Delineation of the thalamic nuclei with a microelectrode in stereotaxic surgery for parkinsonism and cerebralpalsy

1973 ◽  
Vol 39 (2) ◽  
pp. 214-225 ◽  
Author(s):  
Akira Fukamachi ◽  
Chihiro Ohye ◽  
Hirotaro Narabayashi
Keyword(s):  
Target Point ◽  
Joint Movement ◽  
Thalamic Nuclei ◽  
Perpendicular Line ◽  
Content Type ◽  
Stereotaxic Surgery ◽  
Lower Border ◽  
Sensory Nucleus ◽  
Radiological Control ◽  
Inferior Border

✓ Extracellular thalamic recording with semi-microelectrode during 103 cases of stereotaxic surgery identified the upper and lower borders of the thalamus and the anterior limit of the sensory area. In adults the upper border of the thalamus was found 13 to 21 mm above the intercommissural line and the lower border within 1 mm above and below the intercommissural line. In children under 10 years with cerebral palsy, the upper border was comparable to that in adults while the lower border was about 1 mm below the intercommissural line. In adults the inferior border determined by the thalamocortical evoked potential was always about 2 to 3 mm above the intercommissural line. The anterior limit of the sensory nucleus, which seemed to be specifically related to the neurons activated by muscle compression and active or passive joint movement, was 3 to 4 mm behind the perpendicular line at the midpoint of the intercommissural line. The target point was determined by using these physiological findings combined with radiological control. This method has produced improved operative results in the treatment of parkinsonism.

Histological analysis of the location of effective thalamic stimulation for tremor

2004 ◽  
Vol 100 (3) ◽  
pp. 547-552 ◽  
Author(s):  
Robert E. Gross ◽  
Edward G. Jones ◽  
Jonathan O. Dostrovsky ◽  
Catherine Bergeron ◽  
Anthony E. Lang ◽  
...  
Keyword(s):  
Thalamic Nuclei ◽  
Large Measure ◽  
Content Type ◽  
Parkinsonian Tremor ◽  
Thalamic Stimulation ◽  
Sensory Nucleus ◽  
Chronic Electrical Stimulation ◽  
Ventral Intermediate Nucleus ◽  
Lateral Nucleus ◽  
The Relationship

✓ Chronic electrical stimulation of the thalamus is an effective treatment for essential and parkinsonian tremor. Although the preferred surgical target is generally accepted to lie within the ventral intermediate nucleus (Vim), the relationship between the surgically defined target and the true histologically defined target is addressed in only a few reports, due in large measure to the need for advanced cytoarchitectonic techniques to define the borders of the thalamic nuclei. The authors report on a patient who underwent effective thalamic deep brain stimulation (DBS) for tremor. By defining the boundaries of the thalamic nuclei, they were able to relate effective DBS to electrode location within the anterior region of the ventral posterior lateral nucleus—the proprioceptive shell of the sensory nucleus—and the posteroventral region of the ventral lateral nucleus, which are equivalent to the Vim defined by Hassler, et al.

Thalamic lesions produced by gamma thalamotomy for movement disorders

2002 ◽  
Vol 97 ◽  
pp. 600-606 ◽  
Author(s):  
Chihiro Ohye ◽  
Tohru Shibazaki ◽  
Jie Zhang ◽  
Yoshitaka Andou
Keyword(s):  
Mr Imaging ◽  
Involuntary Movement ◽  
Gamma Knife Radiosurgery ◽  
Target Point ◽  
High Signal ◽  
Thalamic Lesion ◽  
Content Type ◽  
Stereotactic Thalamotomy ◽  
Thalamic Lesions ◽  
Fine Print

