This Includes Three Puzzles from Hooshmand's site Be sure to read through them all Please #23, #74 & # 106http://www.rsdrx.com/rsdpuz4.0/puz_23.htmRSD PUZZLE # 23
WHY NOT SPINAL CORD STIMULATOR (SCS)? (Revised on 3/29/2002)Spinal cord stimulator (SCS) has a limited role in treatment of CRPS. As you are well aware, there are two different types of pain, in two different stages of CRPS. In the early stages, in the first few months, the pain is sympathetically maintained pain (SMP) meaning that the pain responds to sympathetic ganglion blocks. However, on the average of almost a year, the nature of the pain changes from sympathetically maintained pain (SMP) to sympathetically independent pain (SIP).
The spinal cord stimulator is effective in the SMP phase of the CRPS, not the SIP. The recent research has shown that the later in the course of the disease spinal cord stimulator (SCS) is started, the less likelihood SCS will relieve the pain.
As a rule of Thumb, if the stellate ganglion nerve blocks have lost their effect, about the same time the SCS loses its effect. This is because both treatments aim at the sympathetic system. With passage of time, as the pain gradually changes to SIP, such treatment cannot be expected to help.
What it boils down to, is the fact that if the stellate ganglion nerve blocks have lost their therapeutic effect, then what is the sense of doing SCS? If the pain has become SIP, what is the sense of doing SCS treatment?
SCS is a digital stimulator utilized for treatment of an analog symptom (the analog pain modality is random and not time locked or digital). It is not a type of treatment that would be successful in every form of chronic pain.
The reason we do not apply SCS is because if the sympathetic ganglion nerve blocks do not work, then epidural nerve blocks which contain Depo- Medrol® applied to the epidural space in the spinal canal are far more effective, and their pain relief lasts longer. On the other hand, even in a patient who suffers from SMP type of pain, after about a year, the successful treatment with SCS will fade away because the SMP has changed to SIP. Then, the patient is left with a foreign body in the spinal canal not providing any decent pain relief. This foreign body causes disturbance of immune system resulting in skin rash, and dermatitis[1] and skin lesions and allergic reaction to SCS [2].
In CRPS/RSD, the immune system is rogue. This is because the immune system is modulated by sympathetic system. The sympathetic system, under pain input, responds by releasing T-cell lymphocytes (in early stages CD4 or helper lymphocytes, and in late stages CD8 or killer T-cell lymphocytes)[3]. So, after the SCS has lost its effect, the sympathetic system considers the foreign body of the spinal stimulator as a source of sympathetic dysfunction. This causes neuroinflammation manifested as skin rash, edema, and infection.
As the condition becomes chronic, the SCS can lead to spread of pain from the original site to other parts of the body[3].
In rare cases, there are other complications noted with SCS application. These complications consist of the following:
1. Epidural abscess or blood clots.
2. In occasional cases, the sensitization of the spinal cord by the spinal cord stimulator causes spinal cord sensitization in the form of myoclonic akinetic seizures [3]. The sensitization is due to prolonged electrical stimulation causing exhaustion of the inhibitory nerve cells. Treatment with Klonopin®, and removal of the stimulator prevents the sensitization.
Such attacks of myoclonic seizures originating from the spinal cord due to the spinal cord sensitization are not limited to the SCS. They are also seen in other spinal procedures[4]. The diagnosis of spinal cord originated myoclonic seizures is quite difficult, and usually these patients are labeled as "functional" or "hysterical." Such patients respond very nicely to treatment with Klonopin®, brand name rather than generic.
The removal of SCS, as well as Multidisciplinary treatments, aiming at desensitizing the spinal cord, help this condition.
Another problem with the SCS is the tendency for electrode movement due to improper anchoring, and the necessity for the surgeon try to correct the position of the stimulator. Every operation is going to be another new source of CRPS pain.
In the rare and severe cases of spinal cord sensitization, the patient may develop myoclonic jerks, and urgency, frequency, and even incontinence of urine, secondary to SCS irritating the urinary bladder and interstitial cystitis.
H. Hooshmand, M.D.
References
1.McKenna KE and McCleane G: Dermatitis induced by spinal cord stimulator implant. Contact Dermatitis.1999; 41: 229.
