Neuro Exam 5 - spinal reflexes

Localised the (spinal cord) lesion using spinal cord reflexes
i.e. Panniculus reflex, muscle tendon reflexes and perineal reflexes
Spinal reflexes are assessed as normal, reduced or hyperactive and are used to localise the lesion to a certain area of the spinal cord.
The most useful and reliable reflexes are withdrawal (thoracic and pelvic limb), patellar, panniculus and crossed extensor and perineal.
Biceps Forefinger on biceps tendon, tap finger with hammer, elbow flexes slightly (C6-C8, musculocutaneous)
Extensor Carpi radialis Tap muscle or finger on muscle, carpus extends (C7-T1, radial)
Triceps Tap muscle or finger on muscle, elbow extends (C7-T1, radial)
Withdrawal –thoracic Pinch toes, limb withdraws, all joints flex (C6-T2, multiple)
Patellar Tapping patella tendon, stifle should extend (L4-L6, femoral)
Cranial tibial Tap muscle or finger on muscle, hock flexes slightly (L6-L7, peroneal)
Gastrocnemius Tap muscle or finger on muscle, hock extends slightly (L6-S1, sciatic)
Withdrawal – pelvic Pinch toes, limb withdraws, all joints flex (L6-S1, sciatic)
Perineal Touch anus, anal sphincter contracts *S1-S2, perineal)
Crossed extensor Animal in lateral recumbency, pinch toe, ipsilateral limb should withdraw and contralateral limb should not extend. Extension of contralateral limb suggests UMN disease due lack inhibition
Panniculus (cutaneous trunci) Pinch skin and observe cutaneous trunci contracting, move sequentially caudally if looking for cut off point. Superficial sensation, white matter spinal cord, (T2 grey matter, lateral thoracic nerve)
Dermatome cut-off for localising to spinal cord segment in paraplegic animals. Also useful assessing brachial plexus lesions and in neuropathies.