Thalamotomy In Patients Research Articles

794 Gamma Knife Medial Thalamotomy for Treatment of Chronic Pain: Long-term Results

INTRODUCTION: We assessed the long-term effectiveness of gamma knife medial thalamotomy in patients with chronic pain refractory to medical management, and other surgical techniques. METHODS: Between July 1992, and August 1998, sixty-one (61) patients with chronic pain underwent a total of 64 gamma knife medial thalamotomies. The target was the lateral portion of the medial dorsal nucleus, the intralaminar zone, the centrum medianum, and parafascicular nuclei. Radiosurgical maximum doses ranged from 120 to 180 Gy with the 4 mm collimator. Single (31), double (29), and triple (2) isocenter techniques were used. RESULTS: With a median follow-up of 74 months (range, 31–104 mo), 32/61 patients (52.5%) achieved at least a 50% reduction in visual analog scale, pain scores and cessation or significant reduction in narcotics and analgesic usage. Patients with nociceptive pain and those in whom multiple isocenters were used, fared better than those with neuropathic pain, or where the single...

Talamotomía estereotáxica por resonancia magnética para el tratamiento del dolor neural

Medial thalamotomy is one of the first stereotactic operations to have been used for neurogenic pain, has a low complication rate and no risk of the development of iatrogenic neurogenic pain. It represents selective local relief for all types of pain, without causing somatosensorial deficit. We did 39 posteromedial thalamotomies in patients with persistent intractable pain due to various disorders. The pain was assessed pre- and postoperatively on the VAS (Visual Analogic Scale). Half of the patients operated on had relief of pain after thalamotomy. In 84% (n = 39) of our cases this relief occurred on the second day, in 70% (n = 35) after three months, in 63% (n = 27) after six months, in 64% (n = 25) after nine months, in 62% (n = 23) of the patients after 12 months, and in 62% (n = 22) after 24 months. Three patients had temporary complications and one a permanent complication, but this did not make him an invalid. Posteromedial stereotactic thalamotomy under MR guidance can provide safe, effective treatment for persistent, intractable pain.

Neurological and psychological side effects after stereotactic thalamotomy in patients with cerebral palsy.

We describe the incidence of neurological and psychological side effects after stereotactic thalamotomy in 24 patients with abnormal movements secondary to cerebral palsy. The results of operation are outlined only briefly and, in terms of motor improvement, have been satisfactory. The side effects are categorized as motor or sensory impairments, autonomic disturbances, and mental disturbances. Their frequency and the recovery period are indicated; all of the side effects have been transient. Pathophysiological explanations of these side effects are proposed, correlated with different targets and hemispheric dominance. From our data we can conclude that (a) all side effects after stereotactic thalamotomy are more frequent in patients with cerebral palsy than in other patients and (b) the short time required for the side effects to reverse and their complete remission indicate that they are mainly due to perilesional edema, as suggested by computed tomographic scans.

Neurological and psychological side effects after stereotactic thalamotomy in patients with cerebral palsy

Neurological and psychological side effects after stereotactic thalamotomy in patients with cerebral palsy

CT studies in patients operated with stereotaxic thalamotomies

CT has been used in controlling stereotaxic thalamotomies in patients with movement disorders. The results obtained in 12 such patients, with early and delayed scans, are presented.

Prediction of short-term verbal memory disturbance after ventrolateral thalamotomy.

✓ The acute change in short-term verbal memory following ventrolateral thalamotomy in patients with dyskinesia was measured by the technique of Peterson and Peterson. Performance on this test of short-term verbal memory deteriorated following left but not right ventrolateral thalamotomy. This deterioration could not be accounted for solely by disturbance in speech mechanisms after left thalamotomy (although these were present), but may be related to disturbance in retrieval mechanisms of short-term verbal memory. The relative magnitude of this deterioration in performance after left thalamotomy could be partially predicted at the time of operation by some of the effects of electrical stimulation of the ventrolateral thalamus on the same test. A large decrease in recall errors with stimulation during the presentation of material to be later recalled, and a small increase in recall errors with stimulation at the time of recall, correlated with little disturbance of short-term verbal memory following left thalamotomy.

The specific somatosensory system and dyskinesia.

SEVERAL hypotheses have been proposed for the mechanism of abnormal movements, with the greatest emphasis placed upon the role of central structures. 1-3 While the importance of muscle afferents has also been stressed, 4 little attention has been paid to other peripheral receptors. However, observations made during a series of stereotactic thalamotomies suggest that impulses transmitted over the specific somatosensory pathways are also concerned in dyskinesia. Materials and Methods Cortical and subcortical potentials evoked by transcutaneous electrical stimulation of the median nerve were recorded during 42 stereotactic thalamotomies in patients with dyskinesia. The cortical responses were detected by pin electrodes placed in the scalp, and the depth responses by concentric, bipolar, Teflon insulated, stainless steel electrodes with an outer diameter of 1.4 mm and tip separation of 0.5 mm. An averaging computer was used to retrieve the evoked potentials. 5 The electrodes were directed toward nucleus ventralis posterior lateralis

P-1. Stereotactic Thalamotomy in Patients with Central Pain

p-1. Stereotactic Thalamotomy in Patients with Central Pain