Baroreflex Failure Linked to Radiation for Head and Neck Cancer

October 3, 2008 (Salt Lake City, Utah) — Baroreflex failure following chemotherapy is an underrecognized cause of labile blood pressures, resulting in hypertension, orthostatic hypotension, and syncope, researchers warn.

At the American Neurological Association 133rd Annual Meeting, investigators presented a retrospective review highlighting the clinical features and typical findings on autonomic testing in patients with radiation-induced baroreflex failure.

"The important thing is to recognize that patients who've had head and neck radiation may have late complications that may not manifest for years after treatment," second author Sara Schrader, MD, from the Mayo Clinic in Scottsdale, Arizona, told Medscape Neurology & Neurosurgery.

"Radiation can cause multiple cranial neuropathy, which can manifest in many ways," Dr. Schrader noted.

Neck Radiation Associated With Cranial Neuropathy

The researchers were led by Brent Goodman, MD, also from the Mayo Clinic. They identified 34 patients who had a history of neck radiation, labile hypertension, orthostatic hypotension, or syncope. The malignancy type was squamous-cell carcinoma in all but 2 patients.

The mean age of participants at the time of diagnosis was 63 years. The average time from radiation exposure to the development of symptoms was 6.4 years. Radiation doses ranged from 55 Gy to 70 Gy.

Formal autonomic testing was performed in 22 patients. Cardiovascular adrenergic function was the most frequent abnormality, showing impairment in late phase 2 and 4 during the Valsalva maneuver.

Neurological Complications Following Neck Radiation

Signs	Symptoms	Patients (%)
Autonomic	Postural lightheadedness	97
	Labile hypertension	78
	Syncope	73
	Cardiac dysrhythmia	9
Bulbar	Dysphagia	78
	Dysarthria	33
Cerebrovascular	Stroke	12
	Carotid artery stenosis/occlusion	57
	Vertebral artery stenosis	7

"This is a retrospective study, and some of the patients we've seen clinically, but the vast majority, we have not," Dr. Schrader pointed out during an interview. "The data we have for patients were not uniform, and testing may have differed," she noted.

"Nonetheless, this offers a very descriptive overview that may help us look at this prospectively in the future."

The researchers have disclosed no relevant financial relationships.

American Neurological Association 133rd Annual Meeting: Poster M-120. Presented September 22, 2008.

Cite this: Allison Gandey. Baroreflex Failure Linked to Radiation for Head and Neck Cancer - Medscape - Oct 03, 2008.

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