Image-guided percutaneous intralesional administration of mesenchymal stromal cells in subjects with chronic complete spinal cord injury: a pilot study.

BACKGROUND AIMS: The potential of cell therapies to improve neurological function in subjects with spinal cord injury (SCI) is currently under investigation. In this context, the choice of cell type, dose, route and administration regimen are key factors. Mesenchymal stromal cells (MSCs) can be easily obtained, expanded and are suitable for autologous transplantation. Here we conducted a pilot study that evaluated safety, feasibility and potential efficacy of intralesional MSCs transplantation performed through image-guided percutaneous injection, in subjects with chronic complete SCI. METHODS: Five subjects with chronic traumatic SCI (>6 months), at thoracic level, classified as American Spinal Cord Injury Association impairment scale (AIS) grade A, complete injury, were included. Somatosensory evoked potentials (SSEP), spinal magnetic resonance imaging (MRI) and urodynamics were assessed before and after treatment. Autologous MSCs were injected directly into the lesion site through percutaneous injection guided by computerized tomography (CT). RESULTS: Tomography-guided percutaneous cell transplantation was a safe procedure without adverse effects. All subjects displayed improvements in spinal cord independence measure (SCIM) scores and functional independence measure (FIM), mainly due to improvements in bowel movements and regularity. Three subjects showed improved sensitivity to tactile stimulation. Two subjects improved AIS grade to B, incomplete injury, although this was sustained in only one of them during the study follow-up. CONCLUSION: Autologous bone marrow MSC transplantation, performed through CT-guided percutaneous injection, was shown to be safe and feasible. Further studies are required to demonstrate efficacy of this therapeutic scheme.

Comparison of three methods of targeting the subthalamic nucleus for chronic stimulation in Parkinson's disease.

OBJECTIVE: The success of subthalamic nucleus (STN) surgery for Parkinson's disease depends on accuracy in target determination. The objective of this study was to determine which of the following techniques was most accurate and precise in identifying the location for stimulation in STN deep brain stimulation surgery that is most clinically effective: direct targeting, indirect targeting using the positions of the anterior and posterior commissures, or a technique using the red nucleus (RN) as an internal fiducial marker. METHODS: We reviewed 14 patients with Parkinson's disease treated with bilateral STN deep brain stimulation (28 STN targets). Electrode implantation was based on direct and indirect targeting using two-dimensional magnetic resonance imaging with refinement using microelectrode recording. Optimal settings, including the contacts used, were determined during the clinical follow-up. The position of the best contact was defined with postoperative magnetic resonance imaging. This location was compared with the modified direct, indirect, and RN-based targets. The mean distances between the targets and the final position of the optimal contact were calculated. The accuracy and variance of each target were analyzed. RESULTS: The mean position of the best contact was x = 12.12 (standard deviation [SD], 1.45 mm), y = -2.41 (SD, 1.63 mm), and z = -2.39 (SD, 1.49 mm) relative to the midcommissural point. The mean distance between the optimal contact position and the planned target was 3.19 mm (SD, 1.19 mm) using the RN-based method, 3.42 mm (SD, 1.34 mm) using indirect targeting, and 4.66 mm (SD, 1.33 mm) using a modified direct target. The mean distance between the optimal contact and the RN-based target was significantly smaller than the mean distance between the optimal contact and the direct target (post hoc with Tamhane's correction, P < 0.001) but not between the optimal contact and the indirect target. The RN-based target had the smallest variance (F test, P < 0.001), indicating greater precision. CONCLUSION: The use of the RN as an internal fiducial marker for targeting the optimal region of STN stimulation was reliable and closely approximates the position of the electrode contact that provides the optimal clinical results.

Insertion of subdural strip electrodes for the investigation of temporal lobe epilepsy. Technical note.

Temporal lobe epilepsy (TLE) is the most common type of surgically treatable epilepsy, with a considerable number of patients needing invasive electroencephalography monitoring. The authors describe a surgical technique used in the placement of subdural strip electrodes for coverage of the temporal lobe. The electrodes are inserted through an enlarged temporooccipital bur hole using fluoroscopic guidance. With this technique, subdural electrode strips can be safely placed to cover the mesial, inferior, and lateral temporal surfaces, and the seizure focus can be lateralized and localized within the temporal lobe. The technique does not require the use of a craniotomy, stereotactic frame, or neuronavigation systems. The authors compare this technique with previous descriptions of subdural electrode placement for the evaluation of TLE.

