Equine Motor Neuron Disease (EMND) is a neurological disorder that affects the motor neurons of horses, leading to muscle atrophy and weakness. This condition is characterized by the degeneration of lower motor neurons in the spinal cord and brainstem, which are responsible for transmitting signals from the brain to the muscles. Horses with EMND may exhibit clinical signs such as muscle trembling, weight loss, and difficulty standing or walking. The disease is thought to be associated with vitamin E deficiency, although its exact etiology remains under investigation. Research studies focus on the pathophysiology, clinical presentation, diagnostic methods, and potential management strategies for EMND in horses. This page aggregates peer-reviewed research and scholarly articles that explore these aspects of Equine Motor Neuron Disease.
Mohammed HO, Cummings JF, Divers TJ, Valentine B, de Lahunta A, Summers B, Farrow BR, Trembicki-Graves K, Mauskopf A.Equine motor neuron disease (EMND), a newly described neurodegenerative disease, bears a striking resemblance to progressive muscular atrophy (PMA) in humans. We present a comparison of the equine and human diseases and the results of a case-control study conducted to identify intrinsic factors associated with EMND. Cases included all horses with a confirmed diagnosis of EMND diagnosed in the United States since 1985 (32 cases). Controls included horses diagnosed with either cervical stenotic myelopathy, equine degenerative myeloencephalopathy, or protozoan myelitis at the Veterinary Teaching ...
Cummings JF, de Lahunta A, Summers BA, Mohammed HO, Divers TJ, Valentine BA, Trembicki-Graves K.Equine motor neuron disease (EMND) is a sporadic, progressive neurodegenerative disorder that has been identified recently in horses of different breeds in North America. The cause is unknown. Pathologic changes which occur in spinal and certain brain stem motor neurons include chromatolysis, swelling, neurofilamentous accumulation, and development of eosinophilic cytoplasmic inclusions. Punctate eosinophilic inclusions, the type usually encountered in degenerating neurons, resembled Bunina bodies at the light microscopic level, but differed in their ultrastructural composition. These and less...
Cummings JF, de Lahunta A, George C, Fuhrer L, Valentine BA, Cooper BJ, Summers BA, Huxtable CR, Mohammed HO.A spontaneous motor neuron disease or neuronopathy was identified in 10 horses from the northeastern United States. Signs of generalized weakness, muscle fasciculations, muscle atrophy and weight loss progressed over 1 to several months in young and old horses of various breeds. Pathologic studies revealed that degeneration and loss of motor neurons in the spinal cord and brain stem resulted in axonal degeneration in the ventral roots and peripheral and cranial nerves and denervation atrophy of skeletal muscle. Many spinal neurons were swollen, chromatolytic and contained neurofilamentous accu...
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 ...
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.
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...
Cummings JF, de Lahunta A, Mohammed HO, Divers TJ, Summers BA, Valentine BA, Jackson CA.Two spontaneous neurodegenerative diseases of the horse, equine motor neuron disease (EMND) and equine degenerative myeloencephalopathy (EDM), have been associated with alpha-tocopherol deficiency, and both were characterized by prominent accumulations of endothelial lipopigment in the small vessels of the spinal cord. These endothelial pigment deposits appear to be reversible. In EMND horses pasture-supplemented for 9 months or more after the progression of weakness and wasting had arrested, there was very little endothelial lipopigment. The origin and the potential effects of these endotheli...
Cutler TJ, Brooks DE, Andrew SE, Denis HM, Biros DJ, Gelatt KN, Komaromy AM, Kallberg M.The appearance of the equine fundus is reviewed from the perspective of differentiating normal variations from disease, and the descriptions have been updated to include recently published ocular fundic abnormalities. Most pathological lesions are identified near the optic nerve head, and typically involve depigmentation or hyperpigmentation. Depending upon configuration and appearance, linear pigmented bands may reflect the course of the vortex veins, the transition from tapetal to nontapetal fundus, or indicate chorioretinitis or equine motor neuron disease. Choroidal vasculature is readily ...
Finno CJ, Kaese HJ, Miller AD, Gianino G, Divers T, Valberg SJ.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 ...
