Bilateral pallidal stimulation for sargoglycan epsilon negative myoclonus.

We report on the clinical efficacy of bilateral globus pallidus internus deep brain stimulation in two patients with myoclonus dystonia/essential myoclonus who lack mutations in the epsilon sarcoglycan gene. The primary outcome measures were the Burke-Fahn-Marsden Dystonia Scale motor severity and the Unified Myoclonus Rating Scale scores, and the secondary outcome measure was the 36-item Short Form Health Survey score at the last postoperative follow up. Neuronal firing rates were also calculated from microelectrode recordings. At the last postoperative follow-up (16 weeks for Patient 1 and 18 weeks for Patient 2), there was 57.1% (Patient 1) improvement in the Burke-Fahn-Marsden Dystonia Scale motor severity score and 31.3% (Patient 1) and 69% (Patient 2) in the Unified Myoclonus Rating Scale score while individual SF-36 scores showed improvement in most subdomains. Bilateral globus pallidus internus deep brain stimulation can be effective in ameliorating epsilon sarcoglycan negative myoclonus with or without concurrent dystonia. Whether an epsilon sarcoglycan negative status represents a less favorable prognostic factor for pallidal deep brain stimulation remains to be elucidated.

Low-frequency subthalamic nucleus deep brain stimulation for axial symptoms in advanced Parkinson's disease.

Axial symptoms such as freezing of gait and falls are common manifestations of advanced Parkinson's disease (PD) and are partially responsive to medical treatment. High-frequency (≥130 Hz) deep brain stimulation (DBS) of the subthalamic nucleus (STN) is highly efficacious in ameliorating appendicular symptoms in PD. However, it is typically less effective in improving axial symptomatology, especially in the long term. We have studied the effects of low-frequency stimulation (LFS) (≤80 Hz) for improving speech, gait and balance dysfunction in the largest patient population to date. PD patients with bilateral STN-DBS and resistant axial symptoms were switched from chronic 130 Hz stimulation to LFS and followed up to 4 years. Primary outcome measures were total motor UPDRS scores, and axial and gait subscores before and after LFS. Bivariate analyses and correlation coefficients were calculated for the different conditions. Potential predictors of therapeutic response were also investigated. Forty-five advanced PD patients who had high frequency stimulation (HFS) for 39.5 ± 27.8 consecutive months were switched to LFS. LFS was kept on for a median period of 111.5 days before the assessment. There was no significant improvement in any of the primary outcomes between HFS and LFS, although a minority of patients preferred to be maintained on LFS for longer periods of time. No predictive factors of response could be identified. There was overall no improvement from LFS in axial symptoms. This could be partly due to some study limitations. Larger prospective trials are warranted to better clarify the impact of stimulation frequency on axial signs.

Catheterization of the thoracic spinal subarachnoid space in mice.

The availability of genetically manipulated mice offers a golden opportunity for the study of the contribution of the genome to diseases. Because of the technical difficulty in performing spinal subarachnoid catheterization in mice, this opportunity has hitherto been less harnessed in investigations on the role of the spinal cord in the physiological or pathological processes. Even less explored are spinal mechanisms that underlie cardiovascular regulation since subarachnoid catheterization of the mouse thoracic spinal cord, where preganglionic sympathetic neurons governing vasomotor tone are located posts the highest challenge because of the restricted operating area. We report a procedure for subarachnoid catheterization of the thoracic spinal cord in mice that did not require laminectomy or drilling of the lamina proper, and compared the suitability of two candidate catheters, polyethylene PE-5 catheter (0.51mm, OD) and polyurethane PU-10 catheter (0.25mm, OD). Whereas all implanted mice resumed normal feeding one day after surgery and were devoid of bladder dysfunction or self-mutilation, the smaller and softer PU-10 catheter compared favorably because of lower post-operative mortality rate and no unilateral lower limb paresis.

Involvement of the human pedunculopontine nucleus region in voluntary movements.

