Posts Tagged ‘spinal cord’

Coming Soon? Restored Breathing for Spinal Cord Injury Patients

Wednesday, July 20th, 2011

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The online version of the journal Nature publishes an article today about a potential breakthrough in the treatment of spinal cord patients. While I do not have access to the full article, medicalnewstoday.com provides an overview of the research work. The highlight is that the researchers from Case Western Reserve University School of Medicine were able to restore breathing in rodents with spinal cord injuries.

This research provides optimism for similar success in humans (clinical trials with humans are hopefully forthcoming). In the recently released studies, the scientists combined “…an old technology a peripheral nerve graft, and a new technology an enzyme” to be able to restore 80-100% of breathing function in the rodents.

Using a graft from the sciatic nerve, surgeons have been able to restore function to damaged peripheral nerves in the arms or legs for 100 years. But, they’ve had little or no success in using a graft on the spinal cord. Nearly 20 years ago, [Jerry Silver, professor of neurosciences at Case Western Reserve and senior author,] found that after a spinal injury, a structural component of cartilage, called chondroitin sulfate proteoglycans, was present and involved in the scarring that prevents axons from regenerating and reconnecting. Silver knew that the bacteria Proteus vulgaris produced an enzyme called Chondroitinase ABC, which could break down such structures. In previous testing, he found that the enzyme clips the inhibitory sugary branches of proteoglycans, essentially opening routes for nerves to grow through.

In this study, the researchers used a section of peripheral nerve to bridge a spinal cord injury at the second cervical level, which had paralyzed one-half of the diaphragm. They then injected Chondroitinase ABC. The enzyme opens passageways through scar tissue formed at the insertion site and promotes neuron growth and plasticity. Within the graft, Schwann cells, which provide structural support and protection to peripheral nerves, guide and support the long-distance regeneration of the severed spinal nerves. Nearly 3,000 severed nerves entered the bridge and 400 to 500 nerves grew out the other side, near disconnected motor neurons that control the diaphragm. There, Chondroitinase ABC prevented scarring from blocking continued growth and reinnervation.

“All the nerves hook up with interneurons and somehow unwanted activities are filtered out but signals for breathing come through,” Silver said. “The spinal cord is smart.”

Three months after the procedure, tests recording nerve and muscle activity showed that 80 to more than 100 percent of breathing function was restored. Breathing function was maintained at the same levels six months after treatment”

From medicalnewstoday.com

This could be life-changing for those spinal cord injury patients who currently need ventilators to survive. If human studies prove the efficacy of such treatment, patients would have the hope of being able to breath on their own again. Not only would this dramatically improve these patients’ quality of life, but it would also provide a dramatically improved outcome for these patients. Currently, “[r]estoration of breathing is the top desire of people with upper spinal cord injuries. Respiratory infections, which attack through the ventilators they rely on, are their top killer.”

The BBC is reporting that “[r]esearchers hope to begin trials in humans. They are also investigating whether bladder function can be restored, which can be lost when the lower spine is damaged.”

The CDC’s most recent statistics, which are a few years old, suggest that there are currently about 200,000 people in the United States who are living with spinal cord injuries. This number increases by approximately 12,000-20,000 new patients annually. If some portion of these individuals could be provided hope for breathing on their own and or regaining bladder function, their lives could be dramatically improved.

Related Articles:

Spinal Cord Injury Updates: More Reasons for Optimism?

New Treatment Holds Promise for Patients With Spinal Cord Injuries

New Microchip Promises to Make Life Much Easier for Paraplegic Patients

Spinal Stroke: An atypical cause of back pain

Monday, April 11th, 2011

When one hears the word stroke, what typically comes to mind is a “brain attack” with slurred speech or numbness and weakness of the right or left side of the body. Well, the spinal cord is considered part of the central nervous system and is truly a direct connection to the brain. All of the data received through nerve endings in our bodies passes through the spinal cord to be interpreted in the brain. Likewise, the messages our brain is sending to our bodies, both consciously and unconsciously (e.g. walk, run, write, speak; and digest food, breath, increase heart rate, etc.), travel through the spinal cord to our peripheral nerves.

The spinal cord is a vital structure that has its own blood supply, much like other organs, including the heart and brain. Just like the blood vessels supplying the other organs, the spinal arteries, especially the anterior spinal artery, can become occluded (i.e. blocked) resulting in spinal cord ischemia or infarction. The nerve information can no longer travel to and from the brain or the body freely; it is interrupted. This equates to a “stroke” of the spinal cord with resultant numbness, weakness, paralysis, as well as bowel and bladder dysfunction below the level of the infarction/stroke.

What causes a “spinal stroke”?

