PubMed Health⌕ Search

Biomedical subjects

C H Tator

Publications and source records attributed to C H Tator.

At least 163 records · Page 9Linked to original sources

National survey of spinal injuries in hockey players.

There has been an alarming increase in the number of spinal injuries in hockey players. Between 1976 and 1983, 42 were reported to the Committee on Prevention of Spinal Injuries due to Hockey. The median age of the injured players was 17 years. Of the 42 players 28 had spinal cord injuries, and 17 of them had complete paralysis below the vertebral level of the injury. Strikes from behind and collisions with the boards were common mechanisms of injury. Many of the players had suffered a burst fracture of the cervical spine following a blow to the top of the helmet when the neck was slightly flexed. The committee studied a number of possible etiologic factors and made several recommendations regarding prevention. League officials, coaches, players and equipment manufacturers can all play a role in prevention.

Adolescent↗

Spinal injuries due to hockey.

Although many types of sports and recreational activities have been identified as common causes of acute spinal cord injury, hockey has been a rare cause of acute cord injury in Canada or elsewhere. For example, from 1948 to 1973 there were no patients with cord injuries due to hockey in a series of 55 patients with acute cord injuries due to sports or other recreational activities admitted to two Toronto hospitals. In contrast, between 1974 and 1981, the Acute Spinal Cord Injury Unit, Sunnybrook Medical Centre treated six patients with cervical spinal injury due to hockey, five of whom were seen during a 13 month period from September, 1980 to October, 1981. Five of the six sustained a severe acute cervical spinal cord injury, and one a cervical root injury. The cord injury was complete in two cases, while three had complete motor loss but incomplete sensory loss below the level of the lesion. All were males aged 15 to 26 years. Of the players with cord injury, four struck the boards with the neck flexed, and one struck another player with the neck flexed. The one player without cord injury struck the boards with his neck extended. The commonest bony injury was a burst fracture of C5 or C6. One of the patients with a complete cord injury died three months later of a pulmonary embolus, and the other patients with cord injury showed some recovery of root function, but little or no cord recovery. The reasons for the increase in spinal injuries in hockey are unknown.

Adolescent↗

The University of Toronto head injury treatment study: a prospective, randomized comparison of pentobarbital and mannitol.

Fifty-nine patients were treated in a prospective, randomized comparison of pentobarbital and mannitol for the control of intracranial hypertension resulting from head injury. Patients with elevated intracranial pressure (ICP) after evacuation of intracranial hematomas were randomized to one of two treatment groups; mannitol initially or pentobarbital initially, followed by the second drug as required by further elevation of ICP. Similarly, patients with raised ICP but without hematomas requiring evacuation were randomly assigned to two treatment groups in an identical paradigm. Those with ICP elevation and no hematoma treated with pentobarbital as initial therapy had a 77% mortality compared to a 41% mortality for those with mannitol as initial treatment. Patients with evacuated hematomas had mortalities of 40% and 43% (no significant difference) for pentobarbital and mannitol respectively. In both no-hematoma and hematoma streams pentobarbital was less effective than mannitol for control of raised ICP. Multivariable statistical analysis indicates that pentobarbital coma is not better than mannitol for the treatment of intracranial hypertension and may be harmful in no-hematoma patients with intracranial hypertension after head injury.

Adult↗

Effect of acute spinal cord injury on axonal counts in the pyramidal tract of rats.

The concentration of axons in the pyramidal tract of normal and spinal cord-injured rats was determined by counting axons in sections of spinal cord stained by the Holmes technique. In the normal rat the axon concentration was uniform in the cervical, thoracic, and lumbar regions, although the size of the tract diminished progressively with its descent in the cord. After acute cord transection or compression injury, the axon concentration distal to the injury site diminished markedly. However, an appreciable number of distal axons persisted after injury, due to either delayed degeneration or to the presence of an admixture of afferent fibers. The axonal counting technique developed in this study should be helpful in experiments on spinal cord injury and regeneration.

Animals↗

Hearing preservation: a realistic goal in surgical removal of cerebellopontine angle tumors.

Complete excision of small (less than or equal to 2 cm) cerebellopontine angle (CPA) tumors as well as preservation of hearing is possible. In a series of 28 patients with serviceable hearing and small tumors, one in three (32%) had hearing preserved. Our experience with tumors of this size (N = 54) suggests no significant difference in morbidity whether the approach used is suboccipital (prone) as in attempted hearing preservation, or translabyrinthine when hearing is not a factor.

Aged↗

Management of acute spinal cord injuries.

This report describes the results achieved in 144 patients with spinal cord injury admitted during the period 1974 to 1979 to the Acute Spinal Cord Injury Unit of Sunnybrook Medical Centre in Toronto. Several innovations have been made. These are based on a systems analysis approach to care and documentation. It includes epidemiologic studies of, and programs for, urologic and respiratory management and the use of halo devices. The unit has achieved a marked reduction in both mortality and morbidity. Patients have been transferred to the unit earlier after trauma and have been discharged earlier to rehabilitation hospitals partly because of the coordination of the acute and rehabilitation phases of care. There has been a marked reduction in the cost of care, because of fewer complications and a shorter stay in the acute hospital. The study confirms the advantages of regionalization and specialization in the field of acute spinal cord injury.

