Proteolipid protein modulates preservation of peripheral axons and premature death when myelin protein zero is lacking

Protein zero (P0) is the major structural component of peripheral myelin. Lack of this adhesion protein from Schwann cells causes a severe dysmyelinating neuropathy with secondary axonal degeneration in humans with the neuropathy Dejerine‐Sottas syndrome (DSS) and in the corresponding mouse model (P0^null‐mice). In the mammalian CNS, the tetraspan‐membrane protein PLP is the major structural myelin constituent and required for the long‐term preservation of myelinated axons, which fails in hereditary spastic paraplegia (SPG type‐2) and the relevant mouse model (Plp^null‐mice). The Plp‐gene is also expressed in Schwann cells but PLP is of very low abundance in normal peripheral myelin; its function has thus remained enigmatic. Here we show that the abundance of PLP but not of other tetraspan myelin proteins is strongly increased in compact peripheral myelin of P0^null‐mice. To determine the functional relevance of PLP expression in the absence of P0, we generated P0^null*Plp^null‐double‐mutant mice. Compared with either single‐mutant, P0^null*Plp^null‐mice display impaired nerve conduction, reduced motor functions, and premature death. At the morphological level, axonal segments were frequently non‐myelinated but in a one‐to‐one relationship with a hypertrophic Schwann cell. Importantly, axonal numbers were reduced in the vital phrenic nerve of P0^null*Plp^null‐mice. In the absence of P0, thus, PLP also contributes to myelination by Schwann cells and to the preservation of peripheral axons. These data provide a link between the Schwann cell‐dependent support of peripheral axons and the oligodendrocyte‐dependent support of central axons. GLIA 2016;64:155–174     

Structural MRI correlates of cognitive impairment in patients with multiple sclerosis

In a multicenter setting, we applied voxel‐based methods to different structural MR imaging modalities to define the relative contributions of focal lesions, normal‐appearing white matter (NAWM), and gray matter (GM) damage and their regional distribution to cognitive deficits as well as impairment of specific cognitive domains in multiple sclerosis (MS) patients. Approval of the institutional review boards was obtained, together with written informed consent from all participants. Standardized neuropsychological assessment and conventional, diffusion tensor and volumetric brain MRI sequences were collected from 61 relapsing‐remitting MS patients and 61 healthy controls (HC) from seven centers. Patients with ≥2 abnormal tests were considered cognitively impaired (CI). The distribution of focal lesions, GM and WM atrophy, and microstructural WM damage were assessed using voxel‐wise approaches. A random forest analysis identified the best imaging predictors of global cognitive impairment and deficits of specific cognitive domains. Twenty‐three (38%) MS patients were CI. Compared with cognitively preserved (CP), CI MS patients had GM atrophy of the left thalamus, right hippocampus and parietal regions. They also showed atrophy of several WM tracts, mainly located in posterior brain regions and widespread WM diffusivity abnormalities. WM diffusivity abnormalities in cognitive‐relevant WM tracts followed by atrophy of cognitive‐relevant GM regions explained global cognitive impairment. Variable patterns of NAWM and GM damage were associated with deficits in selected cognitive domains. Structural, multiparametric, voxel‐wise MRI approaches are feasible in a multicenter setting. The combination of different imaging modalities is needed to assess and monitor cognitive impairment in MS. Hum Brain Mapp 37:1627‐1644, 2016. © 2016 Wiley Periodicals, Inc.     

Cognitive performance in children with acute early-onset anorexia nervosa

When anorexia nervosa (AN) occurs in children below the age of 14 years, it is referred to as early-onset AN (EO-AN). Over the last years, there has been an increased focus on the role of cognitive functioning in the development and maintenance of AN. Adults with AN show inefficiencies in cognitive functions such as flexibility and central coherence. Systematic neuropsychological examinations of patients with EO-AN are missing. Thirty children with EO-AN and 30 adolescents with AN, as well as 60 healthy controls (HC) underwent an extensive neuropsychological examination. ANOVAs with post hoc tests and explorative regression analyses were conducted. Patients with EO-AN (mean age = 2.17 ± 1.57 years) showed no significant differences in flexibility, inhibition, planning, central coherence, visuospatial short- and long-term memory or recognition in comparison to HC (mean age = 11.62 ± 1.29 years). Performance of adolescents with AN (mean age = 15.93 ± 0.70 years) was not significantly different compared to HC (mean age = 16.20 ± 1.26 years). Explorative regression analyses revealed a significant interaction of age and group for flexibility (adjusted R ²  = 0.30, F = 17.85, p = 0.013, η _p ²  = 0.32). Contrary to expectations, the current study could not confirm the presence of inefficient cognitive processing in children with EO-AN compared to HC. Nonetheless, the expected age-related improvement of flexibility might be disrupted in children and adolescents with AN. Longitudinal neuropsychological examinations are necessary to provide more information about the role of cognitive functioning in the development and maintenance of AN.     

