Basilar invagination: a study based on 190 surgically treated patients

1998 ◽  
Vol 88 (6) ◽  
pp. 962-968 ◽  
Author(s):  
Atul Goel ◽  
Mohinish Bhatjiwale ◽  
Ketan Desai

Object. The authors analyzed the cases of 190 patients with basilar invagination that was diagnosed on the basis of criteria laid down in 1939 by Chamberlain to assess the appropriate surgical procedure. Methods. Depending on the association with Chiari malformation, the anomaly of basilar invagination was classified into two groups. Eighty-eight patients who had basilar invagination but no associated Chiari malformation were assigned to Group I; the remainder of the patients, who had both basilar invagination and Chiari malformation, were assigned to Group II. The principal pathological characteristic was observed to be direct brainstem compression due to odontoid process indentation in Group I and a reduction in posterior cranial fossa volume in Group II. Conclusions. Despite the anterior concavity of the brainstem in both groups, transoral surgery was the most suitable procedure for those patients in Group I and decompression of the foramen magnum was found to be appropriate for patients in Group II. After surgical decompression, a fixation procedure was found to be necessary in most Group I cases, but only in a small minority of Group II cases.

1998 ◽  
Vol 4 (4) ◽  
pp. E1 ◽  
Author(s):  
Atul Goel ◽  
Mohinish Bhatjiwale ◽  
Ketan Desai

Object The authors analyzed the cases of 190 patients with basilar invagination that was diagnosed on the basis of criteria laid down in 1939 by Chamberlain to assess the appropriate surgical procedure. Methods Depending on the association with Chiari malformation, the anomaly of basilar invagination was classified into two groups. Eighty-eight patients who had basilar invagination but no associated Chiari malformation were assigned to Group I; the remainder of the patients, who had both basilar invagination and Chiari malformation, were assigned to Group II. The principal pathological characteristic was observed to be direct brainstem compression due to odontoid process indentation in Group I and a reduction in posterior cranial fossa volume in Group II. Conclusions Despite the anterior concavity of the brainstem in both groups, transoral surgery was the most suitable procedure for those patients in Group I and decompression of the foramen magnum was found to be appropriate for patients in Group II. After surgical decompression, a fixation procedure was found to be necessary in most Group I cases, but only in a small minority of Group II cases.


2004 ◽  
Vol 1 (3) ◽  
pp. 281-286 ◽  
Author(s):  
Atul Goel

Object. The author discusses the successful preliminary experience of treating selected cases of basilar invagination by performing atlantoaxial joint distraction, reduction of the basilar invagination, and direct lateral mass atlantoaxial plate/screw fixation. Methods. Twenty-two patients with basilar invagination—in which the odontoid process invaginated into the foramen magnum and the tip of the odontoid process was above the Chamberlain, McRae foramen magnum, and Wackenheim clival lines—were selected to undergo surgery. In all patients fixed atlantoaxial dislocations were documented. The 16 male and six female patients ranged in age from 8 to 50 years. A history of trauma prior to the onset of symptoms was documented in 17 patients. Following surgery, the author observed minimal-to-significant reduction of basilar invagination and alteration in other craniospinal parameters resulting in restoration of alignment of the tip of the odontoid process and the clivus and the entire craniovertebral junction in all patients. In addition to neurological and radiological improvement, preoperative symptoms of torticollis resolved significantly in all patients. The minimum follow-up period was 12 months and the mean was 28 months. Conclusions. Joint distraction and firm lateral mass fixation in selected cases of basilar invagination is a reasonable surgical treatment for reducing the basilar invagination, restoring craniospinal alignment, and establishing fixation of the atlantoaxial joint.


