Head injury

Mortality prediction in head trauma patients: performance of Glasgow Coma Score and general severity systems

OBJECTIVE

To assess the performance of general severity systems (Acute Physiology and Chronic Health Evaluation [APACHE] II, Simplified Acute Physiology Score [SAPS] II, and Mortality Probability Models [MPM] II) for head trauma patients and to compare these systems with the Glasgow Coma Score, in order to obtain a good estimate of severity of illness and probability of hospital mortality.

DESIGN

Inception cohort.

SETTING

Adult medical and surgical intensive care units in 12 European and North American countries.

PATIENTS

Patients (n = 401) who were diagnosed with head trauma (with/without multiple trauma), leading to intensive care unit admission, and who were not brain dead at the time of arrival.

INTERVENTIONS

Statistical analysis to assess the performance of general severity systems.

MEASUREMENTS AND MAIN RESULTS

Vital status at the time of hospital discharge was the outcome measure. Performance of the severity systems (SAPS II, MPM II0 [MPM at admission], MPM II24 [MPM at 24 hrs], and APACHE II) was assessed by evaluating calibration and discrimination. Logistic regression was used to convert the Glasgow Coma Score into a probability of death. The MPM II system (either MPM II0 or MPM 1124) provided an adequate estimation of the mortality experience in patients with head trauma. SAPS II and APACHE II systems did not calibrate well, although they showed high discrimination (area under the receiver operating characteristic curve 0.95 for SAPS II, 0.94 for APACHE II, and 0.90 for MPM II0 and MPM II24). The logistic regression model containing the Glasgow Coma Score as an independent variable and developed in this group of patients was not as well calibrated as MPM II. The discrimination of this model was very high, in the range observed for the APACHE II, SAPS II, and MPM II systems.

CONCLUSIONS

The MPM II system performs better than APACHE II, SAPS II, and Glasgow Coma Score for head trauma patients. If our results are supported by other studies, MPM II would be an appropriate tool to assess severity of illness in head trauma patients, with applications to clinical practice and clinical research.

Posttraumatic movement disorders after moderate or mild head injury

We examined the occurrence of posttraumatic movement disorders after moderate or mild head injury with a three-level follow-up study including questionnaires, telephone interviews, and personal examinations 4-6 years after the trauma (mean 5.2 years). Sixteen of 158 patients (10.1%) for whom a detailed follow-up was available had developed movement disorders most probably related to craniocerebral trauma. The most frequent finding was a low-amplitude postural/intention tremor that appeared to resemble enhanced physiological or essential tremor. Twelve patients reported transient tremor, two patients had persistent tremor, one patient had transient tremor and persistent hyperekplexia, and another patient had mild persistent cervical myoclonic twitches. Overall, the movement disorder was transient in 12 patients (7.6%) and persisted in only 4 patients (2.6%). These movement disorders were not disabling and did not require medical therapy. Taking into account possible bias by selection of the sample group, the frequency of movement disorders secondary to moderate or mild head trauma might be lower than 10.1%. Posttraumatic movement disorders occurred significantly more often in the group of patients with Glasgow Coma Scores between 9 and 14 than in those with a score of 15. Severe movement disorders such as low-frequency kinetic tremor or hemidystonia were not identified in this survey.

What's new in the diagnosis of head injury?

The diagnosis of DAI is not always easy, and should be based on adequate sampling of appropriate anatomical areas from a sliced, fixed brain. It is now recognised that there is a continuum of traumatic white matter damage, and that DAI represents only the severe end of the scale. Such damage may be detected from very shortly after a head injury-a fact that may give rise to some challenging diagnostic problems. Early axonal injury detected by means of beta APP immunostaining should be interpreted with caution. The most useful tools currently available for detecting axonal damage are antisera to beta APP, PG-M1, and GFAP, used in conjunction with a routine haematoxylin and eosin stain, but even with immunocytochemistry precise dating of histological changes may not be possible.

Post-traumatic bilateral diffuse cerebral swelling

This study confirms that bilateral diffuse cerebral swelling with or without parenchymal haemorrhages (< 15 cc) is a more common occurrence in the paediatric patients with severe head injury as compared with adults, since the analysed sample represented 42.55% and 20.43% of all paediatric and adult patients with severe head injury recorded in our clinic at the time of the study, respectively. The incidence of patients with diffuse cerebral swelling without parenchymal haemorrhages was found to be 27.65% of paediatric patients and 5.37% of adult patients with severe head injury. Secondary neurological deterioration occurred only in 5 (12.5%) paediatric patients and in 4 (10.5%) adult patients with diffuse cerebral swelling and was not to be found associated with parenchymal haemorrhages. A better outcome was seen in paediatric patients. Mortality rates were 12.5% in paediatric patients and 34.21% in adult patients. Our data also suggest that the mortality rate between paediatric and adult patients with diffuse cerebral swelling without parenchymal haemorrhages was similar (15.38% and 20% in paediatric and adult group, respectively), while the adult patients with diffuse cerebral swelling associated with small intraparenchymal haemorrhages have a worse prognosis than paediatric patients.

Progressive dysphagia due to adult Chiari I malformation mimicking amyotrophic lateral sclerosis

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