Thoracic neurenteric cyst in an adult: case report.

OBJECTIVE AND IMPORTANCE: Neurenteric cysts are very rare (particularly in the adult age group) congenital intraspinal cysts of endodermal origin. The patient described was a 48-year-old man who was diagnosed as having an isolated thoracic neurenteric cyst at the T5-T6 level, without a mediastinal enterogenous cyst. Radiological studies demonstrated multiple anterior vertebral column abnormalities. CLINICAL PRESENTATION: The patient presented with a long history of mild midback pain. During the 2 years preceding admission, his midback pain worsened and he experienced right intercostal pain in the midthoracic area. Several months before admission, he noticed right lower extremity weakness, which led him to undergo neurological evaluation and radiological studies. INTERVENTION: Thoracic spine x-rays revealed marked thoracic scoliosis and multiple vertebral abnormalities. Magnetic resonance imaging and myelography revealed an intradural extramedullary cystic mass at the T5-T6 level, severely compressing the spinal cord from the ventral side. Thoracic laminectomy was performed and the cystic lesion was completely removed, with disconnection of the ventral tract. CONCLUSION: This is an unusual presentation, at this age, of a congenital intraspinal cyst in the thoracic area. Such cysts must investigated for early diagnosis and treatment. A neurenteric cyst should be suspected particularly if the cyst is associated with anterior vertebral column abnormalities.

Surgical site after resection of a meningioma.

PURPOSE: Our goal was to characterize MR changes over time at the site of meningioma resection in order to determine optimal timing for detecting residual and recurrent tumor. METHODS: Twenty-one patients were studied with enhanced MR imaging during the first 5 postoperative days and additional studies were obtained 3 to 8 weeks after surgery (16 studies), 3 months to 1 year after surgery (17 studies), and 1 year or more after surgery (32 studies). Images were analyzed for residual tumor, membrane enhancement, parenchymal enhancement, edema, and blood collections. RESULTS: Early postoperative images showed extensive, thin membrane enhancement that thickened by 3 to 8 weeks after surgery and that thinned or resolved and became less extensive by 6 months or more postoperatively. Twelve of 20 patients with long-term follow-up studies had membrane enhancement. Thin, serpiginous foci of enhancement in the surgical bed were identified only on early postoperative studies and probably represent gradual thrombosis of feeding vessels. CONCLUSION: Residual foci of meningioma are best detected on studies obtained within the first 5 days after surgery because membrane thickness increases by 3 to 8 weeks after surgery and may obscure a small residual meningioma. Our study confirms the presence of prolonged membrane enhancement after surgery, although it thins with time and becomes confined to the craniotomy site.

Cervical disk disease and the keyhole foraminotomy: proven efficacy at extended long-term follow up.

Eighty-four consecutive patients with posterolateral cervical disk herniation treated by keyhole foraminotomy between 1980 and 1987 were reviewed. Radicular pain was the most common presenting complaint. Weakness was present in 59 patients. Sixty patients were available for long-term follow up, averaging 6.1 years. Fifty-six patients' results were graded as excellent. Three patients had good results and one fair result was noted. There were no poor results. Preoperative pain symptoms were relieved in all patients. There were no significant complications. The posterolateral keyhole foraminotomy is an efficient means of decompressing lateral soft disk herniations, without the risk of an anterior approach or iliac crest bone harvest. Careful patient selection and use of an operative microscope are essential in obtaining consistent, excellent results.

Comparison of cerebral blood flow measured by laser-Doppler flowmetry and hydrogen clearance in cats after cerebral insult and hypervolemic hemodilution.

Laser-Doppler flowmetry provides a continuous measurement of blood flow without violating the natural state of circulation. The linearity of the laser-Doppler and hydrogen clearance methods of blood flow measurement were compared using a protocol that produced changes in cerebral blood flow that might be experienced in a neurosurgical setting. Cerebral blood flow was measured in both hemispheres of 12 adult cats during the snaring of one common carotid artery, the intracisternal injection of 5 mg of 5-hydroxytryptamine creatinine sulfate, and hypervolemic hemodilution, which produced a 25% reduction in blood hematocrit. The percentage of baseline laser-Doppler flowmetry and hydrogen clearance flows showed an acceptable degree of correlation (R2 = 0.762) over the range of cerebral blood flows measured. More rigorous analysis using Bland and Altman's difference against mean test showed that 10 minutes after hemodilution, the two methods displayed a level of variation outside the limits of agreement (-21.85 to 22.03%). Laser-Doppler flowmetry provided a noninvasive and continuous measure of blood flow, increasing the ability to observe instantaneous changes in cerebral microcirculation. However, laser-Doppler flowmetry did not record absolute blood flow, was affected by cerebral tissue shrinkage, and did not accurately measure flow under conditions of changed blood hematocrit.

