Fronto-temporal vulnerability to disconnection in paediatric moderate and severe traumatic brain injury.

BACKGROUND: In patients with moderate and severe paediatric traumatic brain injury (TBI), we investigated the presence and severity of white matter (WM) tract damage, cortical lobar and deep grey matter (GM) atrophies, their interplay and their correlation with outcome rating scales. METHODS: Diffusion tensor (DT) and 3D T1-weighted MRI scans were obtained from 22 TBI children (13 boys; mean age at insult = 11.6 years; 72.7% in chronic condition) and 31 age-matched healthy children. Patients were tested with outcome rating scales and the Wechsler Intelligence Scale for Children (WISC). DT MRI indices were obtained from several supra- and infra-tentorial WM tracts. Cortical lobar and deep GM volumes were derived. Comparisons between patients and controls, and between patients in acute (<6 months from the event) vs. chronic (≥6 months) condition were performed. RESULTS: Patients showed a widespread pattern of decreased WM FA and GM atrophy. Compared to acute, chronic patients showed severer atrophy in the right frontal lobe and reduced FA in the left inferior longitudinal fasciculus and corpus callosum (CC). Decreased axial diffusivity was observed in acute patients versus controls in the inferior fronto-occipital fasciculus and CC. Chronic patients showed increased axial diffusivity in the same structures. Uncinate fasciculus DT MRI abnormalities correlated with atrophy in the frontal and temporal lobes. Hippocampal atrophy correlated with reduced WISC scores, whereas putamen atrophy correlated with lower functional independence measure scores. CONCLUSIONS: The study isolated a distributed fronto-temporal network of structures particularly vulnerable to axonal damage and atrophy that may contribute to cognitive deficits following TBI.

Prevalence of respiratory colonisations and related antibiotic resistances among paediatric tracheostomised patients of a long-term rehabilitation centre in Italy.

Patients with brain injury are prone to bacterial colonisations because of mechanical ventilation during intensive care and the long-term retention of tracheostomical tubes during rehabilitation. Reduced levels of isolation, typical of rehabilitation, could also contribute to propagate colonisations. We evaluated the presence of bacteria through different stages of healthcare, their antibiotic resistances and their clinical impact in a rehabilitation setting. This retrospective study included all tracheostomised patients referred to the paediatric brain injury unit of the Scientific Institute IRCCS E. Medea (Italy) over a six-year period. Data were collected from antibiograms regarding the presence of bacterial species and antibiotic resistances; clinical data were collected from medical records. Antibiograms revealed bacteria and antibiotic resistances typical of intensive care, while prevalence patterns were characteristic for each species (P. aeruginosa and S. aureus prevailing in the acute setting, K. pneumoniae, A. baumannii and others in rehabilitation). Despite very frequent antibiotic resistances, consistent with Italian averages, we observed a limited clinical impact for these colonisations. We analysed risk factors correlating to the development of respiratory symptoms and found a role for the acute clinical course after brain injury (having undergone neurosurgery; duration of intensive care stay) as well as for rehabilitation (duration of coma). Our data suggest that, in a long-term perspective, an appropriate balance is yet to be found between patient isolation and social interactions, to control respiratory colonisations and antibiotic resistances without compromising rehabilitation. They also suggest that regular containment measures should be complemented by thorough training to non-medic personnel and parents alike.

Pharyngeal spasticity due to dantrolene.

WHAT IS KNOWN AND OBJECTIVE: Dantrolene can be combined with baclofen to better treat spasticity, but may cause muscular weakness and dysphagia. We instead describe a pharyngeal spasm due to dantrolene. CASE SUMMARY: A 12-year-old male received dantrolene 3 mg/kg/day in adjunct to baclofen 2 mg/kg/day, to improve spasticity. After 5 days of full-dose dantrolene, his dysphagia worsened and he developed pharyngeal spasm. Dantrolene was suspected for an adverse reaction and removed. The patient subsequently improved. WHAT IS NEW AND CONCLUSION: Causality analysis determined a probable relationship between dantrolene and pharyngeal spasm. This may be due to direct muscle contraction by dantrolene, an effect seen previously in vitro.

