Tag Archives: Brain

Science: New Research Into Diseases Of The Brain

Take an animated look inside the neuron, and learn how scientists are addressing brain disease. With approximately 86 billion neurons in the brain, humans contain the most complex communications network imaginable. To address diseases of brain development and degeneration, neuroscientists are investigating how and why this network breaks down, and what can be done to repair it.

One area of study is dendrites, which are the tree-like structures of neurons, that receive electrical impulses. Researchers are carefully mapping out brain circuits and uncovering how connectivity changes can result in defects of the visual system or behavioral problems. The core section of the neuron is the cell body. Genetic engineering tools are revealing how mutations impact brain development and contribute to autism spectrum disorder or rare, inherited forms of neurological disease.

The transmission of nerve impulses occurs along the axon, which is insulated, much like an electrical wire, by a fatty layer called the myelin sheath. Scientists have invented a medicine to stop the immune system from mistakenly attacking this layer, which occurs during multiple sclerosis. Other molecules currently in development instruct the body to regenerate the sheath and repair damage. The axon also transports valuable cellular cargo, such as neurotransmitters, along tracks from one end of the neuron to the other.

Researchers are testing drug candidates for their ability to remove molecular traffic jams when this transport system fails, as often occurs in Parkinson’s and Alzheimer’s disease. The axon terminals make connections called synapses with other cells, using neurotransmitters as signals. Some scientists are evaluating how finely tuning the receptors for these chemicals could ease depression and anxiety.

Others are finding ways to promote the regrowth of lost synapses, which could halt neurodegeneration. From genetics to behavior, neuroscience is accelerating new interventions for the most challenging disorders of the nervous system.

Learn more: https://www.scripps.edu/

Stroke: Long Periods Of Sitting Increases Risks

The study involved 7,607 adults who wore a hip-mounted accelerometer (a device that records how fast you move) for a week. Their average age was 63. During a follow-up period averaging 7.4 years, 246 of the participants experienced a stroke.

People who sat for 13 or more hours per day during the initial week of motion tracking were 44% more likely to have a stroke compared with those who’d spent less than 11 hours per day sitting still. In addition, longer bouts of sitting (more than 17 minutes at a time) were linked to a higher risk than shorter bouts (less than eight minutes).

Stroke Care: Deep Brain Stimulation ‘Pacemaker’ Restores Hand Movement

Deep brain stimulation for patients who experience a stroke.

Deep brain stimulation is a surgical procedure that involves implanting electrodes in the brain, which deliver electrical impulses that block or change the abnormal activity that cause symptoms. (Courtesy: Cleveland Clinic)

“He had limited use of his hand. It really wasn’t functioning,” explains Andre Machado, MD, PhD, who is Chairman of the Cleveland Clinic Neurological Institute. “He couldn’t do as much manual work, with both hands, and that was a limitation for his quality of life.”

For the study, Joe first underwent two surgical procedures — one to insert the DBS device under the skin of his chest, just below the collarbone, and the other, to implant the DBS electrode in a part of the cerebellum called the dentate nucleus. Once activated, the device, called an implantable pulse generator, serves as a specially-calibrated pacemaker for the brain, stimulating it to try and enhance motor rehabilitation.

COMMENTARY:

Many times in science, application precedes understanding. Deep brain stimulation, either by electrical or magnetic pulses is a good example.

It is not at all understood how the brain really works, much less how electrical and magnetic stimulation in the brain works. It may stimulate or slow down neural impulses, or interrupt the incoming signals or the outgoing messages. Are there any other possibilities?

At least it does work, Apparently.

One thing for certain is that deep brain stimulation is preferable to previous treatments, which produced small, destructive, irreversible lesions in the brain. At least these stimulations can be stopped if they don’t work.

I enjoyed this posting, since it reignited my interest in the cerebellum. This amazing Organ has more neurons than the rest of the brain combined, represented by innumerable small granule cells. I wasn’t even aware of the dentate nucleus, which is an island of cerebral cortex-like neurons in the white matter of the cerebellum. Apparently the action of the cerebellum is orchestrated through this and a couple of other islands of neurons. All of the coordination, movement, and thought processing accomplished in the cerebellum takes place through these nuclei.

It was also fascinating to learn of a patient who has complete lack of a cerebellum, and suffers only some mild incoordination and speech problems. Apparently, absent the cerebellum, the rest of the brain is largely capable of taking over the function of the missing cerebellum. Once the brain is formed, However, and dependent upon the cerebellum, damage to this organ causes a great deal of coordination, movement, and balance problems.

I’ll put another plug-in for sleep, diet and exercise, as well as being careful with your body. Prevention is far better than treatment.

—Dr. C.

