Patent No. 6430443 Method and apparatus for treating auditory hallucinations

 

Patent No. 6430443

Method and apparatus for treating auditory hallucinations (Karell, Aug 6, 2002)

Abstract

Stimulating one or more vestibulocochlear nerves or cochlea or cochlear regions will treat, prevent and control auditory hallucinations.

Notes:

FIELD OF THE INVENTION

The present invention generally relates to method and apparatus for treating, controlling or preventing auditory hallucinations by the application of modulating electrical signals to a vestibulocochlear cranial nerve or cochlea or cochlear region and/or by the application of audio signals through an ear.

BACKGROUND OF THE INVENTION

Scientific advances have revealed that schizophrenia is primarily organic and not psychological in nature. Scrambled language, distorted thoughts, and auditory hallucinations are the hallmarks of schizophrenia and have been linked to abnormal physical changes in specific areas of the human brain that begin during pregnancy. Auditory hallucinations are a prominent symptom and present in nearly all schizophrenic patients. Hallucinations are defined as sensory perceptions without environmental stimuli and occur as simple experiences of hearing, tasting, smelling, touching, or seeing what is not physically present; they also occur as mixed or complex experiences of more than one simple experience. When these experiences take the form of "voices" arising internally, the subjective experience is of "hearing" the voice of another, an auditory hallucination.

Theories of the etiology of hallucinations include (1) stimulation and/or (2) inhibition. Examples of stimulation are neurochemical (for example, the neurotransmitter dopamine) changes, electrical discharges, and seizure episodes. An example of inhibition causing an hallucination is when there is destruction of normally inhibitory functions, resulting in disinhibition, as in the phantom limb syndrome. Auditory hallucinations arising from the disordered monitoring of inner speech (thinking in words) may be mixed stimulation and inhibition. Other theories of the etiology of schizophrenia include infection, autoimmune or immune dysfunction, and environmental.

Hallucinations occur in a wide range of human experiences. For example, there are physician prescribed medications known to cause hallucinations; and there are drugs of abuse such as alcohol and LSD that are also known to cause hallucinations. Auditory hallucinations may occur in organic brain disorders such as epilepsy, Parkinson's and Alzheimer's disease. Hallucinations may occur to bilingual schizophrenics; for example, they can be perceived in English even though his/her mother tongue may be Spanish.

Hearing impairment (acute or chronic) combined with stress may lead to pseudo-hallucinations in normal persons. Auditory hallucinations may occur in diseases not involving the brain, such as otosclerosis (where the bones in the ear do not move freely); in this case the auditory hallucinations may be cured with surgery.

The brain activity of schizophrenics who hear imaginary voices has been found to be similar to the brain activity of people that are hearing real voices. Schizophrenia may be the result of dysfunction of neurons utilizing dopamine as a neurotransmitter; the antipsychotic (neuroleptic) drugs block dopamine. Auditory hallucinations found in disorders such as schizophrenia are associated with an abnormal pattern of brain activation, as can be seen with brain imaging, such as positron emission tomography (PET), and by other means, such as encephalographic methods.

Auditory hallucinations involve language regions of the cortex in a pattern similar to that seen in normal subjects listening to their own voices but different in that left prefrontal regions are not activated. The striatum plays a critical role in auditory hallucinations. Magnetic resonance imaging (MRI) has shown that the hippocampal-amygdala complex and the parahippocampal gyrus (areas in the temporal lobe) are reduced in schizophrenic patients. Schizophrenics have increased levels of dopamine in the left amygdala. When using functional MRI brain imaging, a patient is positioned within an imaging apparatus; protons within the brain are then made to radiate a signal, which can be picked up with a radio antenna. Active areas of the brain will radiate a different signal than areas of the brain that are at rest; scanning schizophrenics while they are hallucinating is possible.

Magnetic resonance spectroscopy has found that schizophrenic patients have lower levels of several nucleic acids in the brain, including phosphomonoesters and inorganic phosphate and higher levels of phosphodiesters and adenosine triphosphate. Neurotransmitters such as dopanine, serotonin (5-HT), norepinephrine and glutamates are involved. It has been postulated that loss of input to the prefrontal cortex results in lack of feedback to other circuits of the limbic regions which leads to hyperactivity of the dopamine pathways.

