Abstract

A demographic analysis was performed on 1726 patient registration records from 55 countries, at a peer-to-peer social networking website focused on Trigeminal Neuralgia.  While some demographic outcomes aligned with sources in medical literature, the patient demographic for first emergence of neurological facial pain was found to be younger than commonly noted in medical literature,  by at least 14 years (median age slightly under 41 years, versus "sixth decade" or even "seventh decade" commonly reported).  An analysis was performed to evaluate the potential impact of youth bias in this finding,  due to the online and self-selected nature of the patient community; youth bias was not assessed as a significant factor in demographic results.   

Over a fifth of patients in the demographic self-identified their pain as "Atypical" trigeminal neuralgia. Up to 80% of the demographic was female.  In at least a quarter to a third of the demographic, the patient initially mistook their facial pain for a dental problem and saw a dentist as the first medical professional consulted.  In less than a quarter of cases involving a dental practitioner, was the pain promptly recognized to be non-dental in character and the patient referred to a medical doctor.   In a third of cases seen by a dental practitioner, the patient was treated for non-existent dental problems and pain did not resolve.

Introduction

Trigeminal Neuralgia (TN or "Tic Douloureux") is a relatively rare neurological disorder that produces intense pain in one side (or in a few cases both sides at different times) of the face. The disorder has sometimes been called "the suicide disease"[1],[2] and is widely considered to comprise the most debilitating form of pain known in medical practice[3].   TN is also relatively rare, with an estimated incidence rate of new cases on the order of 12  per hundred thousand population per year [4].  Some practitioners recognize two forms of the disorder.  "Type I" or "Classic" TN is said to present as volleys of intense, brief, sharp, electric-shock  jabbing pain, each jab lasting up to 90 seconds and volleys tapering off after one to two hours.  "Type II" or "Atypical" TN pain is described as less-intense, constant 24-7 burning, boring, aching pain. [5]  Distinctive medical mechanisms for these two forms of pain do not appear to have been clearly established in medical literature.

Many sources indicate that more patients are female than male. [6]  Estimated age demographics vary by source.  Some sources assert that Trigeminal Neuralgia most often first presents in the sixth decade of life[7],[8].  Other papers show a skewing of patient populations toward older age cohorts. [9]

Because of its relative rarity and overlaps in symptoms between TN and other neurological or dental problems, the disorder may present challenges to accurate diagnosis. [10]  In a National Patient Registry created by the Trigeminal Neuralgia Association in 1999-2002, over 11,000 surveyed patients reported that they had been seen by an average of six different dental or medical practitioners before obtaining a diagnosis.  Many physicians in general practice also relate that they have never personally seen a case of trigeminal neuralgia during 30 or more years of practice. [11]

In part because of the rarity of neurological facial pain and because of difficulties in obtaining accurate diagnosis and effective treatment,  patients have in recent years increasingly turned to the Internet to find both information and mutual emotional support.  Several on-line communities and Non Profit Organizations have grown up in response to this need.  Prominent among these is the Trigeminal Neuralgia Association [12].  Other patient-to-patient communities having interests in chronic facial pain include the TMJ Association [13], Brain Talk Communities[14]  and many others. 

These on-line communities have significantly increased the visibility of relatively rare neurological disorders -- and on occasion called into question whether they are quite so rare as was once thought.  For instance, in 1998 when the Trigeminal Neuralgia Association began to expand its on-line presence and patient information base,  major Internet search engines such as Google and Web Crawler typically returned on the order of 4,000 "hits" for the term "Trigeminal Neuralgia".  In March 2012, the same search produces over two million five hundred thousand "hits". [15]

One of the more recent entries among patient-to-patient mutual support sites is "Living With TN" (http://www.livingwithtn.org – a subsidiary community of “Ben's Friends”), operated since October 2008.    The present paper analyzes the demographics of patients who have registered at the website, in an effort to address two questions:

            1.  Who gets face pain and at what ages?

            2.  How wide-spread are difficulties in obtaining accurate diagnosis and effective treatment

Demographic Analysis  

The demographics of a substantial group of face pain patients were extracted from a download of "Living With TN" membership registration data, current as of February 5, 2012.   Thirteen fields of membership data were employed to arrive at preliminary conclusions about the membership of the site and some of the outcomes of patient diagnosis and treatment.

