Halothane anesthesia is neuroprotective in experimental spinal cord injury: early hemodynamic mechanisms of action.

The neuroprotective potential of halothane anesthesia was explored in a weight-drop model of spinal trauma in the rat (N = 252). In initial experiments, animals were subjected to 25, 50 or 100 g cm impact injuries at T10 during pentobarbital or halothane anesthesia and their outcomes determined using somatosensory-evoked potentials, blinded neurologic evaluations for two weeks, and post-mortem analysis of spinal serotonin levels. Subsequently, halothane anesthesia was combined with either pentobarbital or nitrous oxide or given as a late treatment to pentobarbital anesthetized rats subjected to 50 g cm injuries. A series of acute studies were then performed in order to assess the hemodynamic and respiratory concomitants of halothane vs. pentobarbital, as well as the effect of mechanical ventilation and bicarbonate treatment upon halothane neuroprotection. Finally, the effect of a 50 g cm impact upon local white matter spinal cord blood flow was measured during halothane or pentobarbital anesthesia using laser-Doppler flowmetry. Results demonstrate an active neuroprotective action for halothane anesthesia that is not altered by the presence of other anesthetics and is most prominent at severe injury levels. The data suggest the importance of immediate injury responses in this action. Late halothane treatment was ineffective when given as early as 10 minutes postinjury while both the electrophysiological and hemodynamic effects of halothane vs. pentobarbital were apparent during this 10 minute period. Thus, halothane was associated with the prevention of spinal ischemia during the first 10 minutes after trauma in comparison to pentobarbital.(ABSTRACT TRUNCATED AT 250 WORDS)

Compression (Salter-Harris Type V) physeal fracture: an experimental model in the rat.

Histologic evidence of damage to the proximal tibial physis of immature rats was documented in greater than 30% of hind limbs subjected to a valgus and compressive force. The lesion was consistent with that theorized for the Salter-Harris Type V fracture. Two additional groups of immature rats were subjected to the same insult and followed to maturity. One of the groups sustained an intentional concomitant ipsilateral femoral shaft fracture. No tibia demonstrated a growth disturbance in the absence of the femoral fracture, while similar angular deformities were noted in four tibiae (13%) in the presence of a fractured femur. Previously theorized traumatic physeal injuries, implicated in subsequent growth disturbances and seen clinically in association with ipsilateral long bone fractures, were identified in this animal study.

[Social and functional results of brachial plexus birth injury].

Long-term results of obstetrical brachial plexus injury were studied. The medical records of 10 females and 9 males (range 16-59 years, mean 27.8) who responded to a questionnaire were reviewed. According to the responses, they all had been leading normal lives, despite various degrees of impairment.

Serotonergic response to spinal distraction trauma in experimental scoliosis.

The effects of distraction injury to the spinal cord on serotonin (5HT) content and metabolism in a rat model of scoliosis were studied. Previous studies in this laboratory (Salzman et al., 1987a) have identified the 5HT response as a major component of the posttraumatic progression of spinal injury after impact trauma in the rabbit. The present study was designed to determine the universality of this response by examining a different model of injury in a different species. The results demonstrate that distraction trauma in the rat, like impact injury in the rabbit, is associated with a rapid and robust increase in the local spinal cord content and metabolism of 5HT and a long-term depletion of 5HT below the site of injury. The roles of the blood platelet and the raphe-spinal tract in the acute response and the disruption of axoplasmic transport during the chronic phase of injury are discussed.

Type V physeal injury: a case report.

A case report is presented to support the recently challenged Salter-Harris classification of type V physeal injury. Asymmetric premature closure of a proximal tibial physis, previously not suspected as injured, supports the classification of this injury as a separate entity. Furthermore, varus or valgus forces, as well as shearing forces, probably play an important role in the etiology of this injury rather than longitudinal compression alone.

Heterotopic ossification in central nervous system-injured patients following closed nailing of femoral fractures.

Heterotopic ossification at the site of insertion of an intramedullary nail was observed in five central nervous system-injured patients with femoral fractures. Three of these patients experienced a reduction in the range of motion of the ipsilateral hip joint, which in two improved with physical therapy. Patients with central nervous system injury who have closed interlocking intramedullary nail fixation may be at increased risk of heterotopic ossification at the surgical site.