OBJECTIVE: The pedunculopontine nucleus region (PPNR) is being investigated as a target for deep brain stimulation (DBS) in Parkinson disease (PD), particularly for gait and postural impairment. A greater understanding of how PPNR activities and oscillations are modulated with voluntary movements is crucial to the development of neuromodulation strategies. METHODS: We studied 7 patients with PD who underwent DBS electrode implantations in the PPNR. PPNR local field potential and EEG were recorded while patients performed self-paced wrist and ankle movements. RESULTS: Back-averaging of the PPNR recording showed movement-related potentials before electromyography onset. Frequency analysis showed 2 discrete movement-related frequency bands in the theta (6- to 10-Hz) and beta (14- to 30-Hz) ranges. The PPNR theta band showed greater event-related desynchronization with movements in the ON than in the OFF medication state and was coupled with the sensorimotor cortices in the ON state only. Beta event-related desynchronization was observed in the PPNR during the premovement and movement execution phases in the OFF state. In contrast, premovement PPNR beta event-related synchronization occurred in the ON state. Moreover, beta band coherence between the PPNR and the midline prefrontal region was observed during movement preparation in the ON but not the OFF state. CONCLUSIONS: Activities of PPNR change during movement preparation and execution in patients with PD. Dopaminergic medications modulate PPNR activities and promote the interactions between the cortex and PPNR. Beta oscillations may have different functions in the basal ganglia and PPNR, and may be prokinetic rather than antikinetic in the PPNR.

Pallidal stimulation in cervical dystonia: clinical implications of acute changes in stimulation parameters.

BACKGROUND AND PURPOSE: Deep brain stimulation (DBS) of the globus pallidus internus (GPi) is successful in dystonia, but the role of each electrical parameters of stimulation is unclear. We studied the clinical effects of acute changes of different parameters of GPi-DBS in cervical dystonia (CD). METHODS: Eight CD patients with bilateral GPi-DBS at 28.6 +/- 19.2 (mean +/- SD) months after surgery were recruited. Mean improvement in the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) severity score was 54.5% compared to before surgery. Ten settings, including a combination of a wide range of pulse widths (PWs), low and high frequencies and voltage, were administered in a randomized double blinded fashion. Clinical benefit was assessed by two raters using the TWSTRS and by the patients using an analogue rating scale. RESULTS: The TWSTRS severity scores were reduced by 56.7% with stimulation at the best settings. Improvement was significantly associated with high frequency (> or = 60 Hz) and high voltage. Stimulation at 130 Hz showed the best clinical improvement. Increasing PWs (from 60 to 450 micros) did not result in a significant improvement. CONCLUSION: Frequency and amplitude appear to be the most important factors in the acute anti-dystonic effects in GPi-DBS patients with CD.

Long-term outcome of bilateral pallidal deep brain stimulation for primary cervical dystonia.

Ten patients with severe cervical dystonia (CD) unresponsive to medical treatment underwent bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) and were followed for 31.9 +/- 20.9 months. At last follow-up, the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) severity score improved by 54.8%, the TWSTRS disability score improved by 59.1%, and the TWSTRS pain score improved by 50.4%. Bilateral GPi DBS is an effective long-term therapy in patients with CD.

Differential contribution of N-methyl-D-aspartate and non-N-methyl-D-aspartate receptors in the intermediolateral cell column of the thoracic spinal cord to sympathetic vasomotor tone during experimental endotoxemia in the rat.

