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Andres M Lozano - One of the best experts on this subject based on the ideXlab platform.
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location of active contacts in patients with primary dystonia treated with Globus pallidus deep brain stimulation
Neurosurgery, 2008Co-Authors: Clement Hamani, Elena Moro, Cindy Zadikoff, Yuyan Poon, Andres M LozanoAbstract:Objective Deep brain stimulation of the Globus pallidus internus has been used for the treatment of various forms of dystonia, but the factors influencing postoperative outcomes remain unknown. We compared the location of the contacts being used for stimulation (active contacts) in patients with cervical dystonia, generalized dystonia, and Parkinson's disease and correlated the results with clinical outcome. Methods Postoperative magnetic resonance scans of 13 patients with cervical dystonia, six patients with generalized dystonia, and five patients with Parkinson's disease who underwent Globus pallidus internus deep brain stimulation were analyzed. We assessed the location of the active contacts relative to the midcommisural point and in relation to the anteroposterior and mediolateral boundaries of the pallidum. Postoperative outcome was measured with the Toronto Western Spasmodic Torticollis Rating Scale (for cervical dystonia) and the Burke-Fahn-Marsden Dystonia Rating Scale (for generalized dystonia) during the last follow-up. Results We found that the location of the active contacts relative to the midcommisural point and the internal boundaries of the pallidum was similar across the groups. In our series, the contacts used for stimulation were clustered in the posterolateral region of the pallidum. Within that region, we found no correlation between the location of the contacts and postoperative outcome. Conclusion The location of the active contacts used for Globus pallidus internus deep brain stimulation was similar in patients with cervical dystonia, generalized dystonia, and Parkinson's disease.
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neuronal firing rates and patterns in the Globus pallidus internus of patients with cervical dystonia differ from those with parkinson s disease
Journal of Neurophysiology, 2007Co-Authors: Joyce K H Tang, William D. Hutchison, Andres M Lozano, Anthony E Lang, Elena Moro, Neil Mahant, Jonathan O. DostrovskyAbstract:Cervical dystonia (CD) is a movement disorder that involves involuntary turning and twisting of the neck caused by abnormal muscle contraction. Deep brain stimulation (DBS) in the Globus pallidus i...
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bilateral Globus pallidus internus deep brain stimulation in tardive dyskinesia a case report
Movement Disorders, 2004Co-Authors: Hazem A Eltahawy, Anthony E Lang, Jean A Saintcyr, Anthony Feinstein, Farouk Khan, Andres M LozanoAbstract:The clinical response of a 53-year-old woman with tardive dyskinesia treated with bilateral Globus pallidus interna deep brain stimulation is described. At 18 months follow-up, her Burke-Fahn-Marsden Dystonia Rating Scale score fell from 52 (preoperative) to 21 (60% improvement).
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bilateral Globus pallidus stimulation for huntington s disease
Annals of Neurology, 2004Co-Authors: Elena Moro, Alain Dagher, William D. Hutchison, Anthony E Lang, Antonio P Strafella, Yuyan W Poon, Pablo M Arango, Andres M LozanoAbstract:Bilateral Globus pallidus internus (GPi) deep brain stimulation (DBS) was performed in a patient with Huntington's disease (HD) with severe chorea. Stimulation at 40 and 130 Hz improved chorea. Stimulation at 130 Hz slightly worsened bradykinesia overall, whereas 40 Hz had little effect. A [15O] H2O positron emission tomography showed increased regional cerebral blood flow in motor decision making and execution areas more evident at 40 Hz. Adjustment of stimulation parameters in GPi DBS may have the potential to optimize the motor response in HD, improving chorea without aggravating bradykinesia.
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microstimulation induced inhibition of neuronal firing in human Globus pallidus
Journal of Neurophysiology, 2000Co-Authors: Jonathan O. Dostrovsky, William D. Hutchison, Ron Levy, R R Tasker, Andres M LozanoAbstract:Neurosurgical treatment of Parkinson's disease (PD) frequently employs chronic high-frequency deep brain stimulation (DBS) within the internal segment of Globus pallidus (GPi) and can very effectiv...
Anthony E Lang - One of the best experts on this subject based on the ideXlab platform.