Comparison of smoking habits between patients with surgically confirmed herniated lumbar and cervical disc disease and controls.

There have been numerous studies that implicate cigarette smoking as a risk factor for the development of back pain or disc disease. The purpose of this article is to review patients who underwent surgery for cervical or lumbar radiculopathy and to investigate the relationship between cigarette smoking and development of surgical disc disease. A cigarette smoking study of 205 surgical patients with lumbar and cervical disc diseases was done, with the surgical patients compared to 205 age-sex-matched inpatient controls during 1987-1988. This study was conducted at the Pennsylvania Hospital in Philadelphia, Pennsylvania. There were 163 patients with lumbar disc disease and 42 patients with cervical disc disease. The ratio of men to women was 1.5:1 for lumbar disc and 2.5:1 for cervical disc disease. Smoking history (current and ex-smokers) was strikingly increased in both prolapsed lumbar intervertebral disc (56% vs. 37% of controls, p = 0.00029) and cervical disc disease (64.3% vs. 37% of controls, p = 0.0025). Calculated relative risks for smokers were 2.2 for lumbar disc and 2.9 for cervical disc diseases. This association between cigarette smoking and disc disease was more significant when comparing between current smokers versus nonsmokers (p = 0.000011 for lumbar disc disease, and p = 0.00064 for cervical disc disease). Relative risks for current smokers were 3.0 for lumbar disc and 3.9 for cervical disc diseases. This correlation was significant for both males (p = 0.000068 for lumbar disc disease, p = 0.043 for cervical disc disease) and females (p = 0.018 for lumbar disc disease, p = 0.006 for cervical disc disease).(ABSTRACT TRUNCATED AT 250 WORDS)

Seasonal and latitudinal occurrence of cerebral vasospasm and subarachnoid hemorrhage in the northern hemisphere.

Using patient data obtained from the International Cooperative Aneurysm Study that evaluated clinical records from 68 neurosurgical centers in 14 countries, we evaluated the data as to the monthly occurrence of cerebral vasospasm and subarachnoid hemorrhage relative to the latitude of the medical center where the data were gathered. Using the Edwards analysis for cyclic patterns, we examined peak to trough ratios and months of peak to assess the strength and nature of the cyclic variations between December 1980 and July 1983. Of the 3,521 subarachnoid hemorrhage patient records examined, 685 developed some grade of vasospasm as defined symptomatically, angiographically, and by the Fisher Grading Scale. Cyclic analysis demonstrated a strong seasonal occurrence for the incidence of subarachnoid hemorrhage, with a peak in February, in the northern hemisphere. Cerebral vasospasm incidence, after controlling for subarachnoid hemorrhage occurrence, exhibited only a small peak to trough ratio (1.15) relative to the larger ratio (1.74) seen with unadjusted vasospasm data. Age was related to both incidence and location. In populations at high risk for cerebrovascular diseases, climatic conditions may act as synchronizers of pathologic vascular events.

Circannual and latitudinal variation in the incidence of subarachnoid hemorrhage.

Numerous epidemiological studies have shown a preponderance of cerebrovascular accidents occurring during the winter or colder months in both hemispheres. However, many of these studies used no or inappropriate statistical tests to demonstrate cyclic trends or relied on a small number of poorly documented cerebrovascular accident cases. Data were obtained for this study from the International Cooperative Aneurysm Study that evaluated 3,521 clinical records from 68 neurosurgical centers in 14 countries. We used the Edwards cyclic trends method to examine the monthly occurrence of subarachnoid hemorrhage between March 1981 and February 1983. Significant (p < 0.05) seasonal variation was noted with more subarachnoid hemorrhage cases occurring during the winter relative to the summer in the northern hemisphere, whereas the reverse of this was noted in the southern hemisphere. Significant (p < 0.025) seasonal periodicity was noted above the latitude of 43.2° N, but not below it. This report, and others, suggest that subarachnoid hemorrhage may be a seasonal and geographic risk disease. An overview of the literature examining seasonality and cerebrovascular accidents is also presented.

