This article was written by Eric S.
Fishman, M.D., Orthopedic Surgeon,
and founder of 21st Century Eloquence.
"We have had substantial experience curing
Carpal Tunnel Syndrome with the use of
Voice Recognition Software such as
Dragon NaturallySpeaking"
Carpal Tunnel Syndrome, clearly the most common of the cumulative trauma disorders, can present secondary to a large number of primary causes. We will discuss here those causes which involve repetitive motions of a modest force. However, single acute traumatic events can cause CTS. Fractures of the wrist bones (the carpal bones) as well as fractures of the distal radius near the wrist can cause CTS. Acute injuries which merely stress the wrist excessively, even if for only a very short period of time, such as in a rear end motor vehicle accident while grasping the steering wheel, can cause this problem. In fact the list of potential causes for CTS is exceedingly long, and includes: alcoholism, hemophilia, local tumors such as a lipomata or ganglia, hormonal changes, menopause, pregnancy, rheumatoid arthritis, thyroid imbalance, acromegaly, multiple myeloma, amyloidosis, diabetes mellitus, and local trauma to the wrist as is sometimes seen in motor vehicle accident victims such as the driver who is clutching the steering wheel and experiences a deceleration injury or even the passenger who tries to restrain himself on the dashboard injuring the palmar surface of the hands.
Carpal tunnel has also been exhibited in children that are clinically found to have atrophy of the index finger. Some of the traumatic clinical presentations of carpal tunnel syndrome are in patients with fractures of the distal radius. It is believed that 60% of the patients at some time during the recovery of a distal radial fracture may have compression on the median nerve. Luckily, not all of these patients need to be treated surgically. A large portion improve with time and conservative measures.
What is CTS? It is a condition in which one of the major nerves of the hand, the Median nerve, malfunctions. It is perceived at first as an uncomfortable feeling in the hand, frequently associated with tingling, or paresthesias. These paresthesias become more and more frequent as the condition progresses, and sometimes can be continuous. They occur significantly more frequently at night, during sleep, and will frequently wake patients up from sleep. The classic comment includes 'I wake up in the middle of the night with my hands tingling and I have to shake them to make them stop.'
Some other initial symptoms of carpal tunnel syndrome may be inability to manipulate objects that in the past were easy to handle and control. The patient may also complain of weakness, hypesthesia, or paresthesias. This numbness and tingling would be in the distribution of the median nerve which include the thumb, index, and middle finger. The patient may also notice an increase in symptomatology when performing repetitive grasping.
Other early symptoms include pain at the wrist which migrates into the upper arm or even into the shoulder region. The pain that is found migrating from the wrist to the elbow and forearm region is somewhat unusual but is sometimes seen with carpal tunnel syndrome.
These paresthesias eventually lead to a more dense sensory abnormality consisting of diminished sensation and eventually numbness in the fingers which are controlled by the injured nerve: the thumb, index, long, and ½ of the ring finger. It is frequently described as feeling as if there were a rubber or leather glove on the hand. Depending upon the discrimination of the person involved, the symptoms, particularly in the early stages, can be perceived as being throughout the entire hand. An explanation for this phenomenon has not been adequately described. However, it is not exceptionally uncommon to have symptoms coming from the Ulnar nerve simultaneously, and this is one potential cause for this more global symptomatology.
As the Median nerve becomes further damaged the diminished sensations can turn into frank numbness. However, in most instances, long before the numbness appears motor difficulties surface. The first of these is a general feeling of a lack of co-ordination. This occurs quite frequently with Ulnar nerve injuries, to be discussed in the chapter on Cubital Tunnel Syndrome. However, it is also a common occurrence with Carpal Tunnel Syndrome. As the disease progresses this lack of co-ordination turns into a generalized weakness, and eventually a severe debilitating weakness. This weakness involves most particularly the thumb; specifically the motion of opposition, or the movement of bringing the thumb out of the plane of the hand. If you hold your hand flat on a desk, with the palm facing up, opposition is the movement of bringing the thumb to point towards the ceiling: It is common to see wasting of the muscles of the 'fleshy' part of the hand, near the thumb, in advanced Carpal Tunnel Syndrome.
Carpal Tunnel Syndrome has been described and studied since 1863 by one of the first true pioneers, Sir James Paget.