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neuronal firing rates and patterns in the Globus pallidus internus of patients with cervical dystonia differ from those with parkinson s disease
Journal of Neurophysiology, 2007Co-Authors: Joyce K H Tang, William D. Hutchison, Andres M Lozano, Anthony E Lang, Elena Moro, Neil Mahant, Jonathan O. DostrovskyAbstract:Cervical dystonia (CD) is a movement disorder that involves involuntary turning and twisting of the neck caused by abnormal muscle contraction. Deep brain stimulation (DBS) in the Globus pallidus i...
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bilateral Globus pallidus stimulation for huntington s disease
Annals of Neurology, 2004Co-Authors: Elena Moro, Alain Dagher, William D. Hutchison, Anthony E Lang, Antonio P Strafella, Yuyan W Poon, Pablo M Arango, Andres M LozanoAbstract:Bilateral Globus pallidus internus (GPi) deep brain stimulation (DBS) was performed in a patient with Huntington's disease (HD) with severe chorea. Stimulation at 40 and 130 Hz improved chorea. Stimulation at 130 Hz slightly worsened bradykinesia overall, whereas 40 Hz had little effect. A [15O] H2O positron emission tomography showed increased regional cerebral blood flow in motor decision making and execution areas more evident at 40 Hz. Adjustment of stimulation parameters in GPi DBS may have the potential to optimize the motor response in HD, improving chorea without aggravating bradykinesia.
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bilateral Globus pallidus internus deep brain stimulation in tardive dyskinesia a case report
Movement Disorders, 2004Co-Authors: Hazem A Eltahawy, Anthony E Lang, Jean A Saintcyr, Anthony Feinstein, Farouk Khan, Andres M LozanoAbstract:The clinical response of a 53-year-old woman with tardive dyskinesia treated with bilateral Globus pallidus interna deep brain stimulation is described. At 18 months follow-up, her Burke-Fahn-Marsden Dystonia Rating Scale score fell from 52 (preoperative) to 21 (60% improvement).
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deep brain stimulation of the subthalamic nucleus or the pars interna of the Globus pallidus in parkinson s disease
The New England Journal of Medicine, 2001Co-Authors: Jose A Obeso, Rajeev Kumar, C W Olanow, M C Rodriguezoroz, Paul Krack, Anthony E LangAbstract:BACKGROUND Increased neuronal activity in the subthalamic nucleus and the pars interna of the Globus pallidus is thought to account for motor dysfunction in patients with Parkinson's disease. Although creating lesions in these structures improves motor function in monkeys with induced parkinsonism and patients with Parkinson's disease, such lesions are associated with neurologic deficits, particularly when they are created bilaterally. Deep-brain stimulation simulates the effects of a lesion without destroying brain tissue. METHODS We performed a prospective, double-blind, crossover study in patients with advanced Parkinson's disease, in whom electrodes were implanted in the subthalamic nucleus or pars interna of the Globus pallidus and who then underwent bilateral high-frequency deep-brain stimulation. We compared scores on the motor portion of the Unified Parkinson's Disease Rating Scale when the stimulation was randomly assigned to be turned on or off. We performed unblinded evaluations of motor function preoperatively and one, three, and six months postoperatively. RESULTS Electrodes were implanted bilaterally in 96 patients in the subthalamic-nucleus group and 38 patients in the Globus-pallidus group. Three months after the procedures were performed, double-blind, crossover evaluations demonstrated that stimulation of the subthalamic nucleus was associated with a median improvement in the motor score (as compared with no stimulation) of 49 percent, and stimulation of the pars interna of the Globus pallidus with a median improvement of 37 percent (P<0.001 for both comparisons). Between the preoperative and six-month visits, the percentage of time during the day that patients had good mobility without involuntary movements increased from 27 percent to 74 percent (P<0.001) with subthalamic stimulation and from 28 percent to 64 percent (P<0.001) with pallidal stimulation. Adverse events included intracranial hemorrhage in seven patients and infection necessitating removal of the leads in two. CONCLUSIONS Bilateral stimulation of the subthalamic nucleus or pars interna of the Globus pallidus is associated with significant improvement in motor function in patients with Parkinson's disease whose condition cannot be further improved with medical therapy.
