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Foot Drop and Peroneal Neuropathies at the Fibular Head

Peroneal neuropathies at the fibular head. Our case is a 55 year old woman who presents with a three week history of right sided footdrop after waking up from sleeping on a chaise lounge outdoors at a party foot drop. She admits to drinking alcohol at the party. Now she has difficulty walking and easily falls because of the right foot drop. She has no back pain. There is a sensory loss over the dorsum of her right foot and the lateral aspect of that leg. Physical exam reveals 0 out of 5 ankle Dorsiflexion, 2 out of 5 ankle eversion, and 5 of 5 ankle inversion and normal strength of all other muscles tested. Sensation is reduced to pinprick and light touch over the dorsum of the right foot, including the first web space and over the lateral aspect of the right leg. All reflexes are present and symmetric. Well, she had a EMG (electrodiagnostic study) and the impression was an abnormal study. There was evidence of an acute peroneal neuropathy at the fibular head.

Typical presentation is footdrop and weak ankle eversion. Stepage and slapage gait. Stepage gate, the best way to think about what is what, is we need our Dorsiflexors in two parts of our gait cycle. The first is when we are in swing phase. We need our toes cleared, so that is when we Dorsiflex, to clear our toes. If we only have a three out of five muscle strength, we will have to increase our hip flexion so that we can clear our toes during the swing phase of gait, and that is called a stepage gate. A person will do this when they walk, and you will be able to tell what is going on. Slapage gate is when you have a four out of five muscle strength because the other part, other time that Dorsiflexion is used is or eccentric contraction during the stance phase when you heel strike. So that, you will hear a (thump) like that when they walk and you will be able to see it and that is called a slapage gate, the foot is slapping down because there is no eccentric contraction to plantar flexion, so it doesn’t slowly go down, it sharply goes down.

This is just an outline of what the peroneal nerve, the common peroneal gives off a superficial in the deep and the deep peroneal goes to the first web space in terms of its sensation. In terms of the things that we care most about, is the tibialis anterior, the main Dorsiflexor and the extensive digitorum longus. The superficial peroneal, the sensory enervation is a lot more, it is the lateral aspect of the leg and whole dorsum of the foot, except for the first web space and a little bit of the lateral aspect of the foot, which is the sural nerve. In terms of strength, it is both the peroneal longus and brevis only enervation. Obviously, that is how we get the ankle eversion problem.

Now etiologies are compression which is habitual leg crossing, precipitous weight los, a hard mattress or bed railing in patients who are debilitated, comatose or under the influence of drugs or alcohol. The typical patient that you might see, more commonly, is your hospitalized patients in ICU. They come out and they have footdrop. That is because they are lying with their hips externally rotated and their peroneal nerve is being entrapped or compressed by the fibular head.

Next case is a cervical radiculopathy and this is a 40 year old mechanic who slipped on a wet greasy floor two weeks prior to being seen. He tried to prevent the fall by grabbing an overhead beam and this caused his neck to jerk strongly and felt something snap in his neck. He now presents with a persistent neck pain referred down the arm and it is associated with numbness of his thumb. On physical exam, sensation is decreased in the thumb. He has some weakness of resisted external rotation of the right shoulder and abduction of his shoulder, especially through the first 30 degrees which is the supraspinatus, the main portion of abduction to this angle is through the supraspinatus. On resisted forward thrust of an outreached arm, there is slight wing of the

In terms of treatment, conservatively it is what I am obviously a big proponent of, doing the non-steroidals, the adjuvant treatment, such as Neurontin, tricyclics, Trazodone, steroid injections are very helpful. Medrol Dose Packs, you get some very nice success. Always remember that the bigger the herniation, the more likely it to shrink back and if you can get them through

Absolute indications for surgery are signs of a cervical myelopathy or spinal cord injuries, so that is a person who all of a sudden is getting weakness in their legs if there is progressive neurologic deficit. If there is any types of bowel or bladder incontinence,