Topic:Neurology
Neurology in horses encompasses the study of the equine nervous system, including its structure, function, and associated disorders. The equine nervous system is divided into the central nervous system (CNS), consisting of the brain and spinal cord, and the peripheral nervous system (PNS), which includes nerves extending throughout the body. Neurological conditions in horses can manifest as gait abnormalities, behavioral changes, or sensory deficits. Common neurological disorders include equine protozoal myeloencephalitis (EPM), cervical vertebral stenotic myelopathy (CVSM), and equine herpesvirus myeloencephalopathy (EHM). Diagnostic approaches may involve clinical evaluation, imaging techniques, and laboratory tests. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, pathophysiology, diagnosis, and management of neurological disorders in horses.
Localization of the 5-hydroxytryptamine 4 receptor in equine enteric neurons and extrinsic sensory fibers. Serotonin plays a pivotal role in regulating gut motility, visceral sensitivity, and fluid secretion via specific receptors. Among these receptors, 5-HT exerts a prominent control on gut motor function. Although the prokinetic effect exerted by 5-HT agonists is well known, the cellular sites of 5-HT expression remain poorly understood in large mammals, e.g., horses. In this study, we evaluated the distribution of 5-HT in the horse intestine and in foals with enteric aganglionosis, reminiscent of human Hirschsprung's disease. Methods: The intestine and spinal ganglia were obtained from three he...
A comparative study of oculomotor, trochlear and abducens nerves in Arabian foals. We investigated the microscopic structure of transverse sections of the oculomotor, trochlear and abducens nerves of Arabian foals using stereological methods. Bilateral nerve pairs from 2-month-old female Arabian foals were analyzed. The tissues were embedded in plastic blocks, then 1 µm thick sections were cut and stained with osmium tetroxide and methylene blue-azure II. Stereology was performed using light microscopy. Morphometry showed that the right and left pairs of nerves were similar. The transverse sectional areas of the oculomotor, trochlear and abducens nerves were 1.93 ± 0.19 mm...
The laminar organization of the motor cortex in monodactylous mammals: a comparative assessment based on horse, chimpanzee, and macaque. The architecture of the neocortex classically consists of six layers, based on cytological criteria and on the layout of intra/interlaminar connections. Yet, the comparison of cortical cytoarchitectonic features across different species proves overwhelmingly difficult, due to the lack of a reliable model to analyze the connection patterns of neuronal ensembles forming the different layers. We first defined a set of suitable morphometric cell features, obtained in digitized Nissl-stained sections of the motor cortex of the horse, chimpanzee, and crab-eating macaque. We then modeled them using a...
Developing a 3-choice serial reaction time task for examining neural and cognitive function in an equine model. Large animal models of human neurological disorders are advantageous compared to rodent models due to their neuroanatomical complexity, longevity and their ability to be maintained in naturalised environments. Some large animal models spontaneously develop behaviours that closely resemble the symptoms of neural and psychiatric disorders. The horse is an example of this; the domestic form of this species consistently develops spontaneous stereotypic behaviours akin to the compulsive and impulsive behaviours observed in human neurological disorders such as Tourette's syndrome. The ability to non...
Therapeutics for Equine Protozoal Myeloencephalitis. Equine protozoal myeloencephalitis is an infectious disease of the central nervous system caused by Sarcocystis neurona or Neospora hughesi. Affected horses routinely present with progressive and asymmetrical neurologic deficits. The diagnosis relies on the presence of neurologic signs, ruling out other neurologic disorders, and the detection of intrathecally derived antibodies to either S neurona and/or N hughesi. Recommended treatment is use of an FDA-approved anticoccidial drug formulation. Medical and supportive treatment is provided based on the severity of neurologic deficits and complic...
Replication of neurovirulent equine herpesvirus type 1 (EHV-1) in CD172a+ monocytic cells. Equine herpesvirus type 1 (EHV-1) is responsible for respiratory disorders, abortion and myeloencephalopathy (EHM) in horses. Two pathotypes of EHV-1 strains are circulating in the field: neurovirulent (N) and non-neurovirulent (NN). For both strains, CD172a monocytic cells are one of the main carrier cells of EHV-1 during primary infection, allowing the virus to invade the horse's body. Recently, we showed that EHV-1 NN strains showed a restricted and delayed replication in CD172a cells. Here we characterize the in vitro replication kinetics of two EHV-1N strains in CD172a cells and investiga...