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Globus pallidus deep brain stimulation for generalized dystonia: Clinical and PET investigation
Neurology, 1999Co-Authors: Rajeev Kumar, Alain Dagher, William D. Hutchison, Anthony E Lang, Andres M LozanoAbstract:Article abstract Bilateral Globus pallidus internus (GPi) deep brain stimulation (DBS) in a patient with severe idiopathic generalized dystonia resulted in immediate improvement of all aspects of dystonia. During joystick movement, GPi DBS reduced PET activation bilaterally in the primary motor, lateral premotor, supplementary motor, anterior cingulate, and prefrontal areas and ipsilaterally in the lentiform nucleus. Altering basal ganglia function with GPi DBS reverses the overactivity of certain motor cortical areas present in dystonia.
William D. Hutchison - One of the best experts on this subject based on the ideXlab platform.
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neuronal firing rates and patterns in the Globus pallidus internus of patients with cervical dystonia differ from those with parkinson s disease
Journal of Neurophysiology, 2007Co-Authors: Joyce K H Tang, William D. Hutchison, Andres M Lozano, Anthony E Lang, Elena Moro, Neil Mahant, Jonathan O. DostrovskyAbstract:Cervical dystonia (CD) is a movement disorder that involves involuntary turning and twisting of the neck caused by abnormal muscle contraction. Deep brain stimulation (DBS) in the Globus pallidus i...
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bilateral Globus pallidus stimulation for huntington s disease
Annals of Neurology, 2004Co-Authors: Elena Moro, Alain Dagher, William D. Hutchison, Anthony E Lang, Antonio P Strafella, Yuyan W Poon, Pablo M Arango, Andres M LozanoAbstract:Bilateral Globus pallidus internus (GPi) deep brain stimulation (DBS) was performed in a patient with Huntington's disease (HD) with severe chorea. Stimulation at 40 and 130 Hz improved chorea. Stimulation at 130 Hz slightly worsened bradykinesia overall, whereas 40 Hz had little effect. A [15O] H2O positron emission tomography showed increased regional cerebral blood flow in motor decision making and execution areas more evident at 40 Hz. Adjustment of stimulation parameters in GPi DBS may have the potential to optimize the motor response in HD, improving chorea without aggravating bradykinesia.
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microstimulation induced inhibition of neuronal firing in human Globus pallidus
Journal of Neurophysiology, 2000Co-Authors: Jonathan O. Dostrovsky, William D. Hutchison, Ron Levy, R R Tasker, Andres M LozanoAbstract:Neurosurgical treatment of Parkinson's disease (PD) frequently employs chronic high-frequency deep brain stimulation (DBS) within the internal segment of Globus pallidus (GPi) and can very effectiv...
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Globus pallidus deep brain stimulation for generalized dystonia: Clinical and PET investigation
Neurology, 1999Co-Authors: Rajeev Kumar, Alain Dagher, William D. Hutchison, Anthony E Lang, Andres M LozanoAbstract:Article abstract Bilateral Globus pallidus internus (GPi) deep brain stimulation (DBS) in a patient with severe idiopathic generalized dystonia resulted in immediate improvement of all aspects of dystonia. During joystick movement, GPi DBS reduced PET activation bilaterally in the primary motor, lateral premotor, supplementary motor, anterior cingulate, and prefrontal areas and ipsilaterally in the lentiform nucleus. Altering basal ganglia function with GPi DBS reverses the overactivity of certain motor cortical areas present in dystonia.
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effects of apomorphine on Globus pallidus neurons in parkinsonian patients
Annals of Neurology, 1997Co-Authors: William D. Hutchison, Andres M Lozano, Jonathan O. Dostrovsky, Ron Levy, Anthony E LangAbstract:Current hypotheses of basal ganglia dysfunction in Parkinson's disease (PD) propose that neuronal hypoactivity in the Globus pallidus externus (GPe), and hyperactivity in the output nuclei and the external and internal portions of the Globus pallidus internus (GPi, e and GPi, i, respectively), result in the cardinal symptoms of PD. To test this theory, the nonselective D1- and D2-dopamine receptor agonist apomorphine (30–100 μg/kg SC) was administered to 14 levodoparesponsive PD patients who were off medication (“of” state) while recording neurons in GP. For 15 neurons that were continuously monitored, apomorphine was found to increase the firing rate of 3 neurons in GPe, and decrease the rate of 12 in GPi. The mean firing rates of many different neurons were determined before (n = 285) and at various intervals after (n = 184) the injection of the drug. The mean rates before apomorphine were as follows: GPe, 45 Hz (SD 15, n = 85); GPi, e, 67 Hz (SD 14, n = 125); and GPi, i, 85 Hz (SD 19, n = 75). At 25 to 35 minutes after APO, the rate of GPe neurons had increased to 72 Hz (SD 18, n = 7), the rate of GPi, e neurons had decreased to 39 Hz (SD 15, n = 15), and in GPi, i the rate decreased to 34 Hz (SD 22, n = 18). Eighty minutes after apomorphine administration, the mean firing rates returned to preadministration values. This study supports current models of basal ganglia dysfunction in PD and suggests that the thereapeutic effect of apomorphine results from a normalization of the imbalance of neuronal activity in the direct and indirect pathways.
