Approach to gait disorders and orthotic management in adult onset neuromuscular diseases.

In order to understand abnormal gait, this article will first review normal gait, discuss how neuromuscular diseases disturb gait patterns and review orthotic interventions. In normal gait, concentric contractions accelerate and eccentric contractions decelerate the limb. Neuromuscular gait disorders can be grouped into (1) proximal weakness, (2) distal weakness, (3) nonlength-dependent or generalized weakness, (4) asymmetric weakness, and (5) sensory disorders. Identification of gait disturbance type in neuromuscular diseases leads to the appropriate orthotic prescription since orthotic strategies are grouped into (1) proximal weakness, (2) distal weakness, and (3) sensory disturbances. Orthotics is not indicated in all types of gait disturbance. Weakness in proximal hip musculature can be managed with gait aids such as walkers. In contrast, distal muscle weakness can be managed with orthotics. Preservation of gait assists in maintenance of daily function and integration in society.

Changes in the excitability of anterior horn cells in a mental rotation task of body parts.

INTRODUCTION/AIMS: Mental rotation (MR), a tool of implicit motor imagery, is the ability to rotate mental representations of two- or three-dimensional objects. Although many reports have described changes in brain activity during MR tasks, it is not clear whether the excitability of anterior horn cells in the spinal cord can be changed. In this study, we examined whether MR tasks of hand images affect the excitability of anterior horn cells using F-wave analysis. METHODS: Right-handed, healthy participants were recruited for this study. F-waves of the right abductor pollicis brevis were recorded after stimulation of the right median nerve at rest, during a non-MR task, and during an MR task. The F-wave persistence and the F/M amplitude ratio were calculated and analyzed. RESULTS: Twenty participants (11 men and 9 women; mean age, 29.2 ± 4.4 years) were initially recruited, and data from the 18 that met the inclusion criteria were analyzed. The F-wave persistence was significantly higher in the MR task than in the resting condition (p = .001) or the non-MR task (p = .012). The F/M amplitude ratio was significantly higher in the MR task than in the resting condition (p = .019). DISCUSSION: The MR task increases the excitability of anterior horn cells corresponding to the same body part. MR tasks may have the potential for improving motor function in patients with reduced excitability of the anterior horn cells, although this methodology must be further verified in a clinical setting.

Arthroscopic inferior leaf meniscectomy of the involved anterior horn in the lateral meniscus horizontal tear via an accessary extreme far anteromedial portal.

BACKGROUND: An accessory extreme far anteromedial portal can improve visualisation and ease inferior leaf meniscectomy in patients with lateral meniscal anterior horn horizontal tears. However, the therapeutic outcomes of adding an accessory extreme far anteromedial portal remain unclear. This study aimed to evaluate the clinical efficacy of adding an accessory extreme far anteromedial portal for treating lateral meniscal horizontal tears involving the anterior horns. METHODS: This retrospective study included 101 patients with anterior horn involvement in lateral meniscal horizontal tears who underwent arthroscopic unstable inferior leaf meniscectomy between January 2016 and December 2020. The pathologies were diagnosed using physical examinations and magnetic resonance imaging. The anterior horn involved in the lateral meniscal horizontal tears was treated using inferior leaf meniscectomy. The primary endpoints were changes in the visual analogue scale, Lysholm, International Knee Documentation Committee, and Tegner scores at the final follow-up. The secondary endpoint was meniscal cure rate at 3 months postoperatively. The preoperative and postoperative functional scores were compared. The occurrence of complications was recorded. RESULTS: All patients were followed up for an average of 4.9 ± 1.2 years (range 2.3-7.5 years). After 4 months, none of the patients experienced pain, weakness, instability, or tenderness in the lateral joint line, achieving an imaging cure rate of 98%. At the final follow-up, significant postoperative improvements were observed in the average values of the visual analogue scale score (3.5 ± 0.7 vs. 0.7 ± 0.6), Lysholm score (62.7 ± 4.4 vs. 91.8 ± 3.1), International Knee Documentation Committee score (61.9 ± 3.7 vs. 91.7 ± 9.5), and Tegner score (2.0 ± 0.7 vs. 6.1 ± 0.7). Excellent Lysholm scores were obtained in 81 patients, and good outcomes were obtained in 18 patients, with an excellent-to-good rate of 98.0%. CONCLUSIONS: Inferior leaf resection via the accessory far anteromedial portal is a safe treatment option for the involved anterior horn in lateral meniscal horizontal tears. This approach enhances visibility and facilitates surgical procedures, with minimal complications.