It wasn't until 1913 that Marie Et Foix described the pathological changes of the median nerve. The name of the syndrome was coined by Moersh in 1938. Extensive research and the first surgical release of the median nerve was performed by Cannon and Love in 1946. In 1950, due to a large number of articles by Dr. Phalen, carpal tunnel release became a common surgical intervention for this syndrome.
Since that time, there have been innumerable case studies as well as major university studies on the subject. Notwithstanding this extensive attention given this condition, many questions remain regarding its exact etiology and proper treatment.
The Carpus is the part of the body that most people call the wrist.
This is constructed of the eight bones called the Scaphoid, Lunate, Pisiform, Triquetrum, Trapezium, Trapezoid, Capitate, and Hamate. These eight bones are contained by larger bones called the metacarpals on one side and, on the other side, are constrained by the ulna and radius. The carpal canal or tunnel is a space on the palmar side of the wrist which is bounded by the carpal bones on the back or posterior aspect, the hook of the Hamate, and Pisiform on the ulnar or little finger side, the Scaphoid on the radial or thumb side, and the transverse carpal ligament on the volar or palmar side.
This Transverse Carpal Ligament is believed, by some, to be the offending structure in Carpal Tunnel Syndrome, but it most probably is the major cause of CTS in only a few situations.
While it is true that the Transverse Carpal Ligament does indeed press on the tissues beneath it, including the Median Nerve, it appears more likely that the reason for this pressure stems not from the ligament itself, but rather from the contents of the Carpal Canal.
Specifically, there are 9 tendons and 1 nerve. There are two flexor tendons to each of the fingers and one flexor tendon to the thumb. The nerve, of course, is the Median Nerve.
Anything that increases the volume of the contents of the carpal canal will increase the pressure within the canal, assuming that the canal does not increase in size.
Obviously ligaments and bone are not very elastic, and therefore the canal is not likely to increase in size. But it does seem unlikely that the ligament itself is the cause of the increased pressure in all but rare situations.
What then will increase the volume of the contents of the carpal canal? Obviously fractures can do this as can severe acute traumatic events.
Equally important, however, is the fact that muscles and tendons which are exercised hypertrophy. The former should be quite obvious to anyone who watches the career of a weightlifter. The more they exercise the bigger the muscles get. When the muscle is the biceps, that's not a problem. However, if the muscle is an anomalous or unusual muscle within the carpal canal, this certainly can be a problem. If there is enlargement of a usually small muscle underneath the Transverse Carpal Ligament then this will obviously increase the pressure within the canal. This is, I believe, a known, but relatively unusual situation which occurs because of 'overuse'.
However, tendons also hypertrophy with stress. As we know, there are 9 flexor tendons within the Carpal Canal. Each of these is stressed each time something is grasped within the flexed hand. Over time these tendons enlarge, causing pressure on themselves and on the Median Nerve. The pressure on the tendons is not of any exceptional interest since tendons are able to withstand significantly more pressure than can nerves. The pressure on the nerve is a different matter.
To complicate the situation even more, there is a structure surrounding each of the tendons within the carpal canal. This structure is synovium. Synovium is a lining tissue which lines most of the joints of the body as well as many tendons. Synovium produces synovial fluid, or the lubricating fluid which is found within the joints and the tendon sheaths. The synovium is most commonly the first structure to enlarge with excessively repetitive motion. This inflammation is probably the singularly most common cause of increased contents within the canal thus causing increased pressure and carpal tunnel syndrome.
The exact physiologic cause of the malfunction may be multifactorial. However, the essential aspect of a Carpal Tunnel Syndrome, the sine qua non, is that the median nerve no longer transmits its impulses as it normally should.
What are the causes for this lack of normal transmission? In most instances there is increased pressure within the carpal canal. Many studies have been performed which clearly show that the pressure within the carpal canal increases with extreme postures of the wrist. Excessive dorsiflexion (extension) causes the greatest increase in intra carpal canal pressure. However, flexion as well as radial and ulnar deviation (moving the wrist from side to side) also cause significant increases in pressure.
There are a large number of preventative measures which are available to attempt to avoid carpal tunnel syndrome, even in the worker who needs to maintain an active income in an occupation which requires a substantial amount of repetitive motion.
