Neurological diseases in horses encompass a range of disorders affecting the central and peripheral nervous systems. These conditions can arise from various etiologies, including infectious agents, genetic predispositions, trauma, or metabolic imbalances. Common neurological diseases in horses include equine protozoal myeloencephalitis (EPM), equine herpesvirus myeloencephalopathy (EHM), and cervical vertebral stenotic myelopathy (CVSM), also known as wobbler syndrome. Clinical signs associated with these diseases may include ataxia, weakness, altered gait, and changes in behavior or mental status. Diagnosis typically involves a combination of clinical evaluation, imaging techniques, and laboratory testing. This page compiles peer-reviewed research studies and scholarly articles that investigate the pathophysiology, diagnostic approaches, and treatment options for neurological diseases in equine populations.
Krunajević T, Bergsten G.The clinical and pathological details of a case of ataxia in a 3-month-old colt are described. A marked protrusion into the vertebral canal of the body of the 3rd cervical vertebra was observed. C and C were immovably joined so that the deformity could not be corrected by extension of the spinal column at this point. There was a compression of the spinal cord corresponding to the protrusion. The cause of this luxation could not be established. It may be assumed that the distortion was congenital, or caused by trauma at an early stage and that clinical symptoms could be observed only when, a ma...
Hall S, McElligott S, Sadek AR, Griffith C, Waters R, Nader-Sepahi A. Accidents during sporting activities are a common cause of head injury, particularly in children and young adults. Whilst most sporting head injuries are minor, there remains a proportion which is associated with high morbidity and mortality. The epidemiology of sports associated head injuries is variable based on geographical region so the aim of this study was to review the management and outcomes of sporting head injuries managed by a single neurosurgical unit in the South of England. A retrospective review of the Trauma Audit and Research Network database was conducted for all patients ad...
Koh RB, Harrison TM.Over the past years, the concept of pain management in veterinary medicine has evolved and led to the establishment of a new concept of multimodal approach to pain management, as the current standard of care. The use of multimodal analgesia combining pharmacologic and nonpharmacologic techniques not only helps optimize the quality and efficacy of analgesia but also may prevent the development of chronic or persistent pain. During the past decade, acupuncture has become more popular and evolved into one of the most used forms of integrative medicine interventions and nonpharmacologic therapeuti...
Martin-Giménez T, Cruz AM, Barragán A, Montero E, Sanchez PG, Caballero G, Corradini I.Occipital condylar fractures (OCFs) causing delayed onset lower cranial nerve paralysis (LCNPs) are rare. We present a 7-year-old Friesian horse with delayed onset dysphagia caused by vagus nerve (CNX) paralysis and suspicion of glossopharyngeal nerve (CNIX) paralysis developed several days after a minor head injury. Endoscopic examination revealed right laryngeal hemiplegia and intermittent dorsal displacement of the soft palate. An area of submucosal hemorrhage and bulging was appreciated over the dorsal aspect of the medial compartment of the right guttural pouch. Radiological examination o...
Vanschandevijl K, Nollet H, Vercauteren G, Ducatelle R, Deprez P.Transcranial magnetic stimulation (TMS) is an electrophysiological technique used to elicit motor evoked potentials (MMEPs) to evaluate the functional integrity of the descending motor fibres in the spinal cord. Successful application of the technique was reported in horses with spinal cord compression. However, limited data are available on the correlation of TMS with histopathological changes. Objective: To determine sensitivity of TMS for assessing the integrity of the spinal cord in horses with compressive lesions of the spinal cord. Methods: Case series. Methods: The study was conducted o...
Mayhew IG.A technique for the subarachnoid perfusion-fixation of the central nervous system was developed to help identify various significant vascular accidents (SVAs) in the central nervous system (CNS) of 24 neonatal foals submitted for necropsy. SVAs, comprising subarachnoid, parenchymal and nerve root haemorrhages, and oedema and necrosis, occurred in 17 foals, more frequently in the spinal cord than the brain. They occurred as frequently in premature foals as in those born at full term, in foals born dead as in foals born alive, and in foals born following dystocia with an assisted delivery as in ...
Polack EW, King JM, Cummings JF, Mohammed HO, Birch M, Cronin T.To compare concentrations of trace minerals in the spinal cord of horses with equine motor neuron disease (EMND) with those of horses without neurologic disease (control horses). Methods: 24 horses with EMND and 22 control horses. Methods: Spinal cord trace mineral concentrations in horses with EMND and control horses were analyzed by use of inductively coupled plasma atomic emission spectroscopy (calcium, phosphorus, sodium, potassium, magnesium, copper, iron, manganese, nickel, zinc, aluminum, cobalt, and chromium), atomic absorption spectrophotometry (lead and cadmium), flameless atomic abs...