Embolization before radiosurgery reduces the obliteration rate of arteriovenous malformations.

OBJECTIVE: To evaluate the arteriovenous malformation (AVM) obliteration rate and the clinical outcome after radiosurgery in patients with and without previous embolization. METHODS: Of 244 patients who underwent linear accelerator radiosurgery for AVMs at the Sunnybrook Health Sciences Centre between 1989 and 2000, 61 patients had embolization before radiosurgery and complete follow-up for at least 3 years. For 47 of these 61 patients (Group A, embolization plus radiosurgery), we were able to find 47 matching patients without previous embolization (Group B, radiosurgery alone). This group of matching patients had the same AVM volume (after embolization in Group A), location, and marginal dose. The radiosurgery-based AVM score and the obliteration prediction index were calculated. RESULTS: The median follow-up period was 44 months. Nidus obliteration was achieved in 22 patients in Group A (47%) and 33 patients in Group B (70%, P = 0.036). Permanent deficit related to hemorrhage or radiation occurred in three patients (6%) in Group A and three patients (6%) in Group B. During the first 3 years after radiosurgery, two patients (4%) in Group A experienced hemorrhage; in Group B, five patients (11%) experienced hemorrhage (P = 0.2). In Group B, two patients (4%) died and two patients (4%) had their AVM surgically removed. Both deaths were related to hemorrhage during the latency period. The excellent outcome (obliteration plus no deficit) in Group A was 47% compared with 64% in Group B (P = 0.146). There was no difference in the obliteration prediction index and the radiosurgery-based AVM score between Groups A and B. The predicted rates of obliteration and excellent outcome were 55 and 62.5%, respectively, according to the obliteration prediction index and the radiosurgery-based AVM score. CONCLUSION: Embolization before radiosurgery significantly decreases the obliteration rate, even in AVMs with the same volume, location, and marginal dose. Although an excellent outcome rate was higher in the group without embolization, this was not statistically significant.

Pediatric arteriovenous malformation: University of Toronto experience using stereotactic radiosurgery.

INTRODUCTION AND BACKGROUND: Arteriovenous malformations (AVMs) are congenital vascular lesions of the brain, which behave differently in pediatric population compared to adults. Treatment of pediatric AVMs includes a combination of microsurgery, embolization and radiation therapies. However, the role of radiosurgery in the treatment of pediatric AVMs is not fully accepted because of concerns regarding the long-term effects of radiation on the pediatric brain. DISCUSSION: In this study, we review our experience at the University of Toronto with treating pediatric AVMs using linear accelerator-based (LINAC) radiosurgery over the past 15 years. We report our results, obliteration rates, and complications on a total of 40 patients. In addition, we provide a review of series published to date combined with our own results to determine whether radiosurgery is a safe and reasonable treatment modality for pediatric AVMs.

Radiosurgical treatment for rolandic arteriovenous malformations.

OBJECT: The authors reviewed the radiosurgical outcomes in patients with arteriovenous malformations (AVMs) located in the rolandic area, including the primary motor and sensory gyri. METHODS: The study population consisted of 38 patients with rolandic-area AVMs who underwent linear accelerator radiosurgery at the University of Toronto between 1989 and 2000. Obliteration rate, risk of hemorrhage during the latency period, radiation-induced complications, seizure control, and functional status were evaluated. Patients were also divided into two subgroups according to AVM volume (< 3 cm3 and > or = 3 cm3). Patients were followed up for a median of 42.4 months (range 30-103 months), and the median age of the patients was 40 years (range 12-67 years). The median AVM volume was 8.1 cm3 (range 0.32-21, mean 8.32 cm3), and the median dose at the tumor margin was 15 Gy (range 15-22, mean 16.8 Gy). The risk of hemorrhage after radiosurgery was 5.3% for the 1st year, 2.6% for the 2nd, and 0% for the 3rd. Two patients (5.3%) sustained adverse effects related to radiation for more than 6 months. Complete nidus obliteration after a single radiosurgical treatment was achieved in 23 patients (60.5%). The obliteration rate for AVMs smaller than 3 cm3 was 83.3% (10 of 12) and that for AVMs larger than or equal to 3 cm3 was 50% (13 of 26). Among the patients who had seizures as the initial presentation, 51.8% were free of seizures after radiosurgery and the seizure pattern improved in 40.7% during the 3rd and last year of follow up. Overall, excellent results (obliteration and no new or worsening neurological deficit) can be achieved in approximately 60% of patients. This percentage varies according to the AVM size and can reach 83% in patients with AVMs smaller than 3 cm3. CONCLUSIONS: Radiosurgery is a safe and effective treatment for people with rolandic AVMs. The low rate of morbidity associated with radiosurgery, compared with other treatments, indicates that this method may be the first choice for patients with AVMs located in this area.

