Swallowing function in patients with spasmodic torticollis.

We examined the oropharyngeal swallowing ability of 43 patients with spasmodic torticollis using a videofluoroscopic procedure. Twenty-two (51.2%) demonstrated objective evidence of swallowing abnormalities; 15 (34.9%) had subjective complaints. Delayed swallowing reflex and vallecular residue were more frequent (p less than 0.0046) than any other abnormality. The constellations of abnormalities were consistent with neurogenic, postural, and mixed neurogenic-postural types of dysphagia.

Anterior temporal lobectomy for complex partial seizures: evaluation, results, and long-term follow-up in 100 cases.

We report evaluation and results in 100 patients who had undergone anterior temporal lobectomy for intractable complex partial seizures. Average follow-up was 9.0 years (range, 2 to 21 years). In the 2nd postoperative year, 63% were seizure free, 16% were significantly improved, and 21% were considered not significantly improved. Mean number of seizures in the last group was 27% of preoperative levels. Surgical results did not change significantly in subsequent postoperative years; good outcomes tended to persist over the longer term. We also examined the utility of continuous depth electrode monitoring in the evaluation of patients with independent bitemporal interictal epileptiform activity. Despite limited numbers of subjects in this category, there was a trend toward improved surgical outcome when such subjects were evaluated with depth electrodes.

Neural control of gastrointestinal motility: evidence for noncholinergic regulatory influences.

Although it is well known that neural control of gastric motility occurs via sympathetic, parasympathetic, noncholinergic, and nonadrenergic fibers contained in the vagus nerve, the central sites of origin of these influences are largely unknown. Recent experiments in our laboratory indicate that noncholinergic neural pathways originating in the posterior hypothalamus can markedly influence gastric motility. At least 2 weeks prior to the experiment, mongrel dogs were surgically prepared with bipolar recording electrodes fixed to the serosal surface of the stomach. This prevented violation of the abdominal cavity on the day of testing. Experiments were performed with the animals under alpha-chloralose anesthesia (100 mg kg-1) in temperature-controlled settings. Under stereotactic guidance, bipolar stimulation of the posterior periventricular hypothalamus produced profound reproducible excitatory or inhibitory effects on gastric myoelectric and motor activity. Changes in the frequency and amplitude of pacesetter potentials (PPs) and in the incidence of action potentials associated with them were observed. Stimulation of various loci in 14 dogs resulted in a 71 +/- 7.5% increase in the incidence of action potentials associated with gastric PPs in "excitatory" areas (n = 7) and a 69.1 +/- 4% decrease in this ratio in "inhibitory" areas (n = 19). In general, more lateral stimulation produced greater inhibitory effects. Responses were frequency dependent, with a threshold greater than 25 Hz in most cases. Excitatory gastric responses to hypothalamic stimulation occurred despite full systemic atropinization (0.1 mg kg-1). The physiologic significance of these noncholinergic excitatory pathways influencing distal gastric motility and the neurotransmitters they employ are as yet unknown.

Segmental analysis of spinal cord monoamines after thoracic transection in the dog.

The noradrenaline, dopamine and serotonin content from 10 segments of the dog spinal cord before and after a T7 transection were measured. The levels of amines were highest in the conus medullaris. However, when calculated per gram cord grey matter, noradrenaline was found to be concentrated in the midthoracic and sacral cord, while serotonin was concentrated in the mid-thoracic region. Levels of dopamine were very low throughout the spinal cord. Up to 3 days after a T7 transection, the levels of all 3 amines did not change in the distal cord segments. Ten days after transection the level of all 3 amines were less than twice tissue blank distally. This segmental analysis of dog spinal cord shows some potentially important differences from previous studies of cat and rat.

CT-guided stereotaxis using a modified conventional stereotaxic frame.

Computed tomographic (CT)-guided stereotaxic procedure have become established in a few major centers but a single optimal system has not yet emerged. At Duke University Medical Center, availability of a stereotaxic frame with design features that lend themselves to CT adaptation made modification of this unit, rather than construction of a new dedicated frame, cost-effective. As other centers may seek to modify available stereotaxic equipment in a similar way, this report documents the modifications ans the early clinical experience in four patients in whom CT-guided stereotaxic biopsy procedures were performed.