Although the rostral ventrolateral medulla maintains neurogenic vasomotor tone via glutamatergic excitation to sympathetic preganglionic neurons located at the intermediolateral cell column (IML) of thoracic spinal cord, the relative contribution of N-methyl-d-aspartate (NMDA) and non-NMDA receptors on IML neurons at rest or during endotoxemia remain unknown. The present study addressed this issue using a combination of physiological, pharmacological, and double-immunofluorescence approaches. Adult male Sprague-Dawley rats maintained under propofol anesthesia were used. Intrathecal administration of equimolar concentrations (75, 150, or 300 nmol) of an NMDA antagonist, dizocilpine (MK801), or a non-NMDA antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione, into T10 to T12 spinal cord elicited a reduction in resting vasomotor tone that was comparable in time course and in magnitude. Although both glutamate receptor antagonists exacerbated mortality and potentiated the elicited hypotension, bradycardia, or reduction in vasomotor tone during experimental endotoxemia induced by intravenous administration of Escherichia coli lipopolysaccharide (30 mg kg-1; results comparable to 6-cyano-7-nitroquinoxaline-2,3-dione at 150 nmol) were obtained only when MK801 was given at 300 nmol. Confocal microscopy further showed that augmented immunoreactivity of NR1 subunit on IML neurons coincided with the phase of endotoxemia when vasomotor tone was augmented; GluR1 immunoreactivity remained stable throughout experimental endotoxemia. These findings suggest that NMDA and non-NMDA receptors on IML neurons contribute to the generation of resting sympathetic vasomotor tone. However, up-regulation of NMDA receptors on IML neurons plays a crucial role in the maintenance of vasomotor tone during endotoxemia.

An improved procedure for catheterization of the thoracic spinal subarachnoid space in the rat.

Catheterization of the subarachnoid space provides a convenient means to deliver drugs to, or collect cerebrospinal fluid from, the spinal cord in animal experiments, and has been instrumental to our understanding of spinal mechanisms that underlie anesthesia, analgesia, or cardiovascular regulation. Experience gained over the years has revealed several shortcomings of this technique. We report a procedure that encompasses the benefits of direct subarachnoid catheterization of the rat thoracic spinal cord but circumvents the known shortcomings. An intrathecal catheter was fabricated with a small silicon bead at one end of a PE-10 catheter, which was cannulated with a 4/0 suture that served as a guide. Using the L-shape hook of the suture guide as an anchorage, the catheter was advanced into the subarachnoid space until the silicon bead was lodged on a drilled hole (2 x 2 mm) over the lamina proper on the T13 vertebrae. With less surgical trauma, greater precision of placement and firmer anchorage of the catheter, less leakage of cerebrospinal fluid, and minimal mortality or morbidity, our modified procedure for catheterization of the thoracic spinal subarachnoid space in the rat compared favorably to previously reported methods.

Pallidal deep brain stimulation in cervical dystonia: clinical outcome in four cases.

OBJECTIVE: Report on the clinical results following bilateral globus pallidus interna deep brain stimulation in four patients (one female and three males) with severe cervical dystonia, mean age 48 years (range 37-67). METHODS: All four patients had failed extensive medical and botulinum toxin treatment. The mean duration of the disease was nine years (range 4-15 years). Patients were assessed pre and postoperatively using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). Pre-operatively, the mean TWSTRS total score was 43.2 (range 28-60.5). Posteroventral pallidal deep brain stimulators were inserted using MRI and microelectrode recording guidance. Last follow-up was 15 months for the four patients. RESULTS: Mean reduction in the TWSTRS total scores at last follow- up was 73% (range 61- 85%). Improvement in pain occurred soon after deep brain stimulation surgery. Motor improvement was delayed and prolonged over several months. Frequent adjustment in the stimulation parameters was necessary in the first three months. CONCLUSION: Bilateral pallidal stimulation is effective in management of selected cases of intractable cervical dystonia.

Aspiration in transtracheal oxygen insufflation with different insufflation flow rates during cardiopulmonary resuscitation in dogs.

