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76 Myelopathy 817

Table 76.3 Neurologic signs associated with spinal cord regions
VetBooks.ir Clinical signs

Evaluations C1 to C5 C6 to T2 T3 to L3 L4 to S3 and caudal segments

Mental status Normal Normal Normal Normal
Posture Normal; wide‐based Normal; wide‐based Normal; falling; Normal; falling; tail tone
stance all limbs; +/‐ stance all limbs, acute – Schiff– decreased or flaccid
recumbency; horizontal recumbent; +/− Sherrington posture,
neck carriage horizontal neck carriage
Gait Normal, GP/UMN ataxia Normal, spastic PL, GP/ GP/UMN PL ataxia, GP PL ataxia, weakness may
(PL > TL), spasticity all UMN ataxia (PL > TL), symmetric or vary; symmetric or
limbs, tetraparesis/ shorten stride TL, asymmetric spastic asymmetric (more often with
plegia, hemiparesis/ tetraparesis/plegia, paraparesis/plegia cauda equina) paraparesis/
plegia hemiparesis/ plegia plegia
Cranial nerves Normal; bilateral or Normal; bilateral or Normal Normal
ipsilateral Horner ipsilateral Horner
syndrome syndrome
Postural Normal, mild‐severe Normal, mild‐severe Mild‐severe deficits; No deficits; mild‐severe
reactions deficits (PL > TL); absent deficits (PL > TL); absent absent deficits; absent
Spinal reflexes Normal, hyperreflexia all Normal, hyporeflexia or Normal to Hypo‐ to areflexia;
limbs absent reflexes TL; hyperreflexia PL pseudohyperreflexic patellar
normal to hyperreflexia reflex with sciatic nerve
PL dysfunction
Spinal None; mild‐severe on None; usually mild; may None; mild‐severe on None; mild‐severe on
hyperesthesia palpation; resists neck resist neck movement palpation palpation; accentuate on tail
movements extension
Sensation Usually normal; severe Usually normal; severe Mild‐severe sensory None; mild‐severe (more
(nociception) lesions may show lesions may show loss; absent common with intumescence
mild‐severe sensory loss mild‐severe sensory loss lesion) sensory loss
Micturition Usually intact; may have Usually intact; may have Usually affected with None; mild‐severe detrusor
detrusor areflexia; detrusor areflexia; loss of motor areflexia; sphincter
sphincter hypertonia sphincter hypertonia function, detrusor hypotonia
areflexia‐sphincter
hypertonia
C, cervical; GP, general proprioceptive; L, lumbar; LMN, lower motor neuron; PL, pelvic limb; S, sacral; T, thoracic; TL, thoracic limb;
UMN, upper motor neuron.

plegia (involvement of pelvic limbs), tetraparesis Postural Abnormalities
(involvement of all limbs) or hemiparesis (involvement
of the ipsilateral thoracic and pelvic limbs). Abnormal postures can be specific for vertebral column
Gait is assessed with regard to coordination, voluntary abnormalities and spinal cord dysfunction. Ventroflexion
motor functions, and direction. The action of gait is of the neck is a common phenomenon in animals with
characterized by swing (flexion) and stance (extension) disorders of neuromuscular weakness (especially cats) or
phases. The voluntary motor system involves recruit- pain. Animals with spinal malformations can show
ment of the flexor muscles to initiate the swing phase kyphosis (dorsal deviation), scoliosis (lateral deviation),
and the postural system recruits extensor muscles for the and lordosis (ventral deviation). A stiff neck or an arched
stance and propulsive phases. Animals with UMN weak- back is often reflective of cervical or generalized spinal
ness will often have a gait of long stride length, whereas pain. Neck pain may manifest with horizontal neck car-
with LMN weakness the stride length is shortened. The riage, increased muscle tone, and intermittent spasms/
gait in animals with spinal pain may have a shortened jerks. The animal tends to move by turning the entire
stride length. Animals with joint, muscle, or meningeal body when changing directions. When the arched back
pain often appear to be “walking on eggshells.” Thoracic is centered to the thoracolumbar region, this may indi-
or pelvic limb lameness may represent radicular pain cate pain localized to the caudal thoracic and lumbar
(nerve root signature). regions. Arching of the back with low head carriage also