1998 ◽  
Vol 89 (3) ◽  
pp. 359-365 ◽  
Author(s):  
Andres M. Lozano ◽  
Graham Vanderlinden ◽  
Robert Bachoo ◽  
Peter Rothbart

Object. The authors evaluated the effectiveness of microsurgical C-2 ganglionectomy in 39 patients with medically refractory chronic occipital pain. In this procedure the neurons transmitting sensory inputs from the occiput are removed and, unlike peripheral nerve ablation, axonal regeneration is not possible. Methods. The patients in this series had symptoms for 1 to 43 years. In 22 patients the occipital pain was caused by trauma; in 17 patients the pain was spontaneous. Pain relief failed in 17 patients who had undergone a previous occipital neurectomy or C-2 rhizolysis. Twenty-three patients experienced pain that was described as shocklike, electric, shooting, jabbing, stabbing, sharp, or exploding (Group I). Eight patients described their pain as dull, pounding, aching, throbbing, or pressurelike (Group II). The patients underwent unilateral or bilateral C-2 open microsurgical ganglionectomies. The postoperative follow-up period ranged from 19 to 48 months. Nineteen patients experienced an excellent result (> 90% reduction in pain). Pain caused by trauma or that described using Group I terms responded best to ganglionectomy (80% good or excellent response). In contrast, the majority of the patients with nontraumatic pain or those described using Group II descriptors did not achieve favorable results. Conclusions. The authors conclude that: 1) patients who suffer from chronic occipital pain after having sustained injury obtain worthwhile benefit from microsurgical C-2 ganglionectomy; 2) patients suffering from migraine, tension, and vascular headaches involving the occipital area are most often not helped by this operation; and 3) terms such as “shock,” “electric,” “shooting,” “jabbing,” and “sharp” used to describe occipital pain predict a favorable pain outcome following a C-2 ganglionectomy.


1999 ◽  
Vol 90 (3) ◽  
pp. 448-454 ◽  
Author(s):  
Giuseppe Cinalli ◽  
Christian Sainte-Rose ◽  
Paul Chumas ◽  
Michel Zerah ◽  
Francis Brunelle ◽  
...  

Object. The goal of this study was to analyze the types of failure and long-term efficacy of third ventriculostomy in children.Methods. The authors retrospectively analyzed clinical data obtained in 213 children affected by obstructive triventricular hydrocephalus who were treated by third ventriculostomy between 1973 and 1997. There were 120 boys and 93 girls. The causes of the hydrocephalus included: aqueductal stenosis in 126 cases; toxoplasmosis in 23 cases, pineal, mesencephalic, or tectal tumor in 42 cases; and other causes in 22 cases. In 94 cases, the procedure was performed using ventriculographic guidance (Group I) and in 119 cases by using endoscopic guidance (Group II). In 19 cases (12 in Group I and seven in Group II) failure was related to the surgical technique. Three deaths related to the technique were observed in Group I. For the remaining patients, Kaplan—Meier survival analysis showed a functioning third ventriculostomy rate of 72% at 6 years with a mean follow-up period of 45.5 months (range 4 days–17 years). No significant differences were found during long-term follow up between the two groups. In Group I, a significantly higher failure rate was seen in children younger than 6 months of age, but this difference was not observed in Group II. Thirty-eight patients required reoperation (21 in Group I and 17 in Group II) because of persistent or recurrent intracranial hypertension. In 29 patients shunt placement was necessary. In nine patients in whom there was radiologically confirmed obstruction of the stoma, the third ventriculostomy was repeated; this was successful in seven cases. Cine phase-contrast (PC) magnetic resonance (MR) imaging studies were performed in 15 patients in Group I at least 10 years after they had undergone third ventriculostomy (range 10–17 years, median 14.3 years); this confirmed long-term patency of the stoma in all cases.Conclusions. Third ventriculostomy effectively controls obstructive triventricular hydrocephalus in more than 70% of children and should be preferred to placement of extracranial cerebrospinal shunts in this group of patients. When performed using ventriculographic guidance, the technique has a higher mortality rate and a higher failure rate in children younger than 6 months of age and is, therefore, no longer preferred. When third ventriculostomy is performed using endoscopic guidance, the same long-term results are achieved in children younger than 6 months of age as in older children and, thus, patient age should no longer be considered as a contraindication to using the technique. Delayed failures are usually secondary to obstruction of the stoma and often can be managed by repeating the procedure. Midline sagittal T2-weighted MR imaging sequences combined with cine PC MR imaging flow measurements provide a reliable tool for diagnosis of aqueductal stenosis and for ascertaining the patency of the stoma during follow-up evaluation.