Jonathan O. Dostrovsky - One of the best experts on this subject based on the ideXlab platform.
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neuronal firing rates and patterns in the Globus pallidus internus of patients with cervical dystonia differ from those with parkinson s disease
Journal of Neurophysiology, 2007Co-Authors: Joyce K H Tang, William D. Hutchison, Andres M Lozano, Anthony E Lang, Elena Moro, Neil Mahant, Jonathan O. DostrovskyAbstract:Cervical dystonia (CD) is a movement disorder that involves involuntary turning and twisting of the neck caused by abnormal muscle contraction. Deep brain stimulation (DBS) in the Globus pallidus i...
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microstimulation induced inhibition of neuronal firing in human Globus pallidus
Journal of Neurophysiology, 2000Co-Authors: Jonathan O. Dostrovsky, William D. Hutchison, Ron Levy, R R Tasker, Andres M LozanoAbstract:Neurosurgical treatment of Parkinson's disease (PD) frequently employs chronic high-frequency deep brain stimulation (DBS) within the internal segment of Globus pallidus (GPi) and can very effectiv...
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effects of apomorphine on Globus pallidus neurons in parkinsonian patients
Annals of Neurology, 1997Co-Authors: William D. Hutchison, Andres M Lozano, Jonathan O. Dostrovsky, Ron Levy, Anthony E LangAbstract:Current hypotheses of basal ganglia dysfunction in Parkinson's disease (PD) propose that neuronal hypoactivity in the Globus pallidus externus (GPe), and hyperactivity in the output nuclei and the external and internal portions of the Globus pallidus internus (GPi, e and GPi, i, respectively), result in the cardinal symptoms of PD. To test this theory, the nonselective D1- and D2-dopamine receptor agonist apomorphine (30–100 μg/kg SC) was administered to 14 levodoparesponsive PD patients who were off medication (“of” state) while recording neurons in GP. For 15 neurons that were continuously monitored, apomorphine was found to increase the firing rate of 3 neurons in GPe, and decrease the rate of 12 in GPi. The mean firing rates of many different neurons were determined before (n = 285) and at various intervals after (n = 184) the injection of the drug. The mean rates before apomorphine were as follows: GPe, 45 Hz (SD 15, n = 85); GPi, e, 67 Hz (SD 14, n = 125); and GPi, i, 85 Hz (SD 19, n = 75). At 25 to 35 minutes after APO, the rate of GPe neurons had increased to 72 Hz (SD 18, n = 7), the rate of GPi, e neurons had decreased to 39 Hz (SD 15, n = 15), and in GPi, i the rate decreased to 34 Hz (SD 22, n = 18). Eighty minutes after apomorphine administration, the mean firing rates returned to preadministration values. This study supports current models of basal ganglia dysfunction in PD and suggests that the thereapeutic effect of apomorphine results from a normalization of the imbalance of neuronal activity in the direct and indirect pathways.
