Project for Understanding the Brain

1. Charcot Marie Tooth
Sumbitted by Karen L. Bauer
One of myclosestfriendswasdiagnosedwithCharcotMarie Tooth,a form of musculardystrophy,when
she was inherlate 20’s. She toldme her firstsymptomwasthat she startedto walkawkwardly.Her
fathersuggestedshe see adoctorto determine whatwascausingthe change inhermobility. She saw
an endocrinologistwhodidextensivebloodworkand neurological testing. Itwas thisdoctorwho
diagnosedCharcotMarie Tooth. Thiswas approximately 30yearsago.
Since thenthe disease hasprogressedslowly. She describeshersymptomsasfollows: She cannotwalk
on the ballsof her feet. Whereasmostpeoplestepheel,ball,toe,she liftsherfootupandplacesit
downflatinfront of her as she walks. There isweaknessinherlegs,particularlyinhershinsandcalves.
She has higharchesand hammertoes. Her forearmsandhandshave weakness. She findsitdifficultto
standfor extendedperiodsof time andtiresmore easilyasshe hasgottenolder.She hassevere
difficultygoingupsteps,butwalkingdownthemiseasier. Accordingtoinformationonthe Charcot
Marie ToothFactSheet, publishedbythe National Institute of Health,these are commonsymptomsof
the disease.
Hammertoes Higharches Musclesin hands Muscle deterioration inlegs
Each year she has an evaluationatamusculardystrophyclinic.Atthe presenttime, she stillplaystennis,
swims,andpracticesyogaeveryweek. She saysthe yogahas helpedherwithherbalance.She tookup
golf lastyear. Although,asshe jokinglyremarks,she will neverbecome aprofessional inanyof these
sports,the doctors encourage hertostay active and if necessary,seektherapy, because physical
therapy,occupational therapy,andphysical activitymayhelpmaintainmuscle strength.
Charcot Marie Tooth(CMT) an inheriteddisorder, isone of the mostcommoninherited neurological
disorders,affectingapproximately1in2,500 people inthe UnitedStates(CharcotMarieTooth Fact
Sheet).There are more than 70 formsof the disorder. Most formsof CMT are passeddownfrom
dominantgenes,however,some formsare inherited fromrecessivegenes. Thismeansthatsomeone
may be affectedbyCMT eventhoughthe parentsdonot have the disease. Thishappenedbecause each
of the parentshasa mutationinone of theirtwocopiesof a CMT gene.If a childinheritsone mutated
CMT gene fromeachof his/herparents,the childwill developCMT.There isa one in fourchance of this
occurring. There is a rare chance CMT will resultfromamutationand notbe inherited.Myfriend’sCMT
isthe resultof recessive inheritance. Hersisterdoesnothave the disease.

2. CMT damage resultsin peripheralnerve damage in one of twoways. Eitherthe myelinsheaths
surroundingthe nervesisdamagedorthe nervesfibersthemselvescanbe damaged. Eitherway,the
damagednerve fibersresultinneuropathy. “The nervesinthe legsandarms,whichare the longest,are
affectedfirst.Nerve fibersthatcreate movement(calledmotorfibers) andnerve fibersthattransmit
sensations(calledsensoryfibers) are bothaffected. Consequently,thesenervesslowlydegenerate and
lose the abilitytocommunicate withtheirdistanttargets.The degenerationof motornervesresultsin
muscle weaknessandatrophyinthe extremities(arms,legs,hands,orfeet),andinsome casesthe
degenerationof sensorynervesresultsinareducedabilitytofeel heat,cold,andpain”(CharcotMarie
ToothFact Sheet).CMT istypicallyaslow progressingdisease. Currentlythere isnocure nor can the
progressionof the disease be slowed, althoughresearchcontinues.
I have gaineda deeperunderstandingof andappreciationforthe complexitiesof the humanbrainand
our neuroanatomy. Ithasgivenme insightintohow amazing,resourceful,andfragilethe humanbody
is.It isamazingthat the brain and nervoussystemcanrecoverfromor compensate fordamages. Ihave
beeninspiredbythe thoughtful commentsanddiscussionsinthe forums. In dayto day interactions
withpeople,Ihave abetterunderstandingof those individualswhoare dealingwithhearing,visual,or
physical impairments. My interactionswithotherswill be enhancedbymyknowledge of their
challenges.
References:
http://www.cmtausa.org/index.php?option=com_content&view=article&id=70&Itemid=159
http://www.ninds.nih.gov/disorders/charcot_marie_tooth/detail_charcot_marie_tooth.htm