Object. The treatment of Parkinson disease and other kinds of involuntary movement by gamma knife radiosurgery (GKS) is presented. This is an extension of previous work. The clinical course and thalamic lesions were the main factors examined. Methods. Seventeen new cases were added to the previously reported 36 cases. The course and results for the whole series of 53 patients were examined. Treatment was undertaken using a single 4-mm collimator shot to deliver 130 Gy to the target. The target was determined in the previously treated patients by using classic methods involved in conventional stereotactic thalamotomy with microrecording. More recently, target localization has been performed by relating the target point to the total length of the thalamus. Points may then be defined as percentages of that length measured from the anterior pole. Targets can then be determined in relationship to the appropriate percentage. Thirty-five patients have been followed for more than 2 years and the longest follow up was 8 years. Two kinds of thalamic lesion were seen after GKS. Volumetric analysis on MR imaging revealed that the larger lesion was 400 to 500 mm3 at the beginning and gradually decreased in size. The smaller lesion occupied approximately 200 mm3 and also shrank over several months. Eighty percent of the treated cases showed good results and no significant complications, with the tremor subsiding at 1 year (Type 1). Several cases deviated from this standard course in four different ways (Types 2–5). If tremor persisted, conventional stereotactic thalamotomy with microrecording was performed. During such operations, normal neuronal activity was recorded from the region adjacent to the GKS thalamotomy target. This was the region showing a high signal on MR imaging. The activity patterns included the rhythmical grouped discharge of tremor rhythm. Conclusions. Gamma thalamotomy for functional disorders is still under development, but because the results with careful target planning are satisfactory, there are grounds for increasing optimism.

Changing concepts in the treatment of colloid cysts

1987 ◽  
Vol 66 (2) ◽  
pp. 186-191 ◽  
Author(s):  
Walter A. Hall ◽  
L. Dade Lunsford
Keyword(s):  
Third Ventricle ◽  
Ct Scanning ◽  
Morbidity Rate ◽  
Ct Guided ◽  
Content Type ◽  
Persistent Symptoms ◽  
The Third ◽  
Stereotaxic Surgery ◽  
Colloid Cysts ◽  
The University

✓ Since computerized tomography (CT) scanning became available at the University Health Center of Pittsburgh in July, 1975, 17 patients have undergone removal of colloid cysts of the third ventricle by transfrontal, transcallosal, or stereotaxic surgery. All patients presented with symptoms and signs of increased intracranial pressure; CT scanning proved to be the best neurodiagnostic test to define the colloid cysts. Since the development of CT-guided stereotaxic surgery, the authors have preferentially performed stereotaxic aspiration in seven patients; three of these subsequently required craniotomies to remove residual cysts producing persistent symptoms. The viscosity of the intracystic colloid material and/or displacement of the cyst away from the aspiration needle were reasons for unsuccessful aspiration; the CT appearance did not correlate with the ability to aspirate the lesion by the stereotaxic technique. Postoperative patency of the ventricular system was documented by intraoperative CT ventriculography performed during stereotaxic surgery. Removal of the cyst wall was not necessary. Because of the low associated morbidity rate, percutaneous stereotaxic aspiration is recommended as the initial treatment of choice for colloid cysts of the third ventricle. If stereotaxic aspiration fails and symptoms persist, craniotomy should be performed.

Withdrawals lower India-China border tensions slightly

2021 ◽  
Keyword(s):  
Content Type ◽  
Lower Border

Headline INDIA/CHINA: Withdrawals lower border tension slightly

A guide to placement of parietooccipital ventricular catheters

1995 ◽  
Vol 82 (2) ◽  
pp. 300-304 ◽  
Author(s):  
Matthew A. Howard ◽  
Jayashree Srinivasan ◽  
Carl G. Bevering ◽  
H. Richard Winn ◽  
M. Sean Grady
Keyword(s):  
Ct Scanning ◽  
Catheter Placement ◽  
Target Point ◽  
Catheter Position ◽  
Content Type ◽  
Ventriculoperitoneal Shunting ◽  
Frontal Horn ◽  
Catheter Tip ◽  
Ventricular Catheters ◽  
Entire Procedure

✓ Accurate placement of parietooccipital ventricular catheters can be difficult and frustrating. To minimize the morbidity of the procedure and lengthen the duration of shunt function, the catheter tip should lie in the ipsilateral frontal horn. The authors describe a posterior ventricular guide (PVG) for placement of parietooccipital catheters that operates by mechanically coupling the posterior burr hole to the anterior target point. In a series of 38 patients who underwent ventriculoperitoneal shunting with the assistance of the guide, postoperative computerized tomography (CT) scanning revealed that 35 (92.0%) had accurate catheter placement. In comparison, a retrospective review of free-hand posterior catheter placement revealed good catheter position in only 22 of 43 patients (51.1%). The use of the guide added less than 5 minutes to the entire procedure, and there were no complications related to its use. The PVG is a simple and useful tool that aids in the placement of parietooccipital ventricular catheters.

