Characteristics and distribution of somatosensory evoked potentials in the subthalamic region

2007 ◽  
Vol 107 (3) ◽  
pp. 548-554 ◽  
Author(s):  
Mayumi Kitagawa ◽  
Jun-Ichi Murata ◽  
Haruo Uesugi ◽  
Ritsuko Hanajima ◽  
Yoshikazu Ugawa ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Somatosensory Evoked Potentials ◽  
Anterior Commissure ◽  
Zona Incerta ◽  
Medial Lemniscus ◽  
Posterior Commissure ◽  
Topographical Distribution ◽  
The Mean ◽  
Deep Brain

Object The aim of the present study is to evaluate the topographical distribution of somatosensory evoked potentials (SSEPs) in the subthalamic area, including the zona incerta (ZI). Determination of this distribution may help in the correct placement of deep brain stimulation (DBS) leads. Methods Intraoperative SSEPs were recorded from contacts of DBS electrodes at 221 sites in 41 patients: three patients with essential tremor and 38 with Parkinson disease who underwent implantation of DBS electrodes for the relief of severe tremor or parkinsonism. Results Two distinct SSEPs were recorded in the subthalamic area. One was a monophasic positive wave with a mean latency of 15.8 ± 0.9 msec, which the authors designated subthalamic P16. Using both cephalic and noncephalic references, subthalamic P16 was only recorded in the ventral part of the ZI (mean 6.6 ± 1. 3 mm posterior to the midcommissure point, 4.8 ± 1.2 mm inferior to the anterior commissure–posterior commissure line, and 9.7 ± 0.6 mm lateral to the midline). When bipolar recordings were made, the traces showed a phase reversal at the caudal part of the ZI. The second potential is a positive–negative SSEP recorded throughout the entire subthalamic area. The mean latencies of the initial positive peak and the major negative peak were 13.6 ± 1.1 msec and 16.4 ± 1.1 msec, respectively. Several small notches were superimposed on the peaks, and their amplitudes were largest at the contact close to the medial lemniscus. Conclusions The results indicate that intraoperative SSEPs from DBS electrodes are helpful in refining stereotactic targets in the thalamus and subthalamic areas.

scholarly journals Cortical Evoked Potentials in Children of Diabetic Mothers

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Mario Brinciotti ◽  
Angela Napoli ◽  
Antonio Mittica ◽  
Olimpia Bitterman ◽  
Maria Matricardi
Keyword(s):  
Evoked Potentials ◽  
Metabolic Control ◽  
Somatosensory Evoked Potentials ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Mean Value ◽  
Evoked Responses ◽  
The Mean ◽  
Diabetic Mothers

Type 1 diabetic mothers' infants show a delay of visual evoked potential (VEP) significantly related to some parameters of poor metabolic control during pregnancy. In the present paper we analyzed the characteristics of VEPs and somatosensory evoked potentials (SEPs) recorded in 16 three-year-old type 1 diabetic mothers' children (DMC). Compared with controls (23 nondiabetic mothers' healthy matched children), DMC showed significantly delayed mean latency of VEP (P2) and SEP (P22). In 3 cases (19%), we found pathological responses (+3 SD from the mean value of controls) of VEPs and SEPs. At the age of 3 years, the offspring of type 1 diabetic mothers showed delay of cortical evoked responses in both visual and somatosensory systems.

scholarly journals Study on topographical distribution of carcinoma larynx

1970 ◽  
Vol 17 (2) ◽  
pp. 96-103
Author(s):  
Md Alamgir Hossain ◽  
Mohammad Idrish Ali ◽  
Masroor Rahman ◽  
SM Nazmul Huque ◽  
Md Morshed Alam ◽  
...  
Keyword(s):  
Anterior Commissure ◽  
Smoking Habit ◽  
Common Symptom ◽  
Glottic Carcinoma ◽  
Nodal Involvement ◽  
Posterior Commissure ◽  
College Hospital ◽  
Carcinoma Larynx ◽  
Supraglottic Carcinoma ◽  
Topographical Distribution