Children in vegetative state and minimally conscious state: patients' condition and caregivers' burden.

Caring for children in vegetative state (VS) or minimally conscious state (MCS) challenges parents and impacts on their well-being. This study aims to evaluate caregivers' health condition, coping, anxiety and depression levels, and how these issues relate to children's disability. 35 children with VS and MCS were administered the disability rating scale (DRS) and 35 caregivers completed the Coping Orientations to Problem Experiences, Short Form-12, Beck Depression Inventory, and the Spielberger State-Trait Anxiety Inventory-Y. Children were mainly males (68.6%), hosted at domicile (77.1%), and diagnosed with VS (60%), with anoxic aetiology (45.7%). Caregivers were mainly mothers (85.7%), married (82.9%), and housewives (51.4%); 60% declared financial difficulties, and 82.9% provided full-time assistance. 57.2% reported depressive symptoms, poor mental health, and high level of state and trait anxiety. "Problem-oriented" (P < 0.001) and "emotional-oriented" (P < 0.001), were more adopted than "potentially dysfunctional" ones. DRS scores (mean = 22.0; SD = 1.9) did not significantly correlate to any psychological measure. Rehabilitative programs for children with SV and SMC should also provide interventions on surrounding systems: improving the network of psychological support and social assistance may decrease the burden of caregivers and, in turn, improve caring abilities and children quality of life.

Growth factors in ischemic stroke.

Data from pre-clinical and clinical studies provide evidence that colony-stimulating factors (CSFs) and other growth factors (GFs) can improve stroke outcome by reducing stroke damage through their anti-apoptotic and anti-inflammatory effects, and by promoting angiogenesis and neurogenesis. This review provides a critical and up-to-date literature review on CSF use in stroke. We searched for experimental and clinical studies on haemopoietic GFs such as granulocyte CSF, erythropoietin, granulocyte-macrophage colony-stimulating factor, stem cell factor (SCF), vascular endothelial GF, stromal cell-derived factor-1α and SCF in ischemic stroke. We also considered studies on insulin-like growth factor-1 and neurotrophins. Despite promising results from animal models, the lack of data in human beings hampers efficacy assessments of GFs on stroke outcome. We provide a comprehensive and critical view of the present knowledge about GFs and stroke, and an overview of ongoing and future prospects.

Stem cell therapy in stroke.

Recent work has focused on cell transplantation as a therapeutic option following ischemic stroke, based on animal studies showing that cells transplanted to the brain not only survive, but also lead to functional improvement. Neural degeneration after ischemia is not selective but involves different neuronal populations, as well as glial and endothelial cell types. In models of stroke, the principal mechanism by which any improvement has been observed, has been attributed to the release of trophic factors, possibly promoting endogenous repair mechanisms, reducing cell death and stimulating neurogenesis and angiogenesis. Initial human studies indicate that stem cell therapy may be technically feasible in stroke patients, however, issues still need to be addressed for use in human subjects.

Nuclear reprogramming and adult stem cell potential.

Cell-based therapy may represent a new strategy to treat a vast array of clinical disorders including neurodegenerative diseases. Recent observations indicate that adult somatic stem cells have the capacity to contribute to the regeneration of different tissues, suggesting that differentiative restrictions are not completely irreversible and can be reprogrammed. Cell fusion might account for some changed phenotype of adult cells but it seems to be biologically irrelevant for its extreme rarity. Other experimental evidences are compatible with the hypothesis of wide multipotency of well-defined stem cell populations, but also with transdifferentiation and/or dedifferentiation. Further studies on nuclear reprogramming mechanisms are necessary to fulfil the promise for developing autologous cellular therapies.

Gait rehabilitation with a high tech platform based on virtual reality conveys improvements in walking ability of children suffering from acquired brain injury.

