Neurologic complications in immune-mediated heparin-induced thrombocytopenia.
OBJECTIVE
To evaluate neurologic complications in patients with immune-mediated heparin-induced thrombocytopenia (HIT) with respect to incidence, clinical characteristics, outcome, and therapy.


METHODS
One hundred and twenty consecutive patients with immune-mediated HIT were recruited over a period of 11 years and studied retrospectively for the occurrence of neurologic complications. Diagnosis of HIT was based on established clinical criteria and confirmed by detection of heparin-induced antibodies using functional and immunologic tests.


RESULTS
Eleven of the 120 patients (9.2%) presented with neurologic complications; 7 suffered from ischemic cerebrovascular events, 3 from cerebral venous thrombosis, and 1 had a transient confusional state during high-dose heparin administration. Primary intracerebral hemorrhage was not observed. The relative mortality was much higher (Chi-square test, p < 0.01) in HIT patients with neurologic complications (55%) as compared to patients without neurologic complications (11%). The mean platelet count nadir in neurologic patients was 38 +/- 25 x 10(9)/l on average, and was lower in patients with fatal outcome compared to those who survived (21 +/- 13 x 10(9)/l versus 58 +/- 21 x 10(9)/l; p < 0.05, Wilcoxon test). In three patients neurologic complications preceded thrombocytopenia. There was a high coincidence of HIT-associated neurologic complications with other HIT-associated arterial or venous thrombotic manifestations.


CONCLUSIONS
Neurologic complications in HIT are relatively rare, but associated with a high comorbidity and mortality. HIT-associated neurologic complications include cerebrovascular ischemia and cerebral venous thrombosis. They may occur at a normal platelet count.
Pohl
C
C
Department of Neurology, Rheinische Friedrich Wilhelms Universität, Bonn, Germany. c.pohl@uni-Bonn.de
Harbrecht
U
U
Greinacher
A
A
Theuerkauf
I
I
Biniek
R
R
Hanfland
P
P
Klockgether
T
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006493:Heparin / Q000009:adverse effects*; D006801:Humans; D008875:Middle Aged; D009422:Nervous System Diseases / Q000150:complications*; D010976:Platelet Count; D011379:Prognosis; D013921:Thrombocytopenia / Q000097:blood / Q000150:complications* / Q000276:immunology*; D013997:Time Factors
D006493:Heparin