1996 ◽  
Vol 85 (5) ◽  
pp. 923-928 ◽  
Author(s):  
Carlos A. David ◽  
Ricardo Prado ◽  
W. Dalton Dietrich

✓ Temporary arterial occlusion has been routinely used as an adjunct in intracranial aneurysm surgery. This has commonly been performed using a protocol of multiple short periods of occlusion alternating with periods of restoration of normal circulation. Recently, the logical basis of this method has come under scrutiny. There is extensive experimental evidence to suggest that repetitive, brief periods of global ischemia may cause more severe cerebral injury than an equivalent single period of global ischemia. Only recently has this issue begun to be addressed with regard to focal ischemia. Hence, despite the common use of temporary clipping, little experimental data are available regarding the ischemic consequences of temporary arterial occlusion with periods of reperfusion versus uninterrupted temporary occlusion. To investigate this issue, a protocol of occlusion/reperfusion that simulates the temporal profile that occurs during surgery was performed in a rat model of focal ischemia. Sixteen anesthetized Sprague—Dawley rats were divided into two groups. The animals in Group I underwent 60 minutes of uninterrupted middle cerebral artery occlusion and the animals in Group II were subjected to six separate 10-minute occlusion periods with 5 minutes of reperfusion between occlusions. Histopathological analysis was performed 72 hours postischemia. Group I had significantly increased mean infarction volumes (50.0 ± 12.1 mm3) compared to Group II (8.7 ± 3.1 mm3) (p = 0.008). Injuries in Group I occurred in both the cortex and striatum, whereas Group II showed only striatal injuries. Furthermore, the extent of the injuries in Group II was less severe, characterized by ischemic neuronal injury rather than frank infarction. The results indicate that intermittent reperfusion is neuroprotective during temporary focal ischemia and support the hypothesis that intermittent reperfusion is beneficial if temporary clipping is required during aneurysm repair.


2003 ◽  
Vol 98 (1) ◽  
pp. 43-49 ◽  
Author(s):  
R. Shane Tubbs ◽  
John C. Wellons ◽  
Jeffrey P. Blount ◽  
Paul A. Grabb ◽  
W. Jerry Oakes

Object. The quantitative analysis of odontoid process angulation has had scant attention in the Chiari I malformation population. In this study the authors sought to elucidate the correlation between posterior angulation of the odontoid process and patients with Chiari I malformation. Methods. Magnetic resonance images of the craniocervical junction obtained in 100 children with Chiari I malformation and in 50 children with normal intracranial anatomy (controls) were analyzed. Specific attention was focused on measuring the degree of angulation of the odontoid process and assigning a score to the various degrees. Postoperative outcome following posterior cranial fossa decompression was then correlated to grades of angulation. Other measurements included midsagittal lengths of the foramen magnum and basiocciput, the authors' institutions' previously documented pB—C2 line (a line drawn perpendicular to one drawn between the basion and the posterior aspect of the C-2 body), level of the obex from a midpoint of the McRae line, and the extent of tonsillar herniation. Higher grades of odontoid angulation (retroflexion) were found to be more frequently associated with syringomyelia and particularly holocord syringes. Higher grades of angulation were more common in female patients and were often found to have obices that were caudally displaced greater than three standard deviations below normal. Conclusions. These results not only confirm prior reports of an increased incidence of a retroflexed odontoid process in Chiari I malformation but quantitatively define grades of inclination. Grades of angulation were not found to correlate with postoperative outcome. It is the authors' hopes that these data add to our current limited understanding of the mechanisms involved in hindbrain herniation.


