Stimulation for treating and diagnosing conditions

Abstract

A method is provided for facilitating a diagnosis of a condition of a subject, including applying a current to a site of the subject selected from the list consisting of: a sphenopalatine ganglion (SPG) of the subject, and a neural tract originating in or leading to the SPG, and configuring the current to increase conductance of molecules from brain tissue of the subject through a blood brain barrier (BBB) of the subject into a systemic blood circulation of the subject. The method also includes sensing a quantity of the molecules from a site outside of the brain of the subject, following initiation of application of the current.

1 . A method for facilitating a diagnosis of a condition of a subject, comprising: 
 applying a current to a site of the subject selected from the list consisting of: a sphenopalatine ganglion (SPG) of the subject, and a neural tract originating in or leading to the SPG;    configuring the current to increase conductance of molecules from brain tissue of the subject through a blood brain barrier (BBB) of the subject into a systemic blood circulation of the subject; and    sensing a quantity of the molecules from a site outside of the brain of the subject, following initiation of application of the current.    
   
   
       2 . The method according to  claim 1 , wherein sensing the quantity of the molecules comprises sampling a fluid of the subject selected from the list consisting of: blood, plasma, serum, ascites fluid, and urine.  
   
   
       3 . The method according to  claim 1 , comprising determining a diagnostically-relevant parameter responsive to sensing the quantity of the molecules.  
   
   
       4 . The method according to  claim 1 , comprising administering a hyperosmolarity-inducing agent to the subject at a dosage sufficient to augment an increase in conductance of the molecules caused by the application of the current.  
   
   
       5 . The method according to  claim 1 , comprising inducing a state of dehydration of the subject, of an extent sufficient to augment an increase in conductance of the molecules caused by the application of the current.  
   
   
       6 . The method according to  claim 1 , comprising administering an agent to the subject that modulates synthesis or metabolism of nitric-oxide (NO) in blood vessels of the brain, at a dosage sufficient to augment an increase in conductance of the molecules caused by the application of the current.  
   
   
       7 . The method according to  claim 1 , wherein applying the current comprises implanting an electrode at the site, designated to remain in the subject for a period greater than about one month.  
   
   
       8 . The method according to  claim 1 , wherein applying the current comprises implanting an electrode at the site, designated to remain in the subject for a period less than about one week.  
   
   
       9 . The method according to  claim 1 , wherein applying the current comprises implanting a control unit in a nasal cavity of the subject.  
   
   
       10 . The method according to  claim 1 , wherein applying the current comprises implanting a control unit at a lower side of a bony palate of the subject.  
   
   
       11 . The method according to  claim 1 , wherein applying the current comprises implanting one or more electrodes in a nasal cavity of the subject.  
   
   
       12 . The method according to  claim 11 , wherein implanting comprises inserting a flexible electrode through a nostril of the subject.  
   
   
       13 . A method for facilitating a diagnosis of a condition of a central nervous system (CNS) of a subject, comprising: 
 stimulating sphenopalatine ganglion (SPG)-related tissue of the subject by applying an electrical signal to the SPG-related tissue, the SPG-related tissue selected from: an SPG of the subject and nerve fibers of the subject which are directly anatomically connected to the SPG; and    configuring the stimulation so as to cause an increase in molecular passage between the CNS and another body compartment of the subject, so as to facilitate the diagnosis of the CNS condition.    
   
   
       14 . The method according to  claim 13 , comprising measuring a constituent of the other body compartment.  
   
   
       15 . The method according to  claim 14 , wherein stimulating the SPG-related tissue comprises directly stimulating the SPG.  
   
   
       16 . The method according  claim 14 , wherein the other body compartment includes a systemic blood circulation of the subject, and wherein configuring the stimulation comprises configuring the stimulation so as to cause the increase in molecular passage between the CNS and the systemic blood circulation.  
   
   
       17 . The method according to  claim 14 , wherein the other body compartment includes plasma of the subject, and wherein configuring the stimulation comprises configuring the stimulation so as to cause the increase in molecular passage between the CNS and the plasma.  
   
   
       18 . The method according to  claim 14 , wherein the other body compartment includes serum of the subject, and wherein configuring the stimulation comprises configuring the stimulation so as to cause the increase in molecular passage between the CNS and the serum.  
   
   
       19 . The method according to  claim 14 , wherein the other body compartment is ascites of the subject, and wherein configuring the stimulation comprises configuring the stimulation so as to cause the increase in molecular passage between the CNS and the ascites.  
   
   
       20 . The method according to  claim 14 , wherein the CNS condition includes Parkinson's disease, and wherein configuring the stimulation comprises configuring the stimulation so as to facilitate the diagnosis of the Parkinson's disease.  
   
