Abstract:
Localized persistent tactile stimulation provides a decreased sensory latency in response to sensory stimulation leading to a mechanism of treating nystagmus and possibly dyslexia and autism by locating the tactile stimulation under guidance of multiple measurements of sensory latency.

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. provisional application 61/577,381 filed Dec. 19, 2011 and U.S. provisional application 61/598,720 filed Feb. 14, 2012 both hereby incorporated in their entirety by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to a method and apparatus for reducing sensory latency such as may underlie certain conditions of nystagmus, dyslexia, attention deficit, hyperactivity and autism. 
         [0003]    In order to see a clear image an individual needs to hold the line of sight steady. Congenital nystagmus is a pathologic oculomotor state of involuntary horizontal eye movements that interferes with this steady line of sight thereby reducing visual acuity. Generally, congenital nystagmus has been considered untreatable although some drugs exist that may be effective against nystagmus for certain individuals. Some studies suggest that acupuncture may be effective against the symptoms of nystagmus when applied on the neck muscles (sternocleidomastoid). 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention provides a method of reducing sensory latency, that is, the delay between sensory stimulus, such as a change in visual pattern, and evoked brain activity as evidenced by EEG measurements. This reduced sensory latency is obtained by long-term local tactile stimulation, for example, by common acupressure beads. The technique appears to provide substantial relief from nystagmus and may provide beneficial effects for the treatment of other disorders linked to sensory latency including dyslexia, attention deficit disorder, hyperactivity and autism.
   Specifically, the present invention provides a method of decreasing sensory latency comprising the steps of: (a) obtaining a baseline reading of sensory evoked potential of the patient; (b) applying at least one source of persistent tactile stimulation to the patient;(c) obtaining a subsequent reading of sensory evoked potential of the patient to evaluate change in sensory latency; and (d) repeating steps (b) and (c) after adjusting a location of at least one source of persistent tactile stimulation to decrease the sensory latency.   
 
         [0006]    It is thus a feature of at least one embodiment of the invention to provide a systematic method of treating conditions having an underlying cause of excessive sensory latency including nystagmus, dyslexia, and autism. 
         [0007]    The reading of the sensory evoked potential may be a reading of visual evoked potential triggered by a visual display. 
         [0008]    It is thus a feature of at least one embodiment of the invention to make use of existing visual evoked potential equipment for implementing and optimizing the present method. 
         [0009]    The sources of persistent tactile stimulation may be at least one bead attached to the patient&#39;s skin to press against the skin. 
         [0010]    It is thus a feature of at least one embodiment of the invention to provide a method that may make use of readily available acupressure beads for the tactile stimulation. 
         [0011]    The beads may include an overlying adhesive backing material adhering to the skin at a periphery of the material and holding a bead toward the center of the material. 
         [0012]    It is thus a feature of at least one embodiment of the invention provide for a multi-day tactile stimulation with a relatively simple and intuitive mechanism. 
         [0013]    The overlying adhesive backed material may hold multiple spaced apart beads. It is thus a feature of at least one embodiment of the invention to provide a simple method of producing repeatable multipoint tactile stimulation. 
         [0014]    The persistent tactile stimulation may be provided in regions from a group consisting of the patient&#39;s face, the inside of the patient&#39;s wrist, the front of the patient&#39;s lower leg, and the region of the patient&#39;s ears. 
         [0015]    It is thus a feature of at least one embodiment of the invention to locate the beads in positions that may provide increased efficacy. 
         [0016]    The method may obtain a frequency domain transformation of the sensory evoked potential to compare spectral power in a low and relatively higher frequency band to deduce a degree of sensory latency. 
         [0017]    It is thus a feature of at least one embodiment of the invention to provide for a quantification of sensory latency that may be used to assess location of the beads and effectiveness of the treatment. 
         [0018]    The low frequency band may be substantially 5 to 10 hertz and the upper frequency band is substantially 16 to 20 hertz. 