Dunkel B, Corley KT, Johnson AL, Witte TH, Leitch M, Marr CM, Weller R.Pneumocephalus is occasionally encountered in horses but poorly described in the literature. The study aimed to describe historical, clinical and diagnostic imaging findings and outcome in horses to increase the awareness and recognition of the condition amongst equine practitioners, allowing appropriate management of these cases. Cases of pneumocephalus from 4 participating institutions were identified and case details extracted from the medical records. Five cases of pneumocephalus were identified. Head trauma with suspected or confirmed fractures of the sinuses was the underlying cause in 4...
Shrauner B, Blikslager A, Davis J, Campbell N, Law M, Lustgarten M, Prange T.The large size of the adult horse prevents the use of advanced imaging modalities in most areas of the axial skeleton, including the lumbosacral vertebral column. Traditional imaging techniques are frequently unable to pinpoint the underlying pathology in horses with caudal back pain. In man, lumbosacral epiduroscopy is used to diagnose and treat subjects with chronic back and leg pain. This technique may close the diagnostic gap in horses with similar clinical signs. Objective: To evaluate the safety and feasibility of lumbosacral epiduroscopy in the standing adult horse. Methods: Descriptive...
Kondo T, Sato F, Tsuzuki N, Chen CJ, Yamada K.Computed tomographic myelography can be a useful tool for evaluating vertebral canal stenosis. However, an index of spinal cord compression is yet to be established. This observational descriptive study aimed to establish an index for spinal cord compression using computed tomography (CT). Twenty-three Thoroughbred horses (age, 155-717 days; weight, 205-523 kg) with suspected cervical vertebral malformation were subjected to computed tomographic myelography in dorsal recumbency using large-bore gantry CT to define the entire cervical vertebrae from C1 to C7. Subsequently, the height of the sp...
Stewart RH, Griffiths JP.In spinal cord disease of horses, a complete history, neurologic examination, and adjunctive diagnostic procedures are very helpful in establishing a tentative diagnosis; however, a definitive diagnosis may be difficult or impossible to establish antemortem. Medical management should be initiated with full consideration of possible etiologies and knowledge of the effects and consequences of medical therapies. This article discusses the drugs commonly used in the management of spinal cord disease and the rationale for their use.
Cole R, Taintor J, Hanson R.An adult gelding was evaluated for bilateral intermittent forelimb lameness of approximately 2 years duration. The horse was found to have grade 2/5 upper motor neuron-general proprioception ataxia with no cranial nerve deficits. During radiographic and gross necropsy examinations a novel atlanto-axial malformation of possible congenital etiology was found. Un hongre adulte a été évalué pour une boiterie intermittente de la jambe avant présente depuis environ 2 ans. On a constaté que le cheval avait une ataxie de proprioception générale des motoneurones supérieurs de grade 2/5 sans d...
Oaks JL, Long MT, Baszler TV.Neurologic disease occurs sporadically in horses infected with the equine infectious anemia virus (EIAV). This report describes a case of clinically severe neurologic disease in a pony experimentally infected with EIAV. This pony did not have fever or anemia, which are the characteristic clinical signs of disease. The histopathologic changes were characterized as lymphohistiocytic periventricular leukoencephalitis. Polymerase chain reaction and in situ hybridization data showed that the brain lesions were directly associated with viral replication and that high-level viral replication occurred...
Finno CJ, Eaton JS, Aleman M, Hollingsworth SR.A 23-year-old female mule was presented for bilateral ocular abnormalities and an abnormal pelvic limb gait. Results: Anisocoria, unilateral enophthalmos, medial strabismus, ptosis, pupillary light reflex deficits, and bilateral reticulated pigmentary retinopathy were observed on ophthalmic examination. Neurologic abnormalities included right-sided facial nerve paralysis, extensive symmetric muscle atrophy, and asymmetric pelvic limb ataxia with an abnormal pelvic limb gait. A positive titer (1:40) for equine protozoal myeloencephalitis (EPM) associated with Neospora hughesi was obtained from ...
Uhlinger C.A herd of 15 mature riding horses with a history of anorexia, weight loss, and lethargy was examined. The animals had been fed a 50/50 mixture of commercial sweet feed and corn screenings contaminated with a heavy growth of Fusarium moniliforme. Thirteen of the horses had one or more neurologic signs. The most characteristic signs were profound depression and mild ataxia. Over the 19-day course of the epizootic, the horses had increasing severe neurologic deficits, including unilateral blindness and delirium. Despite the clinical appearance of dehydration, 12 horses had low PCV (16 to 27%), he...