   
       21 . The method according to  claim 14 , wherein the CNS condition includes epilepsy, and wherein configuring the stimulation comprises configuring the stimulation so as to facilitate the diagnosis of the epilepsy.  
   
   
       22 . The method according to  claim 14 , wherein the CNS condition includes amyotrophic lateral sclerosis (ALS), and wherein configuring the stimulation comprises configuring the stimulation so as to facilitate the diagnosis of the ALS.  
   
   
       23 . The method according to  claim 14 , wherein the CNS condition includes multiple sclerosis (MS), and wherein configuring the stimulation comprises configuring the stimulation so as to facilitate the diagnosis of the MS.  
   
   
       24 . The method according to  claim 14 , wherein stimulating the SPG-related tissue comprises implanting an electrode at the site, designated to remain in the subject for a period greater than about one month.  
   
   
       25 . The method according to  claim 14 , wherein stimulating the SPG-related tissue comprises implanting an electrode at the site, designated to remain in the subject for a period less than about one week.  
   
   
       26 . The method according to  claim 14 , wherein stimulating the SPG-related tissue comprises implanting a control unit in a nasal cavity of the subject.  
   
   
       27 . The method according to  claim 14 , wherein stimulating the SPG-related tissue comprises implanting a control unit at a lower side of a bony palate of the subject.  
   
   
       28 . The method according to  claim 14 , comprising correlating an abnormal concentration of the constituent to a pathology of the CNS condition.  
   
   
       29 . The method according to  claim 14 , wherein the constituent is selected from the group consisting of: a protein, a honnone, an antibody, an electrolyte, a neuropeptide, and an enzyme, and wherein measuring the constituent comprises measuring the selected constituent.  
   
   
       30 . A method for facilitating a diagnosis of a condition of a central nervous system (CNS) of a subject, comprising: 
 stimulating sphenopalatine ganglion (SPG)-related tissue of the subject by applying an electrical signal to the SPG-related tissue, the SPG-related tissue selected from: an SPG of the subject and nerve fibers of the subject which are directly anatomically connected to the SPG; and    configuring the stimulation so as to cause an increase in molecular passage between cerebrospinal fluid (CSF) of the subject and another body fluid of the subject, so as to facilitate the diagnosis of the CNS condition.    
   
   
       31 . The method according to  claim 30 , comprising measuring a constituent of the other body fluid.  
   
   
       32 . The method according to  claim 31 , wherein stimulating the SPG-related tissue comprises directly stimulating the SPG.  
   
   
       33 . The method according to  claim 31 , comprising correlating an abnormal concentration of the constituent to a pathology of the CNS condition.  
   
   
       34 . The method according to  claim 31 , wherein the constituent is selected from the group consisting of: a protein, a hormone, an antibody, an electrolyte, a neuropeptide, and an enzyme, and wherein measuring the constituent comprises measuring the selected constituent.  
   
   
       35 . The method according to  claim 31 , wherein the other body fluid is selected from the list consisting of: whole blood, plasma, serum, and ascites, and wherein measuring the constituent comprises sampling the selected fluid.  
   
   
       36 . The method according to  claim 31 , wherein measuring the constituent comprises extracting the other body fluid from tissue of the subject.  
   
   
       37 . The method according to  claim 31 , wherein applying the current comprises implanting an electrode at the site, designated to remain in the subject for a period greater than about one month.  
   
   
       38 . The method according to  claim 31 , wherein applying the current comprises implanting an electrode at the site, designated to remain in the subject for a period less than about one week.  
   
   
       39 . The method according to  claim 31 , wherein applying the current comprises implanting a control unit in a nasal cavity of the subject.  
   
   
       40 . The method according to  claim 31 , wherein applying the current comprises implanting a control unit at a lower side of a bony palate of the subject.  
   
   
       41 . The method according to  claim 31 , wherein measuring the constituent comprises measuring a plurality of constituents.  
   
   
       42 . The method according to  claim 41 , comprising determining a diagnostic result according to the interrelation between concentrations of the constituents.  
   
   
       43 . A method for facilitating a diagnosis of a condition of a central nervous system (CNS) of a subject, comprising: 
 stimulating sphenopalatine ganglion (SPG)-related tissue of the subject by applying an electrical signal to the SPG-related tissue, the SPG-related tissue selected from: an SPG of the subject and nerve fibers of the subject which are directly anatomically connected to the SPG; and    configuring the stimulation so as to cause an increase in molecular passage between cerebrospinal fluid (CSF) of the subject and a tissue of the subject, so as to facilitate a diagnosis of the CNS condition.    
   
   
       44 . The method according  claim 43 , comprising measuring a constituent of the tissue.  
   
