310 Discussion 



of trouble to find out which part of the brain was particularly affected ; 

 they thought it was the mid-brain, and pointed out various differences 

 from low-calcium tetanus. 



Black : Was there any tremor in your patient, and what was the state 

 of the reflexes? 



Card: There was no obvious tremor, but of course she was extremely 

 ill. She had a very rapid pulse, up to 160, which may have been partly 

 due to magnesium deficiency as the animals showed that too. The deep 

 reflexes were probably gone, but they might have gone in any case. 



McCance: What do you mean by 'gone in any case', when the mag- 

 nesium deficiency was raising the excitability? 



Card: I simply mean that in a patient in this extremely wasted state, 

 with very little muscle tissue remaining, we may not be able to elicit 

 reflexes, quite apart from any electrolyte disturbance. We did an ECG 

 and it was normal. 



Hingerty : Were there any noticeable symptoms of muscular dysfunc- 

 tion when the plasma magnesium was above normal. Dr. Card? In ani- 

 mal experiments we tried to reproduce some of the symptoms of adrenal 

 insufficiency by raising the plasma magnesium by injecting magnesium 

 sulphate. When we got the plasma magnesium and muscle magnesium 

 up to the level seen in adrenal insufficiency, we got very similar disturb- 

 ances in the levels of the hexose esters, phosphocreatine and adenosine 

 triphosphate (Hingerty, D. J. (1957). Biochem. J., 66, 429). 



Card: Again, she was extremely ill, and I would say there was nothing 

 detectable. Only gross changes in the clinical state would have been 

 noticed. I would repeat, the clinical condition itself was most striking. 