Computed tomography in the planning and evaluation of therapeutic stereotaxic surgical procedures of the brain.

Preoperative and serial postoperative computed tomographic (CT) scans were obtained in 38 patients having either stereotaxic thalamotomy, mesencephalotomy, or a cingulumotomy to determine the relevance of the preoperative examination and to evaluate the site and evolution of the surgical lesion. Of the preoperative examinations, 55% were abnormal. The consequences of the stereotaxic procedure were identified in the first 2 postoperative weeks in 26 of the 28 patients having thalamotomy, six of the nine patients having mesencephalotomy, and all three patients having cingulumotomy as a diffuse low-density area (mean attenuation value, 18 Hounsfield units). A central core of increased attenuation due to an intralesional hemorrhage was present on the early postoperative scan in 17% of patients. The late residual lesion studied in seven patients was considerably smaller than the early abnormality. The appearances and temporal sequence of the postsurgical CT changes suggest the early abnormality is due to edema and the late lesion to coagulative necrosis. The findings suggest CT has a role in the preoperative assessment of patients having stereotaxic surgery in defining the target and predicting the stereotaxic coordinates, while postoperatively it documents the site of the lesion and can determine the basis of a complication.

Current status of the DREZ operation: 1984.

The DREZ operation was introduced in 1976 as a method to control deafferentation pain associated with brachial plexus injury. Since then, 250 DREZ operations have been done at Duke Medical Center. At present, the best results of pain relief occur in brachial and lumbosacral root avulsions, paraplegia, and postherpetic pain. Post-DREZ complications have been reduced by the introduction of new lesion techniques, including the recent use of the laser. The neural basis of deafferentation pain is still not solved, nor is the therapeutic effect of the DREZ lesion known.

Dorsal root entry zone lesions for the treatment of postherpetic neuralgia.

These investigators attempted to diminish postherpetic neuralgia in 17 patients by making dorsal root entry zone (DREZ) lesions. They describe the clinical syndrome of pain after herpes zoster, the incidence of which increases with age, and discuss its pathology. They briefly review the medical and surgical treatment of postherpetic neuralgia. The results and complications of the DREZ procedure are reported.

Evolution of neuroablative surgery for involuntary movement disorders: an historical review.

Surgical therapy of involuntary movement disorders has evolved during the past century from gross destructive ablations of the central nervous system to refined, accurate, discrete lesioning of sites deep within the brain. The understanding of neuroanatomic and physiological systems improved tremendously through experimentation in animals and empirical observations of surgery in humans. A continuum of accumulated knowledge has been achieved through ablation or lesioning of virtually all aspects of the central and peripheral nervous system predicated on previous successes or failures. This compilation of surgical history of involuntary movement disorders has provided present neurosurgeons with the foundations on which they base their therapeutic measures and will direct future endeavors within this field.

Theoretical aspects of radiofrequency lesions in the dorsal root entry zone.

The history and physical principles of radiofrequency (rf) lesion making are reviewed. The advantages of the rf lesion method are presented, with emphasis on its importance in small, critical regions such as the dorsal root entry zone (DREZ). The evolution and specifications of a satisfactory DREZ rf electrode are described. DREZ lesion sizes for this electrode at specific electrode tip temperatures were experimentally determined in animals and were used as a guide to determine acceptable clinical lesioning parameters. Emphasis is placed on lesion temperature monitoring and on the stability of electrode penetration into the spinal cord to achieve consistent and safe results.

Dorsal root entry zone lesions for the treatment of brachial plexus avulsion injuries: a follow-up study.

Dorsal root entry zone (DREZ) lesions have been shown to yield short term relief from the pain associated with a brachial plexus avulsion injury. Because of the propensity of pain to recur after neuroablative procedures, 39 patients with pain after a brachial plexus avulsion injury were observed for 14 months to 10 years after DREZ lesions were made. Fifty-four per cent of these patients were afforded good pain relief. Of 21 patients who had multiple small lesions made within the DREZ, 15 (72%) were afforded good pain relief.