Computed tomography (CT) studies have repeatedly shown that the brains of schizophrenic patients have lateral and third ventricular enlargement and some degree of reduction in cortical volume. Other CT studies have reported abnormal cerebral asymmetry, reduced cerebellar volume, and brain density changes.

Changes in the bioelectrical brain activity are recorded in electroencephalography (EEG). The changes for schizophrenic patients are: (1) "choppy activity"--prominent low voltage, with desynchronized fast activity--considered as highly specific for schizophrenia; (2) intermittent occurrence of slow, high amplitude waves; (3) waves most prominent in the frontal region for delta, and in the occipital region for the theta; (4) pattern of increased slow activity; (5) decrease in alpha peak frequencies; (6) increased beta power; (7) increased left frontal delta power; (8) more anterior and superficial equivalent-dipoles in the beta bands. Some EEG changes are best noted during transition from wake to sleep.

In general, there are three changes in the EEG recordings: (i) spontaneous EEG, (ii) Event-Related Potentials and (iii) event-related EEG changes known as Event-Related Desynchronization and Event-Related Synchronization. Both real and imagined movement and both real and imagined voices may cause changes in these three types of EEG recording.

Hallucinations effect evoked potentials and alpha frequency which are noted when using quantitative EEG (qEEG).

Normal brain structures related to language tend to be larger on the left side; however, schizophrenic patients have the asymmetry reversed. Persons who have epilepsy of the left temporal lobe of the brain exhibit symptoms resembling schizophrenia. The brain activity of schizophrenics who hear imaginary voices has been found to be similar to the brain activity of people that are hearing real voices; however, the initiation of this brain activity arises from within rather than from external sources.

The planum temporale is associated with comprehending language, and if one stimulates this area electrically, a person hears complex sounds similar to a schizophrenic's auditory hallucinations.

Recognized in the prior art are methods and apparatus for treating and controlling medical disorders, psychiatric disorders, or neurological disorders, by applying modulating electrical signals to a selected nerve of a patient. For example, in U.S. Pat. No. 5,540,734 to Zabara, 1996, the patient's trigeminal and glossopharyngeal nerves are used, and in U.S. Pat. No. 5,299,569, to Wernicke, 1994 the vagus nerve is used U.S. Pat. No. 5,975,085 issued to Rise, 1999 discusses a method of treating schizophrenia by brain stimulation and drug infusion using an implantable signal generator and electrode and an implantable pump and catheter. A catheter is surgically implanted in the brain to infuse the drugs, and one or more electrodes are surgically implanted in the brain to provide electrical stimulation.

Cochlear implants for deaf individuals are recognized in the art. For example, U.S. Pat. No. 4,988,333 to Engebretson, 1991, and U.S. Pat. No. 5,549,658 to Shannon, 1996 describe how audiologic signals are converted into electrical signals for stimulating a cochlea or cochlear region for conducting to a vestibulocochlear nerve for simulating speech to a deaf individual. The electrical stimulations supplied by the cochlear implant give rise to ascending electrochemical activities reaching the cortex. These activities can be sensed and recorded, for example, with scalp electrodes by evoked potentials or fields techniques. Persons who have had cochlear implants show nerve, neurochemical, and brain function closely comparable to the responses of normal hearing people. For example, both normal hearing and cochlear implant individuals show similar neuronal metabolism's increase which is associated with a cerebral blood flow increase. Single photon or PET and functional MRI demonstrate increased blood flow changes associated with an auditory stimulation and during auditory hallucinations.

The prior art fails to recognize that stimulation of at least one of a patient's vestibulocochlear nerves, cochlea or cochlear regions with or without cochlear implant, can provide the therapeutic treatments according to the instant invention.

The prior art fails to recognize that auditory stimulation, both supra- and sub-hearing as well as hearing frequencies, of at least one of a patient's ears with or without bone conduction can provide the therapeutic treatments according to the instant invention.

