Bilateral pallidal deep brain stimulation in idiopathic dystonic camptocormia

Camptocormia is seen with Parkinson's disease (PD), segmental or generalized dystonia, extensor myopathies, anterior horn cell disorders, and muscle disorders. In severe selected cases of PD with camptocormia and dystonic camptocormia, deep brain stimulation (DBS) has been tried with variable success. In this paper, the first case report of its kind from India, we report a case of dystonic camptocormia who underwent DBS and review the available literature.

A 42-year-old male, presented with dystonia of 5-year duration, that initially started with cervical dystonia and later progressed to severe disturbance of posture causing involuntary truncal flexion induced by standing or sitting. The camptocormia was completely relieved when sitting on a chair or lying down on the bed. Routine blood testing was normal. The workup for secondary dystonia including slit lamp examination for Kayser-Fleischer ring and serum copper studies did not reveal any abnormality. Magnetic resonance imaging of the brain was unremarkable. The electromyogram of the lumbar and thoracic paraspinal muscles was also normal.

The patient was initially treated with multiple drugs and Botulinum A toxin which were ineffective. He underwent bilateral globus pallidus interna (GPi) DBS Over a period of 2 weeks; there was a mild reduction in the dystonia of the trunk and neck. The maximum improvement in dystonia, approximately 30% over baseline, was noted at 2 weeks postsurgery and over a further long-term follow-up, the improvement was 50% as determined by the sub-item (trunk) assessment of the Burke-Fahn-Marsden (BFM) dystonia score. Cervical dystonia improved by >90% in sub-item (neck) assessment of BFM scale.

In this report, we have shown the efficacy of GPi DBS in the treatment of drug refractory dystonia associated camptocormia. Although only reported for PD associated camptocormia, evaluation for truncal extensor myopathy is mandatory in these cases also to achieve a good outcome.