Further experience utilizing the Gildenberg technique for computed tomography-guided stereotactic biopsies.

Initial experience using the Gildenberg technique for computed tomography-guided stereotactic biopsies is reviewed. Of 50 patients, adequate tissue was obtained in 49. In one patient, the stereotactic frame was unable to reach the selected biopsy site. In 32 of 49 patients, the diagnosis was obtained with one biopsy; in the remainder, two to five samples were required. In 4 cases, a subsequent craniotomy was performed; these provided similar histopathological tissue and in no case was the diagnosis altered. The lesions were categorized by CT as ring-enhancing lesions (REL), enhancing lesions with surrounding low density (ELLD), and low density lesions with and without peripheral areas of enhancement. Of the REL, 21 of 23 were primary tumors. Of the ELLD, 5 of 13 were primary tumors; the remainder had a wide spectrum of disease. Of the low density lesions without enhancement, 6 were primary tumors and 1 was an inflammatory process. Three patients had low density lesions with peripheral areas of enhancement and proved to have malignant primary tumors. The remaining patients had multiple lesions with both primary and metastatic disease. Twelve RELs were biopsied in multiple sites. An accurate diagnosis was best obtained by performing the first biopsy in the enhancing rim with additional biopsies as needed in the low density center. Homogeneous lesions could be biospied with target selection based upon a primary regard for safety rather than imaging characteristics. Three patients had transiently increased hemiparesis and one had a transient decrease in level of consciousness after biopsy.(ABSTRACT TRUNCATED AT 250 WORDS)

Dorsal root rhizotomy and avulsion in the cat: a comparison of long term effects on dorsal horn neuronal activity.

We performed an extracellular microelectrode analysis of the neuronal activity of cells located in deeper laminae of dorsal horns that had been deafferented by ipsilateral lumbar dorsal root rhizotomy or avulsion. Special attention was given to those cells that were recorded in preparations that were more than 6 weeks chronic. We compared the results to those obtained in nondenervated controls and in experiments in which the spinal cord was acutely transected at a midthoracic level, but had intact dorsal roots. There was an increase in ipsilateral flank and contralateral input in the chronically deafferented as compared to nondenervated controls. Differences were observed between long term rhizotomized and avulsed dorsal horns. Receptive fields extended on to flank and thoracic dermatomes after rhizotomy, often requiring only light cutaneous stimuli. Receptive fields were more restricted with avulsion injury, generally requiring moderate to strong, superficial or deep pinch. Histological analysis revealed consistent differential damage to the medial portion of Lissauer's tract with avulsion injury and subsequently more gliosis in the substantia gelatinosa. The loss of this propriospinal pathway may explain the lack of receptive field expansion on to the thoracic dermatomes and the stronger natural stimuli that were required. A higher percentage of cells with bilateral and inhibitory receptive fields was found in experiments in which the spinal cord was transected at a midthoracic level than in the controls. Ipsilateral excitatory receptive fields were also expanded as compared with control observations, but were not found on the flank.(ABSTRACT TRUNCATED AT 250 WORDS)

Sacrococcygeal rhizotomy for perineal pain.

Chronic pain in the perineum is a difficult neurosurgical problem. This article evaluates the effectiveness of sacrococcygeal rhizotomy in 28 patients who had cancer-related pain or coccydynia, underwent rhizotomy, and were followed for an average of 3 years. Good pain relief was obtained in 53% (10 of 19 patients) with malignant pain, as opposed to 22% (2 of 9 patients) with nonmalignant pain. Sacral rhizotomy is a reasonable treatment for cancer-related perineal pain, but it is ineffective for coccydynia and other benign perineal pain problems.

Stereotaxic thalamotomy for treatment of posttraumatic movement disorders.