Effects of guaiphenesin on the equine electroencephalogram during anaesthesia with halothane in oxygen. To identify and characterize the effects of guaiphenesin (GGE) on the electroencephalogram during halothane anaesthesia. Methods: Prospective controlled study. Methods: Eight healthy Welsh mountain pony geldings between 5 and 9 years old and weighing between 270 and 330 kg (mean 301 kg). Methods: Anaesthesia was induced with thiopentone and maintained using halothane in oxygen. End tidal halothane was maintained above 0.75 and below 0.85%. The EEG was recorded continuously and a binaural broad band click stimulus was provided throughout the experiment at 6.1224 Hz. An infusion of 1500 mg GGE w...
Feasibility, repeatability, and safety of ultrasound-guided stimulation of the first cervical nerve at the alar foramen in horses. OBJECTIVE To develop and assess the feasibility, repeatability, and safety of an ultrasound-guided technique to stimulate the first cervical nerve (FCN) at the level of the alar foramen of the atlas of horses. ANIMALS 4 equine cadavers and 6 clinically normal Standardbreds. PROCEDURES In each cadaver, the FCN pathway was determined by dissection, and any anastomosis between the first and second cervical nerves was identified. Subsequently, each of 6 live horses underwent a bilateral ultrasound-guided stimulation of the FCN at the alar foramen 3 times at 3-week intervals. After each procedure, ...
Transcriptome profiling of equine vitamin E deficient neuroaxonal dystrophy identifies upregulation of liver X receptor target genes. Specific spontaneous heritable neurodegenerative diseases have been associated with lower serum and cerebrospinal fluid α-tocopherol (α-TOH) concentrations. Equine neuroaxonal dystrophy (eNAD) has similar histologic lesions to human ataxia with vitamin E deficiency caused by mutations in the α-TOH transfer protein gene (TTPA). Mutations in TTPA are not present with eNAD and the molecular basis remains unknown. Given the neuropathologic phenotypic similarity of the conditions, we assessed the molecular basis of eNAD by global transcriptome sequencing of the cervical spinal cord. Differential...
Experience of using hippotherapy in complex effects on muscle spirals in children with spastic forms of cerebral palsy. Matters of physical and medical rehabilitation of children with organic lesions of the nervous system, in particular, with cerebral palsy, are actual in countries around the world. Hippotherapy is neurophysiologically oriented therapy using horses. Determine whether a combination of hippotherapy as a method of rehabilitation in the aftermath of outpatient comprehensive impact on MS on a stationary phase; Study of the effect of hippotherapy as securing and preparation method for learning new postures and movements in children with spastic cerebral palsy forms; The study of the possible optimiza...
Neural modulators of temperament: A multivariate approach to personality trait identification in the horse. A relationship between dopamine and temperament has previously been described in human cases of dopaminergic dysfunction. Adjustment in temperament prior to disease manifestation can enable the early identification of individuals at risk of such conditions, and scope exists to extend this application of temperament alterations to cases of dopaminergic dysfunction in horses. A multivariate and mixed-methods approach utilising a questionnaire along with two inferred measurements of dopamine activity (Spontaneous Blink Rate [SBR] and behavioral initiation rate [BIR]) were recorded from direct obs...
Central Nervous System and Vertebrae Development in Horses: a Chronological Study with Differential Temporal Expression of Nestin and GFAP. The neural system is one of the earliest systems to develop and the last to be fully developed after birth. This study presents a detailed description of organogenesis of the central nervous system (CNS) at equine embryonic/fetal development between 19 and 115 days of pregnancy. The expression of two important biomarkers in the main structure of the nervous system responsible for neurogenesis in the adult individual, and in the choroid plexus, was demonstrated by Nestin and glial fibrillary acid protein (GFAP) co-labeling. In the 29th day of pregnancy in the undifferentiated lateral ventricle...
Pigment retinopathy in warmblood horses with equine degenerative myeloencephalopathy and equine motor neuron disease. A pigment retinopathy has been reported in adult horses with equine motor neuron disease (EMND) arising from chronic α-tocopherol (α-TP) deficiency. A pigment retinopathy has not been identified in horses with neuroaxonal dystrophy/equine degenerative myeloencephalopathy (NAD/EDM) that affects genetically susceptible young horses with α-TP deficiency. The objective of this report is to describe, for the first time, a pigment retinopathy in a family of α-TP-deficient Warmbloods (WB) with clinically apparent NAD/EDM or EMND. Unassigned: Twenty-five WB horses from one farm underwent complete ...
Detection and DNA quantification of Enterococcus casseliflavus in a foal with septic meningitis. CASE DESCRIPTION A 3-month-old 180-kg (396-lb) Hanoverian colt was examined because of fever, lethargy, inappetence, drooping of the left ear, and stiff neck posture. Initial treatment included empirical antimicrobial treatment and NSAIDs. CLINICAL FINDINGS Initial findings were consistent with CNS anomalies. Endoscopy revealed hyperemia, ecchymosis, and some mucopurulent exudate in the right guttural pouch. Hematologic findings were consistent with neutrophilic inflammation. On the third day of hospitalization, severe neurologic signs were observed. Computed tomography of the skull revealed a...