Radiosurgical retreatment for brain arteriovenous malformation.

OBJECTIVE: To analyze our experience with a second radiosurgical treatment for brain arteriovenous malformations (BAVMs) after an unsuccessful first radiosurgical treatment. METHODS: Between 1993 and 2000, 242 patients were treated by the Toronto Sunnybrook Regional Cancer Center using a LINAC system. Fifteen of these patients required a second radiosurgical intervention due to the failure of the first procedure. Data was collected on baseline patient characteristics, BAVM features, radiosurgery treatment plan and outcomes. Brain arteriovenous malformation obliteration was determined by follow-up MRI and angiography and the obliteration prediction index (OPI) calculated according to a previously established formula. RESULTS: The median interval between the first and second treatment was 46 months (range 39-109). The median follow-up after the second procedure was 39 months (range 26 to 72). The mean BAVM volume before the first treatment was 8.9cm3 (range 0.3-21) and before the second treatment was 3.6cm3 (range 0.2-11.6). The mean marginal dose during the first treatment was 18Gy (range 12-25) and during the second treatment was 16Gy (range 12-20). After the second treatment, nine patients had obliteration of their BAVM confirmed by angiography and one patient had obliteration confirmed by MRI, resulting in an obliteration rate of 66.6%, which is very comparable to that predicted by the OPI (65%). After the second treatment two patients had a radiation-induced complication (13.3%). CONCLUSION: Retreatment of BAVM using a second radiosurgery procedure is a safe and effective option that offers the same rate of success as the initial radiosurgery and an acceptable risk of radiation-induced complication.

Testing the radiosurgery-based arteriovenous malformation score and the modified Spetzler-Martin grading system to predict radiosurgical outcome.

OBJECT: The aim of this study was to validate the radiosurgery-based arteriovenous malformation (AVM) score and the modified Spetzler-Martin grading system to predict radiosurgical outcome. METHODS: One hundred thirty-six patients with brain AVMs were randomly selected. These patients had undergone a linear accelerator radiosurgical procedure at a single center between 1989 and 2000. Patients were divided into four groups according to an AVM score, which was calculated from the lesion volume, lesion location, and patient age (Group 1, AVM score <1; Group 2, AVM score 1-1.49; Group 3, AVM score 1.5-2; and Group 4, AVM score >2). Patients with a Spetzler-Martin Grade III AVM were divided into Grades IIIA (lesion >3 cm) and IIIB (lesion <3 cm). Sixty-two female (45.6%) and 74 male (54.4%) patients with a median age of 37.5 years (mean 37.5 years, range 5-77 years) were followed up for a median of 40 months. The median tumor margin dose was 15 Gy (mean 17.23 Gy, range 15-25 Gy). The proportions of excellent outcomes according to the AVM score were as follows: 91.7% for Group 1, 74.1% for Group 2, 60% for Group 3, and 33.3% for Group 4 (chi-square test, degrees of freedom (df) = 3, p < 0.001). Based on the modified Spetzler-Martin system, Grade I lesions had 88.9% excellent results; Grade II, 69.6%; Grade IIIB, 61.5%; and Grades IIIA and IV, 44.8% (chi-square test, df = 3, p = 0.047). CONCLUSIONS: The radiosurgery-based AVM score can be used accurately to predict excellent results following a single radiosurgical treatment for AVM. The modified Spetzler-Martin system can also predict radiosurgical results for AVMs, thus making it possible to use this system while deciding between surgery and radiosurgery.

Comparison of 2-dimensional magnetic resonance imaging and 3-planar reconstruction methods for targeting the subthalamic nucleus in Parkinson disease.