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identification and characterization of neurons with tremor frequency activity in human Globus pallidus
Experimental Brain Research, 1997Co-Authors: William D. Hutchison, Andres M Lozano, Anthony E Lang, R R Tasker, Jonathan O. DostrovskyAbstract:Many previous studies have demonstrated the existence of neurons with tremor-frequency activity (”tremor cells”) in the thalamus of Parkinson’s disease (PD) patients and these neurons are presumed to play a role in the pathogenesis of tremor. Since a major input to motor thalamus (Voa and Vop) is from the internal segment of the Globus pallidus (GPi), neurons with tremor-frequency activity in motor thalamus may receive input from neurons in GPi. The aim of this study was to quantify the characteristics of tremor cells in human Globus pallidus. In three PD patients with tremor undergoing microelectrode exploration of the Globus pallidus prior to pallidotomy, 228 neurons were sampled, and 28 (12.3%) were identified to fire at the same frequency as the tremor. These ”tremor cells” were located in the ventral portion of GPi. Autocorrelogram analysis of the sampled spike trains of these 28 tremor cells was carried out over sequential 10-s time segments, and autocorrelograms showing maximal oscillatory activity were graded from 0 to 10. Average tremor cell oscillation grades ranged from 6.8 to 7.8, similar to those reported in the MPTP-induced primate model of parkinsonism. The average tremor cell oscillation grade varied between patients, as did the clinical measures of tremor severity. Tremor cells had oscillations in spike discharges at the same average frequency (4.2–5.2 Hz) as the patient’s tremor determined from the electromyogram and accelerometry records of one or more limbs (4.0–5.4 Hz), and the individual values were correlated (r 2=0.73) over the total range (3.7–5.6 Hz). The results of this study demonstrate the presence of neurons with 4–6 Hz tremor-frequency activity in GPi, supporting a role of the Globus pallidus in the production of rest tremor in PD patients.
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Globus pallidus internus pallidotomy for generalized dystonia.
Movement disorders : official journal of the Movement Disorder Society, 1997Co-Authors: Andres M Lozano, Rajeev Kumar, Robert E. Gross, W D Hutchison, Nir Giladi, Jonathan O. Dostrovsky, Anthony E LangAbstract:The authors present a young boy with severe generalized dystonia treated with bilateral simultaneous pallidotomy. Microelectrode recordings with the patient under propofol anesthesia showed that the mean discharge rate of Globus pallidus internus (GPi) neurons was between 21 and 31 Hz. This contrasts sharply with the mean GPi neuronal firing rates of approximately 80 Hz that are characteristic of Parkinson's disease. The patient had no immediate benefit from surgery, but a progressive improvement in both axial and limb dystonia began within 3 days. The Burke-Fahn-Marsden scores were 75 (maximum possible = 120) at baseline, 52 at 5 days, and 16 at 3 months after surgery. The mechanism of action of pallidotomy for dystonia and the reasons for the delayed and progressive improvement are unknown. Nevertheless, the magnitude of the improvement and the safety of the procedure in this one patient warrant a careful evaluation of pallidotomy for dystonia.
James Barkovich - One of the best experts on this subject based on the ideXlab platform.
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changes in Globus pallidus with pre term kernicterus
Pediatrics, 2003Co-Authors: Paul Govaert, Maarten H Lequin, Renate Swarte, Simon G F Robben, Rene De Coo, Nynke Weisglaskuperus, Yolanda B De Rijke, M Sinaasappel, James BarkovichAbstract:Objective. We report serial magnetic resonance (MR) and sonographic behavior of Globus pallidus in 5 preterm and 3 term infants with kernicterus and describe the clinical context in very low birth weight preterm infants. On the basis of this information, we suggest means of diagnosis and prevention. Methods. Charts and MR and ultrasound images of 5 preterm infants and 3 term infants with suspected bilirubin-associated brain damage were reviewed. Included were preterm infants with severe hearing loss, quadriplegic hypertonia, and abnormal hypersignal of Globus pallidus on T2-weighted MR imaging (MRI). In 1 infant who died on day 150, the diagnosis was confirmed during the neonatal period. The others were picked up as outpatients and scanned at 12 or 22 months’ corrected age. Three instances of term kernicterus were included for comparison of serial MRI in the neonatal period and early infancy: they were caused by glucose-6-phosphate dehydrogenase deficiency, urosepsis, and dehydration plus fructose 1–6 biphosphatase deficiency. Results. Five preterm infants of 25 to 29 weeks’ gestational age presented with total serum bilirubin (TSB) levels below exchange transfusion thresholds commonly advised. Mixed acidosis was present in 3 infants around the TSB peak. The bilirubin/albumin molar ratio was >0.5 in all, in the absence of displacing drugs. All failed to pass bedside hearing screen tests and had severe hearing loss on auditory brain response testing. Symmetrical homogeneous hyperechogenicity of Globus pallidus was the alerting feature in 1 infant. Globus pallidus was hyperintense on T1-weighted MR images in this child. The other infants presented with severe developmental delay as a result of dyskinetic quadriplegia and hearing loss. Globus pallidus was normal on T1- but hyperintense on T2-weighted MR images at 12 or 22 months’ corrected age. Subthalamic involvement was documented in coronal fluid attenuated inversion recovery MRI in 2 infants. The term infants with classical clinical presentation in the neonatal period had MR behavior similar to the preterms, but pallidal injury was not recognized with targeted sonographic examination. Their neonatal MR images demonstrated pallidal T1 hyperintensity and mild T2 hyperintensity. Conclusion. Acidotic very low birth weight preterm infants with low serum albumin levels develop MR-confirmed pallidal injury and hearing loss facing “accepted” TSB levels. Serial MRI documents a shift from acute mainly T1 hypersignal to permanent T2 hypersignal in Globus pallidus within the late neonatal period. Subthalamic and not thalamic involvement helps to differentiate from ischemic or metabolic disorder. As newborns, these infants are rigid and have severe apnea, before developing hypertonic quadriplegia in infancy.