         [0019]    It is thus a feature of at least one embodiment of the invention to perform frequency measurements in bands that conform to theta and beta EEG waveforms. 
         [0020]    More specifically, the present invention provides a method of treating nystagmus comprising the step of applying a persistent tactile stimulation to patient regions from the group consisting of the patient&#39;s face, the inside of the patient&#39;s wrist, the front of the patient&#39;s lower leg, and the region of the patient&#39;s ears over a multi-day period. 
         [0021]    It is thus a feature of at least one embodiment of the invention to provide a drug-free treatment for nystagmus. 
         [0022]    These particular objects and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is a simplified perspective view of a patient monitored with a visual evoked potential machine for measuring visual evoked potential; 
           [0024]      FIG. 2  is a plot of EEG activity measured by the machine of  FIG. 1  with respect to time after a visual event showing two curves of EEG activity, with and without treatment by the method of the present invention; 
           [0025]      FIG. 3  is a Fourier transform of the curves of  FIG. 2  showing bands of energy measurement for creation of a theta beta ratio; 
           [0026]      FIG. 4  is a cross-sectional view of an acupressure bead pressed against the skin as may be used in the present invention; 
           [0027]      FIG. 5  is a perspective view of the acupressure bead of  FIG. 4  as applied to the skin; 
           [0028]      FIG. 6  is a detail view of a human wrist showing one possible placement of beads for the present invention; 
           [0029]      FIG. 7  is a detail view of a human ear showing three possible locations of beads for the present invention; 
           [0030]      FIG. 5  is a detail view of a patient&#39;s lower leg showing an alternative or additional location of beads per the present invention; 
           [0031]      FIG. 9  is a front elevational view of a human face showing additional or alternative locations for the beads of the present invention; 
           [0032]      FIG. 10  is a perspective view of glasses adapted to provide for behind the ear tactile stimulation such as may be useful in the present invention; and 
           [0033]      FIG. 11  is a simplified flowchart of the principal steps of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0034]    Referring now to  FIG. 1 , an oculomotor testing system  10  may provide for a graphics display screen  12  supported to face toward a seated patient  14  with the display screen  12  at approximately head height of the seated patient  14 . The display screen  12  may provide for a varying visual display under the control of a computer system  15 , for example, the visual display being a checkerboard pattern switching to its negative image at an event time. EEG signals may be obtained from electrodes  16  placed on the front, left and right side, and rear of the patient&#39;s head to collect EEG signals from the patient  14 . These EEG signals may be aligned to the event time and displayed on a diagnostic display  18  to a clinician as will be discussed below. It will be appreciated that computer system  15  provides for standard EEG processing circuitry as well as a general purpose computer processor executing a stored program whose behavior will be described below held in memory. 
         [0035]    Referring now to also to  FIG. 2 , the diagnostic display  18  may display an EEG activity graph  20  providing stored and latest data in the form of a baseline curve  22  and a latest curve  24 , both showing EEG activity by a same patient aligned to the event time. Generally, the baseline curve  22  represents generally EEG activity before treatment or before a change in treatment by the method of the present invention and the latest curve  24  represents generally current EEG measurements after a predetermined length of treatment by the method of the present invention. Both curves  22  and  24  reflect EEG activity as aligned to a time zero being the event time of the change of display on the display screen  12  described above. Generally, successful treatment by the method of the present invention will produce substantially greater variability in latest curve  24  with respect to baseline curve  22 , the greater variability equating to decreased sensory latency. 
         [0036]    An oculomotor testing system  10  of a type suitable for the present invention is commercially available from Diopsys of Pinebrook, N.J. and is described in multiple U.S. patents including Pat. Nos.: 6,475,162; 7,578,795; 8,083,354 and 8,100,533 hereby incorporated by reference. 