OBJECTIVE: The study aims to compare 2-dimensional (2D) and 3-planar (3P) reconstruction magnetic resonance imaging (MRI) methods of targeting the optimal region of the subthalamic nucleus (STN) for chronic stimulation in patients with Parkinson disease. METHODS: We studied 14 patients with Parkinson disease treated with bilateral STN deep brain stimulation (DBS) (28 STN targets). Electrode implantation was based on direct and indirect targeting based upon the position of the anterior and posterior commissures using 2D MRI, with selection of the final target based on microelectrode recording. Optimal settings, including the contacts used, were determined during the clinical follow-up. The position of the best contact was defined with postoperative MRI. Optimal contact position was compared to targets calculated by the direct method from the preoperative 2D MRI and 3P reconstruction. Optimal contact position was also compared to the indirect targets calculated from the preoperative 2D MRI and 3P reconstruction. The distance between the targets and the position of the best contact were calculated. RESULTS: The mean improvement in OFF-period Unified Parkinson Disease Rating Scale III subscores with STN DBS was 52%. The mean distance between the optimal contact position and the direct target was 4.66 mm (SD = 1.33) using the 2D MRI and 3.49 mm (SD = 1.29) using the 3P reconstruction (t test, P < .001). The mean distance between the optimal contact and the indirect target was 3.42 mm (SD = 1.34) using the 2D MRI and 2.61 mm (SD = 0.97; t test, P = .001) using the 3P reconstruction. The variance of the direct target was less using the 3P reconstruction than using the 2D MRI (F test, P = .002), indicating greater precision. Similarly, the variance of the indirect target using the 3P reconstruction was less than using the 2D MRI (F test, P = .012). CONCLUSION: Indirect and direct targets chosen using 3P reconstruction more closely approximate the position of the clinically optimal contact than targets chosen using 2D MRI.

Comparison of three methods of targeting the subthalamic nucleus for chronic stimulation in Parkinson's disease.

OBJECTIVE: The success of subthalamic nucleus (STN) surgery for Parkinson's disease depends on accuracy in target determination. The objective of this study was to determine which of the following techniques was most accurate and precise in identifying the location for stimulation in STN deep brain stimulation surgery that is most clinically effective: direct targeting, indirect targeting using the positions of the anterior and posterior commissures, or a technique using the red nucleus (RN) as an internal fiducial marker. METHODS: We reviewed 14 patients with Parkinson's disease treated with bilateral STN deep brain stimulation (28 STN targets). Electrode implantation was based on direct and indirect targeting using two-dimensional magnetic resonance imaging with refinement using microelectrode recording. Optimal settings, including the contacts used, were determined during the clinical follow-up. The position of the best contact was defined with postoperative magnetic resonance imaging. This location was compared with the modified direct, indirect, and RN-based targets. The mean distances between the targets and the final position of the optimal contact were calculated. The accuracy and variance of each target were analyzed. RESULTS: The mean position of the best contact was x = 12.12 (standard deviation [SD], 1.45 mm), y = -2.41 (SD, 1.63 mm), and z = -2.39 (SD, 1.49 mm) relative to the midcommissural point. The mean distance between the optimal contact position and the planned target was 3.19 mm (SD, 1.19 mm) using the RN-based method, 3.42 mm (SD, 1.34 mm) using indirect targeting, and 4.66 mm (SD, 1.33 mm) using a modified direct target. The mean distance between the optimal contact and the RN-based target was significantly smaller than the mean distance between the optimal contact and the direct target (post hoc with Tamhane's correction, P < 0.001) but not between the optimal contact and the indirect target. The RN-based target had the smallest variance (F test, P < 0.001), indicating greater precision. CONCLUSION: The use of the RN as an internal fiducial marker for targeting the optimal region of STN stimulation was reliable and closely approximates the position of the electrode contact that provides the optimal clinical results.

Radiosurgery for basal ganglia, internal capsule, and thalamus arteriovenous malformation: clinical outcome.