Acute Disease↗

Elimination of root regeneration in studies of spinal cord regeneration.

In experimental studies of spinal cord regeneration, dorsal root regeneration can be erroneously interpreted as regeneration of the central axons. The present study explored the possibility of eliminating root regeneration by preliminary bilateral division of the L-1 and L-2 roots. Clinical performance as measured by the inclined plane technique showed that root transection significantly reduced motor function (p less than 0.01). As expected, root transection produced atrophic changes in the dorsal columns of the spinal cord, but in some animals there were more diffuse changes in the spinal cord, possibly due to a vascular injury. Thus, root transection is not a good adjunct to regeneration of the spinal cord because the procedure induces deleterious clinical and histologic effects.

Animals↗

Successful surgical decompression of spinal extradural metastases of liposarcoma.

Two patients with metastatic liposarcoma to the spine developed neurologic deficits that were successfully reversed by laminectomy and partial tumor resections. Recurrences at later dates were treated similarly with comparable outcomes. Paraplegia was forestalled for approximately two years by each of the surgical interventions.

Aged↗

Effect of triiodo-L-thyronine on axonal regeneration in the rat spinal cord after acute compression injury.

Studies were performed on the effect of triiodo-L-thyronine (T3) on clinical recovery and axonal counts in the pyramidal tract of 56 rats subjected to an acute spinal cord compression injury at T-7. The T3 was given at a daily dose of 5 micrograms/kg for 4 weeks to 28 rats in the treatment group. The treatment and control animals were tested weekly for clinical recovery, and cord function as determined by the inclined-plane technique. Groups of animals were killed at 4 weeks and 12 weeks, and the axons in the pyramidal tract cephalad and caudad to the injury site were counted in sections prepared with Holmes' silver stain. There was no difference in clinical recovery between the treatment and control groups. This negative result contrasts with other studies which showed improved recovery of cord-injured animals treated with thyroid hormones. The possible explanations for this discrepancy are discussed. Similarly, there was no difference in the axon counts between the treated and control groups. Thus, T3 did not improve recovery or axonal regeneration in the pyramidal tract of rats after acute spinal cord compression injury. Between 4 and 12 weeks, there was a marked reduction in the cephalad axon counts in the pyramidal tract in both groups, indicating that approximately 50% of the axons in the pyramidal tract had undergone retrograde degeneration or dying back by 12 weeks after this degree of injury. The T3 did not affect the degree of retrograde degeneration.

Animals↗

Use of phenobarbital and high doses of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea in the treatment of brain tumor-bearing mice.

It has been shown that the nitrosoureas are substrates for hepatic microsomal enzymes in vitro and that phenobarbital (PB) administered in multiple doses prior to nitrosourea administration significantly reduces the activity of the nitrosoureas in murine brain tumor models. In the present study, the effect of PB on 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) was assessed by determining the CCNU dose which would result in the long-term survival of 50% of the treated mice, and the CCNU dose which would result in the toxic death of 50% of the treated mice, with or without PB pretreatment in C56BL/6J mice. The therapeutic index, the CCNU dose which would result in the long-term survival of 50% of the treated mice, per the CCNU dose which would result in the toxic death of 50% of the treated mice, without PB pretreatment was 2.1; the therapeutic index of CCNU after PB pretreatment was 1.7. There is no significant difference between the therapeutic indices. Thus, the reduction in the tumoricidal activity of CCNU after PB pretreatment was restored by increasing the dose of CCNU without a significant change in its lethal toxicity.l

Animals↗

The effect of acute spinal cord compression injury on thyroid function in the rat.

The effect of acute spinal cord injury on thyroid function was studied in rats subjected to severe spinal cord compression at T1. Serum thyroxine (T4), effective thyroxine index (ETI), and thyroid stimulating hormone (TSH) were measured at 1 and 100 minutes at one, three, and seven days after laminectomy and spinal cord injury. Control animals were subjected to laminectomy only. T4 was decreased at 1 minute after laminectomy with or without spinal cord injury, though the animals with cord injury had a much more profound reduction. The effects on TSH at 1 minute were dramatically different: laminectomy alone caused an elevation of TSH, while spinal cord injury produced a marked decline. At the later time intervals both groups showed gradual normalization of T4 and TSH levels, and at seven days there were no significant differences between the groups. Thus, acute spinal cord compression injury produced a major alteration in thyroid function during the acute phase.

Acute Disease↗

Massive gastroduodenal hemorrhage and perforation in acute spinal cord injury.