We investigated whether transtracheal insufflation of oxygen with different insufflation flow rates protects against aspiration of gastric contents during cardiopulmonary resuscitation (CPR). Its ventilation and oxygenation effects were also evaluated. Cardiac arrest was induced in anesthetized and paralyzed 18 mongrel dogs. Chest compression using an automatic thumper was performed while the dogs randomly received no mechanical ventilation (Group I, n = 6) or were transtracheally insufflated with 4 L/min oxygen (Group II, n = 6) or 10 L/min oxygen (Group III, n = 6). Blood samples were drawn every 5 min for 20 min for blood gas analysis. the mouths of the dogs were then filled with 70 mL mixed barium, and 10 min after chest compression, chest radiographs were taken to evaluate the incidence of pulmonary aspiration. Results showed that pulmonary aspiration occurred in all dogs of Group I and three of the six dogs in Group II, whereas dogs in Group III were free from pulmonary aspiration. Both transtracheal oxygen insufflation groups maintained oxygen saturation significantly better than Group I, but mild hypercapnia was observed in all groups after 20 min of CPR. We conclude that transtracheal oxygen insufflation, but not chest compression alone, was able to maintain oxygenation for 20 min during CPR in dogs with cardiac arrest. Mild hypercapnia was noted in all groups. Chest compression alone caused pulmonary aspiration, whereas insufflation of 10 L O(2)/min provided better protection against pulmonary aspiration than that of 4 L O(2)/min.

Aspiration in chest compression alone without mechanical ventilation in the head down position in dogs.

BACKGROUND: Previous work by the authors has shown that chest compressions alone without mechanical ventilation during cardiopulmonary resuscitation in the natural supine position was associated with pulmonary aspiration in dogs. The purpose of this investigation was to test the hypothesis that a head down position may prevent aspiration during chest compressions alone and whether oxygenation can be improved by simply insufflation of oral oxygen 10 min after cardiac arrest. METHODS: Cardiac arrest was induced in ten mongrel dogs which were anesthetized and paralysed. Eight underwent chest compressions alone in different head down positions using an automatic compressor at 9 kg compression force and 3 cm compression depth. The study was composed of two parts. Part 1 evaluated the effect of insufflation of 10 l/min O2, into the mouth of the dogs, 10 min after initiation of resuscitation, using chest compressions alone. Part 2 was designed to test our hypothesis that the head down position may protect the lungs from aspiration during chest compression alone. The mouths of the dogs were filled with mixed barium and the dogs underwent serial episodes of chest compressions, for 10 min each, in the 20 degree head down, 10 degree head down and the natural supine positions. Chest X-rays with antero-posterior and lateral views were taken to evaluate pulmonary aspiration. Two additional dogs underwent direct chest compression alone in the natural supine position and the time of chest compression was shortened to 5 min. RESULTS: All dogs in the natural position showed evidence of pulmonary aspiration of barium, five or six of the dogs showed tracheal aspiration in the 10 degree head down position, while no any barium was visualized in the tracheo-broncheal trees of the dogs in the 20 degree head down position. Supplemental oxygen in the mouth improved the mean PaO2 from 67 +/- 26 to 160 +/- 97 mmHg during chest compressions alone. CONCLUSION: Chest compression alone without mechanical ventilation in the supine position caused pulmonary aspiration in the unprotected airway in dogs. This complication could be prevented by adopting a 20 degree head down position. The 10 degree head down position seemed to reduce the severity of the pulmonary aspiration, but not enough to eliminate the danger altogether. Supplemental oxygen in the mouth can improve oxygenation in chest compressions alone.

Intubation of newborn during delivery with intact umbilical cord--a case report.

A 24-year-old gravida 2, para 1 woman at 38th week gestation was scheduled for elective Cesarean section (C/S) because of a previous C/S and prenatal diagnosis of congenital diaphragmatic hernia. We decided to intubate the newborn during delivery before the umbilical cord was cut. After delivery of the fetal head and part of the shoulders, the mouth of the fetus was cleared and the trachea was intubated orally with a 2.5 mm internal diameter (I.D.) endotracheal tube under sterile conditions while the uteroplacental circulation was still intact. The patient had to be repeatedly resuscitated due to bradycardia in intensive care unit. No surgical correction of the hernia was attempted because of the poor condition of the baby, which died 3.5 hours after birth. Although our case ended up in mortality despite successful perinatal intubation, we recommend that in case where airway or ventilatory problems are anticipated, tracheal intubation is done during delivery before the umbilical cord is clamped. When the fetus is sharing the maternal circulation, it will allow physicians to have more time and safety to perform corrective measures.

