Investigation of the Surgical Target for Alleviation of Involuntary Movement Disorders

Self Cite

A prospective review of 75 of 190 parkinsonian patients undergoing unilateral thalamotomy was displayed with a computer graphics technique examining three equal consecutive groups from the pre-, early, and late L-dopa eras. Histograms for average function and scattergrams of individual patient''s performance preoperatively and up to 2 years postoperatively were prepared. No ipsilateral effects or consistent iatrogenic deterioration of any function were identified. 2 years after surgery, 82% had no tremor in the contralateral fingers or hand and 7% had almost no tremor; contralateral tremor elsewhere was infrequent. Rigidity and manual dexterity improved less strikingly, the latter only reflecting abolition of tremor; locomotion, speech, facial movement and handwriting did not improve. There was no mortality, but 8% had persistent significant complications. VIM thalamotomy remains the treatment of choice for severe drug-resistant parkinsonian tremor.

Section: Methodsmentioning

confidence: 99%

What Happened to VIM Thalamotomy for Parkinson's Disease?

Tasker

Siqueira

Hawrylyshyn

et al. 1983

Self Cite

“…Under local anesthesia, a radiofrequency VIM thalamotomy [3,4] (AC-PC level, posterior quarter of AC-PC line, 13.5 mm from midline) was performed on the side corresponding to the most important tremor. During the same session, a chronic stimulating electrode (Med tronic Pisces) was implanted on the less disabled side.…”

mentioning

confidence: 99%

Combined (Thalamotomy and Stimulation) Stereotactic Surgery of the VIM Thalamic Nucleus for Bilateral Parkinson Disease

Benabid

Pollak²,

Louveau³

et al. 1987

722

601

Stereotactic thalamotomy of the thalamic nucleus ventralis intermedius (VIM) is routinely used for movement disorders. During this procedure, it has been observed that high-frequency (100 Hz) stimulation of VIM was able to stop the extrapyramidal tremor. In patients with bilateral tremor of extrapyramidal origin, who were resistant to drug therapy, the therapeutic protocol associated (1) a radiofrequency VIM thalamotomy for the most disabled side, and (2) a continuous VIM stimulation for the other side using stereotactically implanted electrodes, connected to subcutaneous stimulators. VIM thalamotomy relieved the tremor in all operated cases. Side effects were mild and regressive, VIM stimulation strongly decreasedthe tremor but failed to suppress it as completely as thalamotomy did. This was due in part to the fact that programmable stimulator frequency rate is limited to 130 Hz, while it appeared that the optimal stimulation frequency was 200 Hz. This therapeutic protocol appears to be of interest for patients with bilateralextrapyramidal movement disorders.

“…VL thalamot omy allowed reduced doses or discontinuation of drugs in many cases until akinesia or symptoms on the nonoperated side progressed, in contrast to Vim thalamotomy, which was reported to bring less striking improvement of rigidity and no improvement of locomotion and other skillful movements [14]. In 36% (5/14) of unilateral cases, levodopa be came unnecessary and in another 29% no increase of levodopa was ne cessary.…”

Section: Discussionmentioning

confidence: 99%

“…Tremor persisted in 7-9 and rigidity persisted in 10-12 and 17-19. Rigidity was abolished in [13][14][15][16]. Thalamic lesions were shown on the same side of the atlas for convenience.…”

Section: Methodsmentioning

confidence: 99%

Present Role of Stereotactic Thalamotomy for Parkinsonism

Miyamoto¹,

Bekku²,

Moriyama³

et al. 1985

14 cases of unilateral and 5 cases of bilateral thalamotomy for parkinsonism were reviewed, with 32–144 months’ (mean 67.8) and 54–212 months’ (mean 110) follow-up, respectively, after the initial operation. Rigidity and tremor disappeared in approximately 80% of cases and was reduced in the remaining 20%. 68% improved by one or two grades in the Hoehn-Yahr scale after operation. Thalamotomy abolished dyskinesias and on-off phenomena on the operated sides. 36% of cases discontinued levodopa therapy after operation. CT study of the lesions suggested that destruction of a large part of basal Vop was most important to obtain the best results.