Anterior horn damage in brachial multisegmental amyotrophy with superficial siderosis and dural tear: an autopsy case report.

BACKGROUND: Patients with superficial siderosis (SS) rarely show brachial multisegmental amyotrophy with ventral intraspinal fluid collection accompanied with dural tear. CASE PRESENTATION: We describe spinal cord pathology of a 58-year-old man who developed brachial multisegmental amyotrophy with ventral intraspinal fluid collection from the cervical to lumbar spinal levels accompanied with SS, dural tear, and snake-eyes appearance on magnetic resonance imaging (MRI). Radiological and pathological analyses detected diffuse and prominent superficial deposition of hemosiderin in the central nervous system. Snake-eyes appearance on MRI expanded from the C3 to C7 spinal levels without apparent cervical canal stenosis. Pathologically, severe neuronal loss at both anterior horns and intermediate zone was expanded from the upper cervical (C3) to middle thoracic (Th5) spinal gray matter, and these findings were similar to compressive myelopathy. CONCLUSION: Extensive damage of the anterior horns in our patient may be due to dynamic compression induced by ventral intraspinal fluid collection.

The Course and Neonatal Outcome of Choroid Plexus Extension to the Anterior Horn at the Routine Anatomy Scan.

OBJECTIVES: Our objective was to examine the pregnancy course and immediate neonatal outcome of fetuses with an isolated extension of choroid plexus (CP) to the anterior horn during the second trimester. METHODS: We prospectively collected the cases referred to us between July 2012 and January 2021 with isolated finding of CP extension to the anterior horn. Relevant clinical and demographic information was recorded, and a full anatomy scan including a comprehensive neurosonogram was performed. In cases of confirmed isolated extension of CP to the anterior horns, women were offered further investigation including fetal MRI, and ultrasound follow up. RESULTS: We collected 29 eligible cases for analysis. The mean gestational age (GA ± SD) for diagnosis and referral was 19.24 ± 2.3 weeks. No other intracranial anomalies were detected in any of the cases, and the finding resolved at 25 ± 2.6 weeks. The average extension length and width to the anterior horn were 0.7 ± 0.3 cm, and 0.5 ± 0.1 cm, respectively. Eleven fetuses (38%) had choroid plexus cyst (CPC) in addition to the extension. Ten patients (35%) completed a fetal brain MRI, with no identified abnormalities. Gross neurological exam and Apgar score at birth were normal. CONCLUSION: Extension of CP to anterior horn with or without CPC at mid-trimester seems to have spontaneous resolution with likely a good prognosis and no further implications.

Neurosonographic Measurements of the Fetal Anterior Complex in Singleton Pregnancies.

