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Biomedical subjects

B S Nashold

Publications and source records attributed to B S Nashold.

At least 55 records · Page 3Linked to original sources
PubMed1988

Evaluation of memory and language function pre- and postthalamotomy with an attempt to define those patients at risk for postoperative dysfunction.

Memory and language dysfunction has been sporadically reported following stereotaxic thalamotomies. In order to determine which patients are at greatest risk and to better define the nature of this dysfunction, we have prospectively evaluated 18 patients undergoing stereotaxic thalamotomies for movement disorders (MDs). Patients were evaluated clinically, with computed tomography (CT) and with memory and language protocols (MLPs) pre- and postoperatively. Patients exhibiting postoperative deficits were again evaluated with the MLP on follow-up visits to the clinic. Significant changes in memory and language function occurred in 7 out of 18 patients. These 7 patients had diverse etiologies for their MDs. Five of the 18 patients had undergone previous thalamotomies on the contralateral side. Three of these 5 patients with bilateral thalamotomies experienced postoperative functional impairments in memory and language while only 4 of 13 patients with a unilateral thalamotomy experienced these problems. The postoperative functional impairments noted were primarily those requiring orientation and speech. All patients with postoperative memory and language impairments were again evaluated with MLPs months after the operation. In 3 of 7 patients, no improvement was noted, while the remaining 4 did recover to baseline. More severe deficits tended to occur in those patients with ventriculomegaly or evidence of other major cerebral tissue loss by preoperative CT scan and in those patients with lower MLP scores preoperatively. Postoperative memory and language dysfunction was not correlated with the number or size of the lesions made, the postoperative general neurologic examination or CT scans, or the clinical response of the MDs. From our data, it appears that patients with more profound neurologic compromise and/or bilateral involvement as evidenced by poor performance on the MLP, tissue loss on CT scanning, or previous thalamic lesion, are most at risk for memory and language dysfunction postoperatively. However, this dysfunction is not necessarily permanent. Preoperative evaluation with MLPs and CT scanning appear to be of value in predicting those patients at greatest risk for postoperative and language dysfunction.

Adolescent↗
PubMed1988

The role of monopolar stimulation during computed-tomography-guided stereotactic biopsies.

44 patients underwent intraoperative stimulation with a monopolar electrode prior to computed tomography (CT)-guided stereotactic biopsy. Stimulation at 2-100 Hz resulted in functional responses in 6/21 patients with subcortical or callosal lesions, 4/6 with basal ganglion lesions, 8/10 with thalamic and 4/4 with brainstem lesions. In all but 2 patients with mesencephalic lesions, where limited biopsy sites were available, an alternative biopsy site was used if a functional response was obtained. No morbidity was seen among these patients, although postbiopsy CT scans demonstrated small 3- to 7-mm hematomas in 5/11 patients. Retrospective review of 79 patients who underwent biopsies without stimulation demonstrated hematomas in 6/10 patients and a 3.3% transient surgical morbidity. These data indicate that postbiopsy hematomas are a relatively common occurrence, that intraoperative electrical stimulation within abnormal lesions can identify functional potential, and that avoidance of biopsies within these functional areas may be associated with reduced morbidity.

Biopsy↗
PubMed1988

Neurosurgical technique of the dorsal root entry zone operation.

The dorsal root entry zone operation was introduced in 1976 to relieve the pain of brachial plexus avulsion. Since then it has been applied to pain treatment in paraplegia, postherpetic pain, phantom limb pain and other types of of deafferentation pain. Over 400 operations have been done at the Duke University Medical Center with overall good results in 60% of pain patients.

Humans↗
PubMed1988

Impedance measurements of the spinal cord of man and animals.

The measurement of electrical impedance of normal and pathologic tissue has not been fully utilized in neurosurgery. This is a report of electrical impedance measurement in the central nervous system of both man and animals. We show the results of the laboratory study done in animals, in the brain and in the spinal cord as well. Also we show the clinical experience of the impedance recordings in the DREZ procedure for some chronic pain conditions, correlating the measurements at the time of the operation with normal conditions, with comments about the findings.

Animals↗
PubMed1988

Successful treatment of phantom pain with dorsal root entry zone coagulation.

We studied 22 patients with amputation due to trauma, gangrene, or cancer. All developed postamputation pain, underwent a dorsal root entry zone (DREZ) procedure, and were followed from 6 months to 4 years after surgery. Overall, only 8 (36%) of these 22 patients had pain relief. However, good results were obtained in 6 (67%) of 9 patients with phantom pain alone, and in 5 (83%) of 6 patients with traumatic amputations associated with root avulsion. Poor results were obtained in patients with both phantom and stump pain, or stump pain alone. The DREZ procedure has a well-defined, but limited role in the treatment of postamputation pain.

Adult↗
PubMed1988

Dorsal root entry zone lesions for conus medullaris root avulsions.