   
       45 . The method according to  claim 44 , wherein stimulating the SPG-related tissue comprises directly stimulating the SPG.  
   
   
       46 . The method according to  claim 44 , comprising correlating an abnormal concentration of the constituent to a pathology of the CNS condition.  
   
   
       47 . The method according to  claim 44 , wherein the constituent is selected from the group consisting of: a protein, a hormone, an antibody, an electrolyte, a neuropeptide, and an enzyme, and wherein measuring the constituent comprises measuring the selected constituent.  
   
   
       48 . The method according to  claim 44 , wherein measuring the constituent comprises measuring a plurality of constituents of the tissue.  
   
   
       49 . The method according to  claim 48 , comprising determining a diagnostic result according to the interrelation between concentrations of the constituents of the tissue.  
   
   
       50 . A method for facilitating a diagnosis of a condition of a central nervous system (CNS) of a subject, comprising: 
 applying an electrical signal to at least one site of the subject, the site selected from the list consisting of: a sphenopalatine ganglion (SPG) of the subject, an anterior ethmoidal nerve of the subject, a posterior ethmoidal nerve of the subject, a communicating branch between an anterior ethmoidal nerve and a retro-orbital branch of an SPG of the subject, a communicating branch between a posterior ethmoidal nerve and a retro-orbital branch of an SPG of the subject, a greater palatine nerve of the subject, a lesser palatine nerve of the subject, a sphenopalatine nerve of the subject, a communicating branch between a maxillary nerve and an SPG of the subject, a nasopalatine nerve of the subject, a posterior nasal nerve of the subject, an infraorbital nerve of the subject, an otic ganglion of the subject, an afferent fiber going into the otic ganglion of the subject, an efferent fiber going out of the otic ganglion of the subject, a vidian nerve of the subject, a greater superficial petrosal nerve of the subject, and a lesser deep petrosal nerve of the subject; and    configuring the signal so as to cause an increase in molecular passage between the CNS and another body compartment of the subject, so as to facilitate a diagnosis of the CNS condition.    
   
   
       51 . The method according  claim 50 , comprising measuring a constituent of the other body compartment.  
   
   
       52 . A method for facilitating a diagnosis of a condition of a central nervous system (CNS) of a subject, comprising: 
 applying an electrical signal to at least one site of the subject, the site selected from the list consisting of: a sphenopalatine ganglion (SPG) of the subject, an anterior ethmoidal nerve of the subject, a posterior ethmoidal nerve of the subject, a communicating branch between an anterior ethmoidal nerve and a retro-orbital branch of an SPG of the subject, a communicating branch between a posterior ethmoidal nerve and a retro-orbital branch of an SPG of the subject, a greater palatine nerve of the subject, a lesser palatine nerve of the subject, a sphenopalatine nerve of the subject, a communicating branch between a maxillary nerve and an SPG of the subject, a nasopalatine nerve of the subject, a posterior nasal nerve of the subject, an infraorbital nerve of the subject, an otic ganglion of the subject, an afferent fiber going into the otic ganglion of the subject, an efferent fiber going out of the otic ganglion of the subject, a vidian nerve of the subject, a greater superficial petrosal nerve of the subject, and a lesser deep petrosal nerve of the subject; and    configuring the signal so as to cause an increase in molecular passage between cerebrospinal fluid (CSF) of the subject and another body fluid of the subject, so as to facilitate a diagnosis of the CNS condition.    
   
   
       53 . The method according  claim 52 , comprising measuring a constituent of the other body fluid.  
   
   
       54 . A method for facilitating a diagnosis of a condition of a central nervous system (CNS) of a subject, comprising: 
 applying an electrical signal to at least one site of the subject, the site selected from the list consisting of: a sphenopalatine ganglion (SPG) of the subject, an anterior ethmoidal nerve of the subject, a posterior ethmoidal nerve of the subject, a communicating branch between an anterior ethmoidal nerve and a retro-orbital branch of an SPG of the subject, a communicating branch between a posterior ethmoidal nerve and a retro-orbital branch of an SPG of the subject, a greater palatine nerve of the subject, a lesser palatine nerve of the subject, a sphenopalatine nerve of the subject, a communicating branch between a maxillary nerve and an SPG of the subject, a nasopalatine nerve of the subject, a posterior nasal nerve of the subject, an infraorbital nerve of the subject, an otic ganglion of the subject, an afferent fiber going into the otic ganglion of the subject, an efferent fiber going out of the otic ganglion of the subject, a vidian nerve of the subject, a greater superficial petrosal nerve of the subject, and a lesser deep petrosal nerve of the subject; and    configuring the signal so as to cause an increase in molecular passage between cerebrospinal fluid (CSF) of the subject and a tissue of the subject, so as to facilitate a diagnosis of the CNS condition.    
   
