If your retrosigmoid procedure transected your occipital nerves, headache syndrome may result.
Try Dr Ducic at Georgetown for papers on the subject. This is from his website:
Post Craniotomy Pain & Headache
Click here to view a patient discussion about nerve excision as a treatment for post-craniotomy pain.
As was discussed in the section related to chronic pain following surgery or trauma, any trauma or surgery can result in nerve damage causing chronic pain. When that pain is chronic migraine / headache it assumes whole new dimension.
Presentation can vary widely, but often involves a form of chronic headache or migraine. If these symptoms are mainly located in one part of the head, like back of the head (occipital area) following acoustic neuroma surgery, then it can also be defined as occipital neuralgia. These patients often report:
-Chronic headache/migraine symptoms, either intermittent or constant
-Incisional pain at the site of the neck or scalp where previous surgery took place
-Pain that can radiate from neck and back of the head towards the top, even front of the head
-Limited (sometimes no) effect of medical treatment
-Scar or soft tissue depression, especially following acoustic neuroma
-Symptoms starting soon after surgery or in a delayed fashion
-Symptoms present more then 3 months after initial surgery
Surgical Treatment of Chronic Post-Operative Headache
Unlike medical management which is focused on treating symptoms, peripheral nerve surgery treats the cause of the pain (stump neuroma, damaged peripheral nerve with previous surgery). The involved nerve and its neuroma are surgically removed. Considering these nerves control only sensation, there is no motor deficit of any kind following this procedure. If there is soft tissue depression in patients who had acoustic neuroma surgery, this can be addressed at the same time. Certainly, this all is done after an initial work-up by your neurologist excluding recurrence of acoustic neuroma or other pathology.
During Surgery for Chronic Post-Operative Headache
1. You receive general anesthesia so you won’t feel any pain during the surgery.
2. An incision is made over the involved nerve (occipital for post-acoustic neuroma patients). Damaged nerves are removed and the soft tissue defect is corrected, if present. Skin is then closed in anatomical layers.
3.This surgery is an outpatient procedure; your dressing will be removed about 5-7 days after surgery, while sutures are removed three weeks later. And yes, as appreciated by all patients, I designed my surgical approach in such way that no shaving of the head is needed.
If you are not sure about your eligibility for surgery, and if you are not in the Washington, D.C. area, you can send me your records so I can determine if you are a good candidate for treatment. Visit my patient forms page for a downloadable form."
This is just one possibility, but it is worth considering. Good luck.