This study evaluated preliminary findings on the efficacy of polyethylene glycol (PEG) hydrogel dural sealant capping for the prevention of cerebrospinal fluid (CSF) leakage and pneumocephalus during deep brain stimulation (DBS) surgery in the semisupine position. Group A consisted of 5 patients who underwent bilateral subthalamic nucleus (STN)-DBS surgery without PEG hydrogel dural sealant capping. Group B consisted of 5 patients who underwent bilateral STN-DBS surgery with PEG hydrogel dural sealant capping. The immediate postoperative intracranial air volume was measured in all patients and compared between the 2 groups using the Welch test. Adverse effects were also examined in both groups. The intracranial air volume in Group A was 32.3 ± 12.3 ml (range 19.1-42.5 ml), whereas that in Group B was 1.3 ± 1.5 ml (range 0.0-3.5 ml), showing a significant difference (p < 0.005). No hemorrhage or venous air embolisms were observed in either group. The effect of brain shift was discriminated by STN recordings in Group B. These preliminary findings indicate that PEG hydrogel dural sealant capping may reduce adverse effects related to CSF leakage and brain shift during DBS surgery.
Our previous studies showed differences in striatal D2 receptor functional activity between two different rat parkinsonian models, with lesions induced by 6-hydroxydopamine injection in the striatum and in the medial forebrain bundle (MFB) at both early (4 weeks) and later (6 months) stages after lesioning. The present study compared behavioral changes, including rotational movements induced by methamphetamine and bromocriptine, and the stepping test, in both models at both stages. No differences in behavioral performance were observed between the early and later stages in both striatal and MFB lesion models, whereas simultaneous D2 receptor study showed dynamic change in D2 receptors in MFB lesion rats. Behavioral characteristics might be controlled by comprehensive effects of the whole dopaminergic system, instead of variation in a few parameters of the dopaminergic system. More behavioral tests of different mechanisms with simultaneous molecular studies are needed for evaluation of parkinsonian animal models and the efficacy of treatments.
Patients suffering from epilepsy need long-term medication. However, after the epilepsy is completely under control, the recurrence rate is high once the drug dose is reduced gradually. The present study investigated the possible correlation between the changes shown by ambulatory electroencephalography (EEG) and epilepsy recurrence after medication withdrawal, and assessed the value of ambulatory EEG findings in predicting the recurrence of epilepsy after medication withdrawal, in 265 patients from Southern China followed up for 5 years. Anticonvulsants were withdrawn until onset had been controlled thoroughly for over 3 years and ambulatory EEG detected no abnormalities. Ambulatory EEG was performed at least once per year, and findings at the first visit, during treatment, and before and after medication withdrawal were compared and analyzed. There were 47 patients with recurrent epilepsy in this study. Patients with normal ambulatory EEG findings at the first visit and during treatment had lower recurrence rate (about 8.1%) compared to patients with epileptic waves (25.0%), and patients with focal epileptic waves in the temporal, occipital, frontal, and parietal lobes, or in multiple areas was even higher. Patients with epileptic waves also showed higher clinical recurrence rate during the follow-up period. Abnormal ambulatory EEG findings are an important indicator of epileptic recurrence, and is of great value in predicting the recurrence of epilepsy after medication withdrawal.
Fibrin glue-soaked gelatin sponge (FGGS) has been used for tissue sealing in neurosurgical practice, but too rapid clotting of fibrin glue occasionally prevents good fixation of FGGS. Dilution of thrombin may provide adequate manipulation time between mixing fibrinogen and thrombin on gelatin sponge and application into the tissue defects. The present study characterized the effect of thrombin dilution on the adhesion strength of FGGS and retrospectively assessed the clinical usage of the dilution for filling dead space or sealing arachnoid defect in 255 cases who underwent transsphenoidal surgery for the last 66 months. FGGS was prepared using three different concentrations of thrombin: 250 (standard), 50 (1:5 dilution), and 25 (1:10 dilution) units/ml, and incubated for three different periods (5, 20, and 60 seconds). FGGSs were applied over two adjacently positioned porcine skins placed on two metallic plates. The adhesion strength was evaluated by measuring maximum tensile strength during pulling out the sliding plate at a constant rate of displacement. The maximum adhesion strength was greater for FGGS with 1:10 diluted thrombin solution than for FGGS prepared with higher concentrations (p < 0.05). Adhesion strength did not decay for 20 seconds after the mixture. Only four of 255 cases (1.6%) required second reconstruction of sella floor due to the cerebrospinal fluid leakage. FGGS prepared with diluted thrombin solution can provide adequate adhesion strength for clinical use.