Objectives: To find out the sites of involvement of carcinoma larynx. Methods: A cross sectional study was carried out from January, 2006 to December, 2007 at the Department of ENT and Head-Neck Surgery of Dhaka Medical College Hospital, Dhaka. This study included 147 cases with of carcinoma larynx. Results: Among 147 cases in this study near age was 54.53 years the pearl incidence was 6th to 7th decade; male: female rate 28.4: 1. Majority of case were related to cultivation (42.6%), came for rural area (66.7%), socioeconomic group (68%) and illiterate (49.7%). Regarding habit most of them were more than one habits (87.7%) patients were smokers, duration of smoking habit varied from 2 years to more than 40 years and per day consumption from 3-32 sticks. 100% of female had the, habit of betel leaf chewing in this study. The common symptom was hoarseness of voice (93.8%) followed by dysphagia (61.6%) respiratory distress (52.4%), earache (6.8%) cases, haemoptysis and neck pain in small proportion. Indirect larygoscopic examination: Supraglottic carcinoma extension to one dial wall of pyriform fossa and valecular / bare of the tongue were present in (11.5%) and 8.7 cases respectively. 73.4% cases were more then one subsites involvement. Impaired vocal cord morbidity was found in 30.9% and fixed cord was 49.6%, 55.2% cases were airway inadequate, nodal involvement was 46.9%, 98.6% nodal involvement in supraglotic region, 65.2% were NI stage followed by N2 (21.7% and N3 (13%) distribution of the carcinoma larynx were supraglottic 74.10 glottic 25.10% and subglottic 0.70% more than one insite involvement were 88%, in supraglottic epiglottis 5.5%, any epiglottic folds 4.6% or glend 0.9% and ventricular bands were 0.9%. In the subsite of the glottic carcinoma glottic proper 37.8% followed by more then one insite (32.4%) anterior commissure 18.4% and posterior commissure 10.8%, 55% of the patient were Grade II and 49.6% were stage III. Conclusion: Incidence of supraglottic carcinoma was more common, involvement of more than one single site also common. Key words: Carcinoma larynx; supraglottic. DOI: http://dx.doi.org/10.3329/bjo.v17i2.8848 BJO 2011; 17(2): 96-103

Somatosensory Evoked Potentials

2016 ◽  
pp. 539-566 ◽  
Author(s):  
James C. Watson ◽  
Jonathan L. Carter
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Evoked Potentials ◽  
Somatosensory Evoked Potentials ◽  
Dorsal Column ◽  
Medial Lemniscus ◽  
Prognostic Information ◽  
Technical Aspects ◽  
Non Invasive ◽  
Anoxic Coma

Somatosensory evoked potentials (SEPs) provide a non-invasive, sensitive, and quantitative way of assessing the functional integrity of the peripheral and central proprioceptive, dorsal column–medial lemniscus somatosensory conduction pathways. SEPs can be used to localize lesions in the nervous system, to identify objectively abnormalities in patients with few sensory manifestations or none at all, to determine whether a process potentially affecting the spinal cord is functionally impairing, and to provide prognostic information in the context of post-anoxic coma. This chapter discusses the technical aspects, limitations, and roles of SEPs in the evaluation of neurologic symptoms, and provides examples of SEPs in different diseases.

Somatosensory evoked potentials in children with dystonia help predict outcome from deep brain stimulation

2017 ◽  
Vol 21 ◽  
pp. e221
Author(s):  
V.M. McClelland ◽  
D. Fialho ◽  
D. Flexney-Briscoe ◽  
G.E. Holder ◽  
M.C. Elze ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Evoked Potentials ◽  
Brain Stimulation ◽  
Somatosensory Evoked Potentials ◽  
Deep Brain

Localization of clinically effective stimulating electrodes in the human subthalamic nucleus on magnetic resonance imaging

2002 ◽  
Vol 97 (5) ◽  
pp. 1152-1166 ◽  
Author(s):  
Jean A. Saint-Cyr ◽  
Tasnuva Hoque ◽  
Luiz C. M. Pereira ◽  
Jonathan O. Dostrovsky ◽  
William D. Hutchison ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Subthalamic Nucleus ◽  
Anterior Commissure ◽  
Zona Incerta ◽  
Neurosurgical Procedures ◽  
Posterior Commissure ◽  
Content Type ◽  
Neurophysiological Data ◽  
Fine Print

