An in-depth review of how to conduct a neurological exam in the veterinary patient

The talk begins with an overview of the neurological exam, emphasizing its importance for identifying neurological issues in animals. The exam involves assessing several areas including mentation, posture, cranial nerves, gait, and proprioceptive reactions. Tools needed include a light source and a reflex hammer. The goal is to localize lesions before discussing differentials.

For the neurological exam, it is recommended to observe the animal in a room freely, away from the owners to ensure natural behavior is captured. Various aspects like gait, cranial nerve function, and proprioception are assessed. When testing proprioception, positioning each leg individually helps, especially in smaller animals. Reflexes are also tested to detect any neurological issues.

Various types of paresis or plegia are defined according to which limbs are affected. Specific neurological terms like ataxia and paresis are distinguished. The exam must be thorough, covering cranial nerve checks and proprioceptive testing, and identifying specific reflex reactions that might indicate neurological problems.

In examining reflexes, withdrawal and patellar reflexes are noted, as they provide insight into upper and lower motor neuron diseases. These help in assessing the state of the nervous system, specifically noting depressions in reflexes indicative of nerve issues such as neuropathy. Reflexes and muscle tone help localize neurologic lesions.

Once the neurological exam is completed, the focus shifts to lesion localization, determining whether the problem is intracranial or involves the spinal cord. Intracranial signs differ based on forebrain versus brainstem or cerebellum involvement. Peripheral nervous system problems may involve muscles or nerves and manifest in specific symptoms.

Forebrain lesions typically present with mentation changes and normal gait but may include circling and visual deficits. Cats and dogs may show specific signs like circling or ignoring stimuli on one side due to brain lesions. Differentiating these presentations is crucial for accurate diagnosis.

Brainstem lesions result in significant ataxia or paresis. Clinical signs involve cranial nerves 3 through 12 and result in noticeable balance issues or head tilts. Cerebellar lesions lead to ataxia without weakness, featuring dysmetria and occasional vestibular signs. Such lesions require distinguishing between central and peripheral problems.

Vestibular diseases present with head tilts and nystagmus, helping to identify between central or peripheral origins. Central vestibular symptoms might include additional cranial nerve issues or proprioceptive deficits, whereas peripheral usually involves concurrent Horner's syndrome. Differences in signs dictate treatment paths.

Spinal cord lesions are discussed next, ranging from the cervical spine to sacral spine, each presenting distinct reflex and gait changes. Upper cervical lesions result in normal or heightened reflexes, while lower and thoracic regions might show unique gait patterns like "two-engine" gait with affected proprioception or reflexes.

T3-L3 lesions often result in normal forelimb function but can show severe hindlimb weakness. Unique signs include Sherrington posture and different reactions based on lesion location. Incontinence issues might hint at specific cord involvement. Precise diagnosis is key as spinal localization guides treatment strategies.

Caudal lumbar and sacral lesions cause varying degrees of hindlimb weakness. The range and type of motor deficits help localize lesions, with further details on paralysis unlikely from very caudal problems. Peripheral nervous system issues display decreased tone and may have focal or systemic causes.

Peripheral nervous system lesions are less common and manifest with normal mentation but decreased limb function, possibly due to localized traumas or neuropathies. Distinguishing between the types, including conditions like botulism or tick paralysis, is based on reflex absence across limbs and maintained sensations.

Neuromuscular junction disorders, primarily myasthenia gravis, are characterized by weakness potentially stemming from muscular disorders. Detailed explorations discuss symptom triggers, diagnostic distinctions, and the importance of measuring receptor antibody levels. Handling prognosis with appropriate medications is highlighted.

Myopathies present variedly, with symptoms ranging from decreased tone to hypertrophy. Challenges arise in distinguishing these from orthopedic issues. Diagnostic focus includes high CPK levels and careful differentiation between movement disorders versus systemic muscular issues.

Movement disorders, though infrequent, mimic seizures and involve involuntary, repetitive motions, often requiring video documentation from owners for diagnosis. Various treatment options exist based on specific conditions, with some breeds displaying unique tendencies.