A three-dimensional reconstruction of the human brain stem

1982 ◽  
Vol 57 (4) ◽  
pp. 491-495 ◽  
Author(s):  
Farhad Afshar ◽  
Eric Dykes
Keyword(s):  
Human Brain ◽  
Brain Stem ◽  
Computer Technology ◽  
Three Dimensional ◽  
Three Dimensional Reconstruction ◽  
Content Type ◽  
Stereotaxic Surgery ◽  
Stereotaxic Atlas ◽  
Dimensional Reconstruction ◽  
Fine Print

✓ Advances in computer technology and color graphics have been applied to the sections in a stereotaxic atlas of the human brain stem to enable three-dimensional reconstructions of nuclei and tracts. Techniques for viewing the reconstructed brain stem from multiple directions and in stereo have been achieved. The application of these methods and the use of color graphics are discussed with respect to stereotaxic surgery and computer dissection in neuroanatomical studies.

Stereotactic third ventriculostomy in patients with nontumoral adolescent/adult onset aqueductal stenosis and symptomatic hydrocephalus

1991 ◽  
Vol 75 (6) ◽  
pp. 865-873 ◽  
Author(s):  
Patrick J. Kelly
Keyword(s):  
Obstructive Hydrocephalus ◽  
Aqueductal Stenosis ◽  
Primary Treatment ◽  
Target Point ◽  
Third Ventriculostomy ◽  
Computer Assisted ◽  
Adult Onset ◽  
Absorption Mechanism ◽  
Content Type ◽  
Cerebrospinal Fluid Absorption

✓ Sixteen consecutive patients with obstructive hydrocephalus due to nontumoral aqueductal stenosis of adolescent or adult onset underwent computerized tomography-guided stereotactic third ventriculostomy. Computer-assisted angiographic target-point cross-registration was used in surgical planning to reduce morbidity. The procedure was used as primary treatment in five previously unshunted patients and in 11 patients who had previously received shunts and who presented when their shunts became obstructed (five patients), became infected (five patients), or required multiple revisions (one patient). At the time of third ventriculostomy, shunt hardware was removed in patients with infected shunts and the distal element of the shunt was ligated in all patients with obstructed shunts except one, who later required repeat third ventriculostomy; the distal shunt was ligated at that time. Follow-up data (range 1 to 5 years, mean 3½ years, after surgery) showed that only one of the 16 patients had undergone a shunting procedure after the third ventriculostomy. The other 15 patients are asymptomatic and shunt-independent. In previously shunt-dependent patients, the peripheral subarachnoid space and cerebrospinal fluid absorption mechanism remained patent in spite of shunts placed earlier. Therefore, in patients with obstructive hydrocephalus due to aqueductal stenosis of adolescent or adult onset, stereotactic third ventriculostomy should be seriously considered as primary surgical management in previously unshunted patients and in shunt-dependent patients with obstructed or infected shunts.

Motion and force control method of 7-DOF cable-driven rehabilitation exoskeleton robot

2018 ◽  
Vol 38 (5) ◽  
pp. 595-605 ◽  
Author(s):  
Wencheng Ni ◽  
Hui Li ◽  
Zhihong Jiang ◽  
Bainan Zhang ◽  
Qiang Huang
Keyword(s):  
Design Methodology ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Body Measurements ◽  
Joint Movement ◽  
Content Type ◽  
Rehabilitation Training ◽  
Exoskeleton Robot ◽  
Training Mode ◽  
Active Rehabilitation

Purpose The purpose of this paper is to design an exoskeleton robot and present a corresponding rehabilitation training method for patients in different rehabilitation stages. Design/methodology/approach This paper presents a lightweight seven-degrees-of-freedom (DOF) cable-driven exoskeleton robot that is wearable and adjustable. After decoupling joint movement caused by a cable-driven mechanism, active rehabilitation training mode and passive rehabilitation training mode are proposed to improve the effect of rehabilitation training. Findings Simulations and experiments have been carried out, and the results validated the feasibility of the proposed mechanism and methods by a fine rehabilitative effect with different persons. Originality/value This paper designed a 7-DOF cable-driven exoskeleton robot that is suitable for patients of different body measurements and proposed the active rehabilitation training mode and passive rehabilitation training mode based on the cable-driven exoskeleton robot.

