Question of the Day

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.