Neuroablative central lateral thalamotomy for chronic neuropathic pain

Abstract

Chronic neuropathic pain refractory to medical management can be debilitating and can seriously affect one's quality of life. The interest of ablative surgery for the treatment or palliation of chronic neuropathic pain, cancer-related or chemotherapy-induced, has grown. Numerous regions along the nociceptive pathways have been prominent targets including the various nuclei of the thalamus. Traditional targets include the medial pulvinar, central median, and posterior complex thalamic nuclei. However, there has been little research regarding the role of the central lateral nucleus. In this paper, we aim to summarize the anatomy, pathophysiology, and patient experiences of the central lateral thalamotomy.

Focused Ultrasound Central Lateral Thalamotomy for the Treatment of Refractory Neuropathic Pain: Phase I Trial

“…Our findings affirm previous studies assessing CLT for NP. 13,[19][20][21][22] Adverse events including symptoms related to placement of the Cosman-Roberts-Wells frame and all resolved by 3 months. Two patients experienced transient blurred vision.…”

“…18 Recently, gamma knife and MRgFUS CLT have demonstrated clinical benefit in NP but in limited numbers and centers. [19][20][21][22] While promising, this procedure has been performed for NP of heterogeneous etiologies, and with unidimensional pain outcome measures, calling for further validation. 17,20 Radiological signatures of chronic pain can provide insight after intervention.…”

Commentary: Focused Ultrasound Central Lateral Thalamotomy for the Treatment of Refractory Neuropathic Pain: Phase I Trial

“…Although the lateral group of thalamic nuclei, such as the ventral posterior nucleus, receive significant direct inputs from the ascending spinothalamic and trigeminothalamic pathways, the medial group of thalamic nuclei are involved in regulating the cognitive and affective components of the experience of pain. 8,9 As such, medial thalamotomies are much less likely to cause sensory deficits compared with lateral thalamotomies. The posterior aspect of the central lateral nucleus of the thalamus (CLp) is a cytoarchitectonically and functionally distinct part of the medial group of thalamic nuclei that acts as a regulatory node for a large thalamocortical network involved in somatosensation.…”

“…11,12 Termed "thalamocortical dysrhythmia," these 4 Hz bursts propagate throughout the thalamocortical network and facilitate higher frequency nociceptive cortico-cortical signaling, hypothesized to result in chronic pain states. [8][9][10]13,14 CLp ablation for neuropathic pain has been studied mostly in Europe, where it has clinical regulatory approval (it remains investigational in the United States currently), using radiofrequency ablation, stereotactic radiosurgery, and MR-guided focused ultrasound (MRgFUS) for a variety of chronic pain syndromes, with favorable preliminary results and safety profile. [15][16][17][18] Given the deep location of the CLp, MRgFUS is well-suited as a technique to produce a noninvasive ablation of this target.…”

“…The posterior aspect of the central lateral nucleus of the thalamus (CLp) is a cytoarchitectonically and functionally distinct part of the medial group of thalamic nuclei that acts as a regulatory node for a large thalamocortical network involved in somatosensation. [8][9][10] In the context of chronic neuropathic pain, deafferentation of the CLp and the loss of excitatory inputs results in hyperpolarization of cells and activation of low threshold T-type calcium channel bursts at 4 Hz. 11,12 Termed "thalamocortical dysrhythmia," these 4 Hz bursts propagate throughout the thalamocortical network and facilitate higher frequency nociceptive cortico-cortical signaling, hypothesized to result in chronic pain states.…”