Seizure Inves­ti­ga­tion: Eval­u­a­tion for Epilepsy Surgery (2004)

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What you need to know when you come to the M.N.H.

Intro­duc­tion

ImageEpilepsy is a chronic neu­ro­log­i­cal dis­or­der char­ac­ter­ized by recur­ring seizures. For patients who can­not con­trol their seizures with med­ica­tions, epilepsy surgery may pro­vide a pos­si­ble treat­ment option.

Suit­able can­di­dates are care­fully selected based on age, pre­vi­ous med­ical con­di­tion, pre­vi­ous and cur­rent med­ica­tions, seizure type and an in-​depth inves­ti­ga­tion that starts with an in-​patient assess­ment. You are a sur­gi­cal can­di­date if your seizures are not well con­trolled with med­ica­tion, if we know where your seizures begin and that surgery would not pose sig­nif­i­cant risk to you. With your col­lab­o­ra­tion, we are about to look for the cause of your seizures. Your doc­tors will be using the most sophis­ti­cated tech­nol­ogy in Que­bec. Here is some infor­ma­tion to help you to under­stand the process. After read­ing it, you should feel bet­ter pre­pared and informed dur­ing your stay at the Mon­treal Neu­ro­log­i­cal Hospital.

Once you arrive on your unit, you will meet your nurse, who will per­form a nurs­ing admis­sion. This includes an inter­view and assess­ment of your health. You will also be inter­viewed and assessed by neu­rol­ogy res­i­dents. At any time dur­ing your hos­pi­tal­iza­tion, you are encour­aged to ask ques­tions con­cern­ing the plans for your hos­pi­tal stay. For seizure patients, the length of stay in the hos­pi­tal is approx­i­mately 7 to 10 days..Below are descrip­tions of some of the tests that you might undergo. The tests have a num­ber of goals:

  1. To iden­tify the type of epilep­tic disorder.
  2. To locate where your seizures are­com­ing from.
  3. To dis­cover why your seizures occur.

Your doc­tor will decide, with you, the best treat­ment options. We sug­gest that you read about these tests. As soon as you have one of them, you can mark off the square next to it. In this way, you can fol­low your own inves­ti­ga­tion process.

Elec­troen­cephalog­ra­phy (E.E.G.)

It records elec­tri­cal activ­ity in the brain through the use of elec­trodes placed on the sur­face of your scalp. Record­ing can be done while you are awake or asleep. It is not dan­ger­ous and it does not hurt. By record­ing elec­tri­cal activ­ity within the brain, this test helps in iden­ti­fy­ing where the seizure comes from.

Video Teleme­try

Video teleme­try helps to find the loca­tion of your seizures. Video teleme­try sim­ply means that you will be recorded by a video cam­era, 24 hours a day, on a spe­cial­ized unit located on 3 North. Dur­ing this time, you will be con­nected to an E.E.G.

Video teleme­try also records voices and sounds by using a micro­phone that is placed in the room.. The images are mon­i­tored on screens on 3 North, as well as in the E.E.G. Depart­ment. Teleme­try tech­ni­cians will check your elec­trodes every day.

Video teleme­try allows the nurse and the physi­cian to observe your seizures and record the changes of elec­tri­cal activ­ity dur­ing the seizure. The pur­pose of video teleme­try is for you to have a seizure, which can be recorded in a safer envi­ron­ment. It is known that cer­tain activ­i­ties increase the chances of hav­ing seizures. These activ­i­ties include exer­cise, sleep depri­va­tion (stay­ing up all night) and decreas­ing the dosage of your med­ica­tion. Your doc­tor will indi­cate which of these will apply to you. A nurse will remain by your side when you have a seizure. She will attempt to ask you ques­tions about your speech, vision, mem­ory and your abil­ity to move. This is called seizure test­ing. Nat­u­rally, you will answer only as best you can. A spe­cial teach­ing ses­sion will be done about video teleme­try by your nurse and your E.E.G. tech­ni­cian (when you go onto telemetry).