Head fixation devices are commonly used in neurosurgical procedures and are considered essential tools for microneurosurgery. The Sugita multipurpose head frame system is one of such systems and has been used for more than 30 years worldwide. It is important to understand how to fix a patient's head with head-pins safely, because there are no numerical parameters for head-pin screwing in the Sugita frame. Recently, the Dispo-pin has been available for disposable use as a head-pin in the Sugita frame. In contrast to the conventional head-pin, the tip of the Dispo-pin is separable from the body. Although their appearance is similar, the torque for adequate fixation is different. The relationships between torque and vertical force were analyzed. The torque of the head-pin was linearly correlated with vertical force for both types of head-pin. Different conditions caused different torque increase against a specific increase of vertical force with the conventional head-pin. In contrast, torque increase against a specific increase of vertical force with the Dispo-pin was the same regardless of the situation. The torque originates from friction between the scalp and tip of the conventional head-pin. As friction is different for each patient's condition, the torque at this part is different. The friction between the tip and body of the Dispo-pin is lower than that between the scalp and tip of the head-pin. In consequence, the torque generated from the tip of the Dispo-pin is the same in each situation. It is important to understand the difference between the Dispo-pin and conventional head-pin.
This retrospective study of medical records, surgical protocols, patient observation cards, and imaging files of 100 patients treated for subdural hematoma analyzed the type of hematoma, patient age and sex, operative technique, neurological status, cause of injury, duration of hospital stay, mortality rate, and the number of and reasons for reoperations to determine the effects on treatment outcomes. The time between the head injury and onset of neurological symptoms was analyzed versus the type of hematoma determined from computed tomography (CT) scans. Acute hematomas accounted for 38% of the cases, with subacute hematomas representing 20%, and chronic ones accounting for 42%. In trauma patients, the mean time interval between the injury and onset of neurological symptoms was 0.38 days for acute hematomas, 13.8 days for subacute hematomas, and 23.75 days for chronic hematomas. Repeat surgery was carried out in 26% of the cases. Improvement was obtained in 44% of cases, deterioration in 20%, and no change in neurological status in 36%. Timing of the operations was between 15:00 and 23:00 in 45%, between 23:00 and 7:00 in 33%, and between 7:00 and 15:00 in 22%. The classification of hematomas based on CT presentation corresponds to the classification based on the time elapsed between injury and onset of symptoms, and appears to be appropriate and useful in everyday practice. No preceding injury was identified in 31.6% of acute hematomas, 50% of subacute hematomas, and 61.9% of chronic hematomas. Analysis of reoperations indicates that trepanation may be superior to craniotomy as primary surgery for subacute and chronic hematomas. Subdural hematoma surgeries take place at all times of the day, with most carried out outside the usual working hours.
An early 60s-year-old man suffered reversible dysfunction of the blood-brain barrier (BBB) induced by repeated injection of contrast medium during coil embolization of intracranial unruptured aneurysm. He presented with convulsion during coil embolization, and neurological symptoms of aphasia and right hemiparesis continued for 5 days, and then improved completely. All transient radiological abnormalities were limited to the territory of the left internal carotid artery, where contrast medium was injected repeatedly. Repeated computed tomography, magnetic resonance imaging, single-photon emission computed tomography, and cerebrospinal fluid test findings indicated that temporary dysfunction of the BBB might have occurred. Dysfunction of the BBB in the anterior circulation induced by contrast medium is rare. Tolerance to toxicity of contrast medium may depend on the individual patient, and repeated injection of contrast medium may cause dysfunction of the BBB, leading to toxic dysfunction directly in the brain.