   
       55 . The method according  claim 54 , comprising measuring a constituent of the tissue.  
   
   
       56 . A method for facilitating a diagnosis of a condition of a central nervous system (CNS) of a subject, the method comprising: 
 stimulating at least one site of the subject by applying an electrical current to the site, the site selected from the list consisting of: a sphenopalatine ganglion (SPG) of the subject, an anterior ethmoidal nerve of the subject, a posterior ethmoidal nerve of the subject, a communicating branch between the anterior ethmoidal nerve and the SPG, a communicating branch between the posterior ethmoidal nerve and the SPG, a nerve of the pterygoid canal of the subject, a greater palatine nerve of the subject, a lesser palatine nerve of the subject, a sphenopalatine nerve of the subject, a communicating branch between a maxillary nerve of the subject and the SPG, a nasopalatine nerve of the subject, a posterior nasal nerve of the subject, an infraorbital nerve of the subject, an otic ganglion of the subject, an afferent fiber going into the otic ganglion, and an efferent fiber going out of the otic ganglion;    configuring the stimulation so as to cause an increase in molecular passage between the CNS and another body compartment of the subject;    taking a sample from the body compartment; and    determining a level of a constituent of the sample, so as to facilitate the diagnosis of the CNS condition.    
   
   
       57 . The method according to  claim 56 , wherein the CNS condition includes a neurodegenerative condition, and wherein determining the level of the constituent comprises determining the level of the constituent so as to facilitate the diagnosis of the neurodegenerative condition.  
   
   
       58 . The method according to  claim 56 , wherein the CNS condition includes a neoplastic process, and wherein determining the level of the constituent comprises determining the level of the constituent so as to facilitate the diagnosis of the neoplastic process.  
   
   
       59 . The method according to  claim 56 , wherein the CNS condition is selected from the list consisting of: an immune-related disorder and an autoimmune-related disorder, and wherein determining the level of the constituent comprises determining the level of the constituent so as to facilitate the diagnosis of the selected condition.  
   
   
       60 . The method according to  claim 56 , wherein the CNS condition includes a CNS inflammatory process, and wherein determining the level of the constituent comprises determining the level of the constituent so as to facilitate the diagnosis of the CNS inflammatory process.  
   
   
       61 . The method according to  claim 56 , comprising interpreting a low value of the level as indicative of an increased likelihood that the subject suffers from the CNS condition.  
   
   
       62 . The method according to  claim 61 , comprising interpreting a high value of the level as indicative of a decreased likelihood that the subject suffers from the CNS condition.  
   
   
       63 . The method according to  claim 61 , wherein the body compartment includes a systemic blood circulation of the subject, and wherein configuring the stimulation comprises configuring the stimulation so as to cause the increase in molecular passage between the CNS and the systemic blood circulation.  
   
   
       64 . The method according to  claim 61 , wherein the body compartment includes plasma of the subject, and wherein configuring the stimulation comprises configuring the stimulation so as to cause the increase in molecular passage between the CNS and the plasma.  
   
   
       65 . The method according to  claim 61 , wherein the body compartment includes serum of the subject, and wherein configuring the stimulation comprises configuring the stimulation so as to cause the increase in molecular passage between the CNS and the serum.  
   
   
       66 . The method according to  claim 61 , wherein the body compartment is ascites of the subject, and wherein configuring the stimulation comprises configuring the stimulation so as to cause the increase in molecular passage between the CNS and the ascites.  
   
   
       67 . The method according to  claim 61 , wherein the site includes the SPG, and wherein stimulating the site comprises stimulating the SPG.  
   
   
       68 . The method according to  claim 61  wherein the CNS condition includes Alzheimer's disease, and wherein interpreting the low value comprises interpreting the low value as indicative of the increased likelihood that the subject suffers from Alzheimer's disease.  
   
   
       69 . The method according to  claim 68 , wherein the constituent includes amyloid-beta peptide, and wherein determining the level of the constituent comprises determining the level of the amyloid-beta peptide.  
   
   
       70 . The method according to  claim 68 , wherein the constituent includes presenilin-1, and wherein determining the level of the constituent comprises determining the level of the presenilin-1.  
   