Fatal gastrointestinal hemorrhage or perforation are important problems in the management of patients in the acute phase of spinal cord injury. This paper describes 3 patients with these conditions, and shows some of the associated hazards, especially the danger of painless penetration, perforation, and peritonitis, plus the increased morbidity of these serious problems in the presence of the neurological sequelae of spinal cord injury. Our experience shows that life-threatening hemorrhage from the gastrointestinal tract occurs in about 2.5% of patients with cord injury, and often occurs during the first few days after the accident. We believe that a high index of suspicion and an aggressive therapeutic approach are necessary to save these patients from the traditionally high mortality associated with massive upper gastrointestinal hemorrhage, especially during this critical period of acute spinal cord injury.

Acute Disease↗

The effect of blood transfusion, dopamine, and gamma hydroxybutyrate on posttraumatic ischemia of the spinal cord.

Posttraumatic spinal cord blood flow (SCBF) was assessed after elevating the mean systemic arterial pressure (mSAP) with a blood transfusion, or with an infusion of dopamine. The effect of the anesthetic agent, gamma hydroxybutyrate, was also assessed. Flows were measured using the 14C-antipyrine autoradiographic method. Animals were injured at T-1 by acute compression of the spinal cord with a clip exerting a pressure of 175 gm. Uninjured animals, with mSAP's of 120.0 +/- 17.0 mm Hg, had gray and white matter flows of 74.2 +/- 22.3 and 18.7 +/- 6.7 ml/100 gm/min, respectively, while injured untreated animals had mSAP's of 82.5 +/- 14.1 mm Hg and gray and white matter flows of 13.3 +/- 12.1 and 3.9 +/- 3.9 ml/100 gm/min, respectively, at the injury site. Blood transfusion raised the mSAP's to 127.5 +/- 13.7 mm Hg in the injured animals and doubled the flows in gray and white matter to 25.6 +/- 30.2 and 6.3 +/- 6.4 ml/100 gm/ml, respectively. Dopamine did not have as beneficial an effect as blood transfusion on either the mSAP (101.0 +/- 16.7 mm Hg) or the SCBF (gray and white matter flows of 18.4 +/- 12.4 and 5.8 +/- 5.9 ml/100 gm/min). Gamma hydroxybutyrate (GHB) had almost no effect on the mSAP or SCBF of normal animals, and in injured animals produced only a unilateral increase in flow on the less severely injured side, without affecting the mSAP.

Animals↗

Favorable results with syringosubarachnoid shunts for treatment of syringomyelia.

From 1969 to 1979, 20 patients with syringomyelia were treated with a syringosubarachnoid shunt. The principal indications for this procedure were: significant progressive neurological deterioration and absent or minimal tonsillar ectopia. There were 15 patients with idiopathic syringomyelia, four with posttraumatic syringomyelia, and one with syringomyelia secondary to spinal arachnoiditis. The operations were performed with an operating microscope, and attention was directed to preserving thearachnoid membrane to ensure proper placement of the distal end of the shunt in an intact subarachnoid space. In all cases, a silicone rubber ventricular catheter was inserted into the syrinx through a posterior midline myelotomy. The average follow-up period was 5 years. A favorable result was obtained in 15 of the 20 patients (75%), including an excellent result with improvement of neurological deficit in 11 patients and a good result with cessation of progression in four patients. In the remaining five patients the result was poor with further progression of neurological deficit. A short duration of preoperative symptoms was usually a favorable prognostic feature. Four patients with a history of less than 6 months all had excellent results. Thirteen patients had a syringosubarachnoid shunt only, and all had good or excellent results. Seven patients had other surgical procedures, before, accompanying, or after shunt placement, and two had favorable results. Thus, the syringosubarachnoid shunt is an effective therapeutic modality for many patients with syringomyelia, particularly if there is little or no tonsillar herniation.

Adult↗

Facial nerve preservation in patients with large acoustic neuromas treated by a combined middle fossa transtentorial translabyrinthine approach.

With large acoustic neuromas, the primary goal of surgery is safe total removal of the tumors, and the secondary goal is preservation of nearby neural structures, including the facial nerve. In a series of 15 consecutive patients with large cerebellopontine angle tumors, all of which were more than 2.5 cm in diameter, tumor excision was performed by a one-stage combined middle fossa-translabyrinthine approach. There were 13 acoustic neuromas, 10 of which were more than 4 cm in diameter, one petrous apex meningioma 4 cm in diameter, and one facial neuroma 3 cm in diameter. The tumors were totally removed in all 15 patients. The facial nerve was preserved in 12 of 13 evaluable patients. In the 14th patient the nerve had been transected in a previous suboccipital procedure with incomplete removal, and in the 15th patient the nerve was sutured following excision of a facial neuroma. Thus, the nerve was lost at surgery in only one patient. This combined approach provided very clear visualization of the cerebellopontine angle, including the brain stem and the lower cranial nerves. It enabled identification of both the origin of the facial nerve at the brain stem and the lateral segment of the nerve in the internal auditory canal. Anterior extensions of tumor growing through the tentorial hiatus were easily removed. The results in these 15 patients show that this approach is excellent for total removal of large acoustic neuromas with preservation of the facial nerve. It is especially suitable for large tumors with anterior extensions.

Adult↗