Unsuspected difficult intubation caused by a laryngeal web.

We report a case of unsuspected difficult intubation in an adult caused by laryngeal web formation in the anterior commissure of the larynx. After induction of anaesthesia, most parts of the posterior commissure of the vocal cords were seen clearly at laryngoscopy, but a 7.5-mm internal diameter (id) tracheal tube could not be advanced below the level of the vocal cords because of resistance. Intubation was re-attempted several times after oxygenation by mask with trials of smaller tubes. Finally, a 5.0-mm id cuffed tube was passed successfully through the vocal cords, and secured in place. Because of the unexpected difficulties in intubation, an otolaryngologist was consulted to examine the larynx with a microscope. A web of 0.5 cm in the anterior commissures was found which caused subglottic stenosis.

Comparison of sevoflurane with halothane in pediatric ambulatory anesthesia: an experience in Taiwan.

BACKGROUND: Sevoflurane, with blood/gas partition coefficient of 0.69 and MAC of 1.76 is a fast acting, potent inhalation anesthetic. Its suitability and safety for pediatric ambulatory anesthesia were assessed and compared with that of halothane. METHODS: Thirty two unpremedicated pediatric patients undergoing elective herniorrhaphy on day-surgery basis were randomly allocated to 2 groups of equal number to receive either sevoflurane or halothane anesthesia. Employing mask technique, anesthesia was induced with 60% nitrous oxide and 3 MAC of either sevoflurane or halothane in oxygen. Anesthesia was maintained respectively with 1-1.5 MAC of sevoflurane or halothane. The induction time, emergence time and untoward effects during anesthesia were analyzed and compared. RESULTS: It was shown that both the induction time and emergence time were significantly shorter in patients receiving sevoflurane. None had major complications. CONCLUSIONS: The results strongly suggest that sevoflurane is preferable to halothane for pediatric ambulatory anesthesia.

The depth to the epidural space.

Two hundred and ten patients, 145 males and 65 females, aged 20 to 72 years old, ready to receive extracorporeal shock wave lithotripsy under epidural anesthesia were studied to evaluate if any correlation existed between body weight, body surface area, body mass index and body height and the depth to the epidural space. The mean value for the depth to the epidural space was 4.77 +/- 0.55 cm for males, 4.25 +/- 0.55 cm for females and the overall average was 4.61 +/- 0.60 cm. The range of the depth to the epidural space was 3.0-7.0 cm. Linear regression analysis revealed significant correlation between body weight, body surface area, body mass index, body height an the depth to the epidural space, in the order of BW greater than BSA greater than BMI greater than BH. It is concluded that body weight, body surface area, body mass index and body height affect the depth to the epidural space and play an important role in predicting the depth to the epidural space.

Combined epidural lidocaine-fentanyl-epinephrine for cesarean section.

The combined use of fentanyl-epinephrine-lidocaine in epidural analgesia was investigated in 60 mothers who underwent elective Cesarean section. They were randomly classified into 4 groups of 15 each. Group A received 20 mL of 2% lidocaine 3 mL normal saline. Group B received 20 mL of 2% lidocaine with freshly added 1:200000 epinephrine and 5 mL normal saline. Group C received 20 mL of 2% lidocaine and 2 mL of fentanyl in 3 mL normal saline. Group D received 20 mL of 2% lidocaine and 5 mL normal saline. The duration of action was nearly doubled in the groups with epinephrine added. The quality of the analgesia was assessed by the degree of intraoperative analgesia; 93% of the patients in group A were classified as "Excellent"; while only 67% in group B were classified as "Excellent". The difference in patient's acceptance was statistically significant. 93% vs 27% in Group A and Group C; 67% vs 6.7% in Group B and Group D rated "Excellent". The results suggest that both fentanyl and epinephrine improve intraoperative analgesia. Epinephrine offers a greater analgesic effect than fentanyl.