Hyperpathic Disorder From Intrathecal Alumina Gel Injections

Alumina cream applications to brain and spinal cord have been carried out in several species of laboratory animals, being variously used to produce seizures1,2and other neurological manifestations.3,4The study most relevant to the present one is that of Kennard5who described a chronic sensory hyperirritability in cats produced by the lumbar intrathecal injection of alumina cream. She postulated that abnormal sensations developed at a discrete chronic injury but that spread of symptoms could occur to body parts not involved initially in the pathological process. In this regard, the condition bore a striking similarity to causalgia in man. Through the use of the stimulus-response techniques of neurophysiology, it is now possible to examine the form and distribution of evoked potentials at several levels of the nervous system. Such potentials can be evoked either by tactile or by nerve stimulation. To search for evoked potential changes subsequent to chronic