Anesthesia influences the outcome from experimental spinal cord injury.

The effect of anesthesia upon the functional outcome after experimental spinal cord injury (SCI) was studied in 221 rats subjected to graded weight drop contusion in the thoracic cord. Neurologic function was assessed in a blinded fashion for one week after injury using a modification of the method of Tarlov. The post-mortem concentrations of serotonin and its metabolite were measured in injured and surrounding spinal tissues in a subset of animals in order to estimate the survival of descending long-tract axons. In initial studies using non-ventilated animals where body temperature was not controlled (n = 130), halothane anesthesia was associated with significantly better neurologic scores at all levels of injury (50, 100 and 250 g.cm) in comparison to pentobarbital. In a second experiment under these conditions (n = 53) the effect of halothane was observed after a 50 g.cm injury in comparison to both pentobarbital and nitrous oxide. Improved neurologic recovery was accompanied by the preservation of normal serotonin and metabolite concentrations in spinal tissue caudal to the site of injury. These values did not differ from those measured in sham-operated animals. Separate experiments (n = 12) revealed halothane's preservation of somatosensory-evoked responses during the early postinjury period in animals showing improved neurologic recovery. Subsequent experiments (n = 12) were performed to assess the effect of oxygen supplementation and the control of rectal temperature and a separate series of acute experiments (n = 14) examined arterial blood pressure responses to injury in halothane- and pentobarbital-anesthetized animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Obturator dislocation as a complication of closed reduction of the congenitally dislocated hip: a report of two cases.

Two cases of inferior obturator dislocation complicating treatment of congenital hip dislocation with closed reduction are described. Abduction and hyperflexion appear to be predisposing factors in development of this complication. Application of skin traction before any attempt is made at reduction will lengthen contracted soft tissues and may convert the inferior dislocation to a more manageable position. Open reduction was necessary in both patients, and the results were considered good.

Massive osteolysis of the femur (Gorham's disease): a case report and review of the literature.

A case of Gorham's disease involving the proximal femur of a 12-year-old girl is presented. Although Gorham's disease is rare and has benign histologic characteristics, in this patient it took an aggressive clinical course that resulted in severe morbidity. Diagnosis is difficult to establish; almost all investigative approaches provide only indirect evidence of the pathology. A high index of suspicion and open biopsy performed soon after presentation will establish diagnosis. Treatment modalities may be more effective if applied earlier in the disease process, especially as the osteolytic process appears to escalate after pathologic fractures, which occur frequently in this disorder.

Treatment of patellofemoral instability in Down's syndrome.

In a retrospective review, 16 patients with Down's syndrome with the chief complaint of patellofemoral joint dislocations or subluxations were studied. Twenty-six dislocatable or dislocated patellae were seen in these 16 patients. The degree of patellofemoral instability was not correlated with either the ambulatory status or the form of treatment (operative/nonoperative). An increasing degree of patellofemoral instability was correlated strongly with the presence of deformities. Nonoperative treatment either maintained or improved the ambulatory status in 67% of these knees with either fair or good ambulation, whereas 80% of the knees with poor ambulation did not improve. Operative treatment resulted in good ambulatory ability in 86% of the knees with fair or poor preoperative ambulatory status, but did not effectively correct deformities that subsequently resulted in degenerative arthritis.

The somatosensory evoked potential predicts neurologic deficits and serotonergic pathochemistry after spinal distraction injury in experimental scoliosis.

The validity of the somatosensory evoked potential as an intraoperative spinal cord monitor was evaluated in an experimental model of scoliosis in the rat and a Harrington distraction model of injury. Under these conditions, it was found that any change in latency or amplitude of the major negative wave above a certain level was a significant predictor of an adverse neurologic outcome. Changes in latency of 4% or greater and changes in amplitude of 50% or greater were unequivocal indicators of spinal cord injury. Postmortem analyses of the spinal neurotransmitter serotonin revealed that apparent false-positive results of the SEP were, in fact, true-positive results.