Extrinsic innervation of ileum and pelvic flexure of foals with ileocolonic aganglionosis. Equine ileocolonic aganglionosis, which is also called lethal white foal syndrome (LWFS), is a severe congenital condition characterized by the unsuccessful colonization of neural crest progenitors in the caudal part of the small intestine and the entire large intestine. LWFS, which is attributable to a mutation in the endothelin receptor B gene, is the horse equivalent of Hirschsprung's disease in humans. Affected foals suffer from aganglionosis or hypoganglionosis of the enteric ganglia resulting in intestinal akinesia and colic. In other species with aganglionosis, fibers of extrinsic origi...
Classification of Horse Gaits Using FCM-Based Neuro-Fuzzy Classifier from the Transformed Data Information of Inertial Sensor. In this study, we classify four horse gaits (walk, sitting trot, rising trot, canter) of three breeds of horse (Jeju, Warmblood, and Thoroughbred) using a neuro-fuzzy classifier (NFC) of the Takagi-Sugeno-Kang (TSK) type from data information transformed by a wavelet packet (WP). The design of the NFC is accomplished by using a fuzzy c-means (FCM) clustering algorithm that can solve the problem of dimensionality increase due to the flexible scatter partitioning. For this purpose, we use the rider's hip motion from the sensor information collected by inertial sensors as feature data for the cla...
The Brain of the Domestic Bos taurus: Weight, Encephalization and Cerebellar Quotients, and Comparison with Other Domestic and Wild Cetartiodactyla. The domestic bovine Bos taurus is raised worldwide for meat and milk production, or even for field work. However the functional anatomy of its central nervous system has received limited attention and most of the reported data in textbooks and reviews are derived from single specimens or relatively old literature. Here we report information on the brain of Bos taurus obtained by sampling 158 individuals, 150 of which at local abattoirs and 8 in the dissecting room, these latter subsequently formalin-fixed. Using body weight and fresh brain weight we calculated the Encephalization Quotient (EQ)...
Aquaporin 11, a regulator of water efflux at retinal Müller glial cell surface decreases concomitant with immune-mediated gliosis. Müller glial cells are important regulators of physiological function of retina. In a model disease of retinal inflammation and spontaneous recurrent uveitis in horses (ERU), we could show that retinal Müller glial cells significantly change potassium and water channel protein expression during autoimmune pathogenesis. The most significantly changed channel protein in neuroinflammatory ERU was aquaporin 11 (AQP11). Aquaporins (AQP, 13 members) are important regulators of water and small solute transport through membranes. AQP11 is an unorthodox member of this family and was assigned to a thi...
Changes in Gait Balance and Brain Connectivity in Response to Equine-Assisted Activity and Training in Children with Attention Deficit Hyperactivity Disorder. Equine-assisted activity and training (EAAT) is thought to improve body balance and clinical symptoms in children with attention deficit hyperactivity disorder (ADHD). The study hypostheses were that EAAT would improve the clinical symptoms and gait balance in children with ADHD and that these improvements would be associated with increased brain connectivity within the balance circuit. Methods: A total of 12 children with ADHD and 12 age- and sex-matched healthy control children were recruited. EAAT consisted of three training sessions, each 70 minutes long, once a week for 4 weeks. Brain fun...
Spinal Cord Hamartomatous Myelodysplasia in 2 Horses With Clinical Neurologic Deficits. Two horses euthanized for neurologic deficits were diagnosed with hamartomatous myelodysplasia of the spinal cord. One was a 5-week-old Holsteiner colt exhibiting spasms of muscle rigidity in the extensor muscles of the limbs and epaxial muscles, and the other was a 3-year-old Thoroughbred colt exhibiting progressive ataxia and hypermetria in the pelvic limbs. Each had focal disorganization of the white and gray matter of the spinal cord forming a mass interspersed with neurons, glial cells, and disoriented axon bundles. In the Holsteiner colt, the mass was at the level of C5 and included isla...
P2Y(1) receptors mediate purinergic relaxation in the equine pelvic flexure. In the equine large intestine, the knowledge of the basic mechanisms underlying motility function is crucial to properly treat motility disorders. P2Y1 receptors are responsible for mediating purinergic colonic relaxation in several species. In vitro experimental studies of the circular muscle from the equine pelvic flexure (n = 6) were performed to characterize inhibitory and excitatory neuromuscular transmission. Electrophysiological studies showed that electrical field stimulation (EFS) evoked biphasic inhibitory junction potentials (IJPs) in smooth muscle cells: a fast IJP (IJPf) follo...
