Methods and apparatus for effectuating a lasting change in a neural-function of a patient

This application is a continuation-in-part of U.S. application Ser. No. 10/260,720, filed on Sep. 27, 2002, which claims the benefit of U.S. Application No. 60/325,872 filed on Sep. 28, 2001 and which is a continuation-in-part of U.S. application Ser. No. 09/802,808, filed on Mar. 8, 2001, which, in turn, claims the benefit of U.S. Provisional Application No. 60/217,981, filed Jul. 31, 2000. Each of these applications is incorporated by reference herein in its entirety.

Several embodiments of methods and apparatus in accordance with the invention are related to electrically stimulating a region in the cortex or other area of the brain to bring about a lasting change in a physiological function and/or a mental process of a patient.

A wide variety of mental and physical processes are controlled or influenced by neural activity in particular regions of the brain. The neural-functions in some areas of the brain (i.e., the sensory or motor cortices) are organized according to physical or cognitive functions. Several other areas of the brain also appear to have distinct functions in most individuals. In the majority of people, for example, the occipital lobes relate to vision, the left interior frontal lobes relate to language, and the cerebral cortex appears to be involved with conscious awareness, memory, and intellect.

Many problems or abnormalities can be caused by damage, disease and/or disorders in the brain. Effectively treating such abnormalities may be very difficult. For example, a stroke is a common condition that damages the brain. Strokes are generally caused by emboli (e.g., obstruction of a vessel), hemorrhages (e.g., rupture of a vessel), or thrombi (e.g., clotting) in the vascular system of a specific region of the brain. Such events generally result in a loss or impairment of a neural function (e.g., neural functions related to facial muscles, limbs, speech, etc.). Stroke patients are typically treated using various forms of physical therapy to rehabilitate the loss of function of a limb or another affected body part. Stroke patients may also be treated using physical therapy plus an adjunctive therapy such as amphetamine treatment. For most patients, however, such treatments are minimally effective and little can be done to improve the function of an affected body part beyond the recovery that occurs naturally without intervention.

The problems or abnormalities in the brain are often related to electrical and/or chemical activity in the brain. Neural activity is governed by electrical impulses or “action potentials” generated in neurons and propagated along synaptically connected neurons. When a neuron is in a quiescent state, it is polarized negatively and exhibits a resting membrane potential typically between −70 and −60 mV. Through chemical connections known as synapses, any given neuron receives excitatory and inhibitory input signals or stimuli from other neurons. A neuron integrates the excitatory and inhibitory input signals it receives, and generates or fires a series of action potentials when the integration exceeds a threshold potential. A neural firing threshold, for example, may be approximately −55 mV.

It follows that neural activity in the brain can be influenced by electrical energy supplied from an external source such as a waveform generator. Various neural functions can be promoted or disrupted by applying an electrical current to the cortex or other region of the brain. As a result, researchers have attempted to treat physical damage, disease and disorders in the brain using electrical or magnetic stimulation signals to control or affect brain functions.

Transcranial electrical stimulation is one such approach that involves placing an electrode on the exterior of the scalp and delivering an electrical current to the brain through the scalp and skull. Another treatment approach, transcranial magnetic stimulation, involves producing a high-powered magnetic field adjacent to the exterior of the scalp over an area of the cortex. Yet another treatment approach involves direct electrical stimulation of neural tissue using implanted electrodes.

The neural stimulation signals used by these approaches may comprise a series of electrical or magnetic pulses that can affect neurons within a target neural population. Stimulation signals may be defined or described in accordance with stimulation signal parameters including pulse amplitude, pulse frequency, duty cycle, stimulation signal duration, and/or other parameters. Electrical or magnetic stimulation signals applied to a population of neurons can depolarize neurons within the population toward their threshold potentials. Depending upon stimulation signal parameters, this depolarization can cause neurons to generate or fire action potentials. Neural stimulation that elicits or induces action potentials in a functionally significant proportion of the neural population to which the stimulation is applied is referred to as supra-threshold stimulation; neural stimulation that fails to elicit action potentials in a functionally significant proportion of the neural population is defined as sub-threshold stimulation. In general, supra-threshold stimulation of a neural population triggers or activates one or more functions associated with the neural population, but sub-threshold stimulation by itself does not trigger or activate such functions. Supra-threshold neural stimulation can induce various types of measurable or monitorable responses in a patient. For example, supra-threshold stimulation applied to a patient\'s motor cortex can induce muscle fiber contractions in an associated part of the body.