The Gait Real-time Analysis Interactive Lab (GRAIL) is an instrumented multi-sensor platform based on immersive virtual reality for gait training and rehabilitation. Few studies have been included GRAIL to evaluate gait patterns in normal and disabled people and to improve gait in adults, while at our knowledge no evidence on its use for the rehabilitation of children is available. In this study, 4 children suffering from acquired brain injury (ABI) underwent a 5 session treatment with GRAIL, to improve walking and balance ability in engaging VR environments. The first and the last sessions were partially dedicated to gait evaluation. Results are promising: improvements were recorded at the ankle level, selectively at the affected side, and at the pelvic level, while small changes were measured at the hip and knee joints, which were already comparable to healthy subjects. All these changes also conveyed advances in the symmetry of the walking pattern. In the next future, a longer intervention will be proposed and more children will be enrolled to strongly prove the effectiveness of GRAIL in the rehabilitation of children with ABI.

Neuronal generation from somatic stem cells: current knowledge and perspectives on the treatment of acquired and degenerative central nervous system disorders.

Stem cell transplantation through cell replacement or as vector for gene delivery is a potential strategy for the treatment of neurodegenerative diseases. Several studies have reported the transdifferentiation of different somatic stem cells into neurons in vitro or after transplantation into animal models. This observation has pointed out the perspective of using an ethical and accessible cell source to "replace" damaged neurons or provide support to brain tissue. However, recent findings such as the cell fusion phenomenon have raised some doubts about the real existence of somatic stem cell plasticity. In this review, we will discuss current evidence and controversial issues about the neuroneogenesis from various sources of somatic cells focusing on the techniques of isolation, expansion in vitro as well as the inductive factors that lead to transdifferentiation in order to identify the factors peculiar to this process. The morphological, immunochemical, and physiological criteria to correctly judge whether the neuronal transdifferentation occurred are critically presented. We will also discuss the transplantation experiments that were done in view of a possible clinical therapeutic application. Animal models of stroke, spinal cord and brain trauma have improved with Mesenchymal Stem Cells or Bone Marrow transplantation. This improvement does not seem to depend on the replacement of the lost neurons but may be due to increased expression levels of neurotrophic factors, thus suggesting a beneficial effect of somatic cells regardless of transdifferentiation. Critical understanding of available data on the mechanisms governing the cell fate reprogramming is a necessary achievement toward an effective cell therapy.

Leigh disease: clinical, neuroradiologic, and biochemical study of three new cases with cytochrome c oxidase deficiency.

Three cases of Leigh disease are described. In all three, symptoms began in the first months of life, with muscle hypotonia, lactic acidosis, and psychomotor delay. The diagnosis was made on the basis of the clinical characteristics, biochemical abnormalities, and typical brain magnetic resonance imaging with symmetric lesions suggesting bilateral necrosis at the level of the basal ganglia and of the midbrain. Cytochrome c oxidase (complex IV of the mitochondrial respiratory chain) deficiency was demonstrated in muscle tissue in all patients and confirmed in skin fibroblasts in patient 3. A genetic heterogeneity was present in these patients since only one had a SURF-1 gene mutation. The clinical, biochemical, and neuroradiologic aspects are discussed. Finally, the finding of facial dysmorphisms in the cytochrome c oxidase deficiency observed in one of the described cases is of extreme interest; to our knowledge, this association has never been reported in the literature.

Implementation, testing and pilot clinical evaluation of superelastic splints that decrease joint stiffness.

The present work aims at demonstrating that a customised choice of shape memory alloy (SMA) composition, thermo-mechanical treatment and shaping can lead to effective rehabilitation devices applicable to sub-acute and chronic spastic paresis in paediatric patients. SMA pseudoelasticity is regarded as a means to implement a corrective action on posture without hindering residual voluntary or reflex mobility of the affected limb. Specific hinges containing NiTi or NiTiNb elements were designed and constructed to transfer pseudoelastic recovery force to fitted splints for the elbow or the ankle joint. The devices were mechanically tested and showed complete stability after 20-100 cycles, and unchanged characteristics after 1000 full-range deflections. Repositioning splints equipped with patient-specific pseudoelastic hinges were prescribed to 25 individuals (aged 7.75 ± 5.40 years) with mild to severe spastic tetraparesis. Clinical and instrumental evaluations were carried out during crossover trials with traditional and pseudoelastic splints. The sequence of treatment steps was randomized for each subject. The results show that, compared to fixed-angle braces, pseudoelastic devices decrease passive joint stiffness while providing the same control on limb posture. Dynamic pseudoelastic braces are therefore an innovative treatment for spastic paresis, which may reduce joint stiffness.

