Showing posts with label Genes. Show all posts
Showing posts with label Genes. Show all posts

Monday, August 01, 2016

Tourette's Syndrome - Tic Disorders

What is a tic?
A tic is an involuntary movement. A muscle or group of muscles move - tic - when you don't want them to or you make a noise or grunt rather like the throat-clearing some people do when they get nervous.
 
Tics can be divided into four categories. You can have:
 
1) A transient tic, which can be a movement or making a noise that lasts for more than four weeks but less than twelve. 
2) A chronic tic, which is either a movement or sound (but not both) that is present for more than a year.
3) Tourette's syndrome, which is movement and sounds together for more than a year.
4) A tic disorder (not otherwise specified) that does not fit into any of the other categories.
 
The classic picture of Tourette's syndrome often seen portrayed in films is the exception rather than the rule. The vast majority of children and adults have a variety of minor motor (movement) tics and/or vocal tics.

Although these motor and vocal tics are described as involuntary movements (you can't control them), they can to a certain extent be held back. Some sufferers can stop the tics for a period of time and release them when they are in the privacy of their own home. Therefore, it can come as something of a surprise for a teacher or employer to learn that a child or employee has a tic disorder. Some sufferers can disguise their tics by building them into what might be considered to be normal movements. However, holding back tics comes at a cost. Often when the child gets home his or her behaviour can become very disturbed or they suffer terrible guilt when they finally have to give in to the overwhelming urge.

History 
Tourette's Syndrome was originally described by Gilles de la Tourette as 'maladie des tics convulsifs avec coprolalie' (an illness of convulsive tics with the involuntary use of obscene words). The early documented cases of Tourette's syndrome were of adult patients and it was not until the 1930s that the tics were described in normal children. However, Tourette did note that as well as the involuntary movement tics, vocal tics and swearing, the disorder began in childhood, (usually between the ages of seven and ten), affected males more than females and was, in his opinion, hereditary. He also noted that the tics usually started in the face or upper extremities and that the symptoms waxed and waned and were made worse by stress. 


Disorders associated with Tourette's Syndrome
Some common signs of Tourette's are:
- excessive blinking
- head turning
- throat-clearing
- grimacing
- grunting
- squeaking
- one-sided facial tics
- eyes rolling up

The cause of Tourette's
The exact cause of Tourette's syndrome is unknown, but it appears to be linked to the gene or genes that control certain neurotransmitters, notably dopamine and serotonin. Where these symptoms begin not only goes a long way towards explaining the underlying cause but also presents an opportunity to provide effective treatment. About a third of people with the disorder have relatives with Tourette's syndrome, while another third have family members with milder tic disorders. There is also more obsessive-compulsive disorder and attention deficit hyperactivity disorder in families of people with Tourette's syndrome. Further, because Tourette's is much more frequent in men, the role of hormones has been considered and it has been suggested that the male foetus might be vulnerable to a spike in the female hormone oestrogen from the mother, during a specific stage during pregnancy.

What makes tics worse?
- Just talking about a person's tics - or habits as they are often called - in front of them can set off motor (movement) tics in seconds.
- Being overtired can make a big difference to the occurrence of tics. Children are often worse at the end of term.
- Lack of sleep can cause an upsurge in symptoms.
- Drinking alcohol can make symptoms worse the next day.
- Stress is certainly a big factor. In children the build-up to exams or in adults the period leading up to a big presentation can see an increase in symptoms.
- Diet has also been implicated on numerous occasions. The Mental Health Foundation has suggested that food additives and insufficient omega-3 can play a role in the generation of anxiety and signs of ADHD.

What helps reduce tics?
- Being distracted by something enjoyable or engaging in an activity (e.g. playing piano) can see a complete cessation of tics.
- Getting enough sleep and taking exercise in the fresh air can help prevent a build-up.
- Taking alcohol in moderation.
- A healthy diet as free from artificial sweeteners and additives as possible has been shown to help.
- Supplementing your diet with omega-3 can also provide significant benefits.
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~ The above is from Pauc, R. (2008) Could It Be You? , a well worth reading book for anyone interested in the area of learning difficulties. It's written in a very reader friendly format, detailed but not too taxing on the mind, and covers a range of issues from dyslexia, dyspraxia, ADHD, OCD, Tourette's syndrome, and autism. Recommended.  