The area which has been studied most extensively is in keyboard operators. For instance, it has been shown through numerous studies that slight variations in the position of the wrist can alter the incidence of CTS significantly. Thus we have seen an extensive proliferation of products which have, as their aim, alteration of the wrist, elbow or shoulder position.
These products include keyboards with altered shapes, drawers to place keyboards at different locations, keyboards of standard shape but with adjustments available, such as adjustable heights and angles, keyboards with varying pressure requirement for keystrokes.
Also available are a plethora of rests which can be placed on the desk in front of the keyboard. These come in a variety of shapes, sizes, textures, and colors. They come with magnets and without. Except for the variety of colors available, each of the other parameters appears to be of some importance in altering the incidence of CTS in keyboard operators
Of course furniture has been designed with the cumulative trauma disorder sufferer in mind. There are chairs, backrests, desks, keyboard holders, arm rests, book holders, paper holders, and lighting.
By far the most effective way to avoid carpal tunnel from keyboard use is to avoid keyboard use altogether. There is available a wide variety of voice recognition software which allows users to voice activate their computers. This method completely obviates the need for any typing, thus eliminating the stress placed on the hands via keyboard use.
Of course, not all carpal tunnel syndromes are caused by keyboard entry activities. The list of potential work related causes of CTS is enormous, including check-out clerks, newspaper inserters, assembly line workers, sheet metal workers, hairdressers, manicurists, etc., etc. The specific preventative methods which are appropriate vary significantly by work environment, and the best method of minimizing the potential for carpal tunnel syndrome in these workers is a personalized evaluation by a Physiatrist, Occupational Therapist, or other health-care worker who is well versed in the complexities of this type of cumulative trauma disorder.
However, there are a number of basic principles which can be utilized as a first step in minimizing the potentially devastating effects of CTS. These include teaching the use of alternating hands in the activity. Using the left hand for the morning and the right in the afternoon can be helpful, as can using the left hand for the first activity immediately alternating with the right.
Placing the worker in a proper location with respect to the work at hand can be very effective. Methods as simple as offering an employee a step stool of a few inches can alleviate the straining position of the wrist which might have been required when working at the wrong vertical alignment.
The use of splints, to be discussed at length elsewhere, can be of assistance.
For those using hand tools, such as mechanics, altering the handle of the hand tools can significantly alter the mechanics of grip, thus minimizing the amount of force present within the tendons within the carpal canal. This can be helpful for auto mechanics as well as construction workers. Frequently increasing the size of the grip, particularly in conjunction with making specific notches for the fingers can be of assistance. This has the effect of diminishing the amount of force required to hold the tool in place, and as has been noted elsewhere, the frequency of cumulative trauma disorders is highly correlated with the degree of force needed with each repetition of the activity.
Similarly, altering the angle between the handle of the hand tool and the working portion of the hand tool can be effective. As we have discussed, the pressure within the carpal canal increases drastically when the wrist is held in positions far away from the neutral position. Thus, if you need to hold the wrist in either extension or flexion, or in radial or ulnar deviation while working, moving the handle to a more natural angle can be all that is needed to prevent the problem from occurring.
The alteration in the design of hand held tools has been considered so important that there are custom made designs for each of the following types of hand tools: crimpers cutters, dicers, drills, grinders, hammers, jacks, knives, mallets, pliers, sanders, screwdrivers, scissors, spray guns, surgical instruments, tweezers, wire strippers, wrenches, and a host of other equipment.
There are almost as many treatments for CTS as there are theories about its causes. First, one must diagnose the reason for the CTS. If it is a hormonal problem, such as Thyroid dysfunction, the underlying condition requires treatment, and frequently successful resolution of the underlying problem leads to resolution of the CTS.
Assuming that we have concluded that the underlying cause of CTS in your instance is not one of the more unusual causes, but rather either a specific impact upon the wrist, or more commonly, cumulative micro-trauma, the earliest form of treatment is rest.
Rest, however, does not always imply a complete lack of activity. Relative rest can be adequately effective for situations in which the excessive activity is the major cause of the problem. Thus, for most people with early CTS caused by repetitive motions, such as assembly workers, keyboard operators and cashiers, merely discontinuation of the activity is sufficient to alleviate the symptoms, and sometimes cure the problem. This, obviously, is not adequate advice for those who need to work at the specific job at which they are currently working. However, in situations where employees have the liberty of changing occupations or activities at their workplace, this simple method can be the most effective method of treatment available.