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Mayo Clinic: Treatments For Brain Aneurysms

Robert D. Brown Jr., M.D., M.P.H., E. Paul Lindell, M.D.,Giuseppe Lanzino, M.D., and Harry Cloft, M.D., Ph.D., explain what a brain aneurysm is and the different treatment options there are at Mayo Clinic for a patient with a brain aneurysm.

Mayo Clinic neurovascular experts care for 17,000 people each year with aneurysms, strokes, and other blood vessel and cerebrovascular conditions. Each brain aneurysm is unique. Your doctor will use state-of-the-art arterial imaging to evaluate, diagnose and assess the aneurysm’s risk of rupture.

Every patient has team of doctors working together to create an individualized path of care. Some aneurysms do not require surgery and are closely monitored instead.

Find out about the care you can receive for brain aneurysms at Mayo Clinic at https://mayocl.in/370ZldS

Neurological Disorders: ‘Tension-Type Headache’

Multiple Sclerosis: The Early Signs & Symptoms

MS symptoms vary depending on the brain or spinal cord area that’s affected. According to the National Multiple Sclerosis Society, more common symptoms include:

  • Fatigue so extreme it interferes with ability to function at home and work.
  • Numbness or tingling often felt in the torso, face, arms and legs.
  • Problems with walking because of balance, muscle weakness, stiffness or fatigue.
  • Visual issues such as blurred vision and pain with eye movement.
  • Dizziness and vertigo with feelings of being off balance or lightheaded.
  • Constipation or loss of control of the bowels.
  • Bladder issues.
  • Problems with cognitive function like short-term memory and processing.

Infections: Cryptococcus Neoformans (Fungi)

Cryptococcus neoformans and gattii are fungi that most commonly infect people with immunodeficiency, especially AIDS, which is highly prevalent in Africa. Cryptococcus is the final cause of death in perhaps 25% of AIDS patients and preventative treatment is sometimes used if the lymphocyte count is too low.

It is an opportunistic fungus, with similarities to pneumocystis carina, which is discussed in a previous entry.

The areas in the body most commonly affected are the lungs, the skin, and the brain. The lung and skin, being exposed to the environment, are the most common entry points for the fungus, and the brain is a frequently involved area. Chronic meningitis, where the symptoms include headache, blurred vision, and confusion, is frequently caused by cryptococcus.

Sometimes, in healthy people, the skin can be infected with “pigeon breeders disease”. Pigeon droppings are a very common source of cryptococcus organisms.

Infection In the lung is usually restricted to immunocompromised individuals, who develop cough, shortness of breath, and fever. Pulmonary cryptococcosis is a slowly developing disease, can be mistaken for tuberculosis, and frequently gets into the bloodstream and then into the brain.

Treatment is usually with amphotericin B and flucytosine.

—Dr. C.

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INFECTION: OPPORTUNISTIC INVASIVE FUNGI EXPLAINED

Fungi are in the outside air, the inside air, and even the air of isolation units In hospitals. The normal human respiratory tract is able to breathe these fungi in, have them deposited on the mucous membrane surfaces and have no problem. The normal respiratory membranes, with their associated cleansing cilia and normal mucus production are able to sweep the invaders out without sustaining any harm.

Problems arise when the respiratory tract is functionally or structurally abnormal, such as in cystic fibrosis, bronchiectasis and COPD. Immunocompromised conditions have been increasing in frequency with the improvement in medical care in recent years. Intravascular catheters and sensors can provide a resting place for pathogens including fungi, as can cavities, scars and other damage to the lung. The immune system may require suppression to accommodate an organ transplants or ameliorate autoimmune conditions.

Cancers, especially of the hematologic or lymphatic system, such as lymphomas, pose a definite problem. Severe burns and  malnutrition may weaken the immune system, as may Viral infections, especially AIDS, and more recently COVID-19. More subtle immune problems may arise with diabetes, Obesity, or even a lack of sleep and exercise.

These and other conditions give the fungal infections the OPPORTUNITY to invade the body, and a few dozen of the thousands of species of fungi proceed to do just that. Opportunistic fungi often have special features, depending upon the species. Most prefer the respiratory tract, and if they get in to the bloodstream can go to their favored spots.

Aspergillus, and coccidiomycosis , for instance, prefer the lung. Mucormycosis often involves the sinuses and eyes. Blastomycosis can involve bone. Sporothrix is often found infecting the skin.

Symptoms depend upon the area involved. Of course if it’s a respiratory tract, you have coughing, mucus production, sometimes shortness of breath. With the central nervous system you have headache and confusion. You can see the involvement in the skin.

The number of drugs available to fight fungal infection is fairly limited, and currently involves only three different classes. Many fungi are resistant to one or two of these classes, and can be problematic.
However, fungi do not as a rule spread through the air from person to person, and a true epidemic would be unlikely.

—Dr. C.