Wilkins PA, Vaala WE, Zivotofsky D, Twitchell ED.Equine leukoencephalomalacia (ELEM) affected 6 of 10 pleasure horses in adjacent paddocks at a boarding facility. Four of the 6 affected horses died or were euthanized. Two of 3 horses presented for treatment survived with complete resolution of clinical signs. Treatment was primarily supportive. Dimethyl sulfoxide, dexamethasone, flunixin meglumine and thiamine were administered as anti-inflammatory agents and to decrease or prevent cerebral edema. Fusarium monileforme was cultured from ear corn fed the affected horses. Fumonisin B1, B2 and B3 were isolated.
Cavasin JP, Miller AD, Duhamel GE.An 8-year-old Anglo-European gelding with progressive neurological signs was humanely destroyed and submitted for necropsy examination. The right parietal cortex was disrupted by a well-demarcated, intraparenchymal, 1.5 cm diameter, tan, homogeneous, dense mass. Microscopical examination was consistent with an astrocytoma, which was confirmed on the basis of strong immunohistochemical labelling for glial fibrillary acidic protein. The neoplastic population lacked immunolabelling for oligodendrocyte transcription factor 2. Labelling for ionized calcium binding adaptor molecule 1 highlighted la...
Phelps S, Chong D, McKenzie E, Kiupel M, Gorman E.Clinical disease caused by infection with Listeria monocytogenes is rare in adult horses, and there is a paucity of ante-mortem clinicopathologic changes for this species reported in the literature. Confirmatory diagnosis is difficult and often requires post-mortem sampling of the brainstem. This report details a case of meningoencephalitis caused by Listeria monocytogenes in an adult American quarter horse gelding presenting with central neurologic signs. Pre-mortem analysis of the cerebrospinal fluid revealed a mononuclear, primarily lymphocytic, pleocytosis, which is a reported finding in o...
Kyles KW, McGorum BC, Fintl C, Hahn CN, Mauchline S, Mayhew IG.Electromyography was used as an aid to the diagnosis of equine motor neuron disease in a conscious horse while it was under caudal epidural anaesthesia. A muscle biopsy was taken to confirm the diagnosis which was then supported by a postmortem examination.
Chiapetta JR, Baker JC, Feeney DA.An Arabian foal, which was recumbent for 4 days, had signs of extensor rigidity of the thoracic limbs and hypotonic paralysis of the pelvic limbs. Survey radiography revealed a lesion at T15, with radiographic impression of a compression fracture or a hemivertebra. Postmortem examination revealed a fracture at T15. Clinical and pathologic findings in this case were compatible with the Schiff-Sherrington syndrome, which is characterized by thoracic limb extensor hypertonia associated with paraplegia from acute thoracolumbar trauma.
Hall NP, Ragle CA, Farnsworth KD, Caffey SR, Sanclemente JL.To describe a technique for basihyoid-ceratohyoid disarticulation (BCD) in standing sedated horses affected by temporohyoid osteoarthropathy (THO) and report outcomes for horses that underwent the procedure. Methods: 6 client-owned horses. Methods: Electronic medical records of a veterinary teaching hospital were searched to identify horses that underwent BCD for treatment of THO from 2018 to 2019. Signalment, clinical data, use of the horse, and complications were recorded. Follow-up data obtained by telephone interview with owners included the clinical outcome and time to improvement after s...
Ionatamishvili NI, Tsverava DM, Loriia MSh, Avaliani LA.One hundred children with cerebral palsy, aged 3-14 years, were divided into two equal groups, the first one including 50 children assigned to ride therapy and the second one--to Bobath therapeutic gymnastics. All the patients underwent a functional examination, which was rated using score system worked out by the authors, thus enabling a quantitative evaluation of treatment efficacy. In all the cases, physical rehabilitation resulted in a positive but not the same effect, with ride therapy being significantly (p < 0.001) more beneficial treatment compared to therapeutic gymnastics. Ride thera...
Furuoka H, Hasegawa M, Kobayashi Y, Matsui T.A male 14-year-old Arab horse was pathologically diagnosed as equine motor neuron disease (EMND), which was kept as a breeding horse on a farm in Tokachi district of Hokkaido in Japan. On examination of the peripheral nerves, the most characteristic feature was Wallerian-type degeneration revealed by myelinoclasis associated with myelin ovoids which were sometimes infiltrated by macrophages. The other abnormalities were axonal swellings which were surrounded by thin myelin sheaths. Ultrastructurally, the axonal swelling was due to an accumulation of neurofilaments, and was accompanied by a thi...
van Weeren PR, Morales JA, Rodríguez LL, Cedeño H, Villalobos J, Poveda LJ.This article describes a case of massive mortality among horses which was probably due to intoxication by pyrrolizidine alkaloids from Heliotropium indicum. Over 4 years more than 75% of a population of about 110 horses on a farm in Costa Rica died after showing nervous neurological symptoms. Two clinical manifestations were encountered, an acute and a chronic one, both with a fatal outcome. Pathological findings in 2 horses coincided with those reported in the literature for intoxication by pyrrolizidine alkaloids and were not specific for VEE. However Venezuelan equine encephalitis (VEE) was...