Gender [male / female]

Location

Country

Zip

Age

Birthdate

Date joined

Last visit

Membership Type [patient, relative, friend, medical professional, admin, other]

Type of face pain [Typical TN, Atypical TN, Trigeminal Neuropathic Pain, Other]

Date diagnosed

Treatments you have undergone (member narrative)

Share your TN story with us (member narrative)

In several areas discussed below, membership records were updated from the original database to correct member entry errors and omissions. 

Membership at Living With TN is world-wide, from 55 countries.  The largest numbers of members come from the United States (1284), United Kingdom  (156 ), Canada (73), and Australia (58).  Categories of site memberships are indicated in Table 1 below:

 

Table 1:  Types of Website Membership

 

           Site Membership Categories                 Uncorrected Database        Corrected database

                 Admin/Owners                                                             4                                5        

                 Friends                                                                        11                               23

                 Medical professionals/other                                        4                                5                  

                 Relatives of patients                                                   53                            109

                 Member type not entered                                         725*                            71 (narratives blank)

                 Patients - age unknown                                                8                                8

 

                 Patients - age self-entered or estimated            1122                            1695*

                 Patients supported by relatives (age known)      --                                      32**

             Total member records reviewed:                            1919                            1919        

[*]  See "Corrections to the Member Database", below.

[**] 1727 Records were analyzed for the site demographic, including 32 records in which the registered member was a relative who reported the patient's age on first emergence of pain, or diagnosis of pain.

In the site demographic analysis, all records were removed for which a patient age at first emergence of pain was either not explicit in patient narratives, or could not otherwise be bounded by a member-entered date of birth or date of diagnosis.

Pain type(s) were directly entered by 969 members  in the 1726 records analyzed for the demographic.  None of these entries was corrected during database review, though it became evident that perhaps as many as 100 members were dealing with facial neuropathy rather than facial neuralgia

                    Table 2:  Types of Pain -- Corrected Database (+)

 

    Typical or Type I               244           

    Atypical or Type II            335           (98 patient narratives also mention "Atyp")      

    Bilateral pain                      40           (from patient narratives)       

    Other / not sure                383           (includes 3 "trigeminal neuropathic pain")   

    No Type Entered              759            

 

             + Does not sum:  many patients entered multiple types in the “Type of pain” field.

 

Corrections and Additions to the Member Database

The database was reviewed to identify and correct the following types of errors or omissions.

            -   Although all members retained for the demographic had entered a date of birth for themselves or an age for someone whom they were supporting as a friend or relative, almost half of the site members originally did not identify whether they were patients, relatives or “other”.   When "member type" was blank in the member registration data,  patient story narratives and treatment history were scan-read to distinguish between patients, relatives, friends, site administration and medical professionals.  When narratives provided circumstances or relationship words, member-type was added to the entry field originally left blank when the member registered.  By this means, the number of records for which member category was unknown was narrowed from 725 to 71.

            -  In 1101 patient records retained for the demographic, an explicit date of diagnosis was entered by the member.  When additional information on age of pain emergence was not available from patient narratives, the age of the patient when diagnosed was taken as an upper bound on age when pain first emerged.   Given that many patients reported suffering for many years without getting a definitive diagnosis, this bounding probably introduces some upward bias in estimates of median age when pain first emerged.

            -  Patient narratives were reviewed for additional information that might permit estimation of an age when pain first emerged, when lower than the age of the member at registration.  Narratives containing terms such as "my life", "first", “began”, “started”, "years" or “ago” were read to estimate the patient's age from circumstances recorded.  Records of “Friends” or “Relatives” were also read, looking for age data on the patient being supported.

                        a.  When an age was found in member narratives at which pain first emerged, this age was directly entered into a supplemental corrected age column of the database.

                        b.  In 20 patient narratives, age of first pain emergence was qualitatively distinguished from the date of medical diagnosis by use of the words "for years" or "many years" in the patient narrative.  When the phrases "for years" or "several years" appeared, a patient age at first pain emergence was estimated by subtracting five years from the date of diagnosis or the patient's age on registration.  When the term "for many years" appeared, 10 years was subtracted. 

            -  In 624 records of the demographic, a date of diagnosis was not entered by the member. Patient narratives were read to deduce the age at which pain first emerged.  Wording was found in 391 patient narratives which allowed either a direct corrected age entry or a plausible qualitative estimate of patient age when pain first emerged.   

