135 解释神经系统程序 explaining neurological procedures

《医生诊疗英语会话》每日一听第135期

9EXPLAINING NEUROLOGICAL PROCEDURES (135)

explainingneurological procedures

12.9.A
I am going to arrange for you to have a special test of the electrical activityof the brain, which is called an EEG or electroencephalogram. We'll ask you tolie down on the couch and then the technical staff will connect to you up toabout 20 small electrodes which we stick to the surface of the head usingspecial glue. We'll then just ask you to relax and lie still while a specialmachine records the electrical activity of the brain. Sometimes during thistest we'll ask you to breathe very fast to see if that changes the electricalpattern that we record. We'll also flash a bright light very quickly becausethis also can change the pattern of electrical activity that we see on thetracing that we get.
12.9.B
We are going to do some small electrical tests to look at the efficiency withwhich the nerve are working.
The first stage of this test is to measure the speed of conduction of impulsesin the nerves. To do this we'll connect you up to some electrodes and give youa very small electrical impulse. We can then measure the length of time ittakes for the impulse to travel through the nerves, and the machine will recordit on the screen. This feels like a tickle and is not unpleasant. As weincrease the stimulus, you may feel a small electrical shock .It will make yourthumb of your fingers jump. The second stage of the test is to measure theelectric activity in the muscles themselves. This is called an EMG. We need toput a small needle under the skin into the muscles, and then I will ask you tomove some of your muscles. This will then allow me to record the progress ofthe electrical activity in the muscles on the screen.
12.9.C
We want to examine the fluid which circulates around the brain and spinal cord,called cerebrospinal fluid, CSF. To do this we are going to do a lumbarpuncture. I want you to lie on your left-hand side on the couch. Then I amgoing to clean the skin on the back with some antiseptic solution. You'll thenfeel me giving you some anesthetic into the skin to make the surface of theskin go numb. Once the skin is numb, you will feel a little bit of pressure andpushing and pulling While I put a very fine needle through the skin between thebones of the back to let me take off some of the spinal fluid. I will measurethe pressure in the fluid and then collect several samples of the fluid to sendaway for analysis in the lab. Once the needle is taken out I'll put a smallplaster over the site where I did the lumbar puncture. And then I'll ask you tolie flat for about an hour after the lumbar puncture to reduce the risk ofgetting a headache.
12.9.D
We are going to do a scan of the brain cord, CT scan or CAT scan. This is aneasy test. You just need to lie on the special stretcher which moves and runsinto the head scanner. It is a little bit like putting your head in a largewashing machine. You lie still and you will hear the machine making noiseswhile it takes some special cross- sectional X-rays to give us a picture ofyour brain.
12.9.e
We are going to do a special scan of the brain called magnetic resonanceimaging scan or MRI scan. You lie on a stretcher that slides into a long tunnelwhich is the scanner itself. You need to lie still for about 10 or 15 minuteswhile the machine builds up cross sectional pictures of the brain. This test isquite noisy and you will hear a lot of thumbing and banging noises while themachine works. You may feel claustrophobic. So we'll give you a little rubberpump to hold. If you really need to come out, just press the pump.