Friday, 11 March 2016

Parry Romberg Syndrome

Parry Romberg syndrome is a very rare disorder, more common in women than men. It is characterised by progressive deterioration of the facial tissue (hemi-facial atrophy), particularly the left-side, and in severe cases bones. If limbs are affected, it is commonly on the same side as the facial atrophy.

The deterioration begins between the nose and upper lip. This then slowly progresses across the face, and may even affect the roof of the mouth, tongue and gums. Tissue beneath the skin (subcutaneous) and fat shrink, which characterises the atrophy. As a result, sufferers show a sunken appearance in these areas. Due to the extensiveness of the areas affected, a number of conditions can occur. This includes: alopecia, facial pain and seizures due to neurological abnormalities. Of course, the severity of the symptoms vary, with the majority of sufferers experiencing mild deterioration.
Child with facial atrophy on his right side
Atrophy lasts from 2 to 10 years, after which it enters a stable phase. Parry Romberg syndrome can arise both in adulthood and late childhood, although the majority of sufferers have symptoms before the age of 20. Often, the earlier the deterioration begins, the quicker it progresses. 

At the moment, Parry Romberg Syndrome is incurable and untreatable. This is largely because the cause of this disorder is unknown, as the syndrome appears to happen sporadically. However, reconstruction surgery is available, to repair facial tissue.

There are a few theories for the causes of this syndrome. It must be considered that Parry Romberg syndrome may be due to a somatic mutation. This is where a mutation occurs in one of the cells in a zygote, at the very early stage of fertilisation. Thus, cells that had divided from this one cell, will carry the mutation. Furthermore, this 'somatic mutation' hypothesis agrees with the idea that Parry Romberg is not inheritable, which may increase the theory's credibility.


However, a more popular theory for its cause suggests that it is due to an autoimmune reaction, where the body perceives healthy tissue as foreign, thus attacks it with antibodies. In this case, since the antibodies are attacking healthy tissue, they have coined the term autoantibodies. This unusual response may be triggered by an inflammation of the nerves that produce skin and fat.


References:


Medicinenetcom. (2016). MedicineNet. Retrieved 10 March, 2016, from http://www.medicinenet.com/parry-romberg_syndrome/article.htm


Nihgov. (2016). Nihgov. Retrieved 10 March, 2016, from http://www.ninds.nih.gov/disorders/parry_romberg/parry_romberg.htm


Rarediseasesorg. (2016). NORD (National Organization for Rare Disorders). Retrieved 09 March, 2016, from https://rarediseases.org/rare-diseases/parry-romberg-syndrome/

Friday, 4 March 2016

Acromegaly (Gigantism)

Acromegaly, also known as gigantism, has the literal definition of enlargement of the body. It is most commonly caused by a gland tumour (adenoma) in the pituitary gland. This gland is located in the brain with the purpose of secreting growth hormones. Although, the tumour heightens the production of these growth hormones, the tumour itself is benign and therefore has little risk of developing into cancer.
Pituitary gland labelled

The adenoma can grow to 1cm in size which can exert pressure on cranial nerves in the brain and those leading to the eyes. Sufferers can therefore experience blurred vision and headaches.

The condition can be easily identified through physical diagnosis. It is characterised by very large hands, feet, toes and fingers with a prominent jawline and forehead also being common features caused by acromegaly.
Acromegaly common features
However, in order to certify the condition is present, a blood test can be carried out by testing the levels of growth hormone, which would normally decrease when the patient is given a sugary drink. Insulin-like growth factor 1 (IGF-1) is also tested. By it being produced by the liver, it provides an alternative cause for abnormal growth, therefore being liver damage.

The graph below shows that in non-sufferers, growth hormones are secreted predominantly during sleep. However, it is clear in the acromegaly sufferer's graph that GH levels keep at a constant level showing that the pituitary is secreting continuously. 
Graphs comparing Growth Hormone levels between sufferers and non-sufferers
A positive result for the growth hormone leads to MRI scans of the head to see whether there is a tumour present in the pituitary gland.
MRI scan of a Pituitary gland with a tumour
Acromegaly is rarely inherited but can be in the form of familial isolated pituitary adenoma or as part of multiple endocrine neoplasia (MEN). In familial isolate pituitary adenoma, the tumour growth occurs in adolescence, when the bones are still malleable enough for the excess growth hormones to make a significant effect.

The most effective treatment involves the surgical removal of the main cause of the condition, the tumour growth in the pituitary gland. Preferably, the adenoma should not be near any key structures of the brain, in order to limit possible complications during surgery.

An incision is first made under the nose or upper lip to allow an endoscope, and other surgical instruments, to access the sphenoid sinus, hence why it is defined as transsphenoidal surgery. The sinus space leads directly to the pituitary gland and therefore the adenoma. As a result, the tumour can be removed.
Transsphenoidal surgery

References:

nhsuk(2016)WwwnhsukRetrieved 04 March, 2016, from http://www.nhs.uk/conditions/acromegaly/Pages/Introduction.aspx

Nihgov(2016)NihgovRetrieved 04 March, 2016, from https://www.niddk.nih.gov/health-information/health-topics/endocrine/acromegaly/Pages/fact-sheet.aspx

Mayoclinicorg(2016)MayoclinicorgRetrieved 04 March, 2016, from http://www.mayoclinic.org/diseases-conditions/acromegaly/home/ovc-20177622

Hormoneorg(2016)HormoneorgRetrieved 04 March, 2016, from http://www.hormone.org/questions-and-answers/2012/acromegaly