report outlines an interesting first presentation of MS in a 28 year old man.
of water in your bloodstream are maintained at the right level by a process
called homeostasis and more specifically by a hormone called antidiuretic
hormone (ADH). Diuresis is the process of passing urine so the hormone does
exactly what it says in the tin – it stops you peeing.
produced in a neuroendocrine structure called the hypothalamus and is stored in
the pituitary gland which is located in your brain just behind and between your
don’t have enough water on-board i.e. you’re dehydrated or have been sweating,
your pituitary gland releases ADH and this acts on the kidneys to make them
reabsorb more water and you pee less.
drunk too much water, less ADH is released and you therefore have a ‘diuresis’
i.e. you pass more urine through your kidney.
your brain fails to produce/release the ADH or your kidneys don’t respond to it
and this is known as Diabetes Insipidus (not to be confused with diabetes
mellitus that involves insulin). In this condition, your body works on the
assumption that you always have too much water on board (the right hand side of
diagram) resulting in loss of huge amounts of urine from the kidneys. You end
up needing to drink lots of water to stay hydrated which is sometimes easier
said than done.
report describes a gentleman who presented with a 7 year history of drinking
>10 litres of water per day. When he was given a form of ADH by a doctor, he
was able to concentrate his urine which proved that he was not producing ADH
himself but that his kidneys were able to respond to the hormone. He was
diagnosed with diabetes insipidus. Interestingly, he re-presented two months
later with optic neuritis and a diagnosis of MS was made. An MRI of
his brain showed lesions in his hypothalamus which accounted for his inability
to produce ADH.
common first presentation of MS is optic neuritis. In contrast, there have only
been three documented cases of MSers presenting with diabetes insipidus in the
literature. One reason for this may be that demyelinating lesions are hardly
detectable in the hypothalamus using conventional MRI.
first present with an uncommon symptom related to MS?
Did it take
a while for you to be referred to a neurologist?
diagnosis delayed in any way?
paradigm of MS focuses on the importance of starting treatment early – (Prof G
calls this ZeTo) and therefore any delay could potentially represent a missed
opportunity to start treatment. This makes it important that people are referred
to neuros early if their GP suspects they may have MS.
Neurology. 2011 May
31;76(22):1939-40. doi: 10.1212/WNL.0b013e31821d750c.
Diabetes insipidus as a first manifestation in multiple sclerosis.