When back pain needs a neurosurgeon (and when it does not)

Almost all back pain is benign

It is worth starting with the good news. Non-specific low back pain — the kind that appears after an effort, an awkward movement or a week at a desk — is by far the commonest, and most resolves within weeks with controlled activity, analgesia and patience. It does not need an MRI, does not need bed rest, and certainly does not need an operating room.

Prolonged rest, in fact, makes things worse: muscle loses tone, joints stiffen and pain becomes chronic. The best-supported recommendation is to stay active within tolerance and return to routine as soon as possible.

Pain running down the leg is a different conversation

When pain stops being in the low back and runs down the buttock and leg, with tingling or numbness, a nerve root is most likely compressed. That is radiculopathy, popularly sciatica, and although it too often improves on its own, it does warrant being seen by someone who can examine for a neurological deficit.

The finding that changes urgency is not pain intensity but strength. If lifting the front of the foot is difficult, if you catch your toe on steps, if the leg gives way climbing stairs, function is being lost, and that does not allow three months of waiting to see.

The red flags that do demand investigation

There is a set of findings that, in the presence of back pain, demand imaging without delay. A history of cancer. Fever or unexplained weight loss. Pain that wakes you at night and eases in no position. Significant trauma or, in an older adult with osteoporosis, even minor trauma. Prolonged steroid use. And progressive neurological deficit.

One in particular is an immediate emergency: difficulty passing urine or incontinence, together with numbness in the area that touches a saddle, and weakness in both legs. That is cauda equina syndrome and it is dealt with in an emergency department the same day, not in clinic next week.

Why the MRI does not decide on its own

It is worth being explicit here, because this is a constant source of alarm. Studies that have performed lumbar MRI on people with no pain at all frequently find degenerated discs, protrusions and even herniations. In other words: abundant radiological findings turn up in people who are perfectly well.

So an MRI showing a herniation is not equivalent to a surgical indication. What indicates surgery is the agreement of three things: the patient's symptoms, the neurological examination, and the imaging pointing to the same level and the same side. Without that agreement, operating is a gamble.

What to expect from a neurosurgical consultation

A useful consultation spends half its time on history and examination: when it started, what makes it worse, what has been tried, and how strength, reflexes and sensation are. Only then is the imaging opened — and it is opened on screen, with you watching.

And an honest consultation often ends without surgery: with a physiotherapy plan, a concrete timeframe, and a list of signs that mean coming back sooner. Telling a patient it is not their turn to be operated on is also part of the job.