FM-UE and EmNSA-UE was examined in patients with motor and somatosensory impairments (FM-UE ≤ 60 and EmNSA-UE ≤ 37) at baseline. Results. A total of 94 patients were included in the longitudinal analysis. EmNSA-UE increased significantly up to 12 weeks poststroke. The longitudinal association between motor and somatosensory impairment disappeared when correcting for progress of time and was not significantly different for patients with severe baseline somatosensory impairment. Patients with a FM-UE score ≥18 at 26 weeks (n = 55) showed a significant positive association between motor and somatosensory impairments, irrespective of progress of time. Conclusions. Progress of time, as a reflection of spontaneous neurobiological recovery, is an important factor that drives recovery of upper-limb motor as well as somatosensory impairments in the first 12 weeks poststroke. Severe somatosensory impairment at baseline does not directly compromise motor recovery. The study rather suggests that spontaneous recovery of somatosensory impairment is a prerequisite for full motor recovery of the upper paretic limb.

Somatosensory impairments in patients with multiple sclerosis: association with dynamic postural control and upper extremity motor function.

Purpose: We planned this study to bring attention to the somatosensory impairments in patients with multiple sclerosis (PwMS) and to investigate relationship of somatosensory impairments with dynamic postural stability and upper extremity motor function.Methods: Seven males and 23 females, 30 patients with mean EDSS 2.9 (SD = 1.4), aged between 18 and 65 years (mean = 41.43 ± 14.90 years) were included in this clinical study. Light touch sensorial assessment was made with Semmes Weinstein monofilament test and proprioception by distal proprioception test. Hand strength was measured by the Jamar dynamometer, fine motor skill was examined with nine-hole peg test, functional reach test in sitting and standing position was applied. Nottingham Extended Activities of Daily Living Scale (NEADLS) was used to measure everyday activities.Results: We found a negative and moderate correlation between FRT in standing and light touch of the middle of the heel (right: -0.515), metatarsal bone (right r: 0.453, left r: -0.426), and medial of the foot (right r: -0.462). There was a negative and moderate correlation between NEADLS and light touch of the metatarsal bone (right r: -0.564, left r: -0.472), medial of the foot (right r: -0.531, left r: -0.479), and lateral of the foot (right r: -0.526). We found a positive and moderate correlation between proprioception of the ankle (right r: 0.421 left r: 0.588) and NEADLS.Conclusions: We found impairment in light touch and proprioception and, associations between sensorial functions and dynamic postural stability in PwMS. Also impaired sensorial functions cause dependent patients in daily living activities. In the assessment of balance and falling risk, independency in daily living activities; foot light touch and proprioception sense should be taken into account, hence it may provide guidance in planning rehabilitation programmes.Abbreviations: MS: multiple sclerosis; PwMS: patients with multiple sclerosis; VAS: visual analogue scale; FRT: functional reach test; 9-HPT: Nine-hole peg test; EDSS: The Expanded Disability Status Scale; NEADLS: Nottingham Extended Activities of Daily Living Scale.

Cold intolerance and neuropathic pain after peripheral nerve injury in upper extremity.

Cold intolerance and pain can be a substantial problem in patients with peripheral nerve injury. We aimed at investigating the relationships among sensory recovery, cold intolerance, and neuropathic pain in patients affected by upper limb peripheral nerve injury (Sunderland type V) treated with microsurgical repair, followed by early sensory re-education. In a cross-sectional clinical study, 100 patients (male/female 81/19; age 40.5 ± 14.8 years and follow-up 17 ± 5 months, mean ± SD), with microsurgical nerve repair and reconstruction in the upper extremity and subsequent early sensory re-education, were evaluated, using Cold Intolerance Symptoms Severity questionnaire-Italian version (CISS-it, cut-off pathology >30/100 points), CISS questionnaire-12 item version (CISS-12, 0-46 points-grouping: healthy that means no cold intolerance [0-14], mild [15-24], moderate [25-34], severe [35-42], very severe [43-46] cold intolerance), probability of neuropathic pain (DouleurNeuropathique-4; [DN4] 4/10), deep and superficial sensibility, tactile threshold (monofilaments), and two-point discrimination (cutoff S2; Medical Research Council scale for sensory function; [MRC-scale]). A high CISS score is associated with possible neuropathic pain (DN4 ≥ 4). Both a low CISS-it score (ie, < 30) and DN4 < 4 is associated with good sensory recovery (MRC ≥ 2). In conclusion patients affected by upper limb peripheral nerve injuries with higher CISS scores more often suffer from cold intolerance and neuropathic pain, and the better their sensory recovery is, the less likely they are to suffer from cold intolerance and neuropathic pain.

Differential clinicopathologic features of EGPA-associated neuropathy with and without ANCA.