OBJECTIVE: To construct reference ranges of the fetal cerebral anterior complex, including ventricular index (VI), anterior horn of lateral ventricle width (AW), and cavum septi pellucidi (CSP) width, as a function of gestational age (GA), in Thai fetuses. METHODS: Low-risk pregnancies were recruited to measure fetal anterior complex on axial transventricular and coronal transcaudate planes using transabdominal ultrasound. The downside and upside hemisphere were defined as cerebral hemisphere located distal and proximal to the transducer, respectively. The five variables, downside/upside VI, downside/upside AW and CSP width, were measured from each fetus. Best-fit models in predicting mean and standard deviation for each value as a function of GA were constructed, using regression analysis. Distributions of Z-scores of all values based on GA were created to evaluate the fitness of models. Intraclass correlation coefficients were used to assess inter-/intraobserver variability. RESULTS: A total of 395 fetuses were measured for anterior complex. All parameters changed with GA with quadratic function. The models for predicting means and standard deviation of the five parameters as well as percentile charts were created. All models were proven well-fitted. The intra-/interobserver reliability coefficients of all values showed excellent agreement. CONCLUSION: The reference ranges of the fetal anterior complex, including VI, AW, and CSP, in axial transventricular and coronal transcaudate planes have been established and available for clinical use.

Myelitis with flaccid paralysis due to Japanese encephalitis: case report and review of the literature.

BACKGROUND: Japanese encephalitis is an arthropod-borne zoonotic flavivirus infection endemic to tropical and subtropical Asia. A minority of infections leads to a symptomatic course, but affected patients often develop life-threatening encephalitis with severe sequelae. LITERATURE REVIEW: Myelitis with flaccid paralysis is a rare complication of Japanese Encephalitis, which-according to our literature search-was reported in 27 cases, some of which were published as case reports and others as case series. Overall, there is a broad clinical spectrum with typically asymmetric manifestation and partly severe motor sequelae and partly mild courses. Lower limb paralysis appears to be more frequent than upper limb paralysis. An encephalitic component is not apparent in all cases CASE PRESENTATION: We herein add the case of a 29 year-old female who developed encephalitis and myelitis with flaccid paralysis during a long-time stay in Indonesia. Diagnostic workup in Indonesia did not clearly reveal an underlying cause. Upon clinical stabilization, the patient was evacuated to her home country Germany, where further diagnostics confirmed Japanese encephalitis virus as the causative agent. The patient has partly recovered, but still suffers from residual paralysis of the upper limb. CONCLUSION: Flaccid paralysis is a rare, and likely underdiagnosed complication of Japanese encephalitis, which, to the best of our knowledge, has never been diagnosed outside endemic areas before.

Cross-sectional reference values of cerebral ventricle for Chinese neonates born at 25-41 weeks of gestation.

To establish the cross-sectional reference values of cerebral ventricular size for the Chinese newborns by the most correlated explanatory variables. The anterior horn width (AHW), thalamo-occipital distance (TOD), and ventricular index (VI) were collected prospectively from 1- to 7-day neonates without potential neurological problems. All neonates were delivered or treated at the Hunan Provincial Maternal and Child Health Care Hospital or Second Xiangya Hospital of Central South University between February and August 2021. The most correlated explanatory variables were identified with the max-min normalization and multiple regression. The reference values were then established based on the above variables. Additionally, intraclass correlation coefficients (ICC) were applied to evaluate the reliability of the overall data collection process. This prospective study consisted of 1848 neonates. The AHW was most highly correlated with GA; the TOD and VI were most strongly correlated with birth weight. All the foregoing correlations were positive ones. Heteroscedasticity and influential points existed in both TOD and VI. The ICCAHW was the largest to a specific rater or between raters, the ICCTOD the second largest, and the ICCVI the smallest. CONCLUSIONS: We recommend using the GA-based AHW reference values and birth weight-based TOD and VI ones. We also present a comparison of GA-based upper limits from all available reference intervals. Moreover, we determine that measurement errors are the primary cause of influential points and heteroscedasticity in TOD and VI studies and infer that the studies of TOD and VI are vulnerable to them. WHAT IS KNOWN: • Reference values of infantile cerebral ventricles are vital in diagnosing and treating cerebral ventricular dilatation. • Precursors established gestational age-based reference values subjectively. WHAT IS NEW: • We set cross-sectional reference values based on the most correlated variables for Chinese neonates and compared all available gestational age-based upper limits. • Influential points and heteroscedasticity mainly caused by measurement errors are common in TOD and VI studies.

