A computerized scoring system to improve assessment of heparin-induced thrombocytopenia risk.

Essentials Current risk scores for heparin-induced thrombocytopenia (HIT) are not computer-friendly. We compared a new computerized risk score with the 4Ts score in a large healthcare system. The computerized risk score agrees with the 4Ts score 85% of the time. The new score could potentially improve HIT diagnosis via incorporation into decision support. SUMMARY: Background (HIT) is an immune-mediated adverse drug event associated with life-threatening thrombotic complications. The 4Ts score is widely used to estimate the risk for HIT and guide diagnostic testing, but it is not easily amenable to computerized clinical decision support (CDS) implementation. Objectives Our main objective was to develop an HIT computerized risk (HIT-CR) scoring system that provides platelet count surveillance for timing and degree of thrombocytopenia to identify those for whom diagnostic testing should be considered. Our secondary objective was to evaluate clinical management and subsequent outcomes in those identified as being at risk for HIT. Methods We retrospectively analyzed data from a stratified sample of 150 inpatients treated with heparin to compare the performance of the HIT-CR scoring system with that of a clinically calculated 4Ts score. We took a 4Ts score of ≥ 4 as the gold standard to determine whether HIT diagnostic testing should be performed. Results The best cutoff point of the HIT-CR score was a score of 3, which yielded 85% raw agreement with the 4Ts score and a kappa of 0.69 (95% confidence interval 0.57-0.81). Ninety per cent of patients with 4Ts score of ≥ 4 failed to undergo conventionally recommended diagnostic testing; 38% of these experienced persistent, unexplained thrombocytopenia, and 4% suffered life-threatening thrombotic complications suggestive of undiagnosed HIT. Conclusion The HIT-CR scoring system is practical for computerized CDS, agrees well with the 4Ts score, and should be prospectively evaluated for its ability to identify patients who should be tested for HIT.

Predictive value of facial nerve electrophysiologic stimulation thresholds in cerebellopontine-angle surgery.

The predictive value of intraoperative stimulation thresholds for facial nerve function, using a constant-current system, was examined in 49 patients undergoing resection of cerebellopontine-angle tumors. Immediately after surgery, 75% of the 0.1-mA threshold group, 42% of the 0.2-mA group, and 18% of the 0.3-mA or greater group had good (grade I or II) facial nerve function. One year after surgery, 90% of the 0.1-mA group, 58% of the 0.2-mA group, and 41% of the 0.3-mA or greater group had grade I or II function. A statistically significant breakpoint of 0.2 mA was found to predict good postoperative facial function. Delayed facial paralysis occurred in 22% of patients, but the prognosis for these patients was favorable. Both current stimulation threshold and duration are necessary for a meaningful comparison of data between investigators.

Proximal neuropathy in Colles' fracture.

BACKGROUND: Peripheral nerve injury at the wrist following Colles' fracture is rare and usually located in the region of the fracture. Mononeuropathies in the proximal forearm have not been reported. METHOD: We present two patients with Colles' fracture with proximal forearm neuropathies. RESULTS: Both cases were associated with mononeuropathies in the forearm as proximal as the elbow, involving the median, ulnar and radial nerves in one, and the median and ulnar nerves in the other. CONCLUSION: Following Colles' fracture proximal nerve involvement may occur and, with increased awareness, this lesion may be identified more frequently.

Multiple spinal intradural schwannomas in the absence of von Recklinghausen's disease.

A case of multiple spinal schwannomas is reported without any evidence of other manifestations of neurofibromatosis. Although cases of multiple schwannomas have been described in the setting of "Schwannomatosis," this case is unique in that all tumors were within the spinal canal. The presence of a schwannoma should prompt a complete investigation for other tumors of the nervous system preferably with magnetic resonance imaging.

MR imaging of acetabular fractures: value in detecting femoral head injury, intraarticular fragments, and sciatic nerve injury.

OBJECTIVE: The purpose of this prospective study was to compare the value of MR imaging in the detection of injuries associated with acute acetabular fractures (femoral head fracture, free fragments within the hip joint, and injury to the sciatic nerve) with the value of preoperative CT examinations, intraoperative inspection, intraoperative somatosensory evoked potentials (SEP), and clinical neurologic examinations. SUBJECTS AND METHODS: Coronal fat suppressed long TR/TE and unenhanced and contrast-enhanced T1-weighted MR images were obtained preoperatively in 37 patients with acetabular fractures. The sciatic nerve was assessed for injury and the femoral head was assessed for fracture, dislocation, and contusion. MR results were compared with CT findings for acetabular fractures and fractures of the femoral head. The appearance of the sciatic nerve on MR images was correlated with intraoperative changes in SEP and results of the clinical neurologic examination. RESULTS: Although MR images showed acetabular fractures, intraarticular fragments were often obscured. Fragments were readily apparent on CT scans. MR images showed fracture of the femoral head in 10 (27%) of 37 cases. Nine of these fractures also were seen on CT scans. MR images showed subchondral contusion of the femoral head in 24 (65%) of 37 cases. The same areas appeared normal on CT scans. MR images of the sciatic nerve obtained after injection of contrast material showed intraneural or perineural enhancement in all patients with either changes in baseline SEP (n = 19) or preoperative neurologic deficit (n = 10). Although baseline changes in SEP were more common with intraneural enhancement, the difference in the prevalence of neurologic deficits was not significant. The preoperative enhancement pattern alone could not be used to predict a neurologic deficit. CONCLUSIONS: MR imaging of acetabular fractures can be used to detect subclinical injury of the sciatic nerve and occult injuries of the femoral head not readily apparent on CT scans. However, intraarticular fragments may be obscured.