Effects of intracisternally injected serotonin on cerebral blood flow in cats during winter and summer, and after dark exposure.

This investigation reports on two experiments: (a) The examination of the effects of intracisternally injected serotonin on cerebral blood flow and systemic pressure in cats during winter (1/10-3/7) and summer (7/6-9/3) at a latitude of 39' 40", and (b) the effects of similarly injected serotonin on the same parameters in 11 cats after exposure to 3 days of continuous darkness during the summer months. Serotonin (5 mg) injected intracisternally produced significant decreases in cerebral blood flow and systemic pressure that lasted from 60 to 180 min after injection. Blood flow decreases, expressed as percentage change from baseline, seen during winter (n = 24) periods were significantly greater [analysis of variance (ANOVA), p < 0.02] from decreases seen during summer (n = 25) periods. Following serotonin injection, systemic pressure decreases between the winter and summer cats were not significantly different. Eleven summer cats were subjected to 3 days of continuous darkness before being injected with serotonin. Blood flow decreases in the dark-exposed cats were significantly (p < 0.05) greater than those seen in normal light-exposed cats, whereas systemic pressure changes were not different. These studies suggest that the seasonal photoperiod may affect the sensitivity of cerebral vessels to intracisternally injected serotonin in cats.

The results of operations on the lumbar spine in patients who have diabetes mellitus.

The results for sixty-two patients who had had a diagnosis of diabetes mellitus and lumbar disc disease or spinal stenosis and had been managed with a posterior decompressive procedure were compared, in a retrospective study, with those for sixty-two age and sex-matched non-diabetic (control) patients who had had similar operative procedures. Forty-four of the sixty-two diabetic patients and fifty-five of the non-diabetic patients were available for long-term follow-up (mean, five and seven years, respectively). Among the diabetic patients, there were high rates of postoperative infection and prolonged hospitalization compared with the rates for the control group. The long-term result was excellent or good for seventeen (39 per cent) of the forty-four patients who had diabetes mellitus and for fifty-two (95 per cent) of the fifty-five non-diabetic patients. The poor results in the diabetic patients may have been related to coexisting diabetic neuropathy, to the associated microvascular disease that affects the spinal nerve roots in diabetic patients, or to the failure of the nerve roots of these patients to recover after decompressive procedures.

Thoracic disc herniation. Re-evaluation of the posterior approach using a modified costotransversectomy.

A consecutive series of 23 thoracic disc herniations in 21 patients treated between 1980 and 1988 were reviewed. All patients were decompressed through a posterolateral approach (costotransversectomy or transpedicular). Pain and weakness were the most common presenting symptoms. Twenty-one thoracic disc herniations in 19 patients were available for long-term follow-up, averaging 58.1 months. Sixteen patients had an excellent or good result. Three patients had a fair result. There were no poor results. All six patients with significant preoperative lower extremity weakness improved. Pain was relieved in 16 patients and reduced in three. There were no significant neurologic complications associated with the procedure. Posterolateral decompression for thoracic disc herniation remains a viable alternative without the inherent risk and morbidity of the transthoracic approach.

Upper lumbar disc herniations.

This study reviews the presentation, diagnosis, and outcomes of upper lumbar disc herniations (L1-2, L2-3, L3-4). One hundred forty-one patients operated upon at three centers between 1980 and 1990 were analyzed (102 men, 39 women; 3 L1-2, 21 L2-3, 117 L3-4; average age 51.6 years; 10.4% of all lumbar discectomies performed). Preoperative signs and symptoms were highly variable. Sensory, motor, and reflex testing was variable and potentially misleading in suggesting a level of herniation. In analyzing radiographic studies (noncontrast CT, myelography, MRI) individually and using other radiographic studies and operative findings as a standard for comparison, a high false-negative rate was found for all studies when considered individually, especially at the higher L2-3 level. Intraoperative radiographs were employed with increasing frequency as the level of herniation ascended. Six operative complications (4.3%) were identified, all of which were treated and were resolving at the time of discharge. Follow-up obtained at an average of 2.2 years in 87% of patients by chart review showed no reoperations or late complications. Noncompensation patients had a significantly higher percentage of good/excellent results (86%) than those with compensation or legal claims pending (45% good/excellent results). Based upon these data, we recommend myelogram with postmyelogram CT and/or MRI in the workup of these patients and intraoperative radiographs in all cases when decompressing an upper lumbar disc herniation. Patients with compensation/legal claims should be approached cautiously, because their subjective results are significantly worse than those of noncompensation patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Herniated lumbar disc in patients over the age of fifty.

