Zi. Memon et al., PREDICTIVE VALUE OF SERUM IONIZED BUT NOT TOTAL MAGNESIUM LEVELS IN HEAD-INJURIES, Scandinavian journal of clinical & laboratory investigation, 55(8), 1995, pp. 671-677
Despite a wealth of recent literature and research on traumatic brain
injury, very little has been applicable to diagnosing and treating thi
s syndrome at a tissue level. Part of this problem is the inability to
assess rapidly and early in the syndrome the degree or progression of
brain injury at a tissue level using simple biochemical analytes. Wit
h this in mind, we designed a study in 66 human subjects, who presente
d with acute blunt head trauma, to determine whether free, ionized ser
um magnesium (IMg2+) and/or free, ionized serum calcium (ICa2+) levels
correlated with the severity of head trauma (HT) and whether any pred
ictive reliable patterns emerge. By using a new ion-selective electrod
e (ISE) for IMg2+, we have been able to determine IMg2+ and ICa2+ with
in minutes after sampling in the serum of patients early (1-8 h) after
HT. These studies reveal that acute HT is associated with graded defi
cits (up to 62%, mean=25%) in serum IMg2+, but not in total serum Mg,
which are related to severity of injury based on CT scans and other di
agnostic parameters. The greater the degree of injury, the greater the
ICa2+/IMg2+ ratio. These ionic findings are compatible with the idea
that early ischaemia after head trauma may be important in determining
neurological outcome. Our findings provide the first evidence for div
alent cation changes in blood after traumatic brain injury, which coul
d be of both diagnostic and prognostic value in patients with traumati
c brain injury.