Microvascular decompression (MVD) is now the most feasible method of treatment for trigeminal neuralgia (TN). The recurrence of symptoms is rarely encountered postoperatively. A female patient with typical right V3 distribution TN had been successfully treated by MVD at age 56 years by transposing the offending superior cerebellar artery, and she became completely pain-free postoperatively without sequelae. Twenty years after the first MVD, pain recurred on the right V2 distribution at age 76 years and she was operated on a second time to resolve the pain. Re-exploration surgery revealed that the trigeminal nerve was compressed mediocranially by the anterior inferior and posterior inferior cerebellar artery complex, which had not been close to the neural structure during the first surgery. The artery complex was successfully transpositioned to decompress the root exit zone (REZ) of the nerve and she became pain-free again. Although various causal factors likely contribute to recurrence of TN, the present case of recompression of a REZ occurred due to a newly developed offending artery which caused TN a long time after the first surgery.
A 34-year-old female presented with trigeminal neuralgia caused by a venous malformation in the right cerebello-pontine region. Computed tomography and magnetic resonance imaging demonstrated the abnormal draining veins from the venous malformation. The dilated vessels extended around the trigeminal nerve and compressed the root entry zone. Microvascular decompression (MVD) was performed, and her trigeminal neuralgia was completely relieved without neurological deficits. The offending vessel in most cases of trigeminal neuralgia is an arterial branch. Veins may also be associated with trigeminal neuralgia. The present rare case shows that MVD may be useful for the treatment of trigeminal neuralgia associated with venous malformation. Good outcome depends on decompression of the root entry zone without injury to the vessel. Surgical injury in this region can cause severe neurological deficits. Several treatment options should be prepared for the surgery, such as MVD or rhizotomy.
Expanded polytetrafluoroethylene (ePTFE) porous material (GORE® PRECLUDE® Dura Substitute) does not degenerate or deteriorate in vivo, and is currently used as artificial dura mater. This material does not adhere well to the surrounding tissues, but cerebrospinal fluid leakage along the suture line has been observed in several cases. We describe a case of craniotomy for tumor resection performed 14 years after dural repair with ePTFE sheet. Histological examination of the ePTFE sheet revealed that the sheet was structurally intact, with no evidence of tissue adhesion or cellular infiltration. However, collagen deposition was observed around the suture thread. When the suture thread was removed the collagen was also removed, and the original needle hole appeared again. No significant changes were observed in the features of the ePTFE sheet even 14 years postoperatively. The formation of fibrous tissue around the needle hole was important in preventing cerebrospinal fluid leakage.
Extensive multilobar cortical dysplasias occasionally occur in children and can induce seizure onset in early infancy, causing severe epileptic encephalopathy. Surgical interventions in early infancy, such as disconnection of large parts of the brain, are challenging because of the degree of invasiveness and carry greater risks in infants compared with older children. Here we report the successful treatment of intractable epilepsy with multilobar cortical dysplasias in the posterior cortex by posterior disconnection in three infants (age 3 months). The patients showed good postoperative recovery and exhibited excellent seizure control at follow-up evaluation within a year after surgery. Developmental catch-up was also achieved and no early complications have been detected to date. Use of the posterior disconnection technique for early-stage extensive multilobar cortical dysplasias can result in good seizure control and developmental progress with little perioperative morbidity. However, the efficacy of this surgical technique needs to be verified with long-term follow up after surgery.