We have found dorsal root entry zone (DREZ) lesions to be an effective treatment of chronic deafferentation pain in patients who have had avulsions of the dorsal rootlets from the spinal cord. Eight patients were operated in whom chronic pain of the lower extremity resulted from dorsal root avulsions from the conus medullaris. In 7 of the 8 patients, the mechanism of injury was a motor vehicle accident; all 7 sustained severe pelvic trauma. Seven of the 8 patients remained pain-free, off all narcotics, with an average follow-up of 33 months. All patients had DREZ lesions of the conus performed by radiofrequency techniques.

Adult↗
PubMed1988

Dorsal root entry zone coagulation for intractable sciatica.

Chronic back and leg pain which is unresponsive to medical and/or surgical treatment is a common and difficult neurosurgical problem. Twelve patients with this condition underwent dorsal root entry zone coagulation of that region of the conus medullaris which correlated with the pain. Only 2 patients had a favorable result. The implications of this finding are discussed.

Adult↗
PubMed1988

Clinical review of nucleus caudalis dorsal root entry zone lesions for facial pain.

Twenty-seven patients with intractable facial pain underwent dorsal root entry zone thermocoagulation lesion of the nucleus caudalis of the spinal trigeminal nucleus. Retrospective review revealed a success rate of 85% in the immediate postoperative period declining to 52% on subsequent follow-up. The best results were in the subgroup of patients with postherpetic neuralgia, of which 67% achieved definite relief. There tended to be some correlation of satisfactory results and pain quality as well as extent of pain along trigeminal territory. The operative morbidity was low although most patients were observed to have a mild transient ipsilateral dysmetria.

Adult↗
PubMed1988

Anatomic examination of human dorsal root entry zone lesions.

The anatomic delineation of radiofrequency dorsal root entry zone lesions using the Nashold thermocouple electrode is presented. The sharply delineated lesions involve a major portion of the dorsal horn of the spinal cord including Rexed's lamina V and part of VI. The extent of these lesions is appropriate, based on the currently understood mechanisms of spinal generators of chronic deafferentation pain.

Humans↗
PubMed1988

Radiofrequency lesion generation and its effect on tissue impedance.

The method of radiofrequency heat lesion generation is reviewed with specific reference to the dorsal root entry zone. Experimental data on the impedance of electrolytic media as a function of temperature are reported, and their relation to what should be observed during radiofrequency lesioning in the body is commented upon. The future utility of impedance monitoring is discussed as well as possible implications of bipolar lesion electrode systems.

Animals↗
PubMed1988

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.

Adult↗
PubMed1988

Intraoperative somatosensory evoked potentials. A localizing technique in the DREZ operation.

The localization of neural pathology by the evoked potential technique through the use of the Nicolet compact four-signal averager is reviewed. Stimulating electrode application on facial nerves and peripheral nerves of the limbs is described, as well as spinal cord and medullary recording electrode type and placement. Several pathological lesions causing pain are presented and the intraoperative evoked potentials prior to and after lesion production are examined and analyzed.

Adult↗
PubMed1987

Electrical impedance recording for localization in functional neurosurgery of the spinal cord and lower brain stem.

Functional neurosurgery aims to modify or abolish neural messages. Established techniques use confirmatory electrical stimulation prior to ablation and require local anesthesia. Recently developed procedures take place under general anesthesia increasing the chance of damage to adjacent neural structures with postoperative morbidity. We describe a laboratory study correlating changes in measured electrical impedance with transition from white to grey matter in the brain and spinal cord of two mammalian species; this has not previously been easy to undertake, nor felt reliable. Impedances can now be measured simply and reliably. This study confirms our operating theater experience. We recommend that when stimulation cannot be used, impedance can and should be utilized to indicate the need for an electrode to be resited.

Animals↗
PubMed1987

The deafferentation syndrome in the rat: effects of intraventricular neurotensin and cholecystokinin.

A deafferentation syndrome can be produced in rats by dorsal root ganglionectomies. This syndrome consists of scratching and/or biting of the anesthetic limb to the point of amputation. This behavior may serve as an experimental model to study certain aspects of chronic dysesthesias and/or pain caused by deafferentation in man. In this study, we made behavioral observations on the deafferentation syndrome and examined the possibility that intraventricular neurotensin and cholecystokinin alter the course of this syndrome. We found that neurotensin accelerated the scratching component without affecting the biting behavior. Cholecystokinin, however, attenuated the release of both components of the syndrome.

Animals↗
PubMed1987

Stereotactic mesencephalic tractotomy for thalamic pain.

Forty years after its first reported use, stereotactic mesencephalic tractotomy remains effective in relieving thalamic pain. Twenty seven patients suffering central pain following cerebrovascular accidents were treated by this operation and twenty four were reviewed: sixteen (66.7%) reported long term relief. Fourteen underwent surgery at the original 'superior colliculus' target, nine out of twelve (75%) reporting significant relief. Thirteen had surgery at a revised 'inferior colliculus' target, seven out of twelve (58.3%) obtaining relief. Postoperative disorders of ocular movement were reduced from 83.3% to 20%, and significant problems of binocular vision from 50% to nil. The mortality rate was 7.4%.

Adult↗