Diagnostic Tests for Kallmann's Syndrome and Hypogonadotrophic Hypogonadism

Imaging Tests:

In order for the doctor to rule out any other problems with the pituitary gland or hypothalamus they may order a MRI scan of the brain.

 

MRI - magnetic resonance imaging

 

This is painless, non-invasive test which involves taking a very specialised picture of the brain using magnetic waves rather than x-rays.

The scan requires the patient to lie very still for about 20 minutes in an enclosed tube. All you hear is the slight knocking noise of the magnets.

The results enable the doctors to see a image of the hypothalamus and pituitary glands to check for any unusual structures that may be present.

In a majority of Kallmann's syndrome cases it will be apparent there is a problem in the olfactory bulb part of the brain, adjacent to the location where the GnRH releasing cells originate from. This can help in the differentiation of HH from Kallmann's syndrome. In Kallmann's syndrome the olfactory bulb will either be absent or only partially formed.

 



Other tests may include:

Ultrasound: To test for the presence of both kidneys. The absence of one kidney is a rare symptom of x-linked Kallmann's syndrome. Also ultrasound scans are sometimes used to locate the position of the testes if they have not descended correctly.

DEXA bone scan: To determine the level of risk of osteoporosis or ostoepenia.

Bone age determination: An x-ray is taken of the wrist in order for doctors to estimate bone age by comparing the x-ray to standard growth charts. If levels of sex hormones have been low for a length of time the age of the bones will be less than the chronological age of the patient.

Sex hormones are required to cause the ends of the long bones to fuse, harden and to stop growing. Too low levels will cause the bones to carry on growing and may becme weak as a result.

If sex hormones are given to teenagers to help stimulate puberty the bone age is sometimes monitored to prevent early closing of the ends of the bones which may cause shortened height.