Pediatric rehabilitation of severe acquired brain injury: a multicenter survey.

BACKGROUND: Epidemiological and descriptive data concerning the clinical and socio-demographic characteristics of severe acquired brain injuries (ABI) in pediatric age are meager. In particular, in Italy we only find data concerning traumatic brain injury (TBI) in adults. Earlier data show that the most prevalent etiology in ABI is traumatic and that greater clinical impairments are reported for patients with non-traumatic etiologies. AIM: The main aims of the GISCAR (Gruppo Italiano per lo Studio delle Gravi Cerebrolesioni Acquisite e Riabilitazione) study are: 1) to define the clinical features of pediatric patients with severe neurological disabilities; 2) to determine the etiology and onset modality of the cerebral lesions; and 3) to analyse the characteristics of the rehabilitation processes and patient outcome in terms of disability, strategies for treatment and clinical picture. DESIGN: Quasi-epidemiologic. SETTING: In-patient. POPULATION: 184 pediatric patients with severe ABI were recruited. METHODS: Data collection was done by means of an assessment protocol created and used by a group of Italian neurorehabilitation centers. Traumatic and non traumatic aetiologies (NTBI) have been treated separately. RESULTS: Traumatic etiology of ABI is the most prevalent (51.6%, N. 95) and about twice as many males as females are involved. Of these cases, 70.5% (N. 67) are the result of a car accident, either as a pedestrian or as a passenger, representing a crucial area for preventive action by the public health services. Eighty-six (46.7%) patients were in the acute state, 19 (10.3%) in subacute state and 76 (42.9%) in chronic condition. The results show that the positive trend for the TBI group was steeper than for NTBIs. Neuropsychological data are also discussed. CONCLUSIONS AND CLINICAL REHABILITATION IMPACT: We report the first Italian descriptive study on pediatric patients affected by ABI of traumatic or non traumatic etiology. The main points concerning rehabilitation are that major differences between aetiologies must be taken into account and that ABI of any severity in the acute phase may lead to long term disability, confirming the high social and economic impact of this pathology. Our study demonstrates the great importance of providing specialised rehabilitation centers for pediatric patients, and increases awareness of the importance of ABI prevention.

A mitochondrial tRNA(His) gene mutation causing pigmentary retinopathy and neurosensorial deafness.

We have identified a heteroplasmic G to A mutation at position 12,183 of the mitochondrial transfer RNA Histidine (tRNA(His)) gene in three related patients. These phenotypes varied according to mutation heteroplasmy: one had severe pigmentary retinopathy, neurosensorial deafness, testicular dysfunction, muscle hypotrophy, and ataxia; the other two had only retinal and inner ear involvement. The mutation is in a highly conserved region of the T(psi)C stem of the tRNA(His) gene and may alter secondary structure formation. This is the first described pathogenic, maternally inherited mutation of the mitochondrial tRNA(His) gene.

Modulated generation of neuronal cells from bone marrow by expansion and mobilization of circulating stem cells with in vivo cytokine treatment.

The aim of the present study is to determine whether the expansion and mobilization of circulating bone marrow (BM) stem cells by in vivo treatment with granulocyte-colony stimulating factor (G-CSF) and stem cell factor (SCF) increase the amount of BM-derived neuronal cells in mouse brain. The presence of BM-derived cells in the brain was traced by transplanting into lethally irradiated adults and newborns adult BM from transgenic mice that ubiquitously expressed enhanced green fluorescent protein (GFP). GFP+ and Y-chromosome+ donor-derived cells were present in several brain areas of all treated mice (cortical and subcortical areas, cerebellum, olfactory bulb). The presence of GFP+ cells expressing nuclear neural specific antigen (NeuN), neurofilament, and beta-III tubulin in cortical forebrain and olfactory bulb (OB) was higher in G-CSF-SCF treated groups (P < 0.05, analysis of variance, Fisher post hoc). We observed that overall the amount of double positive cells was higher in animals treated at birth than in adults and in OB than in forebrain areas (P < 0.05). Temporal cortical areas of cytokine-treated adult animals revealed a mean threefold increase in the number of GFP+ cells expressing the nuclear neural specific antigen (211 +/- 86 GFP+NeuN+/mm(3) in G-CSF + SCF treated mice and 66 +/- 33 GFP+NeuN+/mm(3) in control animals). GFP+ cells coexpressing neuronal markers contain only one nucleus and have a DNA index (a measure of DNA ploidy) identical to that of surrounding neurons, thus excluding donor cell fusion with endogenous cells as a relevant phenomenon under these experimental conditions. Our results indicate that G-CSF and SCF administration modulates the availability of GFP+ cells in the brain and enhances their capacity to acquire neuronal characteristics. Cytokine stimulation of autologous stem cells might be seen as a new strategy for neuronal repair in neurodegenerative diseases.

