Thoracic outlet syndrome after motor vehicle accidents in a Canadian pain clinic population.

OBJECTIVE: To record symptoms and signs, operative findings, and long-term outcome in operated and nonoperated patients with the diagnosis of thoracic outlet syndrome after a motor vehicle accident. DESIGN: Descriptive prospective study. SETTING: Pain clinic population in the Toronto Hospital (Western Division), Toronto, Ontario, Canada. PATIENTS: Thirty-two patients diagnosed as having thoracic outlet syndrome after injuries sustained in a car accident (based on specific symptoms and signs as well as exclusion of other disorders generating brachialgia). INTERVENTIONS: Conservative management versus transaxillary or supraclavicular exploration of the thoracic outlet. OUTCOME MEASURES: Pain/symptom relief. RESULTS: Most patients presented with pain and paresthesiae, but conspicuous discoloration of the symptomatic extremity was seen in 41%. Osseous anomalies were seen in 22% of the patients in simple neck x-rays. Vascular studies were abnormal in 24% of tested patients. During transaxillary first rib resection in 15 patients, 87% were found to have musculotendinous and less often osseous anomalies compromising primarily the lower trunk of the brachial plexus. Long-term follow up demonstrated very good pain relief (based on patients' estimates) only in 47% of the operated patients and 20% of the conservatively treated patients. Reoperation was necessary in six cases through a supraclavicular decompression with only one patient experiencing substantial improvement with long-term follow-up. The difficulties in diagnosis as well as reasons for failures of conservative and surgical management are discussed, and the authors' current protocol for diagnosis and management is presented.

Fundamental considerations in pacing of the diaphragm for chronic ventilatory insufficiency: a multi-center study.

Records were reviewed of 477 patients who had diaphragm pacemakers implanted for treatment of chronic hypoventilation. Three groups were established for comparison. (1) Center group: 165 patients operated on in six medical centers participating in a cooperative study; (2) Noncenter group, sufficient data available: 203 patients operated on by surgeons with experience limited to a few cases; (3) Nonstudy group, minimal data available: 109 patients operated on as in group 2; vital statistics only were contributed. The protocol for data gathering was comprised of 154 major variables. Basic data on age, sex, diagnosis and etiology were analyzed for homogenicity of data among the groups. A comprehensive analysis of the pacing methods, complication and results from the Center group yielded information on the early experience with diaphragm pacing important to its future application.

Management of chronic ventilatory insufficiency with electrical diaphragm pacing.

We have had experience with diaphragm pacing in 24 patients at the Toronto Western Hospital. Fourteen patients have undergone bilateral implants to treat chronic ventilatory insufficiency (CVI) caused by traumatic tetraplegia at the C1/2 level (eight patients), neurogenic apnea (five) and one case of neonatal apnea. Unilateral stimulators for nocturnal pacing have been implanted in five patients with central alveolar hypoventilation (sleep apnea) and five patients who suffered CVI resulting from various etiologies. Of the patients who were ventilatory dependent, 80% were successfully weaned and in the entire series, 58% of the patients are living. Diaphragm pacing was successful in 67%, partially successful in 8% and ineffective in 25%. The major complications were: death by pneumonia, failure of the radio receivers, and infection. Diaphragm pacing is the treatment of choice for patients who are ventilator dependent and tetraplegic from upper cervical trauma or in some cases of neurogenic apnea; it may be life saving for patients who suffer central alveolar hypoventilation.

Microsurgical resection of solitary intramedullary spinal cord metastases.

Two cases of solitary intramedullary spinal cord metastasis treated primarily by surgical excision are presented. It has been generally thought that appropriate management for the rare metastasis within the spinal cord is radiation and corticosteroids. The excellent palliative results obtained in our patients suggest that, in selected cases, surgical removal is technically feasible and can be of considerable benefit to the patient.

Significance of hemorrhage into brain tumors: clinicopathological study.

A retrospective clinical and pathological review of 905 consecutive brain tumor cases (excluding pituitary adenoma and recurrent tumor) was conducted to identify cases in which intratumoral hemorrhage was confirmed grossly and/or pathologically. There were 132 cases so identified, for an overall tumor hemorrhage rate of 14.6%; of these, 5.4% were classified as macroscopic and 9.2% as microscopic. The presence of hemorrhage was correlated with the neurological presentation. The highest hemorrhage rate (70.0%) was found in patients with prior neurological history who experienced apoplectic deterioration (acute-on-chronic presentation). Only 57.1% of patients with acute deterioration in the absence of prior neurological symptoms had hemorrhages. The highest hemorrhage rate for primary brain tumors was 29.2% for mixed oligodendroglioma/astrocytoma, while the highest hemorrhage rate for any tumor type was 50% for metastatic melanoma. The clinical relevance of tumor hemorrhage is discussed.

Diaphragm pacing and continuous positive airway pressure.