Landolt G, Feige K, Schöberl M.The present study describes the poisoning due to Robinia pseudoacacia in two horses. One of the horses showed mainly intestinal symptoms such as decreased intestinal motility and obstipation of the pelvic flexure. In the second animal central nervous symptoms were predominant. It showed intermittent phases of somnolence alternating with phases of excitation and head pressing. In addition mydriasis and a lacking menace response could be observed. Sensation to the head and the spinal reflexes were reduced. Symptomatic treatment was initiated in both animals and recovery occurred within 2 days.
Kurz JP, Schoenhals KE, Hullinger GA, Van Wettere AJ.Syringomyelia is a form of myelodysplasia defined by the formation of one or more fluid-filled cavities within the spinal cord that do not communicate with the central canal. The defect may be congenital or acquired. Clinical signs correlate to the segment of spinal cord affected and include pain, paresis, proprioceptive deficits, alterations in sensation, scoliosis, and autonomic dysfunction. This report describes the clinical and pathologic changes in a case of acquired syringomyelia in a 10-year-old American Paint Horse mare. The horse had a six-week history of progressive proprioceptive de...
Melrose PA, Douglas RH.Scanning electron microscopy showed that cells in the infundibular recess of prepubertal female horses were devoid of cilia and sparsely covered with stubby microvilli and small blebs, whereas superior ventricular areas were covered with cilia. Ciliated ependymal cells in supraoptic-suprachiasmatic areas were associated with extensive blebbing, and folded tissue adjacent to the inferior borders of the mamillary body displayed distinct bands of cilia regularly interrupted by areas of sparsely ciliated cells which appeared to be undergoing ciliogenesis. Arcuate ependymal areas had well developed...
Böing L, Heun F, Gasse H.The extremely complex surface architecture of the equine brain does not allow a uniform transfer of anatomical data from other mammalian species, e.g., dog or cat. Rather, a special approach is required to elucidate the equine-specific patterns of cerebral vascular ramifications. Therefore, a novel cartographic system was applied. Prior attention was paid to the A. cerebri media (MCA) and to the A. corporis callosi (CA), as they spread over the widest part of the neopallium's Facies convexa (i.e. the lateral and dorsal surface), thus being of particular interest in terms of surgical treatment ...
Thein P, Darai G, Janssen W, Bergle RD, Strube W, Floss G.From spring 1990 to summer 1991 we investigated 21 horses with clinical symptoms of EHV-infection by means of serological and virological methods including DNA-hybridization to identify the causative agents. The results indicated that, as already reported by us, EHV4 may also cause the paralytic form of the infection. The possibility of double infection with EHV4 and EHV1 cannot be excluded. In 3 out of 21 affected horses we could investigate brain tissue and/or spinal fluid by Dotblot hybridization with EHV1 and EHV4-DNA. The investigated samples of all three horses showed hybridization with ...
Johnson SA.Rehabilitation of the neurologic horse represents a unique challenge for the equine practitioner. Improving postural stability and balance control through improving the strength of the spinal stabilizer muscle multifidus remains one of the most promising rehabilitative targets. This muscle can be targeted through the use of physiotherapeutic exercises, various forms of perturbation, and even whole-body vibration. Neuroanatomic localization and diagnosis specificity enable the practitioner to determine suitability for such rehabilitative tasks, and with the advent of evolving strategies and com...
MacKay RJ, Wyer S, Gilmour A, Kongara K, Harding DR, Clark S, Mayhew IG, Thomson CE.Pasture-associated stringhalt is an acquired equine disease characterized by peripheral neuropathy and hyperflexion of the pelvic limbs. The disease occurs most commonly during periods of drought in horses grazing pastures heavily contaminated by Hypochaeris radicata. We hypothesized that stringhalt is caused by neurotoxins elaborated by H. radicata in response to the stress of drought conditions. Supernates were collected from H. radicata that were stressed (or not) by immersion in copper chloride solution, then extracted with ethyl acetate and dried. Dilutions of extracts from stressed (SE) ...