   
       71 . A method for facilitating a diagnosis of a condition of a central nervous system (CNS) of a subject, the method comprising: 
 stimulating at least one site of the subject selected from the list consisting of: a sphenopalatine ganglion (SPG) of the subject, an anterior ethmoidal nerve of the subject, a posterior ethmoidal nerve of the subject, a communicating branch between the anterior ethmoidal nerve and the SPG, a communicating branch between the posterior ethmoidal nerve and the SPG, a nerve of the pterygoid canal of the subject, a greater palatine nerve of the subject, a lesser palatine nerve of the subject, a sphenopalatine nerve of the subject, a communicating branch between a maxillary nerve of the subject and the SPG, a nasopalatine nerve of the subject, a posterior nasal nerve of the subject, an infraorbital nerve of the subject, an otic ganglion of the subject, an afferent fiber going into the otic ganglion, and an efferent fiber going out of the otic ganglion;    configuring the stimulation so as to cause an increase in molecular passage between the CNS and another body compartment of the subject;    taking a sample from the body compartment; and    determining a level of a constituent of the sample, so as to facilitate the diagnosis of the CNS condition.    
   
   
       72 . The method according to  claim 71 , wherein the CNS condition includes a neurodegenerative condition, and wherein determining the level of the constituent comprises determining the level of the constituent so as to facilitate the diagnosis of the neurodegenerative condition.  
   
   
       73 . The method according to  claim 71 , wherein the CNS condition includes a neoplastic process, and wherein determining the level of the constituent comprises determining the level of the constituent so as to facilitate the diagnosis of the neoplastic process.  
   
   
       74 . The method according to  claim 71 , wherein the CNS condition is selected from the list consisting of: an immune-related disorder and an autoimmune-related disorder, and wherein determining the level of the constituent comprises determining the level of the constituent so as to facilitate the diagnosis of the selected condition.  
   
   
       75 . The method according to  claim 71 , wherein the CNS condition includes a CNS inflammatory process, and wherein determining the level of the constituent comprises determining the level of the constituent so as to facilitate the diagnosis of the CNS inflammatory process.  
   
   
       76 . The method according to  claim 71 , comprising interpreting a low value of the level as indicative of an increased likelihood that the subject suffers from the CNS condition.  
   
   
       77 . The method according to  claim 76 , comprising interpreting a high value of the level as indicative of a decreased likelihood that the subject suffers from the CNS condition.  
   
   
       78 . The method according to  claim 76 , wherein stimulating comprises applying magnetic stimulation to the site.  
   
   
       79 . The method according to  claim 76 , wherein stimulating comprises applying electromagnetic stimulation to the site.  
   
   
       80 . The method according to  claim 76 , wherein stimulating comprises applying chemical stimulation to the site.  
   
   
       81 . The method according to  claim 76 , wherein stimulating comprises applying mechanical stimulation to the site.  
   
   
       82 . The method according to  claim 76 , wherein the body compartment includes a systemic blood circulation of the subject, and wherein configuring the stimulation comprises configuring the stimulation so as to cause the increase in molecular passage between the CNS and the systemic blood circulation.  
   
   
       83 . The method according to  claim 76 , wherein the body compartment includes plasma of the subject, and wherein configuring the stimulation comprises configuring the stimulation so as to cause the increase in molecular passage between the CNS and the plasma.  
   
   
       84 . The method according to  claim 76 , wherein the body compartment includes serum of the subject, and wherein configuring the stimulation comprises configuring the stimulation so as to cause the increase in molecular passage between the CNS and the serum.  
   
   
       85 . The method according to  claim 76 , wherein the body compartment is ascites of the subject, and wherein configuring the stimulation comprises configuring the stimulation so as to cause the increase in molecular passage between the CNS and the ascites.  
   
   
       86 . The method according to  claim 76 , wherein the site includes the SPG, and wherein stimulating the site comprises stimulating the SPG.  
   
   
       87 . The method according to  claim 76 , wherein the CNS condition includes Alzheimer's disease, and wherein interpreting the low value comprises interpreting the low value as indicative of the increased likelihood that the subject suffers from Alzheimer's disease.  
   
   
       88 . The method according to  claim 87 , wherein the constituent includes amyloid-beta peptide, and wherein determining the level of the constituent comprises determining the level of the amyloid-beta peptide.  
   
   
       89 . The method according to  claim 87 , wherein the constituent includes presenilin-1, and wherein determining the level of the constituent comprises determining the level of the presenilin-1.  
   
   
       90 . A method for treating a condition of a central nervous system (CNS) of a subject, comprising: 
 applying a current to a site of the subject selected from the list consisting of: a sphenopalatine ganglion (SPG) of the subject, and a neural tract originating in or leading to the SPG;    configuring the current to increase clearance of molecules from brain tissue of the subject through a blood brain barrier (BBB) of the subject into a systemic blood circulation of the subject, so as to treat the CNS condition.    
   
   
       91 . The method according to  claim 90 , wherein the molecules include a toxin, and wherein configuring the current comprises configuring the current to increase the clearance of the toxin from the brain tissue, so as to treat the CNS condition.  
   