2. Ochani TD, Almirante J, Siddiqui A, et al: Allergic reaction to spinal cord stimulator. Clin J Pain. 2000; 16; 178-180.
3. Hooshmand H, Hashmi H: Complex regional pain syndrome (CRPS, RSDS) diagnosis and therapy. A review of 824 patients. Pain Digest. 1999; 9: 1-24. (Click on link to view abstract)
4. Rosenblum, JA: Spinal abdominal myoclonus. The Neurologist. 1996; 2: 784-787.
http://www.rsdrx.com/rsdpuz4.0/puz_74.htm
RSD PUZZLE #74
SPINAL CORD STIMULATOR (SCS) Dear Dr. S.,
Many thanks for your letter of 10/7/96. It was very interesting that you had quite a similar experience regarding the spinal cord stimulator treatment for CRPS (RSD).
I have seen 36 patients so far suffering from RSD who have received spinal stimulator for management of the pain. Of the 36 patients, the pain relief lasted an average of six weeks. Relief was as short lasting as a few hours and as long as over four months. Eventually the pain recurred with more severity.
More importantly, the foreign body of the stimulator in a patient who already had disturbance of plasticity due to long standing RSD, resulted in two phenomena:
1. Spread of RSD to the opposite extremity, as well as development of headache, neck pain and dizziness.
2. Reactive spinal cord ischemia resulting in transient paraparesis and incontinence in two cases, and the development of myoclonic type of jerks in the lower extremities in four other cases.
It is about time to differentiate the neuropathic pain of RSD from the somatic pain of failed neck or failed back syndrome.
In the same follow-up study of the patients, we have noted the effective response in control of the somatic type of pain in 32 failed neck and failed back patients with an average duration of relief being 18 months. No such complications of spread of the disease is noted in somatic (non-CRPS) patients.
In regard to your patient, I am glad she is being treated by you, and if I can be of any help, I will be at your service. Even though we have had excellent results (over 70% success) in 96 RSD patients treated with infusion pump, we always like to save the infusion pump treatment as a last resort because of problems of potential of infection (due to the disturbance of immune system secondary to RSD), and the patients intolerant of even the smallest doses of narcotics in the spinal fluid (noted in 11 patients).
H. Hooshmand, M.D.
http://www.rsdrx.com/rsdpuz4.0/puz_106.htmRSD PUZZLE # 106
Complications Of Spinal Cord Stimulator (SCS)
We have had extensive experience with treating patients who have already undergone spinal cord stimulator (SCS). The SCS is helpful in some patients who suffer from chronic back pain, neck pain, or failed back syndrome. On the other hand, when it is applied to patients suffering from RSD, it may help reduce the pain for anywhere from 7 days to 6-7 months. On average, it helps reduce the pain a little over 2 months. Afterward, SCS will become a new source of pain by stimulating the neuropathic pain sensory fibers in the spinal canal.
Worst of all, the SCS as a foreign body in the spinal canal that instigates a lot of severe pain and inflammation because of the fact that patients with RSD have a tendency to have an abnormal function of sympathetic system, and invariably they suffer from attacks of inflammation in the form of swelling of the extremities, reddish discoloration of the skin, etc. The SCS invariably causes severe inflammatory pain in the spinal canal region. The inflammatory pain is far worse than the original RSD for which the SCS was tried.
The above experience has been the result of treating over 200 patients who already have had SCS treatment. The situation is so bad that when a patient wants to schedule to come to see us for treatment, we first ask the patient to ask the surgeon to remove the SCS before we can give her any effective treatment.
Please ask your doctor to read this letter. At least it will put him on warning that you have more than 95% chance of developing the above mentioned complications.
Another problem with SCS is that it causes disturbance of plasticity and causes rapid acceleration and deterioration of your RSD to later stages of the disease. Another complication of SCS treatment is the fact that it stimulates the sensory neuropathic pain fibers in the spinal canal facilitating the spread of the disease to other extremities.
H. Hooshmand, M.D.
Author
Topic: Information on Spinal Cord Stimulator (SCS) (Read 734 times)