Skull-Mounted Electrical Stimulation System and Method for Treating Patients
Publication Date: 2004-Jan-22
The IP.com Prior Art Database
A system and method for applying electrical stimulation to the brain to treat epilepsy, movement disorders, and other indications uses at least one implantable system control unit (SCU), including an implantable signal/pulse generator (IPG) and one or more electrodes. The IPG is implanted in the mastoid area of the skull and communicates with at least one external appliance, such as a Behind-the-Ear (BTE) unit. In a preferred embodiment, the system is capable of open- and closed-loop operation. In closed-loop operation, at least one SCU includes a sensor, and the sensed condition is used to adjust stimulation parameters.
Background & Summary
This invention relates to implantable stimulator systems and methods, and more particularly relates to implantable stimulator systems and methods utilizing one or more implantable leads for treating epilepsy, movement disorders, and other indications.
Epilepsy is characterized by a tendency to recurrent seizures that can
lead to loss of awareness, loss of consciousness, and/or disturbances of
movement, autonomic function, sensation (including vision, hearing and taste),
mood, and/or mental function. Epilepsy
afflicts 1-2% of the population in the developed world. The mean prevalence of active epilepsy
(i.e., continuing seizures or the need for treatment) in developed and
undeveloped countries combined is estimated to be 7 per 1,000 of the general
population, or approximately 40 million people worldwide. Studies in developed countries suggest an
annual incidence of epilepsy of approximately 50 per 100,000 of the general
population. However, studies in developing countries suggest this figure is
nearly double at 100 per 100,000.
Epilepsy is often but not always the result of underlying brain disease. Any type of brain disease can cause epilepsy, but not all patients with the same brain pathology will develop epilepsy. The cause of epilepsy cannot be determined in a number of patients; however, the most commonly accepted theory posits that it is the result of an imbalance of certain chemicals in the brain, e.g., neurotransmitters. Children and adolescents are more likely to have epilepsy of unknown or genetic origin. The older the patient, the more likely it is that the cause is an underlying brain disease such as a brain tumor or cerebrovascular disease.
Trauma and brain infection can cause epilepsy at any age, and in particular, account for the higher incidence rate in developing countries. For example, in Latin America, neurocysticercosis (cysts on the brain caused by tapeworm infection) is a common cause of epilepsy; in Africa, AIDS and its related infections, malaria and meningitis, are common causes; in India, AIDS, neurocysticercosis and tuberculosis, are common causes. Febrile illness of any kind, whether or not it involves the brain, can trigger seizures in vulnerable young children, which seizures are called febrile convulsions. About 5% of such children go on to develop epilepsy later in life. Furthermore, for any brain disease, only a proportion of sufferers will experience seizures as a symptom of that disease. It is, therefore, suspected that those who do experience such symptomatic seizures are more vulnerable for similar biochemical/neurotransmitter reasons.
Movement disorders are neurologic syndromes characterized by either an excess or a paucity of movement. These disorders affect approximately two million Americans, including over one million suffering from benign essential tremor, and half a million suffering from Parkinson's dis...