   
       92 . The method according to  claim 90 , wherein applying the current comprises implanting an electrode at the site, designated to remain in the subject for a period greater than about one month.  
   
   
       93 . The method according to  claim 90 , wherein applying the current comprises implanting an electrode at the site, designated to remain in the subject for a period less than about one week.  
   
   
       94 . The method according to  claim 90 , wherein applying the current comprises implanting a control unit in a nasal cavity of the subject.  
   
   
       95 . The method according to  claim 90 , wherein applying the current comprises implanting a control unit at a lower side of a bony palate of the subject.  
   
   
       96 . A method for treating a condition of a central nervous system (CNS) of a subject, comprising: 
 stimulating sphenopalatine ganglion (SPG)-related tissue of the subject by applying an electrical signal to the SPG-related tissue, the SPG-related tissue selected from: an SPG of the subject and nerve fibers of the subject which are directly anatomically connected to the SPG; and    configuring the stimulation so as to cause an increase in clearance of a neurotoxic compound from a brain of the subject through a blood brain barrier (BBB) of the subject to a systemic blood circulation of the subject, so as to treat the CNS condition.    
   
   
       97 . The method according to  claim 96 , wherein stimulating the SPG-related tissue comprises directly stimulating the SPG.  
   
   
       98 . A method for treating a condition of a central nervous system (CNS) of a subject, comprising: 
 stimulating sphenopalatine ganglion (SPG)-related tissue of the subject by presenting an odorant to an air passage of the subject, the SPG-related tissue selected from:    an SPG of the subject and nerve fibers of the subject which are directly anatomically connected to the SPG; and    configuring the stimulation so as to cause an increase in clearance of a neurotoxic compound from a brain of the subject through a blood brain barrier (BBB) of the subject to a systemic blood circulation of the subject, so as to treat the CNS condition.    
   
   
       99 . A method for treating a condition of a central nervous system (CNS) of a subject, comprising: 
 stimulating sphenopalatine ganglion (SPG)-related tissue of the subject by applying an electrical signal to the SPG-related tissue, the SPG-related tissue selected from: an SPG of the subject and nerve fibers of the subject which are directly anatomically connected to the SPG; and    configuring the stimulation so as to cause an increase in clearance of a neurotoxic compound from cerebrospinal fluid (CSF) of the subject through a blood brain barrier (BBB) of the subject to a systemic blood circulation of the subject, so as to treat the CNS condition.    
   
   
       100 . The method according to  claim 99 , wherein stimulating the SPG-related tissue comprises directly stimulating the SPG.  
   
   
       101 . A method for treating a condition of a central nervous system (CNS) of a subject, comprising: 
 stimulating sphenopalatine ganglion (SPG)-related tissue of the subject by presenting an odorant to an air passage of the subject, the SPG-related tissue selected from:    an SPG of the subject and nerve fibers of the subject which are directly anatomically connected to the SPG; and    configuring the stimulation so as to cause an increase in clearance of a neurotoxic compound from cerebrospinal fluid (CSF) of the subject through a blood brain barrier (BBB) of the subject to a systemic blood circulation of the subject, so as to treat the CNS condition.    
   
   
       102 . Apparatus for facilitating a diagnosis of a condition of a subject, comprising a stimulator adapted to: 
 apply a current to a site of the subject selected from the list consisting of: a sphenopalatine ganglion (SPG) of the subject, and a neural tract originating in or leading to the SPG, and    configure the current to increase conductance of molecules from brain tissue of the subject through a blood brain barrier (BBB) of the subject into a systemic blood circulation of the subject, so as to facilitate the diagnosis of the condition.    
   
   
       103 . The apparatus according to  claim 102 , wherein the stimulator is adapted to directly stimulate the SPG.  
   
   
       104 . The apparatus according to  claim 102 , wherein the apparatus is adapted to measure a constituent of the other body compartment.  
   
   
       105 . Apparatus for facilitating a diagnosis of a condition of a central nervous system (CNS) of a subject, comprising a stimulator adapted to: 
 stimulate sphenopalatine ganglion (SPG)-related tissue of the subject by applying an electrical signal to the SPG-related tissue, the SPG-related tissue selected from: an SPG of the subject and nerve fibers of the subject which are directly anatomically connected to the SPG, and    configure the stimulation so as to cause an increase in molecular passage between the CNS and another body compartment of the subject, so as to facilitate the diagnosis of the CNS condition.    
   
   
       106 . The apparatus according to  claim 105 , wherein the stimulator is adapted to directly stimulate the SPG.  
   
   
       107 . The apparatus according to  claim 105 , wherein the apparatus is adapted to measure a constituent of the other body compartment.  
   
