Emeritus Professor of Neurology
University of Glasgow, Scotland, UK
THEME: BORDERLANDS OF EPILEPSY REVISITED
A number of metabolic conditions can predispose to convulsions. The formidable array
of differential diagnosis extends from pyridoxine deficiency in infancy, hypocalcemia in
the newborn, hypoparathyroidism in the adolescent, calcium deficiency in the lactating
mother and hypoglycemia in all age groups. Eclampsia is a convulsive state associated
with toxaemia of late pregnancy, considered to be a hypertensive encephalopathy, due
to constriction of cerebral arterioles, accompanied by cerebral oedema. Diagnosis of
seizures secondary to chronic renal disease, hyperventilation in emotional state,
hysterical seizures and alcohol withdrawal seizures, must be based on associated
diseases and on circumstances leading to the convulsion. Inborn errors of amino acid
metabolism due to genetic enzyme deficiency, may cause seizures in children and
ammonia level disturbances with mental retardation may predispose to seizures in a
number of urea cycle disorders of pregnancy.