1988 ◽  
Vol 69 (6) ◽  
pp. 869-876 ◽  
Author(s):  
Patrick Ravussin ◽  
Mounir Abou-Madi ◽  
David Archer ◽  
René Chiolero ◽  
James Freeman ◽  
...  

✓ In view of the current concern that rapid infusion of mannitol might initially aggravate intracranial hypertension, the effects of a mannitol infusion on lumbar cerebrospinal fluid pressure (CSFP) were investigated in 49 patients. The studies were performed when the patients were under general anesthesia prior to elective craniotomy for tumor resection or intracerebral aneurysm clipping. The patients were divided into two groups: 24 patients with normal CSFP (Group I, mean CSFP 10.5 mm Hg) and 25 with raised CSFP (Group II, mean CSFP 20.8 mm Hg). Measurements of CSFP, mean arterial blood pressure (MABP), and central venous pressure (CVP) were made serially during and after the infusion of 20% mannitol (1 gm ⋅ kg−1 infused over a 10-minute interval). In both groups, mannitol infusion provoked a fall in MABP and an increase in CVP. An immediate increase in CSFP was observed in Group II, whereas CSFP increased transiently but significantly in Group I. Analysis of the arterial and venous driving pressures which contribute to CSFP suggests that the transient increase in CSFP after mannitol in Group I was partly due to the increase in CVP. The presence of intracranial hypertension may thus alter the CSFP response to arterial and venous pressure changes. Cerebral blood volume (CBV) was measured in dogs in a separate study analogous to the human protocol. The CBV increased approximately 25% over control values after mannitol infusion both in the normal animals and in those with CSFP raised by an epidural balloon. The response of the CSFP to mannitol infusion differed between both groups in a fashion similar to that observed in the human subjects. Thus, differences in CBV changes after mannitol do not account for the difference in CSFP response between normal subjects and those with raised CSFP.


2001 ◽  
Vol 95 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Yoichi Katayama ◽  
Masahiko Kasai ◽  
Hideki Oshima ◽  
Chikashi Fukaya ◽  
Takamitsu Yamamoto ◽  
...  

Object. A blinded evaluation of the effects of subthalamic nucleus (STN) stimulation was performed in levodopaintolerant patients with Parkinson disease (PD). These patients (Group I, seven patients) were moderately or severely disabled (Hoehn and Yahr Stages III–V during the off period), but were receiving only a small dose of medication (levodopa-equivalent dose [LED] 0–400 mg/day) because they suffered unbearable side effects. The results were analyzed in comparison with those obtained in patients with advanced PD (Group II, seven patients) who were severely disabled (Hoehn and Yahr Stages IV and V during the off period), but were treated with a large dose of medication (500–990 mg/day). Methods. The patients were evaluated twice at 6 to 8 months after surgery. To determine the actual benefits afforded by STN stimulation to their overall daily activities, the patients were maintained on their medication regimen with optimal doses and schedules. Stimulation was turned off overnight for at least 12 hours. It was turned on in the morning (or remained turned off), and each patient's best and worst scores on the Unified Parkinson's Disease Rating Scale during waking daytime activity were recorded as on- and off-period scores, respectively. The order of assessment with respect to whether stimulation was occurring was determined randomly. The STN stimulation markedly improved daily activity and total motor scores in Group I patients. The percentage time of immobility (Hoehn and Yahr Stages IV and V) became 0% in patients who were intermittently immobile while not receiving stimulation. Improvements were demonstrated in tremor, rigidity, akinesia, and gait subscores. The STN stimulation produced less marked but still noticeable improvements in the daily activity and total motor scores in Group II patients. The percentage time of immobility as well as the LED was reduced in patients who displayed intermittent immobility with pronounced motor fluctuations while not receiving stimulation. Improvements were demonstrated in tremor, rigidity, and dyskinesia subscores in these patients. In contrast, STN stimulation did not improve the overall daily activities at all in patients who had become unresponsive to a tolerable dose of levodopa and were continuously immobile, even though these patients' tremor and rigidity subscores were still improved by stimulation. Conclusions. Consistent with earlier findings, the great benefit of STN stimulation in levodopa-intolerant patients is that STN stimulation can reduce the level of required levodopa medication. This suggests that STN stimulation could be a therapeutic option for patients with less-advanced PD by allowing levodopa medication to be maintained at as low a dose as possible, and to prevent adverse reactions to the continued use of large-dose levodopa.


