NAVLE® Question of the day

MO TU WED TH FR

April 25, 2024

NAVLE

A stray dog is presented after being hit by a car.

The dog has hypotonic forelimbs and spastic paresis in the hinds. All four limbs have proprioceptive deficits and sensation loss-signs are worse in the forelimbs.

Where is the lesion?

A - Cannot say without cutaneous trunci reflex results

B - Cervicothoracic: C6-T2

C - Cranial cervical: C1-C5

D - Lumbosacral L4-S3

E - Thoracolumbar T3-L3

Fantastic work! You chose B - Cervicothoracic: C6-T2

Weak, hypotonic (i.e., lower motor neuron a.k.a. "LMN") forelimbs and spastic paresis (i.e., upper motor neuron a.k.a. "UMN") hindlimbs are signs of a cervicothoracic (C6-T2) lesion. May see worse signs in forelimbs than hindlimbs.

NOTE: This is the OPPOSITE presentation as Schiff-Sherrington syndrome - i.e., SEVERE acute spinal cord trauma in the region of T3-L3 and, when in lateral recumbency, the thoracic limbs are rigid and extended and the pelvic limbs appear flaccid in comparison. However, pelvic limb reflexes are normal to increased, as would be expected with an upper motor neuron lesion.

Can localize T3-L3 lesions by checking cutaneous trunci reflex - the lesion is usually 1-2 vertebrae cranial to where the reflex disappears.

With C1-C5 would expect UMN signs in all four limbs, usually worse in hinds.

With a T3-L3, would see UMN hind limb signs and normal forelimbs.