Friedreich’s Ataxia with Dysautonomia and Labile Hypertension

Abstract

An Amerindian girl with Friedreich's ataxia presented at the age of 14 years with intermittent bifrontal headaches and abdominal aching, often associated with nausea and recurrent vomiting and an evanescent pink, blotchy rash on the upper trunk. In these attacks she also had hypertension up to 210/160 mm Hg. Renal function studies, including intravenous pyelogram and angiography, were normal. Plasma renin activity (2.5 ng/ml/hr) was also normal. Total body CT scan was negative for phaeochromocytoma, and repeated estimations of 24-hour excretion of urinary VMA were normal or borderline high. Levels of total catecholamines in 24-hour urine were normal twice, but two random specimens during the paroxysmal episodes contained abnormally high levels of norepinephrine and dopamine. Plasma catecholamine concentrations were increased but not as high as with phaeochromocytoma. Blood pressure monitoring demonstrated marked fluctuations with position and temperature. A clonidine suppression test showed a substantial fall of plasma catecholamine levels, consistent with dysautonomia and not with phaeochromocytoma. It is concluded that the patient has dysautonomia of central origin, probably as a manifestation of Friedreich's ataxia. These findings are discussed in relation to the recent demonstration of increased levels of plasma catecholamines in that disease.