Neuroectodermal and microglial differentiation of bone marrow cells in the mouse spinal cord and sensory ganglia.

There is now evidence that bone marrow (BM) can generate cells expressing neuronal antigens in adult mouse brain. In the present study, we examined the spinal cord and dorsal root ganglia (DRG) of adult mice 3 months after BM cell transplantation from transgenic donor mice expressing the enhanced green fluorescent protein (GFP). To determine whether GFP(+) cells acquire neuroectodermal phenotypes, we tested, by immunocytochemistry followed by confocal analysis, the coexpression of the astrocytic marker glial fibrillary acidic protein (GFAP) and the neuronal markers NeuN, neurofilament (NF), and class III beta-tubulin (TuJ1). Rare GFP(+) cells coexpressing TuJ1, NF, and NeuN were found both in spinal cord and in sensory ganglia. These cells have small dimensions and short cytoplasmic processes, probably reflecting an immature phenotype. Double GFP and GFAP positivity was found only in spinal cord. To determine whether cell fusion with endogenous cells occurred, we investigated the nuclear content of cells coexpressing GFP and neuronal or astrocytic markers, demonstrating that these cells have only one nucleus and a DNA ploidy that it is not different from that of surrounding neurons and astrocytes. Large numbers of GFP(+) cells are also positively stained for F4/80, a microglial-recognizing antibody, and present a characteristic microglial-like morphology both in spinal cord and, with a higher frequency, in sensory ganglia. These data support a potential role for BM-derived stem cells in spinal cord neuroneogenesis. They also confirm that the microglial compartment within the CNS and in DRG undergoes a relatively fast turnover, with the contribution of hematopoietic stem cells. Both these findings might prove useful for the development of treatments for spinal cord neurodegenerative and acquired disorders.

Neuronal differentiation of murine bone marrow Thy-1- and Sca-1-positive cells.

Recent evidence suggests that cells from bone marrow can acquire neuroectodermal phenotypes in cell culture or after transplantation in animal models and in the human brain. However, isolation of the bone marrow cell subpopulation with neuronal differentiation potential remains a challenge. To isolate and expand neural progenitors from whole murine bone marrow, bone marrow was obtained from hind limb bone of C57BL6 mice and plated in culture with neuronal medium with basic fibroblast growth factor and epidermal growth factor. After 5-7 days in culture, cellular spheres similar to brain neurospheres appeared either floating or attached to culture dishes. These spheres were collected, dissociated, and expanded. The bone marrow-derived spheres were positive for nestin as assessed by immunocytochemistry and by reverse transcriptase polymerase chain reaction. Thy-1- and Sca-1-positive bone marrow cells selected by magnetic cell sorting resulted in a higher yield of nestin-positive spheres. After exposure to neuronal differentiative medium retinoic acid with and without Sonic hedgehog, cells positive for neuronal markers tubulin III (TuJ-1) and neurofilament (NF) were detected. The mRNA profile of these cells included the expression of TuJ-1, neuronal-specific enolase (NSE), and NF-light chain. To evaluate the in vivo behavior of these cells, spheres derived from bone marrow-derived cells of transgenic green fluorescent protein (GFP) mice were transplanted into newborn mouse brain. Two months later, the mouse neural cortex contained a minor proportion of GFP(+) cells co-expressing neuronal markers (TuJ-1, NF, MAP-2, NeuN). Although cell fusion phenomena with the host cells could not be ruled out, bone marrow-derived neurosphere transplantation could be a strategy for cellular mediated gene therapy.