Tetanic stimulation of the peripheral nerve augments motor evoked potentials by re-exciting spinal anterior horn cells.

Tetanic stimulation of the peripheral nerve, immediately prior to conducting transcranial electrical stimulation motor evoked potential (TES-MEP), increases MEP amplitudes in both innervated and uninnervated muscles by the stimulated peripheral nerve; this is known as the remote augmentation of MEPs. Nevertheless, the mechanisms underlying the remote augmentation of MEPs remain unclear. Although one hypothesis was that remote augmentation of MEPs results from increased motoneuronal excitability at the spinal cord level, the effect of spinal anterior horn cells has not yet been investigated. We aimed to investigate the effect of tetanic stimulation of the peripheral nerve on spinal cord anterior horn cells by analyzing the F-wave. We included 34 patients who underwent elective spinal surgeries and compared the changes in F-waves and TES-MEPs pre- and post-tetanic stimulation of the median nerve. F-wave analyses were recorded by stimulating the median and tibial nerves. TES-MEPs and F-wave analyses were compared between baseline and post-tetanic stimulation time periods using Wilcoxon signed-rank tests. A significant augmentation of MEPs, independent of the level corresponding to the median nerve, was demonstrated. Furthermore, F-wave persistence was significantly increased not only in the median nerve but also in the tibial nerve after tetanic stimulation of the median nerve. The increased F-wave persistence indicates an increase of re-excited motor units in spinal anterior horn cells. These results confirm the hypothesis that tetanic stimulation of the peripheral nerve may cause remote augmentation of MEPs, primarily by increasing the excitability of the anterior horn cells.

The mystery of monozygotic twinning I: What can Amyoplasia tell us about monozygotic twinning and the possible role of twin-twin transfusion?

Amyoplasia is a very specific, nongenetic clinically recognizable form of arthrogryposis, representing about one-third of individuals with arthrogryposis surviving the newborn period. There is a markedly increased number of individuals with Amyoplasia who are one of monozygotic (MZ) twins, with the other twin being normal. Thus, it would appear that Amyoplasia is definitely associated with and may be caused by an MZ twinning event. The twin-twin transfusion seen in MZ twins could play an etiologic role in producing Amyoplasia. In this article, Amyoplasia twinning is compared to twinning in other forms of arthrogryposis. The accompanying paper examines various types of MZ twinning (Hall, 2021). Amyoplasia is primarily associated with spontaneous MZ twinning.

Curious case of steroid responsive diffuse anterior horn cell disease associated with COVID-19 infection.

Covid-19-associated neurological manifestations are being reported with increased frequency throughout the world. In a study from China, symptoms referable to peripheral nervous system (PNS) were described in approximately 9% of hospitalized Covid-19 patients. Common PNS symptoms reported in the study were loss of taste/smell and muscle pains. With this communication, we expand the spectrum of PNS manifestations of Covid-19 infection by reporting an association of steroid responsive diffuse anterior horn cell disease with Covid-19 infection from a tertiary care centre in India. Neurological manifestations of Covid-19 are diverse, and our case which to best of my knowledge is the first case in literature to report an occurrence of steroid responsive diffuse anterior horn cell disease associated with Covid-19 infection, adds to the ever-increasing spectrum of neurological manifestations associated with this pandemic causing virus. Good response to steroid in our case serves to provide an insight into the possible pathogenesis of this manifestation and also paves the way for future therapeutic decisions related to this association.

Neuropathology of the spinal nerve roots, spinal cord, and brain in the first autopsied case of Charcot-Marie-Tooth disease 4F with a D651N mutation in the periaxin gene.