OBJECTIVE: To investigate the clinicopathologic features of eosinophilic granulomatosis with polyangiitis (EGPA)-associated neuropathy with a focus on the presence or absence of anti-neutrophil cytoplasmic antibodies (ANCAs). METHODS: We examined the clinical features and pathologic findings of sural nerve biopsy specimens from 82 patients with EGPA-associated neuropathy. Of these patients, 32.9% were myeloperoxidase (MPO)-ANCA positive, and 67.1% were MPO-ANCA negative. PR3-ANCA was negative in all of 78 examined patients. RESULTS: Upper limb symptoms were more frequently reported as initial neuropathic manifestations in the MPO-ANCA-positive group than in the MPO-ANCA-negative group (44.4% vs 14.6%, p < 0.01). The serum levels of C-reactive protein were significantly higher in the MPO-ANCA-positive group than in the MPO-ANCA-negative group (p < 0.05). Sural nerve biopsy specimens showed findings suggestive of vasculitis (i.e., destruction of vascular structures) in epineurial vessels; these results were seen more frequently in the MPO-ANCA-positive group than in the MPO-ANCA-negative group (p < 0.0001). Conversely, the numbers of eosinophils in the lumen of the epineurial vessels (p < 0.01) and epineurial vessels occluded by intraluminal eosinophils (p < 0.05) were higher in the MPO-ANCA-negative group than in the MPO-ANCA-positive group. Furthermore, the incidence of eosinophil infiltration in the endoneurium was higher in the MPO-ANCA-negative group than in the MPO-ANCA-positive group (p < 0.01). CONCLUSIONS: This study suggests that the pathogenesis of EGPA comprises at least 2 distinct mechanisms: ANCA-associated vasculitis resulting in ischemic effects and inflammation, which is prominent in MPO-ANCA-positive patients, and eosinophil-associated vascular occlusion leading to ischemia and eosinophil-associated tissue damage, which is conspicuous in MPO-ANCA-negative patients.

CMT2Q-causing mutation in the Dhtkd1 gene lead to sensory defects, mitochondrial accumulation and altered metabolism in a knock-in mouse model.

Charcot-Marie-Tooth disease (CMT) is a group of inherited neurological disorders of the peripheral nervous system. CMT is subdivided into two main types: a demyelinating form, known as CMT1, and an axonal form, known as CMT2. Nearly 30 genes have been identified as a cause of CMT2. One of these is the 'dehydrogenase E1 and transketolase domain containing 1' (DHTKD1) gene. We previously demonstrated that a nonsense mutation [c.1455 T > G (p.Y485*)] in exon 8 of DHTKD1 is one of the disease-causing mutations in CMT2Q (MIM 615025). The aim of the current study was to investigate whether human disease-causing mutations in the Dhtkd1 gene cause CMT2Q phenotypes in a mouse model in order to investigate the physiological function and pathogenic mechanisms associated with mutations in the Dhtkd1 gene in vivo. Therefore, we generated a knock-in mouse model with the Dhtkd1Y486* point mutation. We observed that the Dhtkd1 expression level in sciatic nerve of knock-in mice was significantly lower than in wild-type mice. Moreover, a histopathological phenotype was observed, reminiscent of a peripheral neuropathy, including reduced large axon diameter and abnormal myelination in peripheral nerves. The knock-in mice also displayed clear sensory defects, while no abnormalities in the motor performance were observed. In addition, accumulation of mitochondria and an elevated energy metabolic state was observed in the knock-in mice. Taken together, our study indicates that the Dhtkd1Y486* knock-in mice partially recapitulate the clinical phenotypes of CMT2Q patients and we hypothesize that there might be a compensatory effect from the elevated metabolic state in the knock-in mice that enables them to maintain their normal locomotor function.

Isolated Insular Stroke: Clinical Presentation.

The symptoms related to insular ischemia have been the object of several studies in patients affected by stroke, although they are often accompanied by other ischemic alteration of adjacent brain structures supplied by the middle cerebral artery (MCA). The insula is vulnerable because of an ischemia due to thromboembolic vascular occlusion of the M1 MCA segment and the 2 main MCA branches (M2), mainly when they abruptly arise from the principal stem at a right angle. This topographical and anatomical peculiarity could enable an embolic formation, especially due to atrial fibrillation (AF), to occlude the transition pathway between M1 and M2, while the proximal origin of vascular supply protects the insula from ischemia due to hemodynamic factors. The aim of the study is to characterize the clinical aspects of acute ischemic strokes as a first event in the insular territory with specific attention to atypical manifestation. We have considered 233 patients with a first event stroke involving the insular territory and 13 cases of isolated insular stroke (IIS), from the stroke registry of the Policlinico "G.Martino", University of Messina, between the February 10, 2014 and the February 7, 2018. IIS patients showed CT/MRI lesions restricted to the insular region. Exclusion criteria were coexisting neurological diseases, structural brain lesions, extension to the subinsular area >50% of the total infarct volume. We identified 13 IIS patients (mean age 74 years), with an isolated symptom or a combination of typical and atypical aspects. Furthermore, we observed high frequency detection of cardiac disturbances. To our knowledge, just a few previous studies have described IIS; their incidence is still not well defined. IIS manifested with a combination of deficits including motor, somatosensory, speaking, coordination, autonomic and cognitive disturbances. After an ischemic stroke, AF manifestation could follow briefly the major event and its duration could be very short, as an autonomic dysfunction due to an insular infarction. This clinical condition requires a continuous cardiac monitoring for this dangerous occurrence.