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changes in Globus pallidus with pre term kernicterus
Pediatrics, 2003Co-Authors: Paul Govaert, Maarten H Lequin, Renate Swarte, Simon G F Robben, Rene De Coo, Nynke Weisglaskuperus, Yolanda B De Rijke, M Sinaasappel, James BarkovichAbstract:Objective. We report serial magnetic res- onance (MR) and sonographic behavior of Globus palli- dus in 5 preterm and 3 term infants with kernicterus and describe the clinical context in very low birth weight preterm infants. On the basis of this information, we suggest means of diagnosis and prevention. Methods. Charts and MR and ultrasound images of 5 preterm infants and 3 term infants with suspected biliru- bin-associated brain damage were reviewed. Included were preterm infants with severe hearing loss, quadri- plegic hypertonia, and abnormal hypersignal of Globus pallidus on T2-weighted MR imaging (MRI). In 1 infant who died on day 150, the diagnosis was confirmed dur- ing the neonatal period. The others were picked up as outpatients and scanned at 12 or 22 months' corrected age. Three instances of term kernicterus were included for comparison of serial MRI in the neonatal period and early infancy: they were caused by glucose-6-phosphate dehydrogenase deficiency, urosepsis, and dehydration plus fructose 1- 6 biphosphatase deficiency. Results. Five preterm infants of 25 to 29 weeks' ges- tational age presented with total serum bilirubin (TSB) levels below exchange transfusion thresholds commonly advised. Mixed acidosis was present in 3 infants around the TSB peak. The bilirubin/albumin molar ratio was >0.5 in all, in the absence of displacing drugs. All failed to pass bedside hearing screen tests and had severe hear- ing loss on auditory brain response testing. Symmetrical homogeneous hyperechogenicity of Globus pallidus was the alerting feature in 1 infant. Globus pallidus was hyperintense on T1-weighted MR images in this child. The other infants presented with severe developmental delay as a result of dyskinetic quadriplegia and hearing loss. Globus pallidus was normal on T1- but hyperin- tense on T2-weighted MR images at 12 or 22 months' corrected age. Subthalamic involvement was docu- mented in coronal fluid attenuated inversion recovery MRI in 2 infants. The term infants with classical clinical presentation in the neonatal period had MR behavior similar to the preterms, but pallidal injury was not rec- ognized with targeted sonographic examination. Their neonatal MR images demonstrated pallidal T1 hyperin- tensity and mild T2 hyperintensity. Conclusion. Acidotic very low birth weight preterm infants with low serum albumin levels develop MR- confirmed pallidal injury and hearing loss facing "ac- cepted" TSB levels. Serial MRI documents a shift from acute mainly T1 hypersignal to permanent T2 hypersig- nal in Globus pallidus within the late neonatal period. Subthalamic and not thalamic involvement helps to dif- ferentiate from ischemic or metabolic disorder. As new- borns, these infants are rigid and have severe apnea, before developing hypertonic quadriplegia in infancy. Pediatrics 2003;112:1256 -1263; preterm, kernicterus, glo- bus pallidus, albumin, acidosis.