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K J Burchiel

Publications and source records attributed to K J Burchiel.

At least 19 recordsLinked to original sources
PubMed1992

Image-based functional neurosurgery.

The development of computerized tomography and compatible stereotactic frame and localization devices has improved the ease and accuracy of functional stereotactic neurosurgery. Computerized tomograph-directed functional stereotaxy appears to be a safe and effective means of target development. Magnetic resonance imaging holds the promise of greater anatomical definition and direct sagittal imaging. Significant questions remain, however, concerning the reliability of MRI-based stereotactic neurosurgery, and these must be addressed. Presently, these techniques should be viewed as a means to localize a target region, not the target per se, and, as stated by Apuzzo, "It is not envisioned, however, that the need for intraoperative stimulation will be mitigated by such refinements."

Brain Mapping↗
PubMed1991

Intrathecal narcotics for relief of pain from head and neck cancer.

We describe our experience with nine patients with head and neck pain of malignant origin who were treated with continuous low-dose intrathecal morphine via a lumbar catheter and implantable subcutaneous drug delivery pump. All patients had failed prior attempts at oral narcotic pain control due to either poor pain control or intolerable side effects. Using a visual analogue scale where the most severe pain is rated as 10 and no pain is rated as 0, the mean visual analogue scale was reduced from 7.6/10 (range, 5 to 10/10) before implantation to 1.9/10, 2.0/10, and 0.5/10 at 1 week, 1 month, and 2 months after implantation, respectively. Complications were acceptable. We conclude that intrathecal administration of morphine is a safe and effective means of pain control. This method deserves serious consideration in patients with intractable pain secondary to head and neck malignancy.

Analgesia↗
PubMed1991

Pathophysiology of injured axons.

In this article we have touched briefly upon certain changes in peripheral axonal physiology which may, in part, explain the mechanisms of painful nerve injury. The next article discusses surgical approaches to these disorders and how they may relate to the known pathophysiology of injured axons.

Animals↗
PubMed1991

Surgical management of post-traumatic neuropathic pain.

The optimum management strategies for painful neuromas and neuromas-incontinuity are still unknown. Basic research and clinical development in this area is potentially rewarding and exciting. Neurosurgeons have the necessary basic and clinical neuroscience background to contribute significantly to this field and are trained in the requisite microsurgical techniques. Only by careful and thoughtful approach to individual cases can we hope to make future progress in these extraordinarily difficult pathologic conditions.

Humans↗
PubMed1991

Role of the sympathetic nervous system in painful nerve injury.

The purpose of this article has been to heighten awareness of the recognition, diagnosis, and therapy of the sympathetically maintained pain syndromes. Classification of RSD and causalgia as semantic subdivisions of SMP should be maintained until further laboratory and clinical analyses, with strict uniform diagnostic criteria, define similarities or differences in clinical behavior and therapeutic responses.

Autonomic Nerve Block↗
PubMed1990

Surgical decompression without transposition for ulnar neuropathy: factors determining outcome.

Fifty-one surgical decompressions without nerve transposition for ulnar neuropathy were performed in 46 patients. All of the patients were men with an average age of 59 years at the time of surgery. The follow-up range was between 5 and 32 months (average, 17.8 months). The disease involved the nondominant arm in 24 patients (52%) and was bilateral in 5 (11%). In 23 cases (50%), no predisposing condition could be identified, whereas 15 patients (33%) abused alcohol and 8 patients (17%) had diabetes mellitus. Fifty-seven percent of the patients helped by surgery had symptoms for less than 1 year, whereas only 30% of patients with symptoms for more than 1 year had symptomatic improvement. The relative magnitude of the slowing of ulnar nerve conduction velocity across the elbow was not significantly correlated with the success of decompression in relieving symptoms. Ulnar nerve conduction velocities across the elbow were 36.13 +/- 11.76 m/s in those responding to surgery and 38.97 +/- 13.91 m/s in those not responding (c = 0.06, dF = 50, P less than 0.3). A total of 37 patients showed symptomatic improvement after decompression. Simple decompression of the ulnar nerve was performed under local anesthesia without transposition of the nerve. In all of these cases, compression of the nerve occurred predominantly in the epicondylar groove. Narrowing of the nerve in the groove was present in 28 cases (55%); scar tissue was found adhering to the nerve in 21 cases (41%); and two pseudoneuromas were found (4%). Forty-one operations (80%) resulted in symptomatic improvement, typically noted by the patient within the first month postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Use of stimulation mapping and corticography in the excision of arteriovenous malformations in sensorimotor and language-related neocortex.