   
       108 . The apparatus according to  claim 107 , wherein the other body compartment includes a systemic blood circulation of the subject, and wherein the apparatus is adapted to measure the constituent of the systemic blood circulation.  
   
   
       109 . The apparatus according to  claim 107 , wherein the other body compartment includes plasma of the subject, and wherein the apparatus is adapted to measure the constituent of the plasma.  
   
   
       110 . The apparatus according to  claim 107 , wherein the other body compartment includes serum of the subject, and wherein the apparatus is adapted to measure the constituent of the serum.  
   
   
       111 . The apparatus according to  claim 107 , wherein the other body compartment is ascites of the subject, and wherein the apparatus is adapted to measure the constituent of the ascites.  
   
   
       112 . Apparatus for facilitating a diagnosis of a condition of a central nervous system (CNS) of a subject, comprising a stimulator adapted to: 
 stimulate sphenopalatine ganglion (SPG)-related tissue of the subject by applying an electrical signal to the SPG-related tissue, the SPG-related tissue selected from: an SPG of the subject and nerve fibers of the subject which are directly anatomically connected to the SPG, and    configure the stimulation so as to cause an increase in molecular passage between cerebrospinal fluid (CSF) of the subject and another body fluid of the subject, so as to facilitate the diagnosis of the CNS condition.    
   
   
       113 . The apparatus according to  claim 112 , wherein the stimulator is adapted to directly stimulate the SPG.  
   
   
       114 . The apparatus according to  claim 112 , wherein the apparatus is adapted to measure a constituent of the other body fluid.  
   
   
       115 . Apparatus for facilitating a diagnosis of a condition of a central nervous system (CNS) of a subject, comprising a stimulator adapted to: 
 stimulate sphenopalatine ganglion (SPG)-related tissue of the subject by applying an electrical signal to the SPG-related tissue, the SPG-related tissue selected from: an SPG of the subject and nerve fibers of the subject which are directly anatomically connected to the SPG, and configure the stimulation so as to cause an increase in molecular passage between cerebrospinal fluid (CSF) of the subject and a tissue of the subject, so as to facilitate the diagnosis of the CNS condition.    
   
   
       116 . The apparatus according to  claim 115 , wherein the apparatus is adapted to directly stimulate the SPG.  
   
   
       117 . The apparatus according to  claim 115 , wherein the apparatus is adapted to measure a constituent of the tissue.  
   
   
       118 . Apparatus for facilitating a diagnosis of a condition of a central nervous system (CNS) of a subject, comprising a stimulator adapted to: 
 apply an electrical signal to at least one site of the subject, the site selected from the list consisting of: a sphenopalatine ganglion (SPG) of the subject, an anterior ethmoidal nerve of the subject, a posterior ethmoidal nerve of the subject, a communicating branch between an anterior ethmoidal nerve and a retro-orbital branch of an SPG of the subject, a communicating branch between a posterior ethmoidal nerve and a retro-orbital branch of an SPG of the subject, a greater palatine nerve of the subject, a lesser palatine nerve of the subject, a sphenopalatine nerve of the subject, a communicating branch between a maxillary nerve and an SPG of the subject, a nasopalatine nerve of the subject, a posterior nasal nerve of the subject, an infraorbital nerve of the subject, an otic ganglion of the subject, an afferent fiber going into the otic ganglion of the subject, an efferent fiber going out of the otic ganglion of the subject, a vidian nerve of the subject, a greater superficial petrosal nerve of the subject, and a lesser deep petrosal nerve of the subject, and configure the signal so as to cause an increase in molecular passage between the CNS and another body compartment of the subject, so as to facilitate the diagnosis of the CNS condition.    
   
   
       119 . The apparatus according to  claim 118 , wherein the apparatus is adapted to measure a constituent of the other body compartment.  
   
   
       120 . Apparatus for facilitating a diagnosis of a condition of a central nervous system (CNS) of a subject, comprising a stimulator adapted to: 
 apply an electrical signal to at least one site of the subject, the site selected from the list consisting of: a sphenopalatine ganglion (SPG) of the subject, an anterior ethmoidal nerve of the subject, a posterior ethmoidal nerve of the subject, a communicating branch between an anterior ethmoidal nerve and a retro-orbital branch of an SPG of the subject, a communicating branch between a posterior ethmoidal nerve and a retro-orbital branch of an SPG of the subject, a greater palatine nerve of the subject, a lesser palatine nerve of the subject, a sphenopalatine nerve of the subject, a communicating branch between a maxillary nerve and an SPG of the subject, a nasopalatine nerve of the subject, a posterior nasal nerve of the subject, an infraorbital nerve of the subject, an otic ganglion of the subject, an afferent fiber going into the otic ganglion of the subject, an efferent fiber going out of the otic ganglion of the subject, a vidian nerve of the subject, a greater superficial petrosal nerve of the subject, and a lesser deep petrosal nerve of the subject, and    configure the signal so as to cause an increase in molecular passage between cerebrospinal fluid (CSF) of the subject and another body fluid of the subject, so as to facilitate the diagnosis of the CNS condition.    
   