For surgeons operating in the standing position, the manipulation of foot switches involves shifting of the weight to the pivoting leg and the possible loss of contact between the switch and the foot. We solved this problem by changing the position of the switch that operates bipolar forceps. Our novel device is made of aluminum plates. The base plate features a foot strap and a height-adjustable overhang over the switch-operating foot. A commercially-available disc type foot switch is attached to the underside of the overhang in upside-down position, so the switch is operable with the toe. To turn on the switch, the toe is flexed dorsally to push the switch pedal, so the action is limited to the part distal to the metatarsophalangeal joints. Our switch was used in more than 100 consecutive microsurgeries performed by surgeons operating in the standing position. The switch manipulation required no shifting of the weight and was easier and quicker than manipulation of conventionally-placed switches. The surgeons were able to change the foot position freely with the modified switch, thereby avoiding loss of contact with the switch. The modified switch placement reduced physical fatigue in the lower extremities, annoyance related to the manipulation of conventionally-placed switches, and increased the comfort of surgeons operating in the standing position.
In cases of severe uncontrollable brain swelling, simple skin closure often increases intracranial pressure. This study examined the efficacy of a new technique of decompressive skinplasty to decrease intracranial pressure following decompressive craniectomy in cases of severe traumatic brain injury with uncontrollable brain swelling. In our technique, we use artificial dermis to avoid elevation of intracranial pressure. After performing decompressive craniectomy and duraplasty with artificial dura, decompressive skinplasty with artificial dermis was performed in 5 patients for whom simple skin closure caused the intracranial pressure to elevate under intracranial pressure monitoring. Artificial dermis was grafted onto the region to cover the skin defect and sutured to the skin with 4-0 nylon sutures. Two weeks after surgery, the silicone layer of the artificial dermis was removed and ointment treatment was continued until complete epithelialization was achieved. In all cases, decompressive skinplasty contributed dramatically to decreasing the intracranial pressure in patients with uncontrollable brain swelling. The technique of decompressive skinplasty with artificial dermis contributed to dramatically decreasing the intracranial pressure. More cases are required to investigate the indications for this technique.
Quadrilateral dural window is opened with a conventional incision design, such as a pair of diagonal lines or a rectangular shape, but the total cutting length is not the shortest possible. Shorter incision length will have a lower risk of dysraphia associated with cerebrospinal fluid (CSF) liquorrhea or related CSF infection. We propose a new and effective dural incision design with the shortest cutting length for quadrilateral dural openings. We investigated the design of the dural incision using a simple planar geometrical figure. We discovered the shortest network design to connect the four vertices of the quadrilateral. The shortest network design was formed of five line segments with two three-pronged interconnections (TPIs) with the same angle of 2π/3 between any two lines (2π/3-TPI). In practice, first we must draw a quadrilateral W horizontally then add two equilateral triangles outside W. Using a 2π/3-bent wire, the 2π/3-TPIs are traced on the path connecting the outward vertices of the equilateral triangles. Using this method, we can reduce the incision length by 10% from conventional designs using a pair of diagonal lines.
A method to enhance the withstanding pressure of fibrin sealant in gasket-seal closure to prevent cerebrospinal fluid (CSF) leakage after extended transsphenoidal surgery (ETSS) was investigated by adjusting the mixing ratio of the components. A plastic chamber (200 ml) was constructed with a lid made of hydroxyapatite with a hole 10 mm in diameter. The chamber could be pressurized via an opening in the side wall. The hole in the hydroxyapatite lid was covered with a Gore-Tex sheet, 15 mm in diameter. The margin of the sheet was free. Solutions A (fibrinogen 80 mg/ml) and B (thrombin 250 units/ml) of fibrin sealant were mixed in volume ratios of 1:1, 2:1, and 5:1, and applied to the Gore-Tex sheet, then water was introduced to cover the fibrin sealant. The pressure was measured at which air leakage occurred from the side of the Gore-Tex sheet. The pressure values for A/B ratios of 1:1, 2:1, and 5:1 were 117 ± 23.8 mmH2O (mean ± standard error) (n = 5), 234 ± 38.8 mmH2O (n = 5), and 345 ± 36.4 mmH2O (n = 5), respectively, in the acute phase (5 minutes after application of fibrin sealant). Pressures were increased after 24 hours, and that for 5:1 was the highest (373 ± 40.4 mmH2O, n = 5). The use of devices such as syringes specially designed to mix solutions A and B in the ratio of 5:1 can easily enhance the preventive effect of fibrin sealant against CSF leakage in ETSS.