1 Gamma Knife Center of the Pacific, Honolulu, Hawaii; Department of Neurosurgery, University of New Mexico, Albuquerque, New Mexico; Division of Neurosurgery, Atkinson Research Lab, and Division of Neurology, Barrow Neurological Institute, Phoenix, Arizona
✓The authors report the neuroimaging features, treatment planning, and outcome in a case of radiosurgical thalamotomy targeting the centromedian nucleus (CMN) for stroke-induced thalamic pain.
A 79-year-old man, with embolic occlusion of the left middle cerebral artery and large hemispheric infarction involving the thalamus, suffered a right hemiplegia and expressive aphasia. One year poststroke, severe right-sided facial, scalp, arm, and trunk pain developed and was exacerbated by any tactile contact. Medical treatment had failed. Medical illness, including mandatory anticoagulation therapy for atrial fibrillation, precluded surgical procedures. Minimally invasive radiosurgery was offered as an alternative. Magnetic resonance imaging and computed tomography were used to localize the left CMN. A single shot of 140 Gy was delivered to the 100% isodose line by using the 4-mm collimator helmet.
The patient was evaluated at regular intervals. By 12 weeks posttreatment, he had significant improvements in pain control and his ability to tolerate physical contact during activities of daily living. Magnetic resonance imaging demonstrated baseline encephalomalacia from his prior stroke, and signal changes in the left CMN consistent with gamma irradiation–based thalamotomy. Currently, nearly 7 years after radiosurgery, he continues to enjoy a marked reduction in pain without the need of analgesic medications.
Thalamic pain syndrome is generally refractory to conventional treatment. Neurosurgical interventions provide modest benefit and carry associated risks of invasive surgery and anesthesia. The CMN is readily localized with neuroimaging and is an approximate target to reduce the suffering aspect of pain. In this case, radiosurgery was a safe and effective treatment, providing durable symptom control and improved quality of life.
Abbreviations used in this paper: AC–PC = anterior commissure–posterior commissure; CMN = centromedian nucleus of the thalamus; CT = computed tomography; DBS = deep brain stimulation; dpIns = dorsal posterior insula; GKS = Gamma Knife surgery; MDvc = ventrocaudal dorsal medial nucleus; MR = magnetic resonance; VC = ventrocaudal; VMpo = ventromedial posterior; VPL = ventroposterior lateral; VPM = VP medial.
Address reprint reprint requests to: Marcus F. Keep, M.D., Department of Neurosurgery, University of New Mexico Health Science Center, MSC10 5615, University of New Mexico, Albuquerque, New Mexico 87131. email: email@example.com.
CraigAD: Insights from the thermal grill on the nature of pain in humans, inHandwerkerH, , BruneK(eds): Hyperalgesias: Molecular Mechanisms and Clinical Implications. Seattle: IASP Press, 2004, pp 311–328
CraigAD: Insights from the thermal grill on the nature of pain in humans, inHandwerkerH, BruneK(eds): Hyperalgesias: Molecular Mechanisms and Clinical Implications. Seattle: IASP Press, 2004, pp 311–328)| false