Myofascial Pain

We tend to imagine a "pinched nerve" as two bloody ends of bones rubbing together with the hapless nerve caught in between but that is car-wreck Emergency Room trauma.

Far more every-day common are nerves (and veins and arteries) pulled, sheared, squeezed and strangled by tight muscles, fascia, and adhesions, causing bizarre down-stream symptoms and altering the results of standard neurological tests.

For example, tight scalene muscles in the neck or the pronator teres muscle of the elbow are the most common causes of the neurological symptoms attributed to the carpal tunnel of the wrist.

Constriction of the hiatus in the adductor magnus of the inner thigh can be so effective in strangling nerve and blood supply to the lower leg that all deep tendon reflexes may be lost.

Before you submit to carpal tunnel surgery, be sure the cause is actually the carpal tunnel (rare!) The characteristic tingling thumb and forefinger is far more likely to be due to the scalenes of the neck, the pectoralis minor of the chest, or the pronator teres of the elbow. These muscles entrap the brachial plexus and/or the branch known as the median nerve.

Tingly ring and little fingers are not "carpal tunnel syndrome." The median nerve doesn't supply those fingers. They are supplied by the radial nerve which may be entrapped by a tight triceps muscle.

While migraine is now said to be a disease of the central nervous system, the evidence for this comes from brain inflammation revealed by PET scans. Unfortunately, the PET scan can't tell whether the inflammation began in a peripheral nerve and travelled to the brain, or began in the brain and referred elsewhere. Surgeons (some of whom are migraine sufferers) working with these entrapped nerves now suspect that the migraines begin with peripheral nerves and trigger a localized meningitis in the brain.

The role of the trigeminal nerve in migraine headaches has been studied for over 30 years but is rarely mentioned to patients. Trigeminal fibers are actually part of an elaborate network intended to protect the brain. Stimulation of the trigeminal nerve or its branches releases neuropeptides such as substance P (SP), calcitonin, and other substances that cause inflammation and vasodilation.

This response is apparently intended to flush toxins out of the brain but often this strategy goes wrong. Instead of helping, it hurts. When this protective strategy goes wrong, producing exquisitely painful migraines, there has been surprising relief via Botox injections. A more radical approach has been complete removal of the corrugator muscle which entraps branches of the trigeminal nerve.

There are better ways to do this than surgery. The biggest and best is to not irritate the nerve in the first place, perhaps by something as simple as not frowning! — and keeping other muscles relaxed and healthy.

See also Common Diagnoses with Possible Muscular Components. The chart below lists the neurovascular structures and entrappers behind the symptoms and the diagnoses.

Again, muscles are involved with many symptoms attributed to other causes. But check all symptoms with your physician. Good differential diagnosis is critical!

Structure	Restricted By
Anterior Primary Ramus of spinal nerve	Rectus Abdominis
Axillary Artery	Pectoralis minor
Brachial plexus	Pectoralis minor, Omohyoid, Scalenes (anterior and medial)
Buccal Nerve	Pterygoid, Lateral)
Cluneal nerve	Gluteus maximus
Digital nerves	Interossei
Dorsal Primary Ramus of spinal nerve	Iliocostalis lumborum, Longissimus thoracis
Eustachian Tube	Tensor veli palatini
Femoral Nerve, Artery, and Vein	Adductor Magnus
Genitofemoral Nerve	Iliopsoas
Greater Occipital Nerve	Semispinalis capitis, Trapezius (upper fibers)
Ilioinguinal and Iliohypogastric Nerves	Iliopsoas
Lateral Femoral Cutaneous Nerve	Sartorius, Tensor fascia lata, Psoas
Maxillary Vein	Masseter
Median nerve	Pronator teres
Musculocutaneous nerve	Coracobrachialis
Peroneal Nerve	Peroneus longus, Extensor digitorum longus
Pudendal Nerve	Obturator internus
Pudendal Nerve, Artery, and Vein	Piriformis
Radial Nerve (cutaneous branch)	Brachialis
Radial Nerve (sensory branch)	Triceps (lateral head), Extensor carpi radialis brevis
Radial Nerve, deep (motor branch)	Supinator
Sciatic nerve	Piriformis
Spinal Accessory Nerve	Sternocleidomastoid
Subclavian Vein and lymphatic drainage	Scalenus anterior and Scalenus medius
Supraorbital Nerve	Frontalis, Corrugator supercilii
Supratrochlear Nerve	Corrugator supercilii
Superior Gluteal Artery, Nerve, and Vein	Piriformis
Tibial Nerve, Posterior Tibial Artery and Vein	Soleus
Ulnar nerve (motor and sensory branches)	Flexor carpi ulnaris
Zygomaticotemporal (branch of trigeminal nerve)	Temporalis