Surgical Treatment of Tethered Cord Syndrome in Adults: A Systematic Review and Meta-Analysis.

OBJECTIVE: In the healthy spine, the spinal cord moves unimpeded with spinal fluid pulsation in the rostral and caudal directions. When a portion of the spinal cord becomes attached to lesions within the spinal column, excess strain can cause signs and symptoms such as pain, motor deficits, sensory deficits, bladder dysfunction, and bowel dysfunction. This condition is termed tethered cord syndrome. There are no clear guidelines for offering surgical intervention, although there is a general consensus that worsening signs and symptoms increase the likelihood that patients will need surgery. METHODS: In this article, we conduct a systematic review and meta-analysis for all available literature within the Ovid (MEDLINE), PubMed, and Google Scholar databases to evaluate common symptoms among patients with tethered cord and to examine how surgery affects symptoms. RESULTS: Within the cohort of 730 patients, 708 (97%) were treated surgically by a detethering procedure. The most common preoperative sign or symptom was pain (81%), followed by motor deficits (63%), sensory deficits (61%), bladder dysfunction (56%), and bowel dysfunction (15%). One percent of patients had no deficit or symptom. Pain was the symptom that was most responsive to surgery, with 81% of patients reporting that their pain improved after detethering. CONCLUSIONS: Tethered cord syndrome should be included in the differential diagnosis in patients presenting with back or leg pain, somatosensory symptoms of the lower extremities, muscular weakness, urodynamic dysfunction, or bowel dysfunction. After a definitive diagnosis is made, patients should be counseled about surgical detethering as an option.

Dual-Component Structural Plasticity Mediated by αCaMKII Autophosphorylation on Basal Dendrites of Cortical Layer 2/3 Neurones.

Sensory cortex exhibits receptive field plasticity throughout life in response to changes in sensory experience and offers the experimental possibility of aligning functional changes in receptive field properties with underpinning structural changes in synapses. We looked at the effects on structural plasticity of two different patterns of whisker deprivation in male and female mice: chessboard deprivation, which causes functional plasticity; and all deprived, which does not. Using 2-photon microscopy and chronic imaging through a cranial window over the barrel cortex, we found that layer 2/3 neurones exhibit robust structural plasticity, but only in response to whisker deprivation patterns that cause functional plasticity. Chessboard pattern deprivation caused dual-component plasticity in layer 2/3 by (1) increasing production of new spines that subsequently persisted for weeks and (2) enlarging spine head sizes in the preexisting stable spine population. Structural plasticity occurred on basal dendrites, but not apical dendrites. Both components of plasticity were absent in αCaMKII-T286A mutants that lack LTP and experience-dependent potentiation in barrel cortex, implying that αCaMKII autophosphorylation is not only important for stabilization and enlargement of spines, but also for new spine production. These studies therefore reveal the relationship between spared whisker potentiation in layer 2/3 neurones and the form and mechanisms of structural plasticity processes that underlie them.SIGNIFICANCE STATEMENT This study provides a missing link in a chain of reasoning that connects LTP to experience-dependent functional plasticity in vivo We found that increases in dendritic spine formation and spine enlargement (both of which are characteristic of LTP) only occurred in barrel cortex during sensory deprivation that produced potentiation of sensory responses. Furthermore, the dendritic spine plasticity did not occur during sensory deprivation in mice lacking LTP and experience-dependent potentiation (αCaMKII autophosphorylation mutants). We also found that the dual-component dendritic spine plasticity only occurred on basal dendrites and not on apical dendrites, thereby resolving a paradox in the literature suggesting that layer 2/3 neurones lack structural plasticity in response to sensory deprivation.

Dysphasia and Other Higher Cortical Dysfunctions During the Migraine Aura-a Systematic Review of Literature.

PURPOSE OF THE REVIEW: Although visual and somatosensory disturbances are the most common migraine aura (MA) symptoms, patients can also experience other symptoms during their MA. The aim of this review is to provide an overview of studies that report symptoms of dysphasia and other higher cortical dysfunctions (HCDs) during MA, as well as to determine the frequency of HCDs. RECENT FINDINGS: Five studies met the inclusion criteria, corresponding to 697 patients overall. The most frequently reported HCDs were those of the language group (range 10-53%). The occurrence of visual HCDs was noted in 12-40 patients, somatosensory HCDs in 12-20%, and memory disturbances in 10-22% of the patients during MAs. MA is associated with a wide range of neurological symptoms, including symptoms of HCD. A better strategy for investigation of the HCD symptoms is needed to correctly stratify patients thus allowing meaningful studies of aura pathophysiology.