Sciatic Neuropathy

The terms lumbar radiculopathy and sciatica are used interchangeably to indicate radiating pain, numbness and weakness in a leg from a pinched nerve root in the back.

However, it is important to recognize that similar symptoms and signs can be caused by injury or compression of the sciatic nerve outside the spine, either in the buttock or thigh.

The sciatic nerve is the longest and widest nerve in the body, extending from the spine all the way to the foot, and contributes most of the nerve supply to the leg:
Sciatic-Nerve-Anatomy

Sciatic nerve injury presents with:

1. Numbness affecting the entire leg, aside from the front of the thigh.

2. Weakness of the hamstrings, and all movement at the ankle.

3. Absent ankle jerk.

http://www.youtube.com/watch?v=z2YrjAGChBw&feature=youtu.be&rel=0

Sciatic Nerve Injury in the Buttock:

The nerve can be injured by misplaced buttock injections, gunshot wounds and knife injury. Buttock injections should be given in the upper outer quadrant to avoid the sciatic nerve

Buttock injections should be given in the upper outer quadrant to avoid the sciatic nerve

The sciatic nerve injury can also be injured by prolonged sitting on a toilet seat, either from direct nerve compression or hemorrhage and compartment syndrome into the gluteal muscles.  This has been reported in cases of  severe prolonged diarrhea, or drug induced coma on the toilet, so called toilet seat neuropathy.

toilet

Sciatic Nerve Injury at the Hip:

The sciatic nerve runs behind the hip joint as it travels through the buttock.
The sciatic nerve is frequently injured by a posterior dislocation of the hip:
9588.jpg

Sciatic nerve injury occurs in as many as 1%–3% of patients who undergo total hip replacement surgery, usually from a stretch injury to the nerves, but occasionally from a misplaced crew, broken piece of wire, fragment of bone or cement pressing on the nerve:

Sciatic nerve injury after hip arthroplasty. (a) The skin incision for the transgluteal approach is in a continuous line. The cross on the left shows the ischium and the one on the right shows the trochanter. Between them, the skin projection of the sciatic nerve is seen. (b) The sciatic nerve was freed from all attachments. The arrows identify acrylic material from the hip arthroplasty, which was damaging the nerve

Sciatic nerve injury after hip arthroplasty. (a) The skin incision for the transgluteal approach is in a continuous line. The cross on the left shows the ischium and the one on the right shows the trochanter. Between them, the skin projection of the sciatic nerve is seen. (b) The sciatic nerve was freed from all attachments. The arrows identify acrylic material from the hip arthroplasty, which was damaging the nerve

Piriformis Syndrome:

However, symptoms of sciatic neuropathy most often result from nerve compression by the piriformis muscle at the level of the sciatic notch, so-called piriformis syndrome.

piriformis

This presents with buttock tenderness and pain, radiate down the posterior thigh.  Symptoms are made worse by prolonged sitting, bending at the waist, and activities involving hip adduction and internal rotation.  The pain can be reproduced by deep palpation over the sciatic notch.

Diagnostic modalities such as CT, MRI, ultrasound, and EMG may all be normal in piriformis syndrome, but are still useful for excluding other conditions.

Magnetic resonance neurography is a specialized imaging technique which can confirm the presence of sciatic nerve irritation or injury of the sciatic nerve in the piriformis muscle.

Magnetic resonance neurography findings in piriformis syndrome. A: Axial T1-weighted image of piriformis muscle size asymmetry (arrows indicate piriformis muscles). The left muscle is enlarged. B and C: Coronal and axial images of the pelvis (arrows indicate sciatic nerves). The left nerve exhibited hyperintensity. D: Curved reformatted neurography image demonstrating left sciatic nerve hyperintensity and loss of fascicular detail at the sciatic notch (arrows). Filler AG, Haynes J, Jordan SE, et al, "Sciatica of nondisc origin and piriformis syndrome: Diagnosis by magnetic resonance neurography and interventional magnetic resonance imaging with outcome study of resulting treatment," J Neurosurg Spine 2: 99-

MRN findings in piriformis syndrome. A: Axial T1-weighted image of piriformis muscle size asymmetry (arrows indicate piriformis muscles). The left muscle is enlarged. B and C: Coronal and axial images of the pelvis (arrows indicate sciatic nerves). The left nerve exhibited hyperintensity. D: Curved reformatted neurography image demonstrating left sciatic nerve hyperintensity and loss of fascicular detail at the sciatic notch (arrows).

Conservative treatment can include medications, physical therapy and stretching, or injection of a paralysing agent such as botulinum toxin into the piriformis muscle under ultrasound or CT control. Surgery may be necessary for recalcitrant cases.

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6 thoughts on “Sciatic Neuropathy

  1. Hello! I know this is an older article, but I am hoping that you may still answer! I am having lighting bolts of pain starting in my right hip (not by back) and shooting down my leg. I was experiencing this pain a couple times a month when either standing or reclining in an easy chair. This past week it has suddenly gotten much worse, and I am getting bolts of horrific pain down my leg during all sorts of positions. Rest, heat, ibuprofen, strange sleeping positions and DMSO have helped but not completely cured my issues. My entire leg and big toe seems to ache at times as well. Could you please offer any input on what the bolts of pain might be from! Thank you for your time!!!

    • This soujnds like “sciatica”. It could be a lumbar radiculopathy (even without back pain), or a piriformis syndrome. You are probably going to need an EMG and perhaps also a MRI to sort this out. You should see a neurologist

  2. I am having symptoms of sciatica and I have treated for nueropathy the only difference that I see is that the pain is going down the front of mey leg and it seems to stop in the middle of the femur bone on the left leg. My Dr. has not yet tried to see if I have sciatica but we are in the process of running some test, so far i have had an ultra sound done on my legs and I have had some blood work. The pain started in my left leg about mid way on the femur bone then traveled up my back into my neck, I went to the emergency room and they gave me some Lyrica, and some tramadol, this seemed like it would help make the pain less intense, but it makes me so sleepy that I connot do my job. I sit a lot because I am a student and I have a work-study job that requires me to be on my feet and sitting a lot at the computer. But noone has actually given any test to see if I actually have nueropathy but I am taking medicine for that because I am diabetic. But after they gave they lyric should I still take the gabapentin for the nueropathy? Pr should I have my Dr. test me for sciatica and because of my profession How am I going to continue? The medication is strong and it makes me very sleepy I am also on medication for Inflammation Mobic, and flexiril

    • Kim, thanks for your post. The distribution of your pain is NOT typical for sciatica or sciatic nerve compression. If you are having pain in the front of your thigh and you are diabetic, you might actually be having diabetic amyotrophy. You should see a neurologist, and you might need an EMG. Let me know how you get on.

  3. Nice Article about Sciatica Pearland,My friend has this, we desided to see a doctor , i ddnt know why first 3 doctors are not stricks the pain as sciatica, they said its normal back pain,again we checked up, then the results points to Sciatica,so we deside to first of all knowing about Sciatica , so i search alote in website got some are better and are not , any way your article is good ,thanks again.Here i listed where i got ..about Treatment of sciatica
    Sciatica mentions to pain that radiates along the path of the sciatic nerve, which branches from your lower back through your hips and buttocks and down each leg. Typically, sciatica affects only one side of the body. Most cases of acute sciatica can be treated at home with painkillers. Chronic sciatica usually requires a combination of self-help techniques and medical treatment. in http://www.medibird.com/treatment/Sciatica-Surgery.html

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