Experience of using hippotherapy in complex effects on muscle spirals in children with spastic forms of cerebral palsy. Matters of physical and medical rehabilitation of children with organic lesions of the nervous system, in particular, with cerebral palsy, are actual in countries around the world. Hippotherapy is neurophysiologically oriented therapy using horses. Determine whether a combination of hippotherapy as a method of rehabilitation in the aftermath of outpatient comprehensive impact on MS on a stationary phase; Study of the effect of hippotherapy as securing and preparation method for learning new postures and movements in children with spastic cerebral palsy forms; The study of the possible optimiza...
Qualitative and Quantitative Characteristics of the Electroencephalogram in Normal Horses during Administration of Inhaled Anesthesia. The effects of anesthesia on the equine electroencephalogram (EEG) after administration of various drugs for sedation, induction, and maintenance are known, but not that the effect of inhaled anesthetics alone for EEG recording. Objective: To determine the effects of isoflurane and halothane, administered as single agents at multiple levels, on the EEG and quantitative EEG (qEEG) of normal horses. Methods: Six healthy horses. Methods: Prospective study. Digital EEG with video and quantitative EEG (qEEG) were recorded after the administration of one of the 2 anesthetics, isoflurane or halothane...
Direct Conversion of Equine Adipose-Derived Stem Cells into Induced Neuronal Cells Is Enhanced in Three-Dimensional Culture. The ability to culture neurons from horses may allow further investigation into equine neurological disorders. In this study, we demonstrate the generation of induced neuronal cells from equine adipose-derived stem cells (EADSCs) using a combination of lentiviral vector expression of the neuronal transcription factors Brn2, Ascl1, Myt1l (BAM) and NeuroD1 and a defined chemical induction medium, with βIII-tubulin-positive induced neuronal cells displaying a distinct neuronal morphology of rounded and compact cell bodies, extensive neurite outgrowth, and branching of processes. Furthermore, we ...
Extrapyramidal system neurotoxicity: animal models. The central nervous system's extrapyramidal system provides involuntary motor control to the muscles of the head, neck, and limbs. Toxicants that affect the extrapyramidal system are generally clinically characterized by impaired motor control, which is usually the result of basal ganglionic dysfunction. A variety of extrapyramidal syndromes are recognized in humans and include Parkinson's disease, secondary parkinsonism, other degenerative diseases of the basal ganglia, and clinical syndromes that result in dystonia, dyskinesia, essential tremor, and other forms of tremor and chorea. This cha...
Neurologic Deficits Including Auditory Loss and Recovery of Function in Horses with Temporohyoid Osteoarthropathy. Auditory loss is a common deficit in horses with temporohyoid osteoarthropathy (THO), however, recovery of function is unknown. Objective: To investigate neurologic function with emphasis in audition in horses with THO after treatment. To describe anatomical alterations of the petrous temporal bone that might result in auditory loss. Methods: Twenty-four horses with a clinical diagnosis of THO. Methods: Prospective study. A brainstem auditory evoked response (BAER) study was done as part of the criteria for inclusion in horses with a clinical diagnosis of THO from the years of 2005 to 2014. Ph...
Blood and Cerebrospinal Fluid α-Tocopherol and Selenium Concentrations in Neonatal Foals with Neuroaxonal Dystrophy. Equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy (NAD/EDM) is a neurodegenerative disorder affecting genetically predisposed foals maintained on α-tocopherol (α-TP)-deficient diet. Objective: Intramuscular α-TP and selenium (Se) administration at 4 days of age would have no significant effect on serum or cerebrospinal fluid (CSF) α-TP in healthy foals. Serum and CSF α-TP, but not Se, would be significantly decreased in NAD/EDM-affected foals during first year of life. Methods: Fourteen Quarter horse foals; 10 healthy foals supplemented with 0.02 mL/kg injectable α-TP ...
Comparative Study of the Major White Matter Tracts Anatomy in Equine, Feline and Canine Brains by Use of the Fibre Dissection Technique. The spatial anatomy of the white matter tracts is a subject of growing interest not only for researchers but also for clinicians. Imagistic methods have some limitations so that they should be confronted with dissection studies. The aim of this paper was to provide a three-dimensional view of the major white matter tracts in equine, feline and canine brains by use of the fibre dissection technique. Twenty cerebral hemispheres (six equine, four feline and 10 canine brains) were prepared according to the Klingler method. Stepwise mediolateral and lateromedial blunt dissections were performed usi...