1992 ◽  
Vol 76 (6) ◽  
pp. 1029-1031 ◽  
Author(s):  
Edward C. Benzel ◽  
Jay P. Mashburn ◽  
Steven Conrad ◽  
Denise Modling

✓ The absence of spontaneous respirations at a PaCO2 of 60 mm Hg or above has traditionally been accepted as the respiratory criteria for the determination of brain death. The testing of patients for the presence or absence of apnea has been complicated because the rate of PaCO2 elevation may vary substantially from patient to patient, and a nonlinear relationship exists between the rate of PaCO2 increase and the duration of apnea. In an attempt to refine the apnea test and to further elucidate the physiology of hypercapnia in humans, 11 patients who met all but the respiratory criteria for brain death were evaluated using a modification of a previously utilized apnea testing protocol. All patients were brought to a PaCO2 of 40 mm Hg or above prior to the apnea test. Baseline PaCO2 ranged from 40 to 45 mm Hg in six patients (Group I) and from 46 to 51 mm Hg in five patients (Group II). The mean rate of PaCO2 increase was 5.1 ± 1.4 mm Hg/min in Group I and 6.7 ± 3.1 mm Hg/min in Group II. No problems with cardiovascular instability or hypoxia were encountered during testing in this series. This refinement of the apnea test allows for a streamlined and safe approach to brain death detection.


2000 ◽  
Vol 93 (2) ◽  
pp. 305-314 ◽  
Author(s):  
Susan A. Stern ◽  
Brian J. Zink ◽  
Michelle Mertz ◽  
Xu Wang ◽  
Steven C. Dronen

Object. Studies of isolated uncontrolled hemorrhage have indicated that initial limited resuscitation improves survival. Limited resuscitation has not been studied in combined traumatic brain injury and uncontrolled hemorrhage. In this study the authors evaluated the effects of limited resuscitation on outcome in combined fluid-percussion injury (FPI) and uncontrolled hemorrhage.Methods. Twenty-four swine weighing 17 to 24 kg each underwent FPI (3 atm) and hemorrhage to a mean arterial pressure (MAP) of 30 mm Hg in the presence of a 4-mm aortic tear. Group I (nine animals) was initially resuscitated to a goal MAP of 60 mm Hg; Group II (nine animals) was resuscitated to a goal MAP of 80 mm Hg; and Group III (control; six animals) was not resuscitated. After 60 minutes, the aortic hemorrhage was controlled and the animals were resuscitated to baseline physiological parameters and observed for 150 minutes.Mortality rates were 11%, 50%, and 100% for Groups I, II, and III, respectively (Fisher's exact test; p = 0.002). The total hemorrhage volume was greater in Group II (69 ± 32 ml/kg), as compared with Group I (41 ± 18 ml/kg) and Group III (37 ± 3 ml/kg) according to analysis of variance (p < 0.05). In surviving animals, cerebral perfusion pressure, cerebral blood flow (CBF), cerebral venous O2 saturation (ScvO2), and cerebral metabolic rate of O2 did not differ among groups. Although CBF was approximately 50% of baseline during the period of limited resuscitation in Group I, ScvO2 remained greater than 60%, and arteriovenous O2 differences remained within normal limits.Conclusions. In this model of FPI and uncontrolled hemorrhage, early aggressive resuscitation, which is currently recommended, resulted in increased hemorrhage and failure to optimize cerebrovascular parameters. In addition, a 60-minute period of moderate hypotension (MAP = 60 mm Hg) was well tolerated and did not compromise cerebrovascular hemodynamics, as evidenced by physiological parameters that remained within the limits of cerebral autoregulation.


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