Early emotional and behavioral difficulties and adult educational attainment: an 18-year follow-up of the TEMPO study

Children who experience behavioral difficulties often have short and long-term school problems. However, the relationship between emotional difficulties and later academic achievement has not been thoroughly examined. Using data from the French TEMPO study (n = 666, follow-up 1991, 1999, 2009, mean age = 10.5, sd = 4.9 at baseline), we studied associations between internalizing and externalizing symptoms in: (a) childhood and (b) adolescence and educational attainment by young adulthood (< vs. ≥ high school degree), accounting for participants’ age, sex, juvenile academic difficulties, and family income. High levels of childhood (but not adolescent) internalizing and externalizing symptoms were associated with low educational attainment; however, in multivariate models only the association with childhood internalizing symptoms remained statistically significant (OR = 1.75, 95 % CI 1.00–3.02). Supporting children with internalizing problems early on could help improve their long-term educational attainment.     

The value of transesophageal echocardiography in the investigation and management of cryptogenic cerebral ischemia: a single-center experience

The diagnostic utility of transesophageal echocardiography (TEE) has often been challenged in patients with cryptogenic stroke (CS). We estimated the prevalence of different findings on TEE examination of CS patients, their impact on secondary stroke prevention and the presence of potential age or gender disparities. We reviewed all TEE examinations that were performed in a single echocardiography laboratory during a 7-year-old period to identify CS patients that underwent investigation with TEE. Of the 518 total TEE examinations, we identified 88 CS patients. TEE revealed abnormal findings in 69.3 % of them. Patent foramen ovale (PFO) and atrial septal aneurysm (ASA) were identified in 30.6 and 22.7 % of the patients. Ascending aorta and aortic arch atheromatosis was present in 26.1 % of the patients, with complex atheromatosis diagnosed in 14.7 % of them. Cardiac myxomas were uncovered in 2.3 %. Thrombi in the left atrium and in cardiac valves were reported in 3.4 and 2.3 % of the patients, respectively. Based on TEE findings, the therapeutic management would be very likely modified in 9.1 % of the patients. Subgroup analysis revealed no gender disparities on the prevalence of TEE findings and in secondary stroke prevention, while linear regression analyses revealed significant associations of age with the prevalence of PFO, ASA, aorta atheromatosis and complex aorta atheromatosis. TEE examination should be included in the diagnostic work-up of all CS patients, irrespective of age and gender status, since it can reveal potential sources of embolism and has a significant impact for secondary stroke prevention.     

The challenge of basilar artery occlusion wake-up stroke: too late for intravenous thrombolysis?

We describe the case of a patient carried to our emergency department, with the wake-up finding of dysarthria, right hemiplegia and worsening consciousness impairment (NIHSS 12). After performing a CT angiography, which showed complete basilar occlusion, we determined the MR DWI-FLAIR mismatch to estimate the stroke onset time. Because of the favorable mismatch (DWI hyperintensity in the left pons, no FLAIR hyperintensity in the same region), the patient underwent thrombolysis with sudden neurological improvement. In addition, the DWI hyperintensity first observed in the left pons totally regressed after thrombolysis. Wake-up stroke constitutes about 14 % of all strokes, while the percentage of basilar artery occlusion wake-up strokes is still unknown. Although thrombolysis in patients with unknown-onset time is still an off-label therapy, basilar artery occlusion is a potentially fatal event. In our case we used RM DWI-FLAIR mismatch to rapidly estimate the stroke onset time and to treat the patient with an off-label but potentially effective and safe therapy.     

A one-to-one telestroke network: the first Italian study of a web-based telemedicine system for thrombolysis delivery and patient monitoring

Over 10 years after European approval, thrombolysis is still limited by a restricted time window and non-optimal territorial coverage. Implementation of telestroke can give a growing number of patients access to treatment. We hereby present the first Italian telemedicine study applied to both the acute and the monitoring phase of stroke care. From January 2011 to December 2013, we tested a web-based, drip, and treat interaction model, connecting the cerebrovascular specialist of one hub center to the Emergency Department of a Spoke center. We then compared thrombolysis delivered using the telestroke model with thrombolysis provided at the Hub Stroke Unit at the time when the telemedicine program was activated. Telethrombolysis data were then compared with data from the two main international telestroke projects (TEMPiS and REACH), and other European telestroke studies performed at the time of writing. We collected a total of 131 thrombolysis procedures (25 telethrombolysis and 106 thrombolysis patients at the Stroke Unit). Statistical analysis with the t test yielded no statistically significant differences between the two populations in door-to-scan, door-to-needle (DTN), and onset-to-treatment times (OTT). Our OTT and DTN pathway times were longer than the TEMPiS and REACH studies but comparable with other European telemedicine trials, despite different models of interaction and number of centers. Our study in a northeastern province of Italy confirms the potential of applying telemedicine to a cerebrovascular pathology.     