   
       121 . The apparatus according to  claim 120 , wherein the apparatus is adapted to measure a constituent of the other body fluid.  
   
   
       122 . Apparatus for facilitating a diagnosis of a condition of a central nervous system (CNS) of a subject, comprising a stimulator adapted to: 
 apply an electrical signal to at least one site of the subject, the site selected from the list consisting of: a sphenopalatine ganglion (SPG) of the subject, an anterior ethmoidal nerve of the subject, a posterior ethmoidal nerve of the subject, a communicating branch between an anterior ethmoidal nerve and a retro-orbital branch of an SPG of the subject, a communicating branch between a posterior ethmoidal nerve and a retro-orbital branch of an SPG of the subject, a greater palatine nerve of the subject, a lesser palatine nerve of the subject, a sphenopalatine nerve of the subject, a communicating branch between a maxillary nerve and an SPG of the subject, a nasopalatine nerve of the subject, a posterior nasal nerve of the subject, an infraorbital nerve of the subject, an otic ganglion of the subject, an afferent fiber going into the otic ganglion of the subject, an efferent fiber going out of the otic ganglion of the subject, a vidian nerve of the subject, a greater superficial petrosal nerve of the subject, and a lesser deep petrosal nerve of the subject, and    configure the signal so as to cause an increase in molecular passage between cerebrospinal fluid (CSF) of the subject and a tissue of the subject, so as to facilitate the diagnosis of the CNS condition.    
   
   
       123 . The apparatus according to  claim 122 , wherein the apparatus is adapted to measure a constituent of the tissue.  
   
   
       124 . Apparatus for treating a condition of a central nervous system (CNS) of a subject, comprising a stimulator adapted to: 
 stimulate sphenopalatine ganglion (SPG)-related tissue of the subject by applying an electrical signal to the SPG-related tissue, the SPG-related tissue selected from: an SPG of the subject and nerve fibers of the subject which are directly anatomically connected to the SPG, and    configure the stimulation so as to cause an increase in clearance of a neurotoxic compound from a brain of the subject through a blood brain barrier (BBB) of the subject to a systemic blood circulation of the subject, so as to treat the CNS condition.    
   
   
       125 . The apparatus according to  claim 124 , wherein the stimulator is adapted to directly stimulate the SPG.  
   
   
       126 . Apparatus for treating a condition of a central nervous system (CNS) of a subject, comprising a stimulator adapted to: 
 stimulate sphenopalatine ganglion (SPG)-related tissue of the subject by presenting an odorant to an air passage of the subject, the SPG-related tissue selected from: an SPG of the subject and nerve fibers of the subject which are directly anatomically connected to the SPG, and    configure the stimulation so as to cause an increase in clearance of a neurotoxic compound from a brain of the subject through a blood brain barrier (BBB) of the subject to a systemic blood circulation of the subject, so as to treat the CNS condition.    
   
   
       127 . Apparatus for treating a condition of a central nervous system (CNS) of a subject, comprising a stimulator adapted to: 
 stimulate sphenopalatine ganglion (SPG)-related tissue of the subject by applying an electrical signal to the SPG-related tissue, the SPG-related tissue selected from: an SPG of the subject and nerve fibers of the subject which are directly anatomically connected to the SPG, and    configure the stimulation so as to cause an increase in clearance of a neurotoxic compound from cerebrospinal fluid (CSF) of the subject through a blood brain barrier (BBB) of the subject to a systemic blood circulation of the subject, so as to treat the CNS condition.    
   
   
       128 . The apparatus according to  claim 127 , wherein the stimulator is adapted to directly stimulate the SPG.  
   
   
       129 . Apparatus for treating a condition of a central nervous system (CNS) of a subject, comprising a stimulator adapted to: 
 stimulate sphenopalatine ganglion (SPG)-related tissue of the subject by presenting an odorant to an air passage of the subject, the SPG-related tissue selected from: an SPG of the subject and nerve fibers of the subject which are directly anatomically connected to the SPG, and    configure the stimulation so as to cause an increase in clearance of a neurotoxic compound from cerebrospinal fluid (CSF) of the subject through a blood brain barrier (BBB) of the subject to a systemic blood circulation of the subject, so as to treat the CNS condition.