            -  76 records were excluded from the demographic because the patient and the member were different people and no patient age could be estimated from narratives.   However, in most of these records, an approximate generational age relative to the member could be determined for the patient being supported.  A bias check was performed to see if the demographics of this  excluded group were substantively different from the group included in the demographic. No bias was found.

Gender Demographics

There were 1919 records in the uncorrected member database, of which 918 entered themselves as Female and 222 as Male, with 777 having made no entry.   Records down-selected for the demographic analysis were those in which entered data was that of a patient or a relative acting on behalf of a patient whose age was known.  A review was conducted of member user names during this down-selection, to identify female versus male user names.  The resulting gender demographic is shown in Table 3, below:

              Table 3:  Patient Gender Demographic, Living With TN

 

Records entered or inferred as Female                1255    (80% of gender-attributable records)

Records entered or inferred as Male                      302    (20% of gender-attributable records)

Records not attributable by gender                        170

   Total Records, Corrected Database                   1727

 

Analysis of Patient Story Narratives and Treatments

The analyzed demographic sample omitted site administrators, medical professionals and members for whom the age of the patient could not reliably be determined.  Of the 1726 patient records in the demographic, 1596  had text in the “patient story” and 1703 in “treatments you have undergone or will undergo”.   In a few instances, text comprised “none” or “will fill in later”.

Text string searches were performed to estimate the number of instances in which key words appeared in the membership story or treatment history narrative fields.  Word selection was guided by the author's 17-year experience as a patient advocate and webmaster for Internet chronic facial pain sites. The incidence of several key word strings is summarized in Table 3 below. 

Review of patient narratives revealed that some members had a history of face pain from causes other than Typical or Atypical Trigeminal Neuralgia.  There were 60 mentions of "MS" or "sclerosis" in patient stories,  of which 20 were associated with a pending or confirmed diagnosis of the disease.  There were 46 mentions of "tumor", 10 of "cyst" and 3 of "Chiari".   26 patient stories mentioned facial injuries from automobile accidents, assault, or other blunt force trauma.

Not surprisingly,  a significant number of members had diagnosed themselves with trigeminal neuralgia or neuropathic pain by researching their own symptoms on the Internet.   82 patient records explicitly mentioned "research" and 30 more  mentioned "internet".   Several narratives also noted that multiple doctors and dentists had failed to diagnose Trigeminal Neuralgia ; some were actively resistant or dismissive to diagnosing the disorder in younger patients.  By contrast, many patients reported a willingness on the part of dental practitioners to perform multiple extractions or root canals which did not resolve their pain -- despite an absence of evidence for abscess in dental X-rays, often over a period of years and on occasion involving the extraction of large numbers of teeth

 

                                        Table 3:  Keyword String Occurrences

            Key word string             Patient Stories            Treatment Narratives       

 

               “dentist”                                371                                    11 

               “dental”                                 157                                    17  

                         (1 or both terms occur in a total of 469 patient records)

                “tooth”                                     270                                       4

                “teeth”                                     326                                      11

                 “canal”                                   145                                       9

                 “extract”                                   71                                      10

                 "pull"                                        95                                       4

                 “bite”                                        19                                       4

                 “TMJ”                                      73                                        8

               “mouth”                                    114                                       1

       1 or more among 8 above         631                                    36

 

        (Keyword strings are combined below from patient stories, treatment history or both)

             “migr” *                                                 104          

             “effects”                                                 168         (“side effects”)

 

             "convul"                                                   62          (anti-convulsive)

             “tegr”                                                     413         ("tegretol", "tegretal", "tegratol")

             “carb”                                                    215          ("oxcarbamaz.." or "carbamaz..")