Unilateral varus osteotomy of the proximal femur in children with cerebral palsy: a five-year follow-up of the development of both hips

Background  

Varus osteotomy of the proximal femur (VOPF) is one treatment option to prevent hip dislocation in children with cerebral palsy (CP). It is questioned whether the osteotomy should be performed in the displaced hip only, or if it should be performed bilaterally to prevent later displacement of the contralateral hip. CPUP is a register and healthcare programme for children with CP that was initiated in 1994 in southern Sweden. In the programme, range-of-motion and radiographic examination of the hips is performed regularly. These data have been analysed preoperatively and for 5 years postoperatively in children treated with unilateral VOPF.     

Surgical treatment of symptomatic cerebral cavernous malformations in eloquent brain regions

Background

Despite the increased risk of hemorrhage and deteriorating neurological function of once-bled cerebral cavernous malformations (CM), the management of eloquently located CMs remains controversial.

Methods

All eloquently located CMs (n?=?45) surgically treated between 03/2006 and 04/2011 in our department were consecutively evaluated. Eloquence was characterized according to Spetzler and Martin's definition. The following locations were approached: brainstem, n?=?16; sensorimotor, n?=?8; visual pathway, n?=?7; cerebellum (deep nuclei and peduncles), n?=?7; basal ganglia, n?=?4, and language, n?=?3. Follow-up data was available for 41 patients (91 %) with a median interval of 14 months. Outcomes were evaluated according to the Glasgow outcome and the modified Rankin scale.

Results

Immediately after surgery, 47 % (n?=?21) had a new deficit. At follow-up, 80 % (n?=?36) recovered to at least preoperative status or were better than before surgery, 9 % (n?=?4) exhibited a slight, and 7 % (n?=?3) had a moderate neurological impairment. Only two cases (4 %) with a new permanent severe deficit were observed, both related to dorsal brainstem surgery. The outcome after the surgery of otherwise located brainstem CMs was as beneficial as that for non-brainstem CMs. Patients with initially poor neurological performance fared worse than oligosymptomatic patients.

Conclusions

Despite the high postoperative transient morbidity, the majority improved profoundly during follow-ups. Compared with natural history, surgical treatment should be considered for all eloquent symptomatic CMs. Dorsal brainstem location and poor preoperative neurological status are associated with an increased postoperative morbidity.

     

Parathyroidectomy improves bone geometry and microarchitecture in female patients with primary hyperparathyroidism: a one-year prospective controlled study using high-resolution peripheral quantitative computed tomography

Following parathyroidectomy (PTX), bone mineral density (BMD) increases in patients with primary hyperparathyroidism (PHPT), yet information is scarce concerning changes in bone structure and strength following normalization of parathyroid hormone levels postsurgery. In this 1‐year prospective controlled study, high‐resolution peripheral quantitative computed tomography (HR‐pQCT) was used to evaluate changes in bone geometry, volumetric BMD (vBMD), microarchitecture, and estimated strength in female patients with PHPT before and 1 year after PTX, compared to healthy controls. Twenty‐seven women successfully treated with PTX (median age 62 years; range, 44–75 years) and 31 controls (median age 63 years; range, 40–76 years) recruited by random sampling from the general population were studied using HR‐pQCT of the distal radius and tibia as well as with dual‐energy X‐ray absorptiometry (DXA) of the forearm, spine, and hip. The two groups were comparable with respect to age, height, weight, and menopausal status. In both radius and tibia, cortical (Ct.) vBMD and Ct. thickness increased or were maintained in patients and decreased in controls (p < 0.01). Radius cancellous bone architecture was improved in patients through increased trabecular number and decreased trabecular spacing compared with changes in controls (p < 0.05). No significant cancellous bone changes were observed in tibia. Estimated bone failure load by finite element modeling increased in patients in radius but declined in controls (p < 0.001). Similar, albeit borderline significant changes in estimated failure load were found in tibia (p = 0.06). This study showed that females with PHPT had improvements in cortical bone geometry and increases in cortical and trabecular vBMD in both radius and tibia along with improvements in cancellous bone architecture and estimated strength in radius 1 year after PTX, reversing or attenuating age‐related changes observed in controls. © 2012 American Society for Bone and Mineral Research.