Basic Evaluation: InterStim Therapy Test Stimulation
InterStim Therapy is unique in that test stimulation can be performed to assess the
effectiveness of the therapy prior to placing the more permanent neurostimulator
implant. This test is designed to determine whether your urinary symptoms can be
improved through stimulation of the sacral nerves which help to control the bladder.
You will be asked to complete a 4-day bladder diary and bring it to the test appointment.
It is important that this diary be as accurate as possible since it will provide the
baseline for your bladder symptoms and help to determine the success of the
The test will be done in the doctor’s office and will take approximately 60 minutes
including prep time and post-procedure instructions. You will be awake and required to
lie on your stomach for 20-30 minutes. The doctor will numb the sacral area (above your
tailbone) with a local anesthetic injection. Two temporary test wires (leads) will be
placed under the skin, one on the left and one on the right, through a needle which is
removed once they have been placed. During the testing you will be asked to identify
the location of the stimulation you are feeling. Generally, the stimulation feels like a
pulsing, tingling or vibrating sensation felt in the “bicycle seat” area near the vagina or
Following the procedure for placing the test wires, you will receive a stimulator box that
will be connected to a white cable; the white cable is connected to the implanted wire in
your back. There will be 2 white cables, one for each test wire. You will test the 1st
white cable for 3 days while keeping a bladder diary, then you will then test the 2nd
white cable for the remainder of the week continuing to keep the bladder diary. It is
important that these diaries be as accurate as possible. You will bring your completed
diaries to your test wire removal appointment which will be scheduled for 1 week
following your procedure.
The amount of stimulation is under your control and should be prominent enough to feel
it comfortably. It should never be uncomfortable. You may turn the stimulation up and
down, on and off using the “A” dial on the stimulator box. Stimulation should always be
turned on, day and night, unless driving and should always be felt during this test
phase. The intensity of the stimulation may change with standing up, sitting down, lying
down, etc. You should adjust the intensity to always feel the stimulation comfortably.
If you are unable to feel the stimulation:
1. Try increasing the intensity, if you get to 10, turn the stimulator off, wait 10 seconds
and turn it on again.
2. Change the battery in the stimulator box. You should have an extra 9-volt battery
available at home.
3. Check to see that the white cable is connected to the stimulator box and that it is not
frayed or broken.
4. If unable to restart stimulation, call the physician’s office.
Avoid showers, tub baths, hot tubs, and swimming pools during the entire test.
You may “sponge bath” but do not get the test wires, dressings or the test stimulator box
Do not change the dressings. Instead, reinforce or retape them if they become loose.
Always turn off the stimulator while operating motorized vehicles. Occasionally a
position change while driving may cause the stimulation to increase and startle you
which could cause an accident.
Please wear comfortable, loose fitting pants and slip on shoes on your test date
(i.e. sweatpants or other elastic waist pants and sandals or loosely tied sneakers).
You may drive yourself home following the procedure.
• Take it easy for the test week. Limiting your physical activities will help to prevent
the test wires from moving or pulling out.
• Sense the stimulation at all times at a level that is identifiable but not
uncomfortable. If the stimulation has moved significantly or you do not sense
stimulation, please contact your physician’s office.
• Watch for the blinking GREEN light on your stimulator. If the GREEN light is not
blinking, simply turn off the unit and reset the stimulator by turning it back on to a
comfortable level. If the stimulator does not reset, change the battery and try
again. If you cannot get the unit turned back on, call your physician’s office.
• Complete your voiding diary as accurately as possible. Try not to alter your fluid
intake, caffeine intake or medications during the test period.
• Contact your physician’s office if you have any questions or concerns.
DO NOT’s for your Test Stimulation Procedure:
• Do NOT take a bath or shower. Do not enter a hot tub or swimming pool.
• Do NOT wear your stimulator while washing up.
• Do NOT “scoot” when you get in and out of a chair or an automobile.
• Do NOT bend over. Try to squat or kneel instead, keeping your back straight.
• Do NOT twist your body or lift heavy items