         [0037]    Referring now also to  FIG. 3 , a Fourier transform of curves  22  and  24  may be performed to provide spectral curves  26  and  28 , respectively. As is understood in the art, a Fourier transform produces a frequency spectra, in this case an EEG power versus frequency in hertz. The power spectra may be divided into a theta band  30  of frequency approximately 7 to 10 hertz and a beta band  32  of frequency from approximately 16 to 20 hertz. A ratio of the integral of power within these bands (for example for the first 100 ms of curves  22  and  24 ) provides a theta beta ratio presenting a quantifiable indication of sensory latency. In the example of  FIG. 3 , for curve  26  being based on baseline curve  22  before treatment by the present invention, the theta beta ratio is 4.1. In contrast, for the curve  28  based on curve  24 , the theta beta ratio is 2.25. Generally the present invention will endeavor to locate tactile stimuli on the patient to reduce sensory latency and to lower the theta beta range to a practical minimum and in any event less than three. 
         [0038]    Referring now to  FIGS. 4 and 5 , a convenient source of tactile stimulation is acupressure patches  40  providing, for example, a small magnetic or un-magnetized spherical metal bead  42  (for example stainless steel, gold plated steel, and titanium) typically greater than one millimeter in diameter and often from 1.5 to 2 millimeters in diameter and preferably at least two millimeters in diameter. The bead  42  or multiple beads  42  may be held against the skin  44  by means of an adhesive patch  46  providing, for example, a flexible vinyl or fabric backing layer  48  having an adhesive  50  placed on its lower side toward the skin  44  to hold the bead  42  against the skin  44  in the manner of an adhesive bandage. Pressure by the backing layer  48  on the bead  42 , periodic pressing on the bead  42  by the patient, and inertial forces on the bead  42  provide tactile stimulation at the location of the bead  42 . Beads of this type are generally available in the commercial market for other acupressure purposes, for example, from Lhasa OMS, Inc. of Weymouth, Mass. 
         [0039]    Referring now to  FIGS. 6-9 , the present inventors have identified a number of locations for placement of the acupressure patches  40  that appear to provide efficacy in the present method although this list is not intended to be exhaustive. As shown in  FIG. 6 , a patch  52  of three beads  42  may be placed at a distance  54  approximately three finger widths beneath the hand  56  on the inside of the wrist  58  extending across the wrist  58 . 
         [0040]    Referring to  FIG. 7 , individual beads  42  may be placed at an apex of the outer ear helix  60  (as shown by bead  42   a ) or in the pocket  61  of the ear  62  (scapha) directly below that point of bead  42   a  or bead  42   b  or in a cluster of five beads  42   c  on the scalp  64  behind the ear  62 . 
         [0041]    Referring to  FIG. 8 , a patch  52  holding three beads  42  and similar to the patch described with respect to  FIG. 6  may be placed on the front of the patient&#39;s leg below the knee by a distance  66  of approximately four finger widths. 
         [0042]    Referring to  FIG. 9 , bilaterally symmetric pairs of beads  42   a  may be placed on the bony ridge between a patient&#39;s eyebrows, or between the patient&#39;s eyes on either side of the bridge of the nose as indicated by beads  42   b  or on the bony ridge beneath the patient&#39;s eyes above the nostrils as indicated by beads  42   c.    
         [0043]    Referring now to  FIG. 10 , long-term tactile stimulation in the region of the ear may be provided by glasses  70  having added downward extensions  72  from the earpieces  74  of the glasses  70 , so that the downward extensions fit tightly against a rear surface of the outer ear (not shown). The front of these downward extensions  72  may be studded bead-like projections  76  to provide tactile stimulation against the outer surface of the rear of the individuals ears. A general framework for the downward extensions  72  may be provided by a Croakies™ Reax Device commercially available from Croakies of Bozeman, Mont. 
         [0044]    Referring now to  FIG. 11 , the present invention provides for measurement of a baseline sensory evoked potential as indicated by process block  80  prior to treatment. At succeeding process block  82  tactile stimulation is applied to the patient&#39;s skin in particular locations, for example, selected from those described above. The benefit of the present invention appears to be lost when the stimulation ends and accordingly the stimulation is preferably substantially continuous over 24 hours. 