Dur­ing your time on teleme­try you may expe­ri­ence some itch­ing of your head due to the EEG elec­trode glue. If this does occur inform your nurse who will give you some med­ica­tion to help relieve this.

In order for your seizure inves­ti­ga­tion to be as suc­cess­ful as pos­si­ble, your coop­er­a­tion is very impor­tant. The more time you spend con­nected to video teleme­try, the bet­ter chance there will be of record­ing as many seizures as possible.

As you will be expected to remain in your room con­nected to the teleme­try equip­ment, we rec­om­mend that you bring items that will pre­vent bore­dom (books, cards, knit­ting, puz­zles, video­cas­sette, etc.). There are a few pre­cau­tions that are necessary:

  • Both side rails of your bed should be up.
  • Use a wheel­chair when off the unit.
  • If you are a smoker, the num­ber of times you may go off the unit is limited.

Blood Tests

ImageAt var­i­ous times dur­ing your stay, you will have blood taken to mea­sure the level of your medications.

Mag­netic Res­o­nance Imag­ing (MRI)

This exam­i­na­tion will per­mit the visu­al­iza­tion of struc­tures such as your brain and spinal cord with­out expos­ing you to x-​rays. The test can last for up to 60 min­utes. For your own com­fort, we rec­om­mend that you empty your blad­der before the test. We ask that you remove all metal­lic objects such as jew­elry and all your credit cards because they will be dam­aged by the machine. Before this test, you will be asked to sign a con­sent form.

You will be lying on a plat­form which will slide into a tube. It is required that you remain com­pletely still, oth­er­wise the qual­ity of the pic­ture image will be affected. You will hear a bang­ing. To decrease the dis­com­fort, earplugs will be made avail­able. At all times, it will be pos­si­ble for you to com­mu­ni­cate with the per­son­nel of the depart­ment and for them to see and com­mu­ni­cate with you.

Mag­netic Res­o­nance Spectroscopy

Mag­netic res­o­nance spec­troscopy is a tech­nique that pro­vides infor­ma­tion about the bio-​chemicals in the brain. The scan­ning pro­ce­dure takes 45 to 60 min­utes. The prepa­ra­tion is the same as M.R.I. Dur­ing the first part of the exam, you will hear knock­ing sounds for a few min­utes while the scan­ner makes a pic­ture of your brain and the machine adjusts itself. There are no side effects with this test.

Sin­gle Pho­ton Emis­sion Com­put­er­ized Tomog­ra­phy (SPECT)

For this exam­i­na­tion, a radioac­tive sub­stance will be injected into your veins dur­ing a seizure (Ictal spect) and 24 hours or more after a seizure (Inter­ic­tal spect). There are no side effects to the injec­tion and it will be read­ily absorbed into the brain. The amount of radioac­tive sub­stance injected is extremely small. It is roughly the amount of radioac­tiv­ity received when you travel by plane from Mon­treal to Van­cou­ver. The sec­ond part of the exam­i­na­tion is to have a scan. This is done up to 3 hours after the injec­tion. You will lie on your back and the cam­era will be mov­ing slowly around your head. The doc­tors will exam­ine the way in which your brain has absorbed the radioac­tive sub­stance as a means to iden­tify the focus of your seizures.

Neu­ropsy­chol­ogy

All patients with seizure dis­or­ders who are can­di­dates for elec­tive surgery are assessed with neu­ropsy­cho­log­i­cal tests. A vari­ety of cog­ni­tive tests are admin­is­tered to under­stand how var­i­ous psy­cho­log­i­cal sys­tems (par­tic­u­larly speech and mem­ory) are orga­nized in the brain. These tests show which sys­tems are func­tion­ing nor­mally and which may have been dam­aged by what­ever is caus­ing your seizures. These tests also deter­mine any effects that surgery may have on these sys­tems. These tests require a min­i­mum of 4 to 5 hours.