The excision of an arteriovenous malformation (AVM) located within eloquent neocortex presents a formidable neurosurgical challenge. Compromise of the vascular supply to normal surrounding brain or surgical trauma to essential neighboring neocortex may result in unacceptable postoperative neurological morbidity. In addition, successful removal of these lesions without the benefit of intraoperative corticography may leave in situ areas of highly epileptogenic brain, resulting in continued epilepsy. In this report, we describe eight patients who underwent craniotomy and excision of AVMs at our institutions. Six of these lesions were located in the dominant (left) hemisphere, and two were on the right. All patients underwent preoperative testing with Amytal administered via the carotid artery (Wada test). Subsequently, the patient was placed under local anesthesia, and we performed a craniotomy. Electrocorticography was used to identify epileptogenic brain in the region of the AVM and to establish after-discharge thresholds to electrical stimulation. Stimulation-mapping techniques were then used to delineate critical motor, sensory, and language areas. Trial occlusion of feeding vessels was also carried out to document postocclusion neurological deterioration, if any. At a later time, a second procedure was performed under general anesthesia to excise the lesion and any epileptogenic foci, using the cortical maps derived earlier. Using these techniques, it was possible to effect complete excision of these lesions in seven of eight patients without causing additional neurological deficits.

Adolescent↗
PubMed1988

Carbamazepine inhibits spontaneous activity in experimental neuromas.

In eight adult Sprague-Dawley rats the effect of parenteral carbamazepine on spontaneous discharges from saphenous neuromas (7-42 days following nerve section) was tested. Intravenous carbamazepine produced immediate inhibition of spontaneous activity originating in both A-alpha/beta and A-delta fibers at doses of 2.51-11.2 (7.9 +/- 3.3) mg/kg. In four additional animals, serum levels of carbamazepine were determined following iv administration of the drug. These results indicated that ectopic spontaneous impulse generation from experimental neuromas was inhibited by carbamazepine in the range of serum concentration in which the agent is used to treat trigeminal neuralgia and other painful neuropathies in humans. This implies that the effectiveness of this agent in the treatment of these disorders may result from suppression of peripherally originating ectopic spontaneous activity.

Action Potentials↗
PubMed1988

Spontaneous activity in afferent and efferent fibers after chronic axotomy: response to potassium channel blockade.

Distally propagating spontaneous impulses in acutely and chronically cut rat saphenous nerve were examined to determine (1) the origin(s) of the activity, (2) the fiber types involved, and (3) whether the activity was affected by potassium channel blockade. Under deep pentobarbital anesthesia, six male Sprague-Dawley rats underwent L3 cauda equina section, then unilateral saphenous axotomy. The nerve was then dissected into 30-50 microfilaments and surveyed for spontaneous activity using a modification of the microfilament recording method. Afterward, the nerve was cut back, and a potassium channel blocking agent (gallamine) was administered. The axonal activity was once again surveyed in the same fashion. Twenty-eight rats underwent unilateral saphenous axotomy 1-8 weeks prior to similar recordings, and the neuroma was excised just before microfilament dissection. Spontaneous discharges in these preparations originated from three foci: (1) antidromic activity from in-continuity dorsal root ganglia (DRG), (2) orthodromic activity from sympathetic neurons, and (3) antidromic activation of dichotomizing afferent axons in the peripheral nerve. There was significantly more antidromic activity from DRG in rats with prior axotomies than in control animals (t = 2.38; p less than 0.025), and gallamine produced a significant increase in DRG activity in the chronically lesioned nerve (t = 2.43; p less than 0.005), but not in acutely lesioned controls. However, most of the spontaneous activity in these preparations was from sympathetic efferents. This activity was decreased significantly by chronic axotomy (t = 2.635; p less than 0.01), and it was not affected by potassium channel blockade with gallamine. In two microfilaments, spontaneous antidromic action potentials were observed in conjunction with a clear receptive field on blood vessels in the nearby fascia. Both of these presumably dichotomized axons were found in acutely cut nerve, thus were not the result of retrograde sprouting from a neuroma. It was concluded that (1) chronic axotomy of sensory afferents produced ectopic activity in their respective DRG, (2) gallamine administration increased spontaneous activity from DRG in chronically axotomized rats, (3) ongoing sympathetic efferent activity in rat saphenous nerve was decreased by distal axotomy for up to 8 weeks, and (4) rare branched sensory afferents occasionally exhibit spontaneous activity.

