Neurology medical conditions

Neurologic conditions that may affect companion animals

Cornell's veterinary neurology service diagnoses and treats a variety of neurologic conditions.

Arachnoid Cyst Atlantoaxial Joint Instability Brain Tumors
Cerebellar Disorders Chiari Malformation Deafness
Degenerative Myelopathy Epilepsy Granulomatous Meningoencephalomyelitis
Head Trauma Hydrocephalus Lumbosacral Disease Metabolic Brain Disorders
Myasthenia Gravis Myositis Necrotizing Encephalitis
Neuropathies Neurotoxins Polyneuropathy
Spinal Trauma Tremor Syndromes Vestibular Disease
Wobbler's Syndrome

Arachnoid Cyst:

Cerebrospinal fluid filled cysts that arise from an abnormal development of the arachnoid membrane that covers the brain surface. They may occur over the surface of the brain around or around the skull base. Most arachnoid cysts are discovered incidentally because of a CT scan or MRI obtained for another reason and do not require treatment. On occasion however, some arachnoid cysts enlarge and put pressure on adjacent neural structures such as the optic nerves, brainstem or cerebral cortex and require surgical drainage. This treatment is usually quite effective.

Atlantoaxial Joint Instability:

Atlantoaxial instability is a condition in which the first two cervical (neck) vertebrae are not firmly attached. Normally, the atlas (the first cervical vertebra) and the axis (the second cervical vertebra) are attached by a group of ligaments. They are further stabilized by a prominence on the axis called the dens that protrudes into a hole in the atlas. Pets with congenital atlantoaxial instability are born without ligament support to their atlantoaxial joint, and may also be born without a dens. Trauma to the neck can also cause tearing of the ligaments or fracture of the dens, resulting in atlantoaxial instability.

Brain Tumors:

A brain tumor is an abnormal growth of cells within the brain, which can be cancerous or non-cancerous (benign).

Cerebellar Disorders:

A condition in which there is a deviation from or interruption of the normal structure or function of the cerebellum; manifestations of cerebellar dysfunction include dysmetria, gait ataxia, and muscle hypotonia. Cerebellar disorders have numerous causes, including congenital malformations, hereditary ataxias, and acquired conditions. Symptoms vary with the cause but typically include ataxia (impaired muscle coordination). Diagnosis is clinical and often by imaging and sometimes genetic testing. Treatment is usually supportive unless the cause is acquired and reversible.

Chiari Malformation:

The Chiari is a malformation of the hindbrain, or brainstem associated with myelomeningocele, and can cause hydrocephalus and other symptoms. The cerebellum may be elongated and drop down along the lower brainstem, through the case of the skull and into the cervical canal: the fourth ventricle may be elongated and enter the cervical canal.


Degenerative Myelopathy:

Degenerative myelopathy is progressive rear limb weakness or paralysis.

Degenerative Disc Disease:

Degenerative disc disease is typically associated with aging. As you age, your discs, like other joints in the body, can degenerate (break down) and become problematic: that's a natural part of growing older as your body deals with years of strain, overuse, and maybe even misuse.


A disorder of the central nervous system characterized by loss of consciousness and convulsions

Granulomatous Meningoencephalomyelitis:

GME is an acute, progressive inflammatory disease of the central nervous system (CNS) of dogs. GME is a common differential for dogs that are affected by focal or diffuse neurological diseases. An inflammatory disease like GME can cause severe and often irreversible damage to the CNS. Consequently, a better understanding of the disease is essential.

Head Trauma

Hydrocephalus Lumbosacral Disease

Metabolic Brain Disorders:

Metabolic brain diseases are associated with biochemical disturbances and abnormalities in chromosome structure. They affect the way the brain functions and are also known as encephalopathy, acquired metabolic brain disease or acquired metabolic encephalopathy.

Myasthenia Gravis:

This is a disorder affecting the space between the nerve and the muscle (neuromuscular junction) that results in transient motor weakness of the face and limbs.The disease that interrupts the way nerves communicate with muscles. There is no treatment for the congenital form. The acquired form, which is an autoimmune disease, is treated medically with immunosuppressive agents.


Inflammation of muscle tissue.

Necrotizing Encephalitis:

Any encephalitis in which extensive brain necrosis occurs.


This refers to diseases or injuries affecting nerves or nerve cells.


Neurotoxins are natural or artificial toxic substances that affect nerve tissues.


Spinal Trauma

Tremor Syndromes:

Tremors are a neurologic movement disorder characterized by involuntary fine rhythmic tremor of a body part or parts.

Vestibular Disease:

The vestibular system senses the position of the head and body in space, in relation to gravity and movement. This helps animals maintain balance and coordinate eye movements with movement of the head. The receptors for the vestibular system are located in the inner ear, adjacent to the hearing receptors. Vestibular information is processed in the lower portion of the brain in the brainstem and cerebellum. Therefore a problem in the inner ear or one in the brain can affect the vestibular system. The phrase "vestibular disease" is a general term referring to any abnormality of the vestibular system, although some people use this term to mean idiopathic vestibular disease.

Wobbler's Syndrome:

Wobbler’s syndrome encompasses a number of cervical vertebral abnormalities. These include vertebral malarticulation/malformation, disk extrusion, articular facet hypertrophy, and ligament hypertrophy. Two types of “Wobbler’s syndrome” exist. One is exemplified by the older Doberman pinschers where the disease is characterized by ventral compressive lesions of the caudal cervical area from ligamentous hypertrophy and disk (usually anulus) protrusion. Younger, large breed dogs such as the Great Dane, have a similarly named disease, but with a differing pathophysiology. In this instance, disease of the dorsal articular facets predisposes to hypertrophy of the associated joint capsule and ligaments, resulting also in spinal cord compression. Similar-type compression is rare in older dogs.