         [0045]    After a period of time, for example, at least 24 hours, a comparison sensory evoked potential measurement may be made as indicated by process block  84 . Improvements in threshold latency may be determined as indicated by decision block  86  between the baseline measurement of process block  80  and the latest comparison sensory evoked potential measurement of process block  84 . If a threshold level of decreased sensory latency has been reached or a minimum predetermined number of iterations in adjusting the position of this tactile stimulation, the process is done as indicated by process block  88 . Otherwise, as indicated by process block  90 , the location and/or number of the tactile stimulation locations is changed or increased and the process loops back to process block  84  for a new comparison between the previous measurement at process block  82  and the latest measurements at process block  82 . It will be appreciated that in the event of an increase in sensory latency, comparisons with the previous best decrease in sensory latency will be used in a hill climbing fashion. 
         [0046]    While it will be appreciated that clinical evaluation of nystagmus symptoms per process block  84  with respect to location of the beads is desirable, the invention also contemplates that the acupressure patches  40  may be located and adjusted in a home kit providing the acupressure patches  40  and instructions for trying different locations for the acupressure patches  40  based on periodic self-assessment of improvement in nystagmus symptoms, for example, using an ability to track moving dots provided on a computer display or prerecorded video program. 
         [0047]    In one embodiment, the oculomotor testing system  10  may be combined with automatic electrical stimulation provided by low-power electrical signals applied to the skin in multiple locations. Electrical stimulation allows machine control of process block  82  permitting semiautomatic identification of stimulation points by cycling through different stimulation points while measuring sensory evoked potentials to minimize sensory latency. 
         [0048]    In one embodiment, the oculomotor testing system  10  may be implemented in a low-cost version through the use of commercial brain monitors such as are available commercially under the tradename NeuroSky Mindset or Mindwave EEG monitors from NeuroSky of San Jose Calif. as well as other vendors. These devices provide an output that directly indicates amplitude of standard brainwave bands including the band of theta waves and beta waves that may be used directly calculate the theta beta ratio for an individual as described above. Alternatively, the raw EEG signals may be processed directly, also using the techniques described described above, or after spectral analysis also provided by devices themselves as a standard feature. The use of a commercial brainwave monitor of this type significantly lowers the cost of this system allowing it to be practical for home use. It is believed that a general evaluation of the EEG signals in any of the above-described methods may provide for the necessary guidance with regard to the location of the tactile stimuli without the need for synchronized visual or audio stimulation. 
         [0049]    The present invention also contemplates that it may be used with other sensory evoked potential measuring systems, for example those that substitute an audio signal for the visual signal provided by the oculomotor testing system  10 . 
         [0050]    It is believed that the invention may be applied to other disorders related to sensory latency, for example, attention deficit disorders as noted in: Yordanova J, Heinrich H, Kolev V, Rothenberger A, “Increased event-related theta activity as a psychophysiological marker of comorbidity in children with tics and attention-deficit/hyperactivity disorders”, Neuroimage. 2006 Aug 15; 32(2): 940-55, Epub (2006); and Oades R D, Dittmann-Balcar A, Schepker R, Eggers C, Zerbin D, “Auditory event-related potentials (ERPs) and mismatch negativity (MMN) in healthy children and those with attention-deficit or tourette/tic symptoms”, Biol Psychol. (1996) 12; 43(2):163-85. 
         [0051]    Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. 
         [0052]    When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0053]    References to a computer can be understood to include one or more microprocessors that can communicate in a stand-alone and/or a distributed environment(s), and can thus be configured to communicate via wired or wireless communications with other processors, where such one or more processor can be configured to operate on one or more processor-controlled devices that can be similar or different devices. Furthermore, references to memory, unless otherwise specified, can include one or more processor-readable and accessible memory elements and/or components that can be internal to the processor-controlled device, external to the processor-controlled device, and can be accessed via a wired or wireless network. 
         [0054]    It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications, are hereby incorporated herein by reference in their entireties.