The most common cause of spinal stroke is the same as that for brain stroke or heart attack……atherosclerosis, an accumulation of cholesterol plaque in the arterial wall that ultimately blocks the artery. No blood flow means no oxygen or nutrients to the cells and tissues of the spinal cord resulting in them “starving to death.” There are other causes, as well; anything that compresses one of the supply arteries can block blood flow to a region of the cord and result in “stroke.”

Tumors, either primary or metastatic, can compresses blood vessels and other structures as they grow in the spinal region. Anterior disc herniations and disc ruptures or bone fragments from traumatic fractures of the vertebrae can compress blood vessels in the immediate vicinity.

Collections of pus from infectious processes can interrupt the blood supply either by compressing a vessel or disintegrating the blood vessel.  Small pieces of blood clots (called emboli) can break-off from larger clots (called thrombi) and circulate through the bloodstream until they get “stuck” in a smaller vessel somewhere else in the body; the spinal artery is just one location. Other systemic diseases can result in vasculitis, or an inflammation of the blood vessel, that leads to clotting and occlusion of that vessel, and the spinal artery is just one of the vessels that can be affected.

Surgery and spinal stroke

Interestingly, inter-abdominal and spinal surgical procedures can also lead to spinal cord ischemia and stroke. Individuals undergoing repair of an aortic aneurysm or iliac-to-femoral artery bypass often require “cross-clamping” of the aorta above the level of the surgery. The “golden hour” referred to in heart attack victims can also be applied to other vascular ischemic conditions, like spinal artery ischemia; if complications arise and the cross-clamp time is too long, it can result in ischemia from which the patient may never recover, remaining paralyzed for life. Similarly, an aortic dissection can disrupt blood flow to the smaller arteries branching from the aorta to feed the spinal cord leading to ischemia.

Spinal surgeries take one of two approaches, anterior (going through the belly) or posterior (going through the back). Because of the proximity of all of the vital structures, including the major blood vessels, small errors or retained fragments can lead to occlusion or disruption of the spinal blood supply.

Who is at risk for spinal stroke?

Those individuals with risk factors for heart disease or brain stroke are also at risk for spinal stroke since they share a common etiology. This includes those individuals with poorly-controlled diabetes, high cholesterol or dyslipidemia, abnormal clotting of the blood, peripheral arterial disease or history of aneurysms.

What are the symptoms of a spinal stroke?

Most patients present with sudden, severe pain, much like a heart attack, in either the chest or the back or both. This pain is typically rapidly followed by numbness, or loss of pain sensation and temperature sensation, in the extremities below the level of the stroke. Because of the anatomy of the blood supply, vibration sensation and position sense are maintained in the affected region since the posterior region of the cord has a different blood supply. As the spinal stroke progresses over an hour or so, the extremities affected become weaker and weaker, often experiencing paralysis, and the bowel and bladder lose their innervation leading to dysfunction and incontinence. This is a fairly rapid progression, much different that other myelopathies.

What is the treatment?

Due to the relative rarity of this condition, not many studies have been done regarding treatments. Unlike “heart attack” or “brain attack,” there are no standards of care except for aspirin therapy and (potentially) anti-platelet therapy after the stroke has occurred. More often than not, there is a delay in diagnosing the condition due to the rarity of the condition and the need to confirm the diagnosis by a diffusion-weighted enhanced MRI of the spine, such that “clot-busting” agents are time-excluded from use. Treatments are then focused on preventing additional vascular events, preventing deep vein thromboses in the paralyzed limbs, preventing bladder infections and fecal impactions, preventing decubitus ulcers and soft tissue infections, and preventing the additional morbidity associated with paralysis. This is not a comforting thought!

We are blessed with today’s medical technological advances that allow for so many life-saving procedures and procedures that preserve body function, such as spinal surgery, vascular stenting procedures and epidural injections. Unfortunately, some of these procedures have increased the incidence of spinal strokes due to the nature of the procedures themselves. The current epidemic of obesity and metabolic syndrome is also indicative of more cases of diabetes and atherosclerotic vascular disease which, according to the law of probability, will increase the incidence of this potentially devastating medical condition.

Clinical Trials Underway

Do you know someone who has had a spinal stroke? What was his or her age? What might have precipitated the “attack”? Some individuals have been in their early 20′s when the attack occurred. Needless to say, this is truly devastating! With all of our advanced technology, we should be doing a better job of preventing, diagnosing and treating this condition. The National Institutes of Health (NIH) does offer clinical trials for this condition; please refer to their website for further information. ( http://www.ninds.nih.gov/disorders/spinal_infarction/spinal_infarction.htm)

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