Although it has now been established that surgery is the best way to treat patients with symptomatic tight carotid stenosis, the fact remains that perioperative risks are not negligible. Patients with significant contralateral stenosis and/or no collateral flow capacity through the anterior communicating artery are likely to be at higher risk during surgery. We examined a series of 52 patients pre- and postoperatively with transcranial Doppler (TCD) and compared the results to perioperative stump pressures. Our intention was to find out whether the results of the TCD examination of the circle of Willis could be correlated to the perioperative stump pressures, and whether TCD gives reliable information about the collateral flow. We found relatively high stump pressures in patients with potential function of any communicating artery, and in the group with no collateral function most patients had low stump pressures. We also found that preoperative flow velocity fall in the middle cerebral artery (MCA) on compression of the ipsilateral internal carotid artery correlated with perioperative stump-pressure indices. However, we were unable to predict stump pressures in individual patients by flow velocity measurements in the MCA preoperatively.

We describe a female patient with systemic sarcoidosis and hydrocephalus. She was initially satisfyingly treated with peroral steroids. When she later deteriorated, the treatment had to be changed due to side-effects. High dose intravenous methylprednisolone pulse therapy was tried with some, but insufficient, improvement. Therefore, a ventriculoperitoneal shunt operation was performed with immediate improvement. After that she was treated with intravenous methylprednisolone and her condition has remained proper and stable for 5 years. The possibility that pulse therapy might have contributed to the favourable course in our patient is discussed.

The lack of changes was probably due to well-functioning collaterals and to the partial volume effect, whereby changes in a focal region are hidden when larger volumes are studied.

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