Charcot-Marie-Tooth disease (CMT) 4F is an autosomal recessive, hereditary peripheral neuropathy, mostly caused by mutations in the periaxin gene (PRX). This article reports neuropathological findings of the spinal nerve roots, spinal cord, and brain of a patient with CMT4F and a D651N missense mutation in PRX. The patient was a 74-year-old woman who had a history of peripheral neuropathy with onset at the age of 30 years. She also had a history of infantile paralysis at the age of 18 months. The most pronounced autopsy finding was diffuse enlargement of anterior and posterior nerve roots, accentuated at the lumbo-sacral levels. On microscopy, the swollen nerve roots showed a loss of large-diameter myelinated fibers and formation of numerous onion bulbs. Most of the onion bulbs lacked the central, regenerating thin myelin sheaths, and in large-diameter nerve fibers whose axons had been lost, collagen fibers occupied the center of the onion bulbs. Some nerve roots formed glial bundles at the proximal end. The spinal cord showed degeneration of the gracile fascicles, and the lumbar segment anterior horn showed an asymmetric neuronal loss with rarefaction of the neuropil. The brain did not show any notable changes except for multiple foci of a radial microcolumnar arrangement of neurons in the cerebral cortex. Degeneration of the lumbar segment anterior horn is most likely secondary to the anterior radiculopathy, but a localized circulatory disturbance is another possibility.

Anterior root of lateral meniscus and medial tibial spine are reliable intraoperative landmarks for the tibial footprint of anterior cruciate ligament.

PURPOSE: The aims of the present study were (1) to investigate the tibial footprint location of the anterior cruciate ligament (ACL) in both ACL-ruptured and ACL-intact patients, (2) to identify the relationship of the tibial footprint to the anterior root of the lateral meniscus (ARLM) and medial tibial spine (MTS), and (3) to evaluate the reliability of the ARLM and MTS for identifying the center of the tibial ACL footprint. METHODS: Magnetic resonance images of 90 knees with ACL rupture and 90 matched-controlled knees were used to create three-dimensional models of the tibia. The tibial ACL footprint was outlined on each model, and its location was measured using an anatomical coordinate system. RESULTS: No significant difference in the location of the tibial footprint was found between ACL-ruptured and ACL-intact knees. The tibial ACL footprint was located in very close proximity to the ARLM, especially in the M/L direction. The safe zone of tibial tunnel reaming for avoiding damage to the ARLM was 2.6 mm lateral to the center of the native tibial footprint. Both the ARLM and MTS were reliable intraoperative landmarks for identifying the tibial footprint. CONCLUSIONS: Orthopedic surgeons should be aware of the safe zone of tibial tunnel reaming for avoiding injury to the ARLM. Both the ARLM and MTS might be reliable landmarks for identifying the center of the tibial ACL footprint and may facilitate tibial tunnel placement during anatomical single-bundle ACL reconstruction, especially in cases of revision where the tibial ACL stump is not available. LEVEL OF EVIDENCE: Level III.

Acute flaccid paralysis due to Echovirus 30 in an immunosuppressed transplant recipient.

An Italian 13-year-old boy immunosuppressed due to kidney transplant presented in November 2018 with acute flaccid paralysis with anterior horn cell involvement resembling the clinical, radiological, and laboratory features of poliomyelitis. Enterovirus was molecularly identified in cerebral spinal fluid and stool samples and the sequence analysis of the VP1 gene of enterovirus genome revealed the presence of Echovirus 30 both in CSF and in stool samples. Echovirus 30 is an emerging neurotropic virus able to cause outbreaks of aseptic meningitis and meningoencephalitis all over the world, but acute flaccid paralysis is not a classical manifestation. A 6-month follow-up revealed a poor outcome with severe motor deficits and only slight improvement in disability. Clinicians must be aware of the possible role of Echovirus 30 in acute flaccid paralysis and active surveillance should consider the possible influence of immunosuppression on the symptoms caused by the widening spectrum of enterovirus infections.

Quantitative electromyography: Normative data in paraspinal muscles.

