Progressive damage to the nervous system, leading to low blood pressure when standing, difficulty urinating, and abnormal breathing during sleep
Muscle tremor and rigidity (Parkinsonism)
Slow movement (ataxia)

When autonomic failure predominates, the term Shy-Drager Syndrome is often used.

MSA is associated with the degeneration of nerve cells in specific areas of the brain. This cell degeneration causes problems with movement, balance and automatic functions of the body such as bladder control.

Nerve cells in the affected areas of the brain shrink (atrophy). When brain tissue of a person with MSA is examined under a microscope, structures called glial inclusion bodies can be seen. It is the presence of these inclusion bodies in the movement, balance and automatic control centres of the brain that confirms a diagnosis of MSA.

Symptoms

For men, the first sign is often erectile dysfunction (unable to achieve or sustain an erection). Both men and women often experience problems with their bladders including urgency, frequency, incomplete bladder emptying or an inability to pass urine.

As the disease progresses three groups of symptoms predominate. These are:

parkinsonism (slow, stiff movement, writing becomes small and spidery)
cerebellar (co-ordinating movement and balance)
autonomic (automatic body functions) including:

— postural or orthostatic hypotension, resulting in dizziness or fainting when standing up

— urinary incontinence

— impotence

— dry mouth and skin

— trouble regulating body temperature due to abnormal sweating

— breathing difficulties

Not all patients experience all of these symptoms.

Prognosis

MSA usually progresses more quicly than Parkinsons disease (Bower, 1997). Almost 80% of patients are disabled within 5 years of onset of the motor symptoms, and only 20% survive past 12 years. The mean survival is roughly 6 years. Rate of progression differs in every case and speed of decline may vary widely in individual patients.

Treatment

There is no cure for MSA, so treatment involves treating the symptoms.

One particularly serious problem (the drop in blood pressure on standing up) often responds to fludrocortisone, a synthetic mineralocorticoid.

Levdopa (L-DOPA) does not alleviate the symtops of most MSA patients. In fact, poor response to Levdopa has been suggested as a possible element in the differential diagnosis of MSA from Parkinson's Disease.

Terminology

Other terms have been used to refer to this disorder, based on the predominant systems presented. These terms and their distinctions have been dropped in recent (1996 onwards) medical usage, but are helpful to understanding the older literature about this disease:

Read more at Wikipedia.org

• [List your site here Free!]

Left-leg Atrophy
From National Dragster, 11/5/04 by Dillashaw, Bruce

Tire spin was in 40 years ago, but since the invention and development of centrifugal slider clutches, it's a sign of failure

It used to be that fuel drivers were smart and the clutches were dumb. Now it's the clutches that are smart and the drivers who are ... well, let's just say that before 1967 it was up to the driver of a Top Fueler to put just the right amount of rpm in the engine on the starting line before he banged out the clutch pedal so as to achieve just the right amount of tire spin for a quick and fast run. Since the late 1960s and the invention of the first slipper/centrifugal clutches, the driver only has to hit the gas on time and have the courage to hold it down to the finish line.

In the beginning - we're talking the days of Ford flathead-powered doorslammers on the local abandoned World War II airport runway - the cars didn't have enough power to spin the tires. To get some tire-spinning momentum at the start, the engine had to be revved up and the clutch pedal banged out. That's the way most drag racers learned to leave the line, and they carried that technique with them as they moved up in class through faster cars, eventually to dragsters. By the early 1960s and a move to dragsters, the clutches were still the same pedal- and spring-type' the drivers began with - the kind still used in manual-transmission cars. The drivers were comfortable with the tire-spinning leave, but by then the slingshots they were driving had too much power to traverse the entire quarter-mile while feathering the clutch without at some point spinning the tires when full power was applied.

Many improvements are discovered by accident. It's now part of drag racing lore that some oversized Top Fuel driver in the mid-1960s hopped into a dragster too small for him and didn't have room to retract his leg fully from the clutch pedal, so he made the run while inadvertently slipping the clutch instead of the tires. The result, apparently, was a quicker e.t. than the previous tire-spinning drivers had been able to produce.

The first slipper clutches, of which there were two types - the pedal-activated centrifugal and the purely centrifugal as manufactured by Grower, called the Crowerglide - came on the scene around 1967. The pedal-type had activating springs in the pressure plate, as had always been used, but also had three centrifugal levers that squeezed the two discs as engine rpm increased. The pedal-type allowed the driver to rev 'the engine to any desired rpm on the starting line with the clutch pedal depressed, snap out the pedal, and have the centrifugal levers take over shortly afterward to further engage the clutch for maximum acceleration. This type of hybrid clutch is still used in Top Alcohol Dragster and Top Alcohol Funny Car.

The Crowerglide also had a pedal, but only to provide a neutral function; it had no springs to provide clamping force. With the engine running and the clutch pedal out, as soon as the engine rpm was brought above an idle, the centrifugal levers began squeezing the clutch discs, and if the driver wasn't ready to move, he had better have been practicing his biceps curls with the brake handle. Because fuel cars have more than double the horsepower of the methanol cars and as a result don't need to rev the engine for a quick start, this is the type of clutch they use. For more than 15 years after the first slipper clutches in 1967, the evolution of fuel clutches remained stagnant, though by 1985, six centrifugal fingers were on the pressure plate and up to four discs in the clutch pack. Power was multiplied through a two-speed Lenco transmission.

Clamping down

The installation of data recorders in 1985 provided an eye-opening revelation to fuel tuners. Racing with the assumption until then that the clutches were locking up downtrack, the data graphs immediately showed that the engines were turning as much as 600 rpm faster than the driveshaft. Dale Armstrong, tuner for Funny Car star Kenny Bernstein, was the first to install three auxiliary levers that could be activated downtrack by a timer and provide the extra clamping force needed to lock up the clutch.

The cat jumped out of Armstrong's tuning bag at the 1986 U.S. Nationals. On a solo qualifying run, everybody paying attention heard the engine in Bernstein's Budweiser Funny Car "pull down" on the top end. It sounded as if he had shifted into a third gear. Bernstein qualified No. 1 on the run with a 5.50 at 271 mph that was .16-second quicker a,nd 20-mph faster than the No. 2 qualifier's time. Needless to say, everybody jumped on the lockup clutch, and by the end of the 1980s, the clutches had multiple stages, transmissions were gone, and e.t.s dropped and speeds rose dramatically. The best times in Top Fuel at the 1986 U.S. Nationals were 5.34 and 269 mph. Just two years later, Eddie Hill ran the first Top Fuel four at a tick under 290 mph.

Today's fuel clutches are equipped with as many as six discs and have 18 centrifugal fingers. Six primary fingers are not controlled by the automated air-over-hydraulic clutch-management system. These are always in contact with the clutch pack and are used for the burnout and the initial launch. Before the car clears the Tree, the remaining 12 fingers one at a time begin to squeeze the clutch pack as the preset air timers allow the throwout bearing to move rearward.

Forty years ago, rooster tails of tire smoke off of the dragsters were part of the visceral excitement of big-time drag racing; drivers wanted to smoke the tires. Today, tire smoke on a run is a loathsome thing for tuners to see.

Return to Multiple system atrophy

Home

Contact

Resources

Exchange Links

ebay