Although electrical or magnetic stimulation of neural tissue may be directed toward producing an intended type of therapeutic, rehabilitative, or restorative neural activity, such stimulation may result in collateral neural activity. In particular, neural stimulation delivered beyond a certain intensity, period of time, level, or amplitude can give rise to seizure activity and/or other types of collateral activity. It will be appreciated that collateral neural activity may be undesirable and/or inconvenient in a neural stimulation situation.

The human brain has two hemispheres that are connected via the corpus callosum. Each hemisphere of the brain generally exerts majority control over motor functions and/or sensory functions on the opposite or “contralateral” side of the patient\'s body. Hence, for example, the left hemisphere of the brain has majority control over movement of the right arm and right leg. Through transcallosal connections, though, each hemisphere of the brain exerts some degree of control over the functions on the same or “ipsilaterial” side of the patient\'s body. Hence, the right hemisphere of the brain may have some involvement in controlling movement of the right arm and right leg.

Some studies have concluded that damage to or disorders of the cerebral cortex on one hemisphere can induce long-term changes in the structure and function of a homotopic location of the contralateral hemisphere, namely a location on the undamaged cortex that is at about the same position as the position of the damaged tissue in the opposite cortex. Damage to the cortex in one hemisphere may impact the contralateral homotopic cortex in a variety of fashions, including causing increased cortical thickness, dendritic growth and/or elimination, neuronal hyperexcitability, and synaptogenesis. See, e.g., Nudo, “Recovery After Damage to Motor Cortical Areas,” Current Opinion in Neurobiology, 1999, 9:740-747, the entirety of which is incorporated herein by reference. See also Keyvani et al., “Suppression of Proteasome C2 Contralateral to Ischemic Lesions in Rat Brain,” Brain Research 858, (2000) 386-392.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of neurons.

FIG. 2 is a graph illustrating firing an “action potential” associated with normal neural activity.

FIG. 3 is a flowchart of a method for effectuating a neural-function of a patient associated with a location in the brain in accordance with one embodiment of the invention.

Continue reading about Methods and apparatus for effectuating a lasting change in a neural-function of a patient...
Full patent description for Methods and apparatus for effectuating a lasting change in a neural-function of a patient

Brief Patent Description - Full Patent Description - Patent Application Claims

Click on the above for other options relating to this Methods and apparatus for effectuating a lasting change in a neural-function of a patient patent application.

Patent Applications in related categories:

20090292336 - Neural interface systems and methods - In one embodiment, a neural interface system includes an implantable neural probe having a flexible substrate, electrodes that extend from the substrate that are adapted to contact neural tissue of the brain, a signal processing circuit configured to process neural signals collected with the electrodes, and a wireless transmission circuit ...


###


How KEYWORD MONITOR works... a FREE service from FreshPatents
1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored.
3. Each week you receive an email with patent applications related to your keywords.  
Start now! - Receive info on patent apps like Methods and apparatus for effectuating a lasting change in a neural-function of a patient or other areas of interest.
###


Previous Patent Application:
Closed-loop feedback for steering stimulation energy within tissue
Next Patent Application:
Electrode system for transcutaneous nerve and/or muscle stimulation
Industry Class:
Surgery: light, thermal, and electrical application

###

Design/code © 2009 FreshContext LLC/Freshpatents.com. Website Terms and Conditions - Also read: About this Page
Patent data source: patents published by the United States Patent and Trademark Office (USPTO)
Information published here is for research/educational purposes only (and in conjunction with our Keyword Monitor) and is not meant to be used in place of the full USPTO patent document/images or a comprehensive patent archive search. Complete official applications are on file at the USPTO and often contain additional data/images (Freshpatents is currently text-only). FreshPatents.com is not affiliated with or endorsed by the USPTO or firms/individuals or products/designs/ideas related to listed patents.

FreshPatents.com Support
Thank you for viewing the Methods and apparatus for effectuating a lasting change in a neural-function of a patient patent info.
IP-related news and info


Results in 2.3266 seconds


Other interesting Feshpatents.com categories:
Software:  Finance ,  AI ,  Databases ,  Development ,  Document ,  Navigation ,  Error paws