The in-hospital emergency and the Lipizzan

The in-hospital emergency

(and the Lipizzan)

   

  

It is early in the afternoon, when nurses at a surgical ward call for help: as the team that handles the in-hospital emergencies arrives, the patient is conscious again. The reason for the alert had been a dissociative disorder.  

  

While browsing through the patients findings, an angiomyolipoma of the left kidney and epilepsy with focal starting and secondary generalising tonic-clonic seizures attract attention in between many other diagnosis.  The question of  a team member, wether tuberous sclerosis has been searched for, is denied.

That means: one sees an animal with the looks of a horse, and it has black and white stripes on it. Everyone who got in contact with it so far, was thinking of a Lipizzan, that has been decorated with black stripes, and noone considered a Zebra.

Lipizzan, right before some funny contemporary decorated it with black stripes

  

Some sentences about the prevalence of each disease to substantiate the - admittedly - cynical comparison Lipizzan : Zebra with the help of some numbers:

 

In Austria, epilepsy has a prevalence of 4-8 / 1000 citizens [ www.epilepsie.at  , which is the  homepage of  "Epilepsie Dachverband Österreich"], sporadic angiomyolipoma of the kidney has a prevalence of 3 / 1000 in autopsies respectively 1 / 1000 in ultrasound  [ https://www.urologielehrbuch.de/angiomyolipom.html  ].
    

           Let us calculate - for the beneficial of our colleagues - with the higher numbers. Then, the probability for the accidental combined presence of both diseases is

8 / 1000   x   3 / 1000   =   0,000024

, that is 2,4 patients out of 100 000 citizens. (Calculated with the minor numbers: 4/1000 x 1/1000 = 0,000004, that would be  4 patients out of 1 million - that is too unlikely; moreover, the factor 1/1000 means angiomyolipomas found via ultrasound. They are more common, in fact.)

 

Prevalence of tuberous sclerosis is  1 : 20 000 ([ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4080684/ ]; in some instances it is said from  1:6000 to 1:10 000 ). Let us calculate - to the beneficial of our colleagues again - with the lower prevalence. Then that´s still 5 patients out of 100 000.

 

That means, it is - at least - twice as likely that the patient of the in-hospital emergency has tuberous sclerosis than accidentally epilepsy and sporadic angiomyolipoma combined. If one takes the conspicuous mental behaviour (dissociative disorder) in addition, tuberous sclerosis becomes even more likely - think of TAND (TSC associated neuropsychiatric disorders).



Zebra or Lipizzan, accidentally decorated with black stripes?

For the case above, genetic testing seems to be desirable to detect - or not detect - genetic inheritance. But one has to consider, that in 10 - 25% of TSC-patients mutations of TSC 1-gene or TSC 2-gene can´t be found[ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4080684/ ]. That means detailed clinical examination is obligatory after adverse genetic findings.
   

The patient of the in-hospital emergency might have accidentally combined epilepsy and sporadic angiomyolipoma, perhaps.

    

 Being RARE doesn´t mean, it is NOT.

Okay, that´s not a decorated LIPIZZAN

But: the case above shows how the estimated number of unknown cases arises:

  

We hardly ever bear it in mind!