When changing work status is not an available option, a more formal resting of the wrist and fingers is appropriate. While rest seems easy to accomplish, there are a few products which make it easier to do. A standard easy-on cock-up wrist splint can be utilized both at work as well as at home. These are frequently found to be most helpful if used while sleeping. If utilized at night they frequently diminish or stop the interruption in the sleep pattern caused by waking up with tingling hands.
Exercises can be useful to alleviate the early symptoms of carpal tunnel syndrome. This would at first appear to be contradictory since it is the excessive use in the first place which seems to cause the condition. However, a specialized set of exercises has been shown to be effective in allowing for improvement. Stretching of the flexor groups such as the digitorum, superficialis, abductor pollicis brevis, and palmaris longus will help bring down irritation of the synovial sheath of all of these tendons. Aside from this, the patient would be asked to counterbalance the function of the hand by strengthening the extensors of the wrist thus alleviating some of the strain and demands of the flexor tendons that pass through the carpal tunnel. With the use of both stretching and strengthening, the patient can be treated conservatively to alleviate the early symptoms of carpal tunnel syndrome.
Nutritional factors come into play with CTS as they do with many medical conditions. While the physiologic explanation is lacking, there is widespread evidence the appropriate doses of Vitamin B6, all called Pyridoxine, can alleviate the symptoms of CTS or even, in some instances, cure the underlying disease. This is best supplied in a vitamin called Mega-B which is composed of vitamins A, D, C, E, B1, B2, B6, and B12. The indication for this multi supplement is supplied in capsule-shaped tablets in bottles of 30, 100, and 250. Usual daily dose for an adult is one tablet per day. The warning given by The Physician's Desk Reference is that this is not intended for the treatment of percutaneous anemia or other primary or secondary anemia.
Other more ingenious methods have been developed for resting the wrist and fingers. There is a Pil-O-Splint which allows for almost complete wrist and hand rest at night. It is incompatible with any form of manual activity, however, and can be utilized only when sleeping or resting.
There are many proponents of gentle massage &/or stretching of the tissues for relief of CTS. Manual stretching and massage, by a massage therapist, physical therapist or occupational therapist has proven beneficial in many instances. Commercial appliances are available to put traction on the wrist at home.
Exercises can be useful to alleviate the early symptoms of Carpal Tunnel Syndrome. This would at first appear to be contradictory, since it is the excessive use in the first place which seems to cause the condition. However, a specialized set of exercises has been shown to be effective in allowing for improvement.
The standard surgical treatment for Carpal Tunnel Syndrome is the Carpal Tunnel Release. It has been performed successfully for decades, and many surgeons report over a 90% success rate.
The standard open release can be done under local anesthesia, but is commonly performed under Bier Block anesthesia, with the entire arm asleep and a tourniquet on the upper arm.
A small incision, frequently no larger than 2 inches, is made in the palm of the hand and the transverse carpal ligament is transected or cut in two. Frequently a small piece of synovium can be removed and sent to the laboratory for microscopic examination.
Other forms of carpal tunnel release have been performed more recently including the endoscopic release. In this procedure 2 smaller incisions are made in the palm and instruments are passed under the skin allowing the surgeon to cut the transverse carpal ligament.
There appears to be a significantly higher complication rate with this type of surgery for all but very experienced surgeons. The end results also appear to be quite similar to the standard open method, with the exception that there does appear to be some lessening of the amount of time out of work with this method.
Voice Recognition Software to prevent CTS
© 1997 - 2001, Eric S. Fishman, M.D., All rights reserved. No part of this article may be reproduced in any fashion without the prior written authorization of the author.
Please Note: ALL of the above is for informational purposes ONLY and is not intended to be medical advice. If you have ANY symptoms discussed in this article, it is highly recommended that you seek personal medical attention. Neither Eric S. Fishman, M.D., nor Gold Coast Orthopedics treats patients without first obtaining a history and physical examination in person at the offices of Gold Coast Orthopedics, and no attempt to offer medical treatment is hereby being made via this website.