RESEARCH LETTERS ascertain the general clinical status of the patients. All ten patients had a form of cerebellar tremor that was distinguished clinically into rubral tremor, characterised by severe postural tremor affecting the head, trunk, and upper limbs with a supradded action/intention component that was present during volitional limb movements, or an isolated action/intention tremor. All patients were severely disabled by the movement disorders and had no functional use of their affected upper limb. After computer- tomography-guided ventrolateral thalamotomy, brachial tremor was decreased in nine patients immediately after the operation. 5 In patients with severe rubral tremor, none had complete abolition of their movement disorder, and although it decreased in most tremor remained disabling because of the unmasking or persistence of cerebellar disease. At 1 year follow-up, only three patients, who had the best preoperative Bartel scores, had improved function (patients 4, 5, and 10). At final follow-up median 56 months after surgery) only six patients remained alive, and one (patient 10) still had improved function (table). These findings strongly suggest that in many patients, onset of severe movement disorders is followed by a progressive functional decline, and even death, due to MS. Also, although stereotactic surgery might be temporarily beneficial, a long-term impact is unlikely, mainly because of additional damage to the central nervous system. Adequate assessment of thalamic DBS in patients with MS-associated movement disorders will require long-term follow up. Thalamic DBS, which is a more flexible and non-lesional therapy than thalamotomy, will, however, have only temporary effects if systemic functional decline due to MS is as seen in our patients. This work was funded by the Multiple Sclerosis Society of United Kingdom and Northern Ireland. 1 Kelly P, Gillingham FJ. The long-term results of stereotaxic surgery and L-dopa therapy in patients with Parkinson’s disease. J Neurosurg 1980; 53: 332–37. 2 Haddow LJ, Mumford C, Whittle IR. Sterotactic treatment of tremor due to multiple sclerosis. Neurosurg Q 1997; 7: 23–34. 3 Geny C, Nygen J-P, Pollin B, et al. Improvement of severe postural cerebellar tremor in multiple sclerosis by chronic thalamic stimulation. Mov Disord 1996; 11: 489–94. 4 Whittle IR, Hooper J, Pentland B. Thalamic deep brain stimulation for movement disorders due to multiple sclerosis. Lancet 1998; 351: 109–10. 5 Whittle IR, Haddow LJ. CT guided thalamotomy for movement disorders in multiple sclerosis: problems and paradoxes. Acta Neurochir 1995; 64 (suppl): 13–16. Department of Clinical Neurosciences, Western General Hospital, Edinburgh EH4 2XU, UK (I R Whittle) 1984 THE LANCET • Vol 352 • December 19/26, 1998 and in-vitro immune function, and immunity against opportunistic infections in complete DGA. Potential future uses of lymphocyte transplantation may include immune constitution of children with other T-cell deficiencies, as well as of functionally athymic adults after bone-marrow transplants. 1 Ammann AJ, Stiehm ER. T-cell immunodeficiency disorders. In: Stites DP, Terr AI, Parslow TG, eds. Medical immunology, 9th edn, Stamford, USA: Appleton & Lange, 1997: 345–48. 2 Borzy MS, Ridgway D, Noya FJ, Shearer WT. Successful bone marrow transplantation with split lymphoid chimerism in DiGeorge syndrome. J Clin Immunol 1989; 9: 386–92. 3 Goldsobel AB, Haas A, Stiehm ER. Bone marrow transplantation in DiGeorge syndrome. J Pediatr 1987; 111: 40–41. 4 Maarkert ML, Hummell DS, Rosenblatt et al. Complete DiGeorge syndrome: persistence of profound immunodeficiency. J Pediatr 1998; 132: 15–21. 5 Bell EB, Sparshott SM, Drayson MT, Ford WL. The stable and permanent expansion of functional T cells in athymic nude rats after a single injection of mature T cells. J Immunol 1987; 139: 1379–84. Division of Paediatric Oncology (D C Bowers; e-mail dcbowers@jhmi.edu); Eudowood Division of Paediatric Immunology, Departments of Oncology and Paediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21207, USA Long-term outcome after thalamotomy for movement disorders in multiple sclerosis Julie Hooper, Ian R Whittle Sterotactic thalamotomy is an effective treatment for tremor in Parkinson’s disease with long-term benefits. 1 After thalamotomy for tremor due to multiple sclerosis (MS), 90% of patients show immediate improvement, which remains in 70% of patients at 1 year, but longer-term outcome is not well known. 2 This issue is important since thalamic deep brain stimulation (DBS) is being investigated as an alternative treatment to thalamotomy for management of MS-related movement disorders. 3,4 Since the profile of patients with MS chosen for either thalamotomy or thalamic DBS is probably similar, and there are important clinical, management, and health economic implications to DBS, 3,4 we reassessed the clinical status and functional outcomes of ten patients with MS who underwent thalamotomy between December, 1989, and October, 1994. We aimed to find out outcomes after 1 year in movement disorders after thalamotomy and to Patient Age MS subtype Duration Characteristics of tremor Pre-operative status Current status (years) (years) Duration Severity Type Location Initial result by Bartel index (0–20) Bartel index Follow-up (months (months) after surgery (0–20) after surgery) 1 43 Chronic 7 12 Severe Rubral Head, trunk, Good 4 Dead 14 progressive upper limbs 2 62 Chronic 13 20 Severe Action/ Left upper limb Unchanged 6 0 73 progressive intention 3 36 Chronic 6 5 Severe Rubral Head, trunk, Good 8 0 52 progressive upper limbs 4 36 Chronic 4 36 Severe Rubral Head, trunk, Good 8 Dead 9 progressive upper limbs 5 32 Chronic 2 20 Severe Rubral Head, trunk, Good 9 0 62 progressive upper limbs 6 30 Chronic 13 7 Severe Rubral Head, trunk, Good 8 0 56 progressive upper limbs 7 35 Relapsing- 17 20 Severe Rubral Head, trunk, Good 9 0 56 remitting upper limbs 8 34 Chronic 3 18 Severe Rubral Head, trunk, Good 6 Dead 18 progressive upper limbs 9 32 Chronic 3 15 Severe Rubral Head, trunk, Good 7 Dead 20 progressive upper limbs 10 52 Relapsing- 7 84 Severe Action/ Right upper limb Excellent 10 15 44 remitting intention Table 1: Characteristics of patients