Fifty patients ranging in age between 50-78 years (mean, 56) underwent surgery for a herniated lumbar disc between January 1986 and July 1988. All had objective clinical and radiographic evidence of a herniated disc. All had had failure during an appropriate period of conservative treatment. Far lateral herniation occurred in 8%, and 28% had disc herniations at L2 or L3. Surgical results were 64% excellent, 28% good, 6% fair, and 2% poor. Complications including urinary tract infection, wound infection, myocardial infarction, and pulmonary embolism were observed in 8% of patients. Lumbar disc herniation in the elderly is common. After thorough evaluation to exclude neoplasm or infection, decompression of neural structures can lead to 90% good to excellent results. Spinal stenosis must be carefully considered both preoperatively and intraoperatively. Also, a higher incidence of more cephalad lumbar herniations and far lateral herniations was observed in older patients.

Comparison of intraluminally versus extraluminally administered nimodipine on serotonin-induced cerebral vascular responses in vitro and in situ.

The purpose of our study was to compare the ability of intraluminally and extraluminally administered nimodipine to inhibit serotonin-induced cerebral vascular responses in vitro and in situ. No difference was noted in the ability of nimodipine, whether administered intraluminally or extraluminally, to reduce the contractile response of extraluminally administered serotonin in a closed, pressurized, in vitro bovine middle cerebral artery preparation; histologic studies indicated that the tight endothelial junctions normally found in cerebral arteries remained intact in this preparation. In cats, pretreatment with nimodipine did not significantly reduce the ability of intracisternally injected serotonin to decrease cerebral blood flow; however, nimodipine did reduce the changes in cerebral artery diameter normally noted angiographically after serotonin injection. Although minor differences were noted between the intraluminal and extraluminal routes of administration of nimodipine in situ, in general the effects were comparable.

Extended latency of the cortical component of the somatosensory-evoked potential accompanying moderate increases in cerebral blood flow during systemic hypoxia in cats.

In 24 adult cats, the somatosensory-evoked potential (SEP) and cerebral blood flow (CBF) were measured under paralyzed, anesthetized conditions during exposure to two different ventilatory regimens. Group I cats (ventilated from 20 to 2% oxygen) responded with a significant increase in white matter blood flow from 25.0 +/- 7.8 to 43.8 +/- 10.5 ml/100 g/min recorded at 7% O2. Gray matter blood flows in these animals increased but not to significant levels above the control blood flow measured at 20%. No significant changes in blood flow were observed in group II animals ventilated over the range of 25-3% oxygen as gray matter rose slightly (but not significantly) with hypoxia and white matter flows remained at levels of 25-30 ml/100 g/min. The latency of the cortical component of the SEP was related to the degree of hypoxia. For both groups, significant extensions in the latency to the occurrence of the cortical component of the SEP (normalized to the % of control SEP) occurred in each case (P less than 0.05). An inverse, linear relationship existed between the latency to the appearance of cortical component (ms) and the percentage oxygen concentration of the ventilatory mixture. No significant changes in thalamocortical conduction times were found, which indicates that hypoxia may have generalized effects on the synaptic pathways supporting the conduction of the SEP. The variation in blood flow and the latency of the cortical component observed between groups I and II may reflect the oxygen concentration used at the beginning of the experiment (25 vs 20%) and the gradations between them vs 3 and 2%.(ABSTRACT TRUNCATED AT 250 WORDS)

Laminectomy: a review of the Pennsylvania hospital experience.

Two hundred seventy-four patients were reviewed 1-5 years after laminectomy for spinal stenosis or herniated disks. All patients were treated according to the Pennsylvania Plan Algorithm for Degenerative Disk Disease. Ninety to ninety-five percent of the patients noted good to excellent relief of their leg pain, whereas only 80% noted low-back pain relief. The majority returned to work within 4 months. This review demonstrates that by following an algorithm for the treatment of back and leg pain from degenerative disk disease, the surgical results can be extremely gratifying, assuming the goals are relief of leg pain, the operative findings are definite, and the preoperative surgical indications and patient selection are well developed.