Sciatica Causing Leg Weakness: 5 Things You Need to Know

Sciatica causing leg weakness is a special type of sciatica. In this article, I present 5 groups of essential information to know about this condition.

(With a little fine-tuning beforehand, so as not to get tangled up in another kind of sciatica…).

Happy reading! 🙂

(Any questions, comments or experiences to share? Feel free to use the comments section at the end of the article! 🙏)

♻️ Last updated: July 27, 2025. Written by Nelly Darbois
👨‍⚖️ Declaration of financial interests: none directly related to the subject. My complete declaration of financial interests is available in the legal notice section.

Focus: sciatica causing leg weakness and hyperalgesic sciatica

In common parlance, sciatica is a pain in the lower back that runs more or less down the back of a leg.

This pain can sometimes be so intense that we speak of hyperalgesic sciatica (“algic” meaning “painful” in medical language).

The presence of severe pain is a variant of the main sciatic symptom, and should prompt urgent medical attention.

Severe pain is pain that

• is constantly present;
• discomfort in thinking or speaking;
• prevents sleep ;
• severely disrupts simple activities such as getting out of bed, going to the toilet, washing or getting dressed.

In a sense, this type of pain can lead to a feeling of “paralysis” (muscle weakness).

However, hyperalgesic sciatica, “paralyzing” because of the pain, is something different from paralyzing sciatica in the medical sense.

In this article, I deal with paralyzing sciatica in the medical sense, in which there is genuine neurological paralysis. I’ll come back to this later.

What are the symptoms of paralyzing sciatica?

If you’re wondering about the symptoms of paralyzing sciatica, then I’m guessing you’re in one or other of these situations:

⚫ you feel as if part of a leg is paralyzed (loss of strength in one leg or difficulty making certain leg movements) ;

⚫ or feel paralyzed by intense pain (hyperalgesia). For example, you have great difficulty standing or walking.

If I’m right, then you should know that this type of symptom should prompt you to consult a doctor as soon as possible, regardless of whether or not you have sciatica.

Many problems can lead to paralysis. Not all of them require the same therapeutic strategy, which is why it’s so important to consult a professional.

What causes sciatica causing leg weakness?

If you’ve been diagnosed with paralyzing sciatica, it’s probably due to the nerve roots in your lower back.

A nerve root is a very short type of nerve, linked directly to the spinal cord in the spinal column (see image 1 below).

What can happen to these nerve roots in the event of paralyzing sciatica? Several things:

➡️ most frequently, they are compressed inside the spine due to :

• a backward displacement of the contents of an intervertebral disc (herniated disc; see image 2 below);
• the formation of new bone in the spinal column in cases of osteoarthritis(osteophytes; see image 3 below).

➡️ More rarely, nerve roots may be affected:

• or directly by a nerve tumor (benign or malignant) on the root ;
• or indirectly, by being compressed by a tumor or local infection.

In all cases, only a professional clinical examination coupled with analysis ofimaging results can identify the precise cause of the problem.

(If several nerve roots on several vertebral levels are affected at the same time, this is knownas cauda equina syndrome).

Sources: College of Teachers of Neurology (CEN)

How long does sciatica causing leg weakness last?

Today, paralyzing sciatica is almost systematically treated surgically. As a result, we don’t really know :

• how many of these sciatica could improve on their own, without surgery;
• how much they could improve;
• and in how long.

On the other hand, at least two cases are known to have recovered without surgery in around 4 to 6 weeks. These cases were described in the scientific literature by neurosurgeons in 2018 and 2022.

Sources: Chandankhede, 2022; K V L, 2019

Is sciatica causing leg weakness an emergency?

Here,three questions need to be distinguished:

1. Is it urgent to see a doctor if you think you have paralyzing sciatica?
2. If you can’t find a doctor quickly, should you go to emergency?
3. If we’re diagnosed with paralyzing sciatica, is there an emergency treatment we can implement?

Let’s examine each of these questions in turn.

Do I need to see a doctor in a hurry?

If you think you’ve got paralyzing sciatica, then without hesitation the answer is yes: you need to see a doctor urgently.

And note that, sciatica context or not, paralysis of any part of the body is always a reason to seek urgent medical attention.

Should I go to the emergency room?

Before going to the emergency room for any problems whatsoever, the Assurance maladie recommends that you first take the following steps:

• call your GP;
• seek a consultation at a walk-in clinic near you: to find out whether such a clinic exists, consult this map;
• call 15 (or 114 for the hearing-impaired); depending on your specific situation, a doctor will tell you whether or not you need to go to emergency;
• seek a medical appointment via teleconsultation.

Source: Health insurance, 2023

Is there an emergency treatment?

In the case of proven paralyzing sciatica, which has occurred rather rapidly, surgery is generally scheduled as an emergency.

The aim of the game is to remove the source of the nerve compression causing the paralysis, in order to avoid or minimize motor sequelae.

What exactly are these after-effects? Let’s take a closer look.

What are the possible after-effects of sciatica causing leg weakness?

Following paralyzing sciatica, there can be two main types of after-effects:

1️⃣ the persistence of pain, which can be more or less bothersome in terms of daily activities;

2️⃣ muscular weakness, the result of partial recovery from paralysis. These weaknesses can lead to lameness and balance problems.

The challenge of surgery is to reduce the risk of these after-effects as much as possible.

To my knowledge, in 2024, no study has examined whether surgery is more effective than non-surgical treatment in achieving this goal.

However, it seems plausible, even if we don’t really know how plausible.

By way of illustration, in a 2023 study of 53 patients, the results concerning the ability to raise the ball of the foot were :

• “Excellent” for 31 patients;
• “good” for 8 patients;
• “for 14 patients [Imajo, 2023].

Sources: Hou, 2023; Imajo, 2023

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