Monday, December 28, 2015

Athetosis

Credit: tremorjournal.org

Athetosis is a symptom characterized by slow, involuntary, convoluted, writhing movements of the fingers, hands, toes, and feet and in some cases, arms, legs, neck and tongue. Movements typical of athetosis are sometimes called athetoid movements. Lesions to the brain are most often the direct cause of the symptoms, particularly to the corpus striatum. This symptom does not occur alone and is often accompanied by the symptoms of cerebral palsy, as it is often a result of this disease. Treatments for athetosis are not very effective, and in most cases are simply aimed at the uncontrollable movement, rather than the cause itself.

Signs and Symptoms
Athetosis can vary from mild to severe motor dysfunction; it is generally characterized by unbalanced, involuntary movements of muscle tone and a difficulty maintaining a symmetrical posture. The associated motor dysfunction can be restricted to a part of body or present throughout the body, depending on the individual and the severity of the symptom. One of the pronounced signs can be observed in the extremities in particular, as the writhing, convoluted movement of the digits. Athetosis can appear as early as 18 months from birth with first signs including difficulty feeding, hypotonia, spasm, and involuntary writhing movements of the hands, feet, and face, which progressively worsen through adolescence and at times of emotional distress. Athetosis is caused by lesions in several brain areas such as the hippocampus and the motor thalamus, as well as the corpus striatum; therefore children during the developmental age could possibly suffer from cognitive deficits such as speech impairment, hearing loss, and failed or delayed acquirement of sitting balance.

Causes
Athetosis is a symptom primarily caused by the marbling, or degeneration of the basal ganglia. This degeneration is most commonly caused by complications at birth or by Huntington's disease, in addition to rare cases in which the damage may also arise later in life due to stroke or trauma. The two complications of particular interest are intranatal asphyxia and neonatal jaundice.

Sunday, December 27, 2015

Astigmatism and Your Eyes

Credit: www.eyesonyouseattle.com

Astigmatism and Your Eyes

What Is Astigmatism?
Astigmatism is a common eye condition that's usually corrected by eyeglassescontact lenses, or surgery.

Astigmatism is caused by an eye that is not completely round and occurs in nearly everybody to some degree. For vision problems due to astigmatism, glasses, contact lenses, and even vision correction procedures are all possible treatment options.
A person's eye is naturally shaped like a sphere. Under normal circumstances, when light enters the eye, it refracts, or bends evenly, creating a clear view of the object. However, the eye of a person with astigmatism is shaped more like a football or the back of a spoon. For this person, when light enters the eye it is refracted more in one direction than the other, allowing only part of the object to be in focus at one time. Objects at any distance can appear blurry and wavy.

What Causes Astigmatism?
Astigmatism is a natural and commonly occurring cause of blurred or distorted vision that is usually associated with an imperfectly shaped cornea. The exact cause in not known.

What Are the Symptoms of Astigmatism?
People with undetected astigmatism often have blurred vision which can be associated with fatigue and eyestrain. While these symptoms may not necessarily be the result of astigmatism, you should schedule an eye exam if you are experiencing one or more symptoms.

How Is Astigmatism Diagnosed?
Your eye doctor can diagnose astigmatism with a thorough eye exam. Astigmatism may occur with other vision problems such as nearsightedness and farsightedness. Because astigmatism may increase slowly, you should visit your eye doctor whenever you notice changes in your vision.

How Is Astigmatism Treated?
Almost all degrees of “normal” astigmatism can be corrected with properly prescribed eyeglasses or contact lenses. For a person with only a slight degree of astigmatism, corrective lenses may not be needed at all, as long as other conditions, such as nearsightedness or farsightedness, are not present. If the astigmatism is moderate to high, however, corrective glasses or contact lenses are probably needed.
Irregular astigmatism is far less common and is associated with abnormal conditions affecting the cornea (for example, keratoconus). This condition is more effectively treated with rigid gas permeable contact lenses or corneal procedures.
  • Corrective lenses (eyeglasses or contact lenses). Astigmatism correction can usually be easily incorporated into eye glasses. Alternatively, special soft contact lenses called toric lenses can be prescribed. Soft toric lenses have greater light-bending power in one direction than the other. Another option, particularly for higher amounts of astigmatism, is a gas-permeable rigid contact lens. After performing various tests, your eye doctor will determine the ideal prescription for your astigmatism.
  • Refractive surgery. Another method for correcting astigmatism is changing the shape of the cornea through refractive or laser eye surgery. While there is more than one type of refractive surgery, specific treatments are recommended on an individual basis. Refractive surgeries require healthy eyes that are free from retinal problems, corneal scars, and any eye disease.    Read more >>
Source: http://www.webmd.com/eye-health/astigmatism-eyes