That would be my guess. No hits at all on Thelatomie (none of my medical dictionaries list the term, either), but I did get quite a few hits on ventri-lateral thalamotomy (see below).

I'd say that this is a safe assumption if your text deals with treatment of Parkinson's or therapies for severe pain.

Thalamo|tomie (­; -tom*) f: stereotaktische Operation* mit Koagulation von Kerngebieten des Thalamus bei anders nicht beeinflußbaren Schmerzen, v. a. Anaesthesia dolorosa, Zoster-Neuralgie, Phantomschmerzen, sympathischer Reflexdystrophie, Tumorschmerzen; Kompl.: Schädigung der Pyramidenbahn, Dysästhesie, Ataxie, Apathie.
(deutsch) Thalamotomie
(englisch) thalamotomy, thalamectomy
[Pschyrembel]

[PDF] www.physiol.ox.ac.uk/~rcm/pdf_files/liu_et_al_00.pdf
... out in 11 consecutive patients with MS before and after ventro- lateral thalamotomy. Thalamotomy was significantly more effective if pa- tients had disruptive ...

... room for the last 24 cases for postero-ventral pallidotomies and ventro-lateral (VL) thalamotomies. The technique has been helpful in confirming physiological ...
www.bic.mni.mcgill.ca/research/groups/igns/ATLAS/atlas_home... –

... Threshold stimulation of the lateral thalamus and globus pallidus ... sclerosis by stereotaxic thalamotomy. Confinia Neurol 22 ... array of the ventro-oral nucleus of ...
mcns10.med.nyu.edu/CMD/thalamotomydesc.html -

Hope this helps somewhat...