Insulinoma

Symptoms  

"Whipple' s triad" is regularly found in insulinoma.

Amelioration of symptoms after carbohydrate intake in the absence of chemical hypoglycemia is unspecific and irrelevant.
1.
biochemical proof of hypoglycemia (blood glucose < 50 mg/dl ; < 2.8 mmol/l)
2.
simultaneously existing suspicious symptoms compatible with hypoglycemia
3.
rapid amelioration of symptoms after carbohydrate intake

Symptoms compatible with hypoglycemia occur:
1.
through activation of the sympathetic nervous system and result in uncomfortable adrenergic symptoms posing no danger for the patient
2.
through cerebral shortage of glucose supply and may result in serious and debiliating neurological (neuroglycopenic) symptoms.

The most frequently experienced symptoms are:
1.
dizziness
2.
loss of consciousness
3.

increase in body weight
4.
sweating
5.

seizures

Despite an often remarkabel increase in body weight the patients are generally not overweight rather than at the upper limit of normal weight (median body mass index - BMI: 26 kg/m² - range 16-37 kg/m² - in 110 patients).

Repetitive convulsions may cause the misdiagnosis: "suspected epilepsia". This often leads to intensive neurological diagnostics (CAT, NMR, angiography of the head)

Beware: The inhibitory action of "phenytoine"-containing anticonvulsive drugs upon insulin secretion may mask insulinoma as epilepsia since seizures may effectively be suppressed.

Frequency of individual symptoms

symptoms
 frequency
adrenergic symptoms
frequency
neuroglycopenic symptoms
frequency
© Starke/Saddig 2001 www.insulinoma.net
"Whipple' s triad"
100 %
sweating
36 %
impaired consciousness
49 %
dizziness / collapse
50 %
hunger
16 %
impaired mental concentration
35 %
increase of body weight
40 %
tremor
12 %
seizures
30 %
headaches
12 %
fatigue
29 %
nausea
9 %
diplopia / impaired or blurred vision
27 %
agitation
  
weakness of memory
13 %
nervosity
  
paralyses
9 %
palpitations
  
desorientation
7 %
tachycardia
 
ataxia, impaired coordination
7 %
 
dysarthria
  
apathia
  
 
altered or aggressive behaviour
  

Source: 70 patients with diagnosed and operated insulinoma at the University of Duesseldorf.

Adrenergic symptoms are unspecific and often related to other diseases (e.g .the thyroid gland). General discomfort not caused by any disease has to be considered, too.
Neurological symptoms may be due to underlying and severe neurological disease.
Occurence of the symptoms in combination with hypoglycemia is suspicious for insulinoma as a possible cause of the complaints.
If an insulinoma has to be considered as a cause of the complaints and symptoms or has to be definitely ruled out, the patient should be tested by simple and straightforward endocrine blood tests in an institution able to provide the expertise in the diagnostic work-up of hypoglycemia.