Adrenergic Fibers↗
PubMed1988

Long-term efficacy of microvascular decompression in trigeminal neuralgia.

Forty patients were followed for an average period of 8 1/2 years after 44 consecutive suboccipital craniotomies for trigeminal neuralgia. Among these patients, 36 had microvascular decompression (MVD) of the nerve, four had repeat trigeminal rhizotomy after MVD was not successful in controlling their pain, and four had primary trigeminal rhizotomies. Of the 36 patients undergoing MVD, 17 (47%) experienced recurrent postoperative neuralgic pain: in 11 (31%) pain recurrence was major, and in six (17%) it was minor. Among the eight patients undergoing rhizotomy, four (50%) had major pain recurrences and one (13%) had a minor recurrence, for a 63% total recurrence rate. There was a strong statistical relationship between an operative finding of arterial cross-compression of the nerve and long-term complete pain relief. Patients with other compressive pathology (related to veins or bone structures) did not on the average fare as well. Despite this, there appeared to be no point in time in the postoperative interval when the patient could be considered "cured." Major recurrences averaged 3.5% annually, and minor recurrences averaged 1.5% annually. The implications of these findings for the treatment of trigeminal neuralgia and the current understanding of the mechanism of MVD for this disorder are discussed.

Arteries↗
PubMed1988

Percutaneous retrogasserian glycerol rhizolysis in the management of trigeminal neuralgia.

Sixty patients with trigeminal neuralgia or atypical facial pain were followed for an average of 1 year after percutaneous retrogasserian glycerol rhizolysis. The procedure was initially effective in relieving pain in 80% of the patients with typical trigeminal neuralgia and symptomatic trigeminal neuralgia secondary to multiple sclerosis. However, life-table analysis indicated that 50% of this group had persistence or recurrence of pain within 18 months after the operation. Percutaneous retrogasserian glycerol rhizolysis was ineffective in relieving atypical trigeminal neuralgia or atypical facial pain. Minor complications occurred in 23% of patients, and major morbidity was seen in 1.6%. Facial sensory loss which persisted for more than 1 month was found in 72% of patients, corneal hypesthesia occurred in 15%, and an additional 7% had corneal anesthesia. The data indicate that the success of percutaneous retrogasserian glycerol rhizolysis in relieving trigeminal neuralgia is directly related to the production of facial sensory loss.

Administration, Cutaneous↗
PubMed1987

Has the amount of spontaneous electrical activity in experimental neuromas been overestimated?

Previous studies of experimental neuromas have indicated that some axons terminating in the neuroma exhibit both spontaneous and mechanosensitive discharges. Since these spontaneous discharges appear to occur in potentially nociceptive axons (A delta and C fibers), it has been speculated that this activity may relate to pain that occurs after peripheral nerve injury. Recent results from our laboratory have revealed several possible sources of error in prior electrophysiological studies of neuromas. Most notably, gallamine, a muscle-paralyzing agent that has been used in the majority of previous studies of experimental neuromas, has profound potassium-channel-blocking properties that may increase spontaneous activity in damaged axons. The present study was conducted to re-evaluate the incidence of spontaneous activity in experimental neuromas, and the fiber types involved in these discharges. A group of 44 male Sprague-Dawley rats underwent unilateral saphenous axotomy 1-8 weeks prior to acute neurophysiological recording experiments, and 6 additional rats underwent acute control recording procedures only. Recording was performed in all animals using a modification of the microfilament recording technique to determine the conduction velocities (CVs) and origins of spontaneously discharging axons. A thorough search for spontaneous discharges was made in each nerve both before and after the administration of gallamine. Spontaneous activity was rare in acutely severed saphenous nerve and was not significantly affected by gallamine administration. In rats with 1- to 4-week-old experimental saphenous neuromas, spontaneous activity was rare but was increased by a factor of 12.75 after gallamine treatment. Gallamine administration produced significantly more of both A alpha beta and A delta activity, compared to control recordings. No spontaneous C-fiber activity was found originating in neuromas either before or after gallamine. C-fiber spontaneous discharges in the apparently isolated saphenous nerve segment had receptive fields in fascia, superficial vasculature, and hairy skin of the medial hindlimb. Our conclusions are as follows: (1) Neuromas exhibit only rare spontaneous discharges unless exposed to potassium-channel-blocking agents; (2) all C-fiber activity recorded in saphenous nerve with a distal neuroma is derived from vascular, fascial, and other receptive fields rather than from the neuroma; (3) these data are consistent with known clinical phenomena in that neuromas are not usually spontaneously painful.