One theory is that auditory hallucinations occur because of abnormal brain activation. Stimulation to the vestibulocochlear nerve or cochlea or cochlear region or the combination thereof, causes brain activation similar to normal hearing brain activation. This normal hearing brain activation blocks hallucinatory activation similar to pacer electrical stimulation to the heart blocking abnormal internal electrical discharges. Stimulation may occur without monitoring, in a pulsed or continuous fashion. Stimulation may be patient controlled. Or upon monitoring, for example by qEEG, for early detection of an abnormal brain activation, a signal can be sent through a cochlea or cochlear region or vestibulocochlear nerve for inducing natural brain activation, thereby blocking abnormal brain activation producing auditory hallucinations. Blocking may be done in such a manner as to allow normal auditory speech to proceed and therefore normal brain processing of information, and thereby improve a patient's quality of life. Sounds beyond normal hearing, low frequency tones and/or high frequency tones, may accomplish such blocking. Out of hearing range tones may be converted to modulating electrical signal stimulation of a cochlea or cochlear region or a vestibulocochlear nerve.

Monitoring is usually performed with electrodes. However, monitoring may also be performed with a variety of sensors: implanted electrode sensors; and for example, sensors to pick up the presence of certain chemicals, which may then have a corresponding conversion to electrical impulses. EEG monitoring may be performed, for example, by a patient wearing a multi-electrode scalp hat and changes may be analyzed by a logic circuit means; upon detection of changes consistent with auditory hallucinations, a stimulating current may then be applied qEEG signal processing permits measuring and quantifying multiple aspects of brain electrical activity providing objective, precise information. qEEG provides objective numerical data that can be used for graphical display and for mathematical statistical analysis. The brain voltage fluctuations are digitally converted and compared. There are many signal processing techniques used in qEEG. Distinctive patterns of electrophysiologic abnormalities are now recognized: schizophrenic patients, depressed patients, demented patients, chronic alcoholics, obsessive-compulsive disorders, attention deficit disorders and others. These techniques may be used to actively monitor schizophrenics for hallucinations and to cause a modulated electrical stimulation through electrodes affixed to a vestibulocochlear nerve or cochlea or cochlear region.

SUMMARY OF THE INVENTION

An abnormal brain activation inducing auditory hallucinations may be blocked by applying modulating electrical signal stimulation of a vestibulocochlear cranial nerve or cochlea or cochlear region.

An abnormal brain activation inducing auditory hallucinations may be blocked by applying sound, audible and inaudible, with or without bone conduction to an ear.

An object of the invention is directed to methods of treating, controlling or preventing auditory hallucinations by application of modulating electrical signals directly to at least one of a patient's vestibulocochlear nerves, or cochlea or cochlear regions such as the middle ear.

An additional object of the invention is directed to methods of and apparatus for treating, controlling or preventing auditory hallucinations through use of the brain's natural mechanisms by application of audio signals to at least one ear inducing natural neuron excitation in at least one of a patient's vestibulocochlear nerves. Sounds beyond normal hearing range, that of sub-low frequency or that of high-ultrasound frequencies, may be modulated to induce nerve excitation which will block auditory hallucinations.

An additional object of the invention is to have cochlear implant technology applied to treat patient's having disorders with auditory hallucinations.

An additional object of the invention is to have newly developed techniques of picking up brain activity and monitoring used as a means to detect early audio hallucinations; once detected, to modulate an output signal from a stimulus generator applied to an vestibulocochlear nerve for blocking, controlling or preventing auditory hallucinations.

An additional object of the invention is to have new techniques of monitoring and picking up brain activity used as a means to detect early audio hallucinations and once detected, to modulate an output signal from a stimulus generator applied to a cochlea or cochlear region for blocking, controlling or preventing auditory hallucinations.

An additional object of the invention is that the patient may selectively and manually activate the stimulator or audio input to consciously control his/her auditory hallucinations. The patient may control all parameters of stimulation: frequency, amplitude, wave shape, duration, intermittent or constant.

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The present invention is for treating a specific entity, that of hallucinations; however, electrical stimulation as described may also affect other symptoms of other diseases, such as phobias, panic attacks, obsessive compulsions or depression or other psychiatric disorders. The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.