OBJECTIVE: Radiosurgery is accepted as the first option for treating deep arteriovenous malformations (AVMs), although the clinical outcome in this subgroup of brain AVMs is not well studied. The objective of this study is to review our experience with radiosurgical treatment for these AVMs. METHODS: Between October 1989 and December 2000, 45 patients with deep AVMs (including basal ganglia, internal capsule, and thalamus) underwent stereotactic radiosurgery. Three patients were lost to follow-up and therefore were excluded from this study. Patient characteristics and outcomes were collected and analyzed. The obliteration prediction index and the radiosurgery-based AVM score were calculated and tested. RESULTS: Forty-two patients were followed up for a median of 39 months (range, 25-90 mo; mean, 45.8 mo). The median maximum AVM diameter during the radiosurgery was 1.8 cm (range, 0.9-4.0 cm; mean, 2.07 cm), and the median AVM volume was 2.8 cm(3) (range, 0.2-18.3 cm(3); mean, 4.74 cm(3)). The mean marginal dose was 16.2 Gy (median, 15 Gy), and the median maximum dose was 22.4 Gy (range, 16.6-30 Gy). The AVM cure rate after the first radiosurgical treatment, using angiography- and magnetic resonance imaging-confirmed obliteration, was 61.9%. The predicted obliteration using the obliteration prediction index was 60%. Eight patients developed radiation-induced complications (19%). The deficit was transient in three patients (7.1%) and permanent in five patients (11.9%). The risk of postradiosurgical hemorrhage in this cohort was 9.5% for the first year, 4.7% for the second year, and 0% thereafter. Excellent outcome (obliteration plus no new deficit) was achieved in 70% of the patients in the group with radiosurgery-based AVM score less than 1.5 compared with 40.9% in the group with radiosurgery-based AVM score greater than 1.5% (P = 0.059). CONCLUSION: Radiosurgery for deep AVMs has a satisfactory obliteration rate and acceptable morbidity, considering the risk of hemorrhage without treatment and the risk of morbidity associated with other treatment modalities.

Third ventriculostomy through the lamina terminalis for intracranial pressure monitoring after aneurysm surgery: technical note

OBJECTIVE: A new ventriculostomy technique through the lamina terminalis is described. This technique is applied mainly during aneurysm surgery at the acute stage. METHOD: Thirteen patients were operated on intracranial aneurysms and, during the procedure, had the lamina terminalis fenestrated. A ventricular catheter was inserted into the third ventricule, left in place and connected to an external drainage system for further intracranial pressure (ICP) monitoring and/or cerebrospinal fluid (CSF) drainage. RESULTS: ICP readings and CSF drainage were obtained in all cases. No complication was recorded. CONCLUSION: Third ventriculostomy through the lamina terminalis is a simple and easy technique that can be used as an alternative to conventional ventriculostomy. This procedure can be indicated in cases where the ventricule is not reached by means of another technique, and when the decision to perform ventriculostomy is made at the end of aneurysm surgery

Third ventriculostomy through the lamina terminalis for intracranial pressure monitoring after aneurysm surgery: technical note.

OBJECTIVE: A new ventriculostomy technique through the lamina terminalis is described. This technique is applied mainly during aneurysm surgery at the acute stage. METHOD: Thirteen patients were operated on intracranial aneurysms and, during the procedure, had the lamina terminalis fenestrated. A ventricular catheter was inserted into the third ventricule, left in place and connected to an external drainage system for further intracranial pressure (ICP) monitoring and/or cerebrospinal fluid (CSF) drainage. RESULTS: ICP readings and CSF drainage were obtained in all cases. No complication was recorded. CONCLUSION: Third ventriculostomy through the lamina terminalis is a simple and easy technique that can be used as an alternative to conventional ventriculostomy. This procedure can be indicated in cases where the ventricule is not reached by means of another technique, and when the decision to perform ventriculostomy is made at the end of aneurysm surgery.

Ataques isquêmicos transitórios em pacientes com síndrome da veia cava superior / Transient ischemic attacks in apatient with superio vena cava obstruction: case report

A síndrome da veia cava superior (SVCS) é condiçao relativamente rara. Relatamos o caso de um paciente de 42 anos, masculino, hipertenso há 15 anos, que evoluiu com dor cervical e torácica há um ano, sendo evidenciada oclusao de 95 por cento da coronária direita. Submetido a angioplastia, porém com persistência de dor torácica. Posteriormente evoluiu com episódios recorrentes de hemiplegia à direita associados a crises hipertensivas, que melhoravam com medicamentos anti-hipertensivos. Pela presença de coloraçao vinhosa na face e acentuaçao durante os períodos de ataques isquêmicos transitórios, foi feita a suspeita diagnóstica de provável acometimento do sistema de drenagem venosa, confirmada à venografia pelo achado de dilataçao da veia jugular direita e imagem de estreitamento importante na junçao com a veia cava superior. Em conclusao, nao foi possível definir com certeza a relaçao entre as duas patologias no caso aqui apresentado, porém chamou a atençao a melhora dos sintomas neurológicos após o controle da SVCS com o tratamento instituído.