Cere­bral Angiography

Cere­bral angiog­ra­phy is a study of the blood cir­cu­la­tion of the brain. It is done under local anaes­the­sia in the x-​ray depart­ment. Prior to this test, you need to sign a con­sent form. A small tube is placed into the artery of your groin and it is then advanced into the arter­ies of the neck. Injec­tion of a con­trast sub­stance through this tube will show your brain cir­cu­la­tion. This test can last up to 2 hours, depend­ing on how many arter­ies are being examined.

WADA Test for Speech Orga­ni­za­tion and Mem­ory Function

This test is sched­uled for all patients who:

  • are not right-​handed
  • pro­duce a psy­cho­log­i­cal test pro­file that is not con­sis­tent with speech rep­re­sen­ta­tion in the left cere­bral hemisphere
  • have gen­er­al­ized mem­ory problems

Test­ing is done on two con­sec­u­tive days, usu­ally the brain’s right hemi­sphere on the first day and the left on the sec­ond. The test occurs at about 11 a.m. Patients may have a light break­fast as long as it is eaten at least two hours before the test begins. When the tests are sched­uled for the after­noon, a full break­fast may be eaten.

EEG leads are placed on the head early in the morn­ing and there is E.E.G. record­ing through­out the tests. The tests are done in the angiogram room of the Radi­ol­ogy Depart­ment , as you must first have an angiogram to show which areas of the brain will be affected by the seda­tive. A team of psy­chol­o­gists then estab­lishes base­lines on a vari­ety of speech and mem­ory tasks. The drug is injected and the test con­tin­ues for about another half hour. The catheter is then with­drawn, and you return to your unit where you must remain in bed for at least 6 hours, keep­ing the leg in which the catheter was inserted, usu­ally the right, straight. This is done to pre­vent any com­pli­ca­tions occurring.

Com­puted Tomog­ra­phy (C.T.)

A com­puted tomog­ra­phy (CT) scan is rel­a­tively sim­ple, safe and com­pletely pain­less exam­i­na­tion that radi­ol­o­gists have per­formed for many years. The scan pro­duces a series of images and can detect many con­di­tions that do not show up on con­ven­tional x-​rays. Dur­ing some CT scans, a con­trast medium (com­monly called a dye) is used to out­line blood ves­sels or fill up organs of the body so that they can be seen more eas­ily. If you are aller­gic to iodine or iodine dye, please tell your physi­cian. If your physi­cian orders a CT scan with con­trast, we will ask you not to eat or drink any­thing 3 hours before the test.

Positron Emis­sion Tomog­ra­phy (PET)

In P.E.T. scans, very small quan­ti­ties of sub­stance which is nor­mally used by your body are made radioac­tive and admin­is­tered into your blood­stream. Radi­a­tion detec­tors mea­sure the loca­tion of the radioac­tive sub­stances. This enables your doc­tor to iden­tify nor­mal and abnor­mal func­tions within the brain. There are no side effects expected dur­ing or after the P.E.T. scan.

Con­clu­sion

You might not need to have all these tests. Your doc­tor will advise you about which ones are nec­es­sary. Your coop­er­a­tion is requested dur­ing your stay at the Mon­treal Neu­ro­log­i­cal Hos­pi­tal. Please let us know if you expe­ri­ence any change in the state of your health. We encour­age you to con­sult another pro­fes­sional such as a social worker if you think you need to.


Image For more infor­ma­tion:
Neuro-​Patient Resource Cen­tre
Mon­treal Neu­ro­log­i­cal Hosp­tial Room 354
Tel: (514) 3985358
E-​mail: infoneuro@​muhc.​mcgill.​ca
Web site: http://​infoneuro​.mcgill​.ca/

This infor­ma­tion is for edu­ca­tional pur­poses only, and is not intended to replace the advice of a pro­fes­sional health­care prac­ti­tioner, or to sub­sti­tute for med­ical care.

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Pare­pared by 3 North Nurs­ing Staff
Rev, 2004


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