Peripheral Nerve Entrapments & Neurological Conditions Flashcards

Which clinical finding best differentiates pronator teres syndrome from carpal tunnel syndrome?

Answer: Symptom reproduction with resisted forearm pronation

In pronator teres syndrome, median nerve compression occurs at the pronator teres, so resisted pronation reproduces symptoms; positive Phalen's test and nocturnal worsening are more characteristic of carpal tunnel syndrome.

The sural nerve is typically formed by contributions from which two nerves?

Answer: Tibial and common peroneal nerves

The sural nerve is typically formed by the medial sural cutaneous nerve (from the tibial nerve) and the lateral sural cutaneous nerve (from the common peroneal nerve).

Wartenberg's syndrome (cheiralgia paresthetica) involves entrapment of which nerve at the distal forearm?

Answer: Superficial radial nerve

Wartenberg's syndrome involves entrapment of the superficial branch of the radial nerve where it emerges between the brachioradialis and extensor carpi radialis longus tendons at the distal forearm.

Posterior interosseous nerve (PIN) syndrome produces which characteristic clinical finding?

Answer: Inability to extend the fingers and thumb with preserved wrist extension

The PIN supplies the finger and thumb extensors but not the extensor carpi radialis longus (innervated proximal to PIN branching), so wrist extension is preserved while finger and thumb extension are lost.

Obturator nerve entrapment in athletes most commonly presents as:

Answer: Medial thigh pain worsening with exercise and adductor weakness

Obturator nerve entrapment typically presents with medial thigh pain and paresthesia that worsens with exercise, along with adductor weakness, as the obturator nerve supplies the adductor compartment.

The saphenous nerve, which can be entrapped at the adductor canal, is the largest cutaneous branch of which nerve?

Answer: Femoral nerve

The saphenous nerve is the terminal cutaneous branch of the femoral nerve, supplying sensation to the medial leg and foot.

In the most common anatomical variant of piriformis syndrome, the sciatic nerve is compressed at which anatomical relationship to the piriformis muscle?

Answer: Below the piriformis through the infrapiriform foramen

In the most common variant, the sciatic nerve exits the pelvis below (inferior to) the piriformis through the infrapiriform foramen, where hypertonia or spasm of the piriformis can compress it.