Object. The authors sought to determine the location of deep brain stimulation (DBS) electrodes that were most effective in treating Parkinson disease (PD). Methods. Fifty-four DBS electrodes were localized in and adjacent to the subthalamic nucleus (STN) postoperatively by using magnetic resonance (MR) imaging in a series of 29 patients in whom electrodes were implanted for the treatment of medically refractory PD, and for whom quantitative clinical assessments were available both pre- and postoperatively. A novel MR imaging sequence was developed that optimized visualization of the STN. The coordinates of the tips of these electrodes were calculated three dimensionally and the results were normalized and corrected for individual differences by using intraoperative neurophysiological data (mean 5.13 mm caudal to the midcommissural point [MCP], 8.46 mm inferior to the anterior commissure—posterior commissure [AC—PC], and 10.2 mm lateral to the midline). Despite reported concerns about distortion on the MR image, reconstructions provided consistent data for the localization of electrodes. The neurosurgical procedures used, which were guided by combined neuroimaging and neurophysiological methods, resulted in the consistent placement of DBS electrodes in the subthalamus and mesencephalon such that the electrode contacts passed through the STN and dorsally adjacent fields of Forel (FF) and zona incerta (ZI). The mean location of the clinically effective contacts was in the anterodorsal STN (mean 1.62 mm posterior to the MCP, 2.47 mm inferior to the AC—PC, and 11.72 mm lateral to the midline). Clinically effective stimulation was most commonly directed at the anterodorsal STN, with the current spreading into the dorsally adjacent FF and ZI. Conclusions. The anatomical localization of clinically effective electrode contacts provided in this study yields useful information for the postoperative programming of DBS electrodes.

Cortical and subcortical brain shift during stereotactic procedures

2007 ◽  
Vol 107 (5) ◽  
pp. 983-988 ◽  
Author(s):  
W. Jeffrey Elias ◽  
Kai-Ming Fu ◽  
Robert C. Frysinger
Keyword(s):  
Frontal Cortex ◽  
Anterior Commissure ◽  
Stereotactic Surgery ◽  
Brain Shift ◽  
Posterior Commissure ◽  
Direct Function ◽  
Subcortical Brain ◽  
Duration Of Surgery ◽  
The Mean ◽  
Clinically Significant

Object The success of stereotactic surgery depends upon accuracy. Tissue deformation, or brain shift, can result in clinically significant errors. The authors measured cortical and subcortical brain shift during stereotactic surgery and assessed several variables that may affect it. Methods Preoperative and postoperative magnetic resonance imaging volumes were fused and 3D vectors of deviation were calculated for the anterior commissure (AC), posterior commissure (PC), and frontal cortex. Potential preoperative (age, diagnosis, and ventricular volume), intraoperative (stereotactic target, penetration of ventricles, and duration of surgery), and postoperative (volume of pneumocephalus) variables were analyzed and correlated with cortical (frontal cortex) and subcortical (AC, PC) deviations. Results Of 66 cases, nine showed a shift of the AC by more than 1.5 mm, and five by more than 2.0 mm. The largest AC shift was 5.67 mm. Deviation in the x, y, and z dimensions for each case was determined, and most of the cortical and subcortical shift occurred in the posterior direction. The mean 3D vector deviations for frontal cortex, AC, and PC were 3.5 ± 2.0, 1.0 ± 0.8, and 0.7 ± 0.5 mm, respectively. The mean change in AC–PC length was −0.2 ± −0.9 mm (range −4.28 to 1.66 mm). The volume of postoperative pneumocephalus, assumed to represent cerebrospinal fluid (CSF) loss, was significantly correlated with shift of the frontal cortex (r = 0.640, 64 degrees of freedom, p < 0.001) and even more strongly with shift of the AC (r = 0.754, p < 0.001). No other factors were significantly correlated with AC shift. Interestingly, penetration of the ventricles during electrode insertion, whether unilateral or bilateral, did not affect volume of pneumocephalus. Conclusions Cortical and subcortical brain shift occurs during stereotactic surgery as a direct function of the volume of pneumocephalus, which probably reflects the volume of CSF that is lost. Clinically significant shifts appear to be uncommon, but stereotactic surgeons should be vigilant in preventing CSF loss.

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