Can surgery for insulinoma reverse chronic hypoglycemia-induced peripheral neuropathy?

An insulinoma is a rare tumor of the pancreas that makes too much insulin, causing repeated episodes of low blood sugar (hypoglycemia). Over months or years, those repeated lows can damage nerves, a condition called peripheral neuropathy, which causes numbness, tingling, and burning pain, usually in the hands and feet. The question is whether removing the tumor lets those nerves heal.

The short answer from the available evidence is: partly, but not fully. Surgery fixes the underlying cause by stopping the hypoglycemia, and nerve symptoms often improve. But some nerve damage can remain even after blood sugar is normal again ⁴.

What the research says

The most direct evidence comes from a case report of a 22-year-old woman with a single insulinoma in the pancreas ⁴. She had 6 to 12 months of headaches, blurred vision, and numbness, tingling, and burning pain in her limbs before the tumor was found. Nerve testing showed damage to multiple nerve roots and a sensorimotor polyneuropathy (nerve damage affecting both movement and sensation), mostly in the upper limbs ⁴. Doctors confirmed the diagnosis with a supervised 72-hour fasting test and found the tumor on CT scan, then removed it with a laparoscopic distal pancreatectomy (keyhole surgery to remove the tail of the pancreas) plus spleen removal ⁴.

After surgery, her hypoglycemia resolved quickly, and her tingling, sensory loss, and most nerve test results improved ⁴. However, some problems persisted: her tendon reflexes stayed reduced, and she had mild weakness and balance problems in the lower limbs ⁴. This suggests that removing the tumor reverses the cause but does not always fully repair nerves that were already damaged.

The authors note that peripheral neuropathy from hypoglycemia in insulinoma is uncommon, and whether it can be reversed is still debated in the medical literature ⁴. This is a single case, so it cannot tell us how often nerves recover, how much recovery is typical, or whether the length of time someone had hypoglycemia before surgery matters.

Broader research on hypoglycemia supports why getting blood sugar under control matters. A systematic review of adults with type 2 diabetes found that longer diabetes duration, insulin therapy, having other conditions, and taking many medications were all linked to higher odds of hypoglycemia ⁶. That review is about diabetes, not insulinoma, but it reinforces that repeated low blood sugar is a real and measurable risk. Separately, a network meta-analysis of treatments for diabetic peripheral neuropathy found that current drug options do little to reverse established nerve injury ¹, which fits the pattern seen in the insulinoma case: once nerves are damaged, full recovery is not guaranteed.

What to ask your doctor

• How much of my nerve symptoms are likely to improve after the insulinoma is removed, and how long might that take?
• Will I need repeat nerve tests (electrophysiology) after surgery to track whether the nerves are recovering?
• If some numbness, weakness, or balance problems remain, what options are there for managing them?
• Does how long I had low blood sugar before diagnosis affect my chances of nerve recovery?
• Should I see a neurologist as well as my endocrine team for the nerve symptoms?