Chemotactic factors enhance myogenic cell migration across an endothelial monolayer.

Recent reports revealed that myogenic progenitors, derived from either bone marrow or muscle can migrate into muscle tissue and participate in myofiber regeneration, when injected in the peripheral circulation. This observation might open a new strategy for the treatment of muscular dystrophies. The signals involved in myoblast recruitment from circulation are at present poorly understood. To investigate myoblast migration we used a transwell assay in which murine myoblasts and myogenic cell lines were seeded on microporous membrane covered by an endothelial monolayer and chemotactic factors were added in the lower chamber. We demonstrated that myoblasts are able to cross the endothelium and that this process can be modulated. In particular among tested factors, we observed a gradient of chemotactic activity as follows: HGF >> RANTES > PDGF-A > PDGF-B > FGF >> TNF-alpha > IFN-gamma > EGF. Endothelial and myoblast expression of Pax3 (a transcription factor expressed by embryonic migrating myogenic cells) and cytokine transcripts (TNF-alpha, IFN-gamma) was also monitored either at the basal level and after transmigration. We observed increased Pax3 expression after interaction of C2C12 myoblasts with endothelial cells. We consider that any new report elucidating the molecular signals involved in myoblast migration may be useful toward the development of systemic cellular-mediated gene therapy of muscle diseases.

T-antigen regulated expression reduces apoptosis of tag-transformed human myoblasts.

The generation of human myogenic cell lines could potentially provide a valuable source for cell transplantation in myopathies. The dysregulation of proliferative-differentiative signals by viral oncogenes can result in the induction of apoptosis. Whether apoptosis occurred in myogenic cells expressing large T antigen (Tag) from SV40 upon differentiation was unknown. Human muscle satellite cells were transfected with two different constructs, containing either an origin-defective SV40 genome or Tag under vimentin promoter control. When differentiation was triggered, Tag expression reduced the formation of myotubes and dead cells showing apoptotic features were present. However, the cells expressing SV40 Tag under vimentin promoter control retained their capacity to form myotubes and expressed the myofibrillar proteins as myosin heavy chain and dystrophin when Tag expression was silent. Their apoptotic rate was similar to that of untransfected cells. The observation that apoptosis can be prevented by the down-regulation of Tag suggests that the programmed cell death induced in transformed cells can be reversed, and confirms the regulatory efficiency of the human vimentin promoter.

A subpopulation of murine bone marrow cells fully differentiates along the myogenic pathway and participates in muscle repair in the mdx dystrophic mouse.

Bone marrow (BM) transplantation in mice suggests the existence of pluripotent cells able to differentiate into skeletal muscle tissue, although sustained myofiber reconstitution has not yet been achieved. We investigated the myogenic potential of mouse BM cells and evaluated whether a BM fraction enriched for cells expressing skeletal muscle markers would ameliorate muscle repair, when compared to whole BM, into the dystrophic mdx mouse. We demonstrate that cells expressing striated-muscle-specific proteins are already present in the BM independently from experimentally forced myogenic conversion. We observed the presence of both markers of early myogenic program such as Pax3, Myf5, MyoD, desmin, and late myogenesis such as myosin heavy chain and alpha-sarcomeric actin. These myogenic cells are more represented in the early nonadherent BM fraction, which generates clones able to fully differentiate into myotubes. Transplantation in mdx mice by intravenous injection of whole BM and a tenfold BM myogenic enriched fraction resulted in BM reconstitution and limited dystrophin restoration. Taken together, these data show that a fraction of BM cells have a definite potential for differentiation along the skeletal muscle pathway and can be recruited by muscle repair mechanisms. They also indicate that factors limiting the degree of muscle recruitment and the host stem cell competition should be assessed in order to evaluate the usefulness of BM-derived myogenic cells into the context of cell-mediated gene therapy of inherited muscle diseases.