Abstract
Objectives We present the largest case series to date of patients with long term follow up who developed clinically significant autonomic dysfunction due to baroreflex failure following neck irradiation for head and neck cancer (HNC) and Hodgkin’s lymphoma.
Methods We retrospectively collated clinical, radiological, and autonomic testing data on nine patients who were referred to a quaternary institution in Sydney, Australia for evaluation of autonomic function following head and neck irradiation for malignancy.
Results All patients demonstrated baroreflex failure and had symptomatic orthostatic hypotension. The average time to symptom onset was 9.1 years (range 0 to 26 years). One patient demonstrated isolated baroreflex failure and two patients displayed baroreflex failure and segmental hypohidrosis, suggestive of local nerve damage involving efferent baroreceptor pathways. Five patients demonstrated significant cardiovagal and adrenergic dysfunction and one patient had severe cardiovagal and adrenergic dysfunction with additional features of a length-dependent neuropathy. Five of the six patients with severe pan-autonomic failure received concomitant chemotherapy. The features of baroreflex failure occurred independently of radiologically significant carotid atherosclerotic disease.
Conclusion This case series highlights the phenomenon of radiotherapy-induced damage to blood pressure regulatory structures and provides further commentary on the pathophysiology of baroreflex failure. The appearance of urinary frequency, gastrointestinal disturbance, or abnormal sweating in addition to postural symptoms was more common in patients with pan-autonomic failure. The constellation of presenting symptoms, as well as the presence of paroxysmal hypertension, can in turn guide pharmacotherapeutic management in these cases.