Evaluation of the Position of Mental Foramen for Clinical and Forensic Significance in terms of Gender in Dentate Subjects by Digital Panoramic Radiographs

2016 ◽  
Vol 17 (9) ◽  
pp. 762-768 ◽  
Author(s):  
Amit Mhapuskar ◽  
Shweta Thakare ◽  
Darshan Hiremutt ◽  
Versha R Giroh ◽  
Kedarnath Kalyanpur ◽  
...  
Keyword(s):  
Vertical Plane ◽  
Mental Foramen ◽  
Forensic Identification ◽  
P Value ◽  
Anatomical Landmarks ◽  
Panoramic Radiographs ◽  
Lower Border ◽  
Significant Difference ◽  
Common Position ◽  
Inferior Border

ABSTRACT Introduction Evaluation of the position of mental foramen aids in forensic, surgical, endodontic, as well as diagnostic procedures. Thus, in view of this, the present study was conducted among the population of Pune, a central part of India, to determine the most regular location of the mental foramen and to estimate difference in position of mental foramen based on gender. Materials and methods The present retrospective study was commenced on 200 digital panoramic radiographs of dentate patients. The location of the representation of the mental foramen was traced. Measurements for evaluating distance of superior and inferior borders of the foramen in relation to the lower border of the mandible were made using the reference lines drawn from anatomical landmarks. The data so obtained were statistically analyzed using chi-square test. Results The most common position of mental foramen among Pune population in horizontal plane in both male and female patients was in line with second premolar followed by position in between first and second premolar, whereas in the vertical plane, most common position was at or in line with apex of second premolar followed by in between apex of first and second premolar. The variation in length of superior and inferior border of the foramen in relation to lower border of the mandible with respect to gender was found to be significant, with p-value <0.05. Conclusion There was no difference in position of mental foramen in horizontal and vertical planes based on gender. Clinical significance The stability of location of mental foramen and significant difference in length of superior and inferior border of the foramen in relation to lower border of the mandible with respect to gender offer its application in forensic identification of gender. How to cite this article Thakare S, Mhapuskar A, Hiremutt D, Giroh VR, Kalyanpur K, Alpana KR. Evaluation of the Position of Mental Foramen for Clinical and Forensic Significance in terms of Gender in Dentate Subjects by Digital Panoramic Radiographs. J Contemp Dent Pract 2016;17(9):762-768.

Optimal path search and control of mobile robot using hybridized sine-cosine algorithm and ant colony optimization technique

2020 ◽  
Vol 47 (4) ◽  
pp. 535-545
Author(s):  
Saroj Kumar ◽  
Dayal R. Parhi ◽  
Manoj Kumar Muni ◽  
Krishna Kant Pandey
Keyword(s):  
Mobile Robots ◽  
Ant Colony Optimization ◽  
Optimization Technique ◽  
Optimal Path ◽  
Ant Colony ◽  
Target Point ◽  
Multiple Mobile Robots ◽  
Content Type ◽  
Path Search ◽  
Sine Cosine Algorithm

Purpose This paper aims to incorporate a hybridized advanced sine-cosine algorithm (ASCA) and advanced ant colony optimization (AACO) technique for optimal path search with control over multiple mobile robots in static and dynamic unknown environments. Design/methodology/approach The controller for ASCA and AACO is designed and implemented through MATLAB simulation coupled with real-time experiments in various environments. Whenever the sensors detect obstacles, ASCA is applied to find their global best positions within the sensing range, following which AACO is activated to choose the next stand-point. This is how the robot travels to the specified target point. Findings Navigational analysis is carried out by implementing the technique developed here using single and multiple mobile robots. Its efficiency is authenticated through the comparison between simulation and experimental results. Further, the proposed technique is found to be more efficient when compared with existing methodologies. Significant improvements of about 10.21 per cent in path length are achieved along with better control over these. Originality/value Systematic presentation of the proposed technique attracts a wide readership among researchers where AI technique is the application criteria.

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