Stereotaxic ventrolateral thalamotomies have been successful in treating a wide spectrum of involuntary movement disorders, but very little has been reported concerning their use in posttraumatic movement disorders (MD's). This procedure has been used to treat 11 patients who developed persistent MD following severe closed head injuries. Among these, seven had action tremors, nine hemiballismic movements, two choreoathetoid movements, and two truncal ataxia. In two patients the MD was significant bilaterally, and in eight patients more than one type of MD was present. Standard thermal lesions based on the middle anterior commissure-posterior commissure line, 10 to 15 mm lateral to the midline, were performed following stimulation. Within the immediate postoperative period, all 11 patients had some degree of improvement in their MD; five showed marked improvement, four moderate improvement, and two minor improvement. One patient had recurrence of the MD 24 hours postoperatively requiring a second procedure, with marked improvement subsequently. In five of the six patients who underwent a left-sided procedure, a transient increase in preoperative dysarthria was noted. Nine patients had follow-up examinations 2 months to 3 years following surgery. Some persistent improvement in the MD was noted in all. Of three patients whose dysarthria was worse at 3 to 4 months, subsequent improvement was noted at 9 to 12 months in two. Stereotaxic thalamotomy appears to be an effective form of treatment for persistent posttraumatic MD. The major limitation is increased postoperative dysarthria. Further studies to evaluate risk factors associated with dysarthria and further refinement to prevent its occurrence are needed.

DREZ lesions for relief of pain related to spinal cord injury.

Fifty-six patients with intractable pain following a spinal cord injury were treated with dorsal root entry zone (DREZ) lesions. After a follow-up period ranging from 6 months to 6 years, 50% of patients had good pain relief. Certain pain syndromes tended to respond better to DREZ lesions than did others. Patients with pain extending caudally from the level of the injury and patients with unilateral pain were most likely to obtain pain relief from the procedure; diffuse pain and predominant sacral pain did not respond as well.

Facial pain due to vascular lesions of the brain stem relieved by dorsal root entry zone lesions in the nucleus caudalis. Report of two cases.

One patient with a pontine infarct due to a fusiform basilar artery aneurysm and one with an arteriovenous malformation within the tectum of the mesencephalon developed intractable facial pain. This pain was relieved in both patients by radiofrequency lesions in the dorsal root entry zone of the trigeminal nucleus caudalis.

Combined epidural and peripheral nerve stimulation for relief of pain. Description of technique and preliminary results.

A technique is described that combines percutaneous epidural with peripheral nerve stimulation to provide limited paresthesia to a lower extremity. The peripheral electrode is placed percutaneously and positioned along the course of the anterior division fo the spinal nerve anterolateral to the vertebral bodies. This is accomplished by a modified epidural tap. Combined stimulation was carried out in 23 patients with intractable leg pain. Sixteen patients proceeded to chronic autostimulation; follow-up time extended to 18 months. The procedure proved simple; there were no perioperative and only few minor late complications. Results were similar to those from conventional epidural stimulator implantation. It is concluded that combined epidural-peripheral nerve stimulation constitutes a valid therapeutic alternative for patients with unilateral lower extremity pain.

Percutaneous epidural stimulation of the spinal cord for relief of pain. Long-term results.

Percutaneous epidural stimulation of the spinal cord was carried out in 20 patients with intractable pain. The procedure proved simple, and no major complications were encountered. The long-term results were comparable to the results obtained after a dorsal column stimulator implant by laminectomy. The percutaneous technique allowed extended trial stimulation without committing the patient to a major operation. Those patients in whom stimulation did not alleviate pain could be identified during a 2-week observation period, and the system could be removed easily. Seven patients were placed on chronic autostimulation and only one of those failed to experience continuing pain relief throughout the follow-up time of up to 2 years. It is concluded that percutaneous epidural stimulation constitutes a valid alternative to dorsal column stimulator implantation.

History of spinal cord stereotaxy.

Stereotactic and functional neurosurgery has experienced a remarkable degree of development during the last 50 years, from the plaster of Paris frame of Spiegel and Wycis to the technology of frameless stereotaxis. Although predominantly used for intracranial procedures, stereotaxy has its roots in experimental studies of the spinal cord. The field of spinal cord stereotaxy has not received the same amount of attention as supratentorial surgery, but there have been significant contributions to the field that have helped to further our understanding of spinal cord anatomy and physiology. Now that frameless stereotaxis has reached clinical practice, there may be further developments in the field of spinal surgery: this technique may prove useful for spinal fusion operations and, possibly, intramedullary operations as well.