Reduction of thalamic tremor with deep brain stimulation performed for post stroke chronic central pain.

Deep brain stimulation (DBS) of the sensory thalamus and the periventricular/ peri-aqueductal grey area complex may be applied for the treatment of intractable neuropathic pain syndrome. The presented study concerns a patient who experienced ischemic stroke within the posterolateral part of the left hypothalamus, with subsequent severe burning pain localized in the right upper limb, predominantly within the hand, and thalamic tremor which occurred 4 months after the stroke. After 2 years of ineffective pain treatment, the patient was offered implantation of electrodes to the periventricular grey matter (PVG)/periaqueductal grey matter (PAG), as well as implantation of an electrode to the ventroposterolateral thalamic nucleus (VPL). Soon after starting simultaneous PAG/PVG and PVL stimulation, significant alleviation of the patient's thalamic tremor in the hand was observed, which persisted over subsequent months. The presented study discusses possible mechanism underlying tremor suppression in the patient concerned, probably at the level of the cerebellar outflow pathways. The study highlights the fact that DBS provide more insight into the functional anatomy of the thalamus, which used to be available only from animal studies.