Neurology
Core concepts
Neurology questions test localization before diagnosis. Use the neuroanatomic framework: forebrain, brainstem, cerebellum, vestibular (central vs. peripheral), and spinal cord (C1–C5, C6–T2, T3–L3, L4–S3). Postural reactions, cranial nerve examination, and spinal reflexes allow you to localize lesions. Distinguish upper motor neuron (UMN) from lower motor neuron (LMN) signs. Know the common diseases by location: idiopathic epilepsy (forebrain, diagnosis of exclusion), vestibular disease (paradoxical vs. central), intervertebral disc disease (extrusion vs. protrusion), fibrocartilaginous embolism (acute, non-painful), and myasthenia gravis (exercise-induced weakness, megaesophagus). Understand seizure semiology and when to start anticonvulsants (typically ≥2 seizures in 6 months, cluster seizures, or status epilepticus).
Common traps
- Jumping to a diagnosis without localizing-questions often hinge on localization first.
- Mislabeling peripheral vestibular disease as central (central: proprioceptive deficits, other CN deficits, altered mentation).
- Assuming all seizures require phenobarbital-idiopathic epilepsy in a young dog may be managed after appropriate threshold.
- Forgetting that FCE is typically non-painful and asymmetric.
- Overlooking metabolic causes of seizures (hypoglycemia, hepatic encephalopathy, hypocalcemia) before labeling idiopathic.
Worked rule of thumb
If a dog has acute non-painful asymmetric tetraparesis after exertion with intact nociception, the localization is C6–T2 and the leading differential is FCE; if the same dog had cervical pain, consider disc extrusion or meningitis. Always ask: painful or non-painful?