BACKGROUND: Quantitative electromyography of paraspinal muscle is a valuable diagnostic tool, but normative data are lacking. METHODS: Needle electromyography (EMG) was obtained in 65 healthy subjects (49% men, 51% women) aged 21 to 82 years at C7, Th10, and L5 segments bilaterally. The incidence of spontaneous activity; motor unit potential (MUP) amplitudes, durations, and the incidence of polyphasic potentials; and the recruitment pattern at maximal voluntary contraction (MVC) were evaluated. RESULTS: The incidence of fibrillation potentials was similar to limb muscles. The mean MUP duration and amplitude, and the amplitude at MVC increased caudally, while the incidence of polyphasic potentials was similar at all levels. EMG parameters did not correlate with sex or age. CONCLUSIONS: In contrast to limb muscles, EMG parameters did not change with age, while polyphasic potentials were more frequent in paraspinal muscle than in limb muscles. The EMG gradient suggests larger motor units at more caudal segments.

Inositol hexakisphosphate kinase 2 promotes cell death of anterior horn cells in the spinal cord of patients with amyotrophic lateral sclerosis.

We have previously reported that inositol hexakisphosphate kinase (InsP6K)2 mediates cell death. InsP6K2 is abundantly expressed in anterior horn cells of the mammalian spinal cord. We investigated the role of InsP6K2 in spinal cords of patients with amyotrophic lateral sclerosis (ALS). Autopsy specimens of lumbar spinal cords from ten patients with sporadic ALS and five non-neurological disease patients (NNDPs) were obtained. We performed quantitative real-time PCR, immunostaining, and western blotting for InsP6K1, InsP6K2, InsP6K3, protein kinase B (Akt), casein kinase 2 (CK2), and 90-kDa heat-shock protein (HSP90). In contrast to InsP6K1 and InsP6K3 mRNA expression, InsP6K2 levels in anterior horn cells of the spinal cord were significantly increased in ALS patients compared to NNDPs. In ALS patients, InsP6K2 translocated from the nucleus to the cytoplasm. However, we observed a decrease in HSP90, CK2, and Akt activity in ALS patients compared to NNDPs. A previous study reported that InsP6K2 activity is suppressed after binding to HSP90 and subsequent phosphorylation and degradation by CK2, thus decreasing InsP6K2 activity. However, InsP7, which is generated by InsP6K2, can compete with Akt for PH domain binding. Consequently, InsP7 can inhibit Akt phosphorylation. Our results suggest that InsP6K2 is activated in the spinal cord of patients with ALS and may play an important role in ALS by inducing cell death mechanisms via Akt, CK2, and HSP90 pathways.

International standards for fetal brain structures based on serial ultrasound measurements from Fetal Growth Longitudinal Study of INTERGROWTH-21st Project.

OBJECTIVE: To create prescriptive growth standards for five fetal brain structures, measured using ultrasound, in healthy, well-nourished women at low risk of impaired fetal growth and poor perinatal outcome, taking part in the Fetal Growth Longitudinal Study (FGLS) of the INTERGROWTH-21st Project. METHODS: This was a complementary analysis of a large, population-based, multicenter, longitudinal study. The sample analyzed was selected randomly from the overall FGLS population, ensuring an equal distribution among the eight diverse participating sites and of three-dimensional (3D) ultrasound volumes across pregnancy (range: 15-36 weeks' gestation). We measured, in planes reconstructed from 3D ultrasound volumes of the fetal head at different timepoints in pregnancy, the size of the parieto-occipital fissure (POF), Sylvian fissure (SF), anterior horn of the lateral ventricle, atrium of the posterior horn of the lateral ventricle (PV) and cisterna magna (CM). Fractional polynomials were used to construct the standards. Growth and development of the infants were assessed at 1 and 2 years of age to confirm their adequacy for constructing international standards. RESULTS: From the entire FGLS cohort of 4321 women, 451 (10.4%) were selected at random. After exclusions, 3D ultrasound volumes from 442 fetuses born without a congenital malformation were used to create the charts. The fetal brain structures of interest were identified in 90% of cases. All structures, except the PV, showed increasing size with gestational age, and the size of the POF, SF, PV and CM showed increasing variability. The 3rd , 5th , 50th , 95th and 97th smoothed centiles are presented. The 5th centiles for the POF and SF were 3.1 mm and 4.7 mm at 22 weeks' gestation and 4.6 mm and 9.9 mm at 32 weeks, respectively. The 95th centiles for the PV and CM were 8.5 mm and 7.5 mm at 22 weeks and 8.6 mm and 9.5 mm at 32 weeks, respectively. CONCLUSIONS: We have produced prescriptive size standards for fetal brain structures based on prospectively enrolled pregnancies at low risk of abnormal outcome. We recommend these as international standards for the assessment of measurements obtained using ultrasound from fetal brain structures. © 2020 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Ultrastructure of spinal anterior horn cells in human Niemann-Pick type C (NPC) patient and mouse model of NPC with retroposon insertion in NPC1 genes.