Monday, April 07, 2014

Schizophrenia

Unlike the disruptions of mental tranquillity that disturb everyone from time to time, schizophrenic episodes represent a severe departure from normal mental functioning. The disorder has a distinctly biological character, suggesting that its fierce psychotic episodes reflect physiological alterations in normal brain function.

Schizophrenia is the diagnostic term for a family of severe mental disorders that involve psychotic features - a loss of contact with reality - and a widespread deterioration of the level of mental functioning affecting multiple psychological processes (Kandel, 1991). The disorder always involves delusions, hallucinations, or characteristic disturbances in the form of thought. By definition, schizophrenic disorders are relatively long lasting: brief, isolated psychotic episodes are not classified as schizophrenic. Schizophrenia, strictly defined, has an incidence of approximately 1 in 200. Rates of schizophrenia are generally similar from country to country - about 1 percent of the population. There are variations - but the variance is difficult to track due to differing measuring standards in many countries, etc. It is equally common in men and women.

Delusions are a major abnormality in the content of thought. Schizophrenic delusions - false beliefs about external reality - are often persecutory, as in the belief that a television newscaster is making fun of the viewing individual. Other typical delusions are more bizarre: The individual may believe that his or her thoughts are being broadcast so that everyone nearby can hear them, or that other people are inserting thoughts and their behaviour is controlled by others, perhaps by radio waves. Such delusional beliefs represent a marked failure in assessing reality.

Characteristic abnormalities in the form of thought also frequently occur. Most common is a loosening of associations , in which ideas shift from one topic to another in an apparently unrelated manner. When this is severe, speech becomes incoherent.

Hallucinations - perception without external stimulation of the sensory systems - are also characteristic of schizophrenia. Most hallucinations are auditory, involving voices that may make insulting statements or provide a continuing critical commentary on the individual's behaviour. Tactile and somatic hallucinations, such as the perception of snakes crawling inside the abdomen, also occur. However, visual hallucinations are less common.

The emotions of the schizophrenic patient are usually flattened or inappropriate. ''Flattened'' means a loss of emotional intensity: the patient speaks in a monotone, the face is expressionless, and the patient reports that normal feelings are no longer experienced. At other times, emotion may be present but is inappropriate to the circumstance.

The combination of symptoms leads to a gross distortion of the person's interactions with the real world. There is a deterioration in functioning, resulting in part from a preoccupation with internal thoughts and fantasies. In many cases, the acute active phase of florid schizophrenic symptoms persists for a prolonged period. It may be followed by a relative remission of symptoms, but a complete return to normal function is extremely unusual. In fact, such a recovery calls into question the original diagnosis of schizophrenia.

Despite the bizarre and florid nature of the schizophrenic symptoms, there is still considerable controversy as to the nature of the disorder. Many investigators believe that schizophrenia is not a single disease but forms a group of related psychotic disorders.

In schizophrenia, there seems to be an inheritable predisposition or susceptibility to the disorder. In the general population, the risk of schizophrenia is less than 1 percent. However, this risk is much greater for relatives of schizophrenics. The parents of a schizophrenic child have about a 5 percent risk of schizophrenia, the siblings of a schizophrenic have about a 10 percent risk, and the children of a schizophrenic parent have about a 14 percent chance of developing the disorder. If both parents are schizophrenic, the child has a risk factor of about 50 percent.


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''If you talk to God, you are praying; If God talks to you, you have schizophrenia.''
                                                                                                         ~ Thomas Szasz

Wednesday, November 13, 2013

Fancy some light reading?



The human genome is made up of 23 chromosome pairs with a total of about 3 billion DNA base pairs. It is the complete set of genetic information for humans. When the University of Leicester's Department of Genetics decided to print out an entire human genome, it amounted to 130 volumes of some 300 pages!!!
 
You - in 130 volumes
A total of 3000 million characters - and you thought Game of Thrones had a lot!


The genome print out spans 130 volumes, with each page printed on both sides in 4-point font, with about 43,000 characters per page. The X chromosome is made up of seven volumes, while the Y chromosome occupies one. The total exercise cost a little less than 4,000 pounds.
From start to finish it would take approximately 95 years to read!
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''DNA is like a computer program but far, far more advanced than any software ever created''
                                                                                                       ~ Bill Gates, The Road Ahead