Biomedical subjects

D Sterio

Publications and source records attributed to D Sterio.

29 records · Page 2Linked to original sources

PubMed1995

Anatomic and physiological considerations in pallidotomy for Parkinson's disease.

Our ongoing study of ventral pallidotomy for the control of Parkinson's disease in selected patients has provided the opportunity to explore the topographical and somatotopic organization of the human globus pallidus. Utilizing microelectrode techniques we have obtained recordings which were correlated with data from MPTP-parkinsonian primates. In addition, we performed pre- and post-operative FDG/PET scans in these patients. Our studies reveal similarities between the MPTP-parkinsonian primate model and human Parkinson's disease in terms of physiologic recordings and responses. However, we have encountered significant differences between dominant and non-dominant hemisphere representations, particularly for the hand, in the human. In addition, our PET studies confirmed, as in previous parkinsonian primate models, glucose hypermetabolism in the lenticular area of Parkinson's disease patients. This hypermetabolism is dramatically altered by creation of a lesion in the globus pallidus medialis. This is demonstrated by follow-up PET scans which reveal not only a decrease in metabolism of the operated lenticular region, but also in the frontal cortical projections. These combined observations of the cellular activity in the globus pallidus and the observed changes in PET metabolism support the selection of the pallidum for lesioning and control of Parkinson's disease, and offer insight into the underlying physiology of this disorder. The above physiological and PET data will be clinically correlated with our ongoing series of 35+ patients.

Brain Mapping↗

PubMed1995

Stereotactic ventral pallidotomy for Parkinson's disease.

Eighteen patients with medically intractable Parkinson's disease that was characterized by bradykinesia, rigidity, and marked "on-off" fluctuations underwent stereotactic ventral pallidotomy under local anesthesia. Targeting was aided by anatomic coordinates derived from the MRI, intraoperative cell recordings, and electrical stimulation prior to lesioning. A nonsurgically treated group of seven similarly affected individuals was also followed. Assessment of motor function was made at baseline and at 3-month intervals for 1 year. Following the lesioning, patients improved in bradykinesia, rigidity, resting tremor, and balance with resolution of medication-induced contralateral dyskinesia. When compared with preoperative baseline, all quantifiable test scores after surgery improved significantly with the patients off medications for 12 hours: UPDRS by 65%, and CAPIT subtest scores on the contralateral limb by 38.2% and the ipsilateral limb by 24.2%. Walk scores improved by 45%. Medication requirements were unchanged, but the patients who had had surgery were able to tolerate larger doses because of reduced dyskinesia. Ventral pallidotomy produces statistically significant reduction in parkinsonism and contralateral "on" dyskinesia without morbidity or mortality and with a short hospitalization in Parkinson's disease patients for whom medical therapy has failed.

Adult↗

PubMed1994

Neurophysiological properties of pallidal neurons in Parkinson's disease.

Neuronal properties of the human globus pallidus (GP) are not known. Since GP is the major output of the basal ganglia, it may be involved in the pathophysiology of Parkinson's disease. We studied 12 patients with medically resistant Parkinson's disease by using single cell recording of the GP during stereotaxic pallidotomy to define neuronal firing rate and its modulation during active and passive movements. Different frequency and pattern of single cell activity was found in globus pallidus externus compared with globus pallidus internus. Discharge rates of 19% of GP cells were modulated by passive contralateral movements. Pallidal units were most often related solely to single joint movement. Different patterns of activity in relation to the two different movements of the same joint were often observed. We identified somatotopically arranged cell clusters that alter discharge rate with related movements. These findings suggest at least a partial somatotopic organization of the human GP and similarity with experimental results in both healthy and MPTP monkeys, providing a rationale for surgical or pharmacological targeting of GP for treating Parkinson's disease.

Brain Mapping↗

PubMed1994

Anatomic and physiological considerations in pallidotomy for Parkinson's disease.

Our ongoing study of central pallidotomy for the control of Parkison's disease in selected patients has provided the opportunity to explore the topographical and somatotopic organization of the human globus pallidus. Utilizing microelectrode techniques we have obtained recordings which were correlated with data from MPTP-parkinsonian primates. In addition, we performed pre- and postoperative FDG/PET scans in these patients. Our studies reveal similarities between the MPTP-parkisonian primate model and human Parkinson's disease in terms of physiological recordings and responses. However, we have encountered significant differences between dominant and nondominant hemisphere representations, particularly for the hand, in the human. In addition, our PET studies confirmed, as in previous parkinsonian primate models, glucose hypermetabolism in the lenticular area of Parkinson's disease patients. This hypermetabolism is dramatically altered by creation of a lesion in the globus pallidus medialis. This is demonstrated by follow-up PET scans which reveal not only a decrease in metabolism of the operated lenticular region, but also in the frontal cortical projections. These combined observations of the cellular activity in globus pallidus and the observed changes in PET metabolism support the selection of the pallidum for lesioning and control of Parkinson's disease, and offer insight into the underlying physiology of this disorder. The above physiological and PET data will be clinically correlated with our ongoing series of 35+ patients.

Brain Mapping↗

PubMed1992

[Atypical symptomatic headache in the developmental period--case report].

The authors report a case of atypical symptomatic headache in developmental age. It is a complex headache in which three etiologic factors are permeated and superposed. The basic mechanism is connected with the presence of vascular congenital malformation (a. trigemini primitiva persistens), second mechanism is associated with immunologic events (leucopenia-dyshematopoiesis) in which central nervous system is secondarily involved with headaches partly superposed and personality features mildly neurotic, which would represent the third etiologic factor. Since it is the case of symptomatic headache as a notorius clinical entity but with peculiar, puzzling, atypical clinical features and course, the authors point to the complexity of this type of headache, diagnostic speculations and difficulties encountered in therapeutical approaches.

Adolescent↗

PubMed1991

[Cerebellitis? Case report of acute cerebellar ataxia in childhood].

The authors present a severe clinical manifestation of acute cerebellitis with a favorable outcome, most likely of viral etiology, without fever. An emphasis is placed on the value of complex investigations, clinical as well as laboratory ones, and the exclusion of other diseases which come into consideration in differential diagnostics.

Acute Disease↗

PubMed1986

[Participation of pentagastrin and oxytocin in organizing neural activity of the dorsal hippocampus during result- and conflict-oriented feeding behavior in rabbits].

Single unit activity of CA3 dorsal hippocamp has been registered in free moving rabbits. The influence of microiontophoretic application of pentagastrin and oxytocin on neuronal involvement into feeding or defensive behaviour has been studied. The change of the dominant feeding motivation to defensive was shown to cause resettings in the typical feeding activity of most neurons. Microiontophoretic application of pentagastrin induces typical feeding activity even if rabbits demonstrate defensive behaviour. It is believed that pentagastrin presence in perineuronal area leads to the involvement of most hippocampal neurons into the organization of the feeding behaviour.

Animals↗

PubMed1985