             “neuront”                                               161                  

              “gabapen”                                           230

              “trilep”                                                    37         ("Trileptal")

              “depr” **                                                 91          ("anti-depr..." or "depress")

 1 or more of seven above                          831

 

              “surg”                                                    542        (surgical, surgery, sometimes dental)

            “proced”                                                 107         (procedure, sometimes dental)

             “MVD”                                                   309  

             "vascu"                                                    95         (vascular [de]compression)

            “otomy”                                                   149         (rhizotomy)

              “radio”  or "rf"                                       216         (radio frequency)

            “knife”                                                     179          (Gamma Knife, Cyber Knife)

              "alcohol"                                                 14          (alcohol rhizotomy)

              "glycer"                                                   41         (glycerol rhizotomy)

              "balloon"                                                 35         (balloon compression rhizotomy)

  1 or more of 10 above                                  822

               "Botox"                                                   45

               "bloc"                                                    114     ("nerve block", "stellate ganglion block")

Notes to Table 1:

*   “migr” = word root for “migraine” which is sometimes misspelled in patient-entered data

** “depr” appears in multiple contexts, including “anti-depressant” and “depressed”.

--- --- ---

Strong patterns stood out in the patient data with respect to outcomes of facial pain diagnosis or treatment by dental practitioners (dentists, periodontists, endodontists, oro-facial surgeons).   One or more of nine dental terms or word roots appeared in 631 patient stories and 36 treatment histories.  It was  remarkable that many of the practitioners acceded to insistent patient demands for root canal or dental extraction -- despite a lack of X-ray evidence confirming abscess or other dental problems.

The terms “dentist” or “dental” or both,  occurred in 469 member narratives.  At least 174 additional  patient records also indicated a history of dental work, described without these two words.  Reading of patient story narratives revealed the following range of outcomes and contexts for dental terms:

            1.  In 60 of 469 patient records reviewed, mention of the terms "dental" or "dentist" was peripheral, imprecise, or context was otherwise unclear.              

            2.  In 71 patient narratives,  pain initially believed by the patient to be "dental" in character was evaluated by one or more dental practitioners, with a finding that the pain was not dental in origin.  A practitioner then referred the patient to a family doctor, general practitioner or neurologist.

            3.  In 132  patient narratives, the patient had acute facial pain, saw dental practitioners and received neither a diagnosis nor a dental procedure.   Patients in this group later saw a medical doctor or neurologist on their own initiative or at the suggestion of someone they knew.  Several diagnosed themselves by performing Internet searches on their symptoms, before seeing a medical doctor.  About 40 records included "online" referring to patient research or online support groups, or "research" or "self-diagnose".

            4.  In 154 patient narratives, the patient saw one or more dental practitioners and was treated with antibiotics, root canals, multiple dental extractions (sometimes at their own urgent request), TMJ therapy, bite correction, dental guards  or major dental surgery.  The terms "misdiagnose" or "mis-diagnose"  appeared in 32 patient story narratives, and "unnecessary" in 14. 

            5.   In 50 narratives, the patient saw a dental practitioner for routine dental work (cleaning, cracked tooth, crown replacement, other).  Within hours to weeks after dental work was performed, the patient experienced extreme facial pain which they later believed was an outcome of something done by the practitioner.

Estimated Age at First Emergence of Face Pain

            Median patient age in 1726 records                                40
            Average patient age                                                          40.8

            Median member age in 1726 records                             44
            Average member age                                                        44.8

            Number of patients 30 and younger                                 370  (21.4%)
            Number of patients 60 and older                                      109

The youngest age at which pain was reported to have emerged was about 2 years old, and the oldest was 86.  Half of all patient pain cases first presented between age 35 and 49. 

Estimated patient age at first emergence of face pain in the corrected database is plotted in Figure 1 below, versus the number of patients in each year group.  Shape of the statistical curve appears closely symmetrical about the median and Gaussian in shape.  The mean and median closely aligned near 41 years of age.  We do not see in this statistical curve, an assymetrical skewing toward older patients which is reported in some sources. [16]

 

Figure 1:  Patient Age at First Presentation of Pain, Living With TN

 

Potential Demographic Biases of Patient Self Selection

The patient sample reported in this paper was self-selected.  Each member searched the Internet for key words, or was referred by someone else to "Living With TN", as a website that provides information and support for people with facial pain, neuralgia or neuropathy.  The process of patient self-selection may potentially introduce two potential biases into demographic analysis:

            1.  Historically,  Internet users have tended to be younger, more affluent and better educated than National populations overall.  For some types of demographic analysis, this may introduce a youth bias in results.

            2.  People who join a patient-to-patient Internet support community as patients or close relatives  are often dealing with bad outcomes of previous medical and/or dental diagnosis and treatment.  Patients who have had a successful outcome from treatment are less likely to join or remain active in a support community focused on the needs of people in pain.