The effect of changes in continuous positive airway pressure (CPAP) on the tidal volume generation by the diaphragm during electrical stimulation of the phrenic nerves in a quadriplegic patient is presented. Measurements of tidal volume, end-tidal PCO2, arterial PCO2, oxygen consumption, physiologic dead space to tidal volume ratio, diaphragm length, and thoracic and abdominal dimensions were made at values of CPAP from 0 to 20 cm H2O during periods of diaphragm pacing. Total respiratory compliance (TRC) was measured during controlled ventilation with incremental positive end-expiratory pressure (PEEP) from 0 to 20 cm H2O. A significant negative correlation was found between increasing CPAP and generated tidal volumes. This correlation was seen to occur even when TRC was constant at degrees of CPAP from 0 to 7.5 cm H2O. When phrenic nerve stimulation was commenced, oxygen consumption rose significantly from values obtained during controlled ventilation, but there was no significant correlation between changes in CPAP and the rise in oxygen consumption. Using inductance methods, thoracic and abdominal diameters were seen to rise as CPAP was increased. As suggested by the decrease in the length of the vertical and horizontal portions of the diaphragm in the chest roentgenogram, the conformation of the diaphragm also changed. It is suggested that the operating length and conformation of the diaphragm are principal factors affecting tidal volume generation during electrical stimulation of the phrenic nerves.

Chiari malformation in adults: a review of 40 cases.

Forty adult patients (average age 40 years), with the clinical and radiological features of the Chiari malformations, were seen at the Toronto Western Hospital between 1967 and 1984. Surgical confirmation of the diagnosis was obtained in 32 cases; of these, 23 were classified as Chiari I malformation while 9 fulfilled the anatomic criteria of Chiari II. The patient population consisted of 22 males and 18 females. Common presenting symptoms included head and neck pain (60%), sensory complaints (60%), upper extremity weakness (42%), and gait disturbance (40%). Neurological findings included signs of central cord dysfunction (73%), long-tract motor and/or sensory findings (58%), brainstem signs (38%), cerebellar dysfunction (18%), and increased intracranial pressure (15%). The majority of patients underwent myelography with or without computed tomography of the cervical-medullary junction. Two recent patients had 0.15T MRI scans which helped demonstrate an intramedullary syrinx. Thirty-three patients underwent 47 operative procedures (discounting spinal fusion and CSF shunt revisions). Open surgical management was performed in 32 patients, with CSF shunting along in one patient. Five patients (15%) incurred surgical complications within a six week postoperative period. Follow-up to date, ranges from one month to 11 years. In the 33 surgically treated patients, 18 are improved (55%), 10 are neurologically stable (30%), and five have worsened clinically (15%), including one death. Based on this study it appears that the Chiari II malformation may be more common in adults than previously recognized. Surgical intervention has a favourable outcome in the majority of patients but a significant proportion continue to deteriorate.

Subarticular entrapment of the dorsal root ganglion as a cause of sciatic pain.

Eleven patients who presented with sciatica that was aggravated by standing and walking had definite neurologic signs in only half the cases and normal myelograms in seven. Differential blocks of the L4, L5, and S1 nerve roots identified the symptomatic levels by temporarily relieving the pain in all patients done. CT scans showed minimal enlargement of the articular facets, but an absence of periradicular fat and an increased volume of neural tissue due to the presence of proximally placed dorsal root ganglia in the nerve root canal. Decompression of the symptomatic ganglia by surgical removal of the medial third of the overlying apophyseal joint resulted in satisfactory pain relief in 70% of these patients.

Spontaneous arterial subdural hematoma.

the occurrence of spontaneous arterial subdural hematomas is very rare. We report five patients who presented with sudden severe headache and who developed progressive neurological deficits, two becoming comatose. None had a history of trauma. A diagnosis of subarachnoid hemorrhage was suspected in all patients, but all proved to have subdural hematomas caused by "spontaneous" rupture of a cortical artery. Nineteen similar cases have been reported in the English literature. The source of bleeding was identified as a cortical artery located near the sylvian region in four of our five patients and in most of the reported cases. There are several possible anatomical situations that may predispose a cortical artery to "spontaneous" rupture: (a) spontaneous rupture of a cortical artery at the point of origin of a fragile arterial twig, especially a right-angled branch, a point of potential weakness; (b) rupture of a small artery traversing the subdural space and connecting a cortical artery to the dura mater (a "bridging" artery); (c) adhesions between a cortical artery and arachnoid or dura mater; (d) a knuckle of cortical artery protruding through the arachnoid and adherent to the dura mater. In each situation, the artery is probably torn by a sudden movement of the brain during a vigorous head movement, not severe enough to be considered trauma.

Lung function in diaphragm pacing.

Electric stimulation of the diaphragm via the phrenic nerve to induce ventilation has recently been used for the long-term management of chronic ventilatory insufficiency. Since 1973 three patients with inadequate alveolar ventilation have been treated with diaphragm pacing at the Toronto Western Hospital. Two, who had quadriplegia due to lesions of the spinal cord in the upper cervical region and a severe restrictive ventilatory defect, were treated with continuous diaphragm pacing. The third patient required assisted nocturnal ventilation because of primary alveolar hypoventilation. All three patients tolerated the diaphragm pacing well, and pulmonary function tests showed satisfactory gas exchange with the patients breathing room air. This form of therapy seems to be a practical clinical method of managing chronic ventilatory failure in patients with lesions of the upper cervical cord or primary alveolar hypoventilation.

Primary alveolar hypoventilation treated with nocturnal electrophrenic respiration.

A case of primary alveolar hypoventilation is described. Despite characteristic clinical findings, the diagnosis was delayed for 4 years. Alleviation of nocturnal hypoxemia and hypercapnia initially by a rocking bed and subsequently by phrenic nerve stimulation was accompanied by reversal of cor pulmonale and polycythemia. Electrophrenic respiration is an effective form of long-term management in primary alveolar hypoventilation.