Niemann-Pick disease type C (NPC) is a neurovisceral lipid-storage disease. Although NPC patients show lipid storage in anterior horn cells of the spinal cord, little information is available regarding the electron microscopic analyses of the morphologies of intra-endosomal lipid like-materials in the anterior horn cells of NPC patients. In this study, we elucidated the intra-endosomal ultrastructures in spinal anterior horn cells in an NPC patient, as well as in mutant BALB/c NPC1-/- mice with a retroposon insertion in the NPC1 gene. These morphologies were classified into four types: vesicle, multiple concentric sphere (MCS), membrane, and rose flower. The percentages of the composition in the NPC patient and NPC1-/- mice were: vesicle (55.5% and 14.9%), MCS (15.7% and 3.4%), membrane (23.6% and 57.1%), and rose flower (5.2% and 24.6%), respectively. Formation of the intra-endosomal structures could proceed as follows: (i) a vesicle or MCS buds off the endosome into the lumen; (ii) when a vesicle breaks down, a membrane is formed; and (iii) after an MCS breaks down, a rose flower structure is formed. Our new finding in this study is that ultrastructural morphology is the same between the NPC patient and NPC1-/- mice, although there are differences in the composition.

Polio-Like Manifestation of Powassan Virus Infection with Anterior Horn Cell Involvement, Canada.

Evidence of spinal cord involvement in Powassan virus infection is largely limited to mouse models. We report a case of a polio-like illness caused by Powassan virus infection in a 62-year-old man in Canada. Magnetic resonance imaging showed T2 hyperintensities in the anterior horns of the cervical spinal cord.

Visualization of the periventricular Virchow-Robin spaces with ependymal openings.

PURPOSE: The morphological relationships between the periventricular Virchow-Robin spaces (VRSs) and cerebral ventricles have been poorly documented. The present study aimed to explore the issue using magnetic resonance imaging. METHODS: A total of 211 patients were included in this study. T2-weighted and constructive interference in steady state (CISS) sequences were performed in thin-sliced, coronal sections. RESULTS: On T2-weighted sequence, the periventricular VRSs with ependymal openings were identified in 34% of 139 subjects. All the openings were located in the lateral wall of the anterior horn. In CISS sequences, such VRSs were found in 39% of 72 subjects. The mean age was significantly higher in the population with such VRSs compared to those without VRSs (p = 0.0047). Of the 58 periventricular VRSs with ependymal openings identified on T2-weighted images, 16% were located in the upper, 36% in the middle, and 48% in the lower part of the lateral wall. Of the 38 such VRSs identified on CISS images, 32% were located in the upper, 24% in the middle, and 42% in the lower part of the lateral wall, and 3% in the upper part of the medial wall. CONCLUSIONS: The ependymal openings of the periventricular VRSs may be centered in the lateral wall of the anterior horn. The coronal CISS sequence can sensitively delineate the VRSs with ependymal openings.