Action Potentials↗
PubMed1986

Delayed brain abscess related to a retained foreign body with culture of Clostridium bifermentans. Case report.

Although it is well documented that retained foreign bodies are associated with delayed intracranial abscess, there are few reports of anaerobic organism growth. A case is presented in which a left parieto-occipital abscess surrounded a metallic fragment implanted when a mortar shell exploded in Vietnam 15 years before. The diagnostic evaluation and surgical management of this case are presented.

Adult↗
PubMed1985

Spontaneous activity of primary afferent neurons in diabetic BB/Wistar rats. A possible mechanism of chronic diabetic neuropathic pain.

The mechanism of painful diabetic neuropathy remains unknown. Spontaneous activity in nociceptive primary afferents has been implicated in the genesis of chronic pain due to peripheral nerve injury, and diabetic axonopathy shares some histologic features with traumatic neuropathy. We hypothesized that spontaneous hyperactivity of nociceptive neurons might represent the neurophysiologic mechanism of diabetic neuropathic pain. To test this, we examined the spontaneous activity of primary afferent axons from diabetic BB/Wistar and normal Wistar rat saphenous nerves isolated from central and peripheral connections. Microfilament recordings from diabetic nerves showed a significantly higher incidence of spontaneous discharges in comparison to normal nerves. Furthermore, this spontaneous hyperactivity occurred almost exclusively in potentially nociceptive C-fibers. We conclude that in the diabetic BB/Wistar rat, spontaneous impulses are generated in potential nociceptive primary afferent neurons, and that this may represent the mechanism of chronic diabetic neuropathic pain.

Action Potentials↗
PubMed1985

Spontaneous activity of ventral root axons following peripheral nerve injury.

In 18 Sprague-Dawley rats, the left sciatic nerve was divided at the mid-femur level. Seven to 9 days later, microfilament recordings were made from the ipsilateral L-5 ventral root. Spontaneous activity in the ventral root, ranging from 0.1 to 6.1 Hz, was recorded in 12 of the 18 animals. Conduction velocity determinations showed this activity to be in A-beta and A-delta fibers. Recordings in 10 normal L-5 ventral roots from five control rats showed no spontaneous activity. In the rats with sciatic nerve division, the ongoing discharge appeared to originate in the cut end of the nerve since mechanical stimulation of the neuroma produced synchronous ventral root activity. Furthermore, cooling of the neuroma inhibited the spontaneous discharge, whereas with rewarming it returned. Spontaneous ventral root activity was also increased by systemic application of epinephrine. This activity was qualitatively similar to spontaneous activity that has been recorded in dorsal root microfilaments after peripheral nerve injury. The observation of an ongoing discharge in potentially nociceptive ventral root axons subsequent to nerve injury may be relevant to the mechanism of chronic pain of peripheral origin.

Animals↗
PubMed1985

Effects of potassium channel-blocking agents on spontaneous discharges from neuromas in rats.

Thirty-five Sprague-Dawley rats with saphenous neuromas underwent acute microfilament recording in the proximal nerve. The effect of the potassium channel-blocking agents, tetraethylammonium bromide (TEA) and 4-aminopyridine, on spontaneous activity in A fibers terminating in the neuroma was observed. The effects of gallamine were also tested. Of the two channel-blocking agents, TEA reliably increased spontaneous firing in active fibers and initiated spontaneous activity in some fibers with no spontaneous baseline discharge. 4-Aminopyridine had no effect on baseline activity of either spontaneously active or quiescent fibers: however, it inhibited spontaneous activity induced by prior TEA treatment. Gallamine application produced effects similar to TEA in that spontaneous activity was dramatically increased. These results imply that a tonic potassium conductance is present in regenerating fibers in the neuroma and that this conductance moderates the tendency toward hyperexcitability and spontaneous firing. Spontaneous activity in nociceptive afferent fibers may represent the mechanism of chronic pain and paresthesias that often accompany peripheral nerve injury. These results suggest that agents which either increase potassium conductance or selectively inhibit the sodium current in regenerating axons might be effective in the treatment of these chronic pain syndromes.

4-Aminopyridine↗