Image registration strategy of T(1)-weighted and FIESTA MRI sequences in trigeminal neuralgia gamma knife radiosurgery

BACKGROUND/AIMS

In Gamma Knife radiosurgery, T(1) MRI is most commonly used and is generally sufficient for targeting the trigeminal nerve. For patients whose trigeminal nerves are unclear on T(1) MRI, FIESTA MRI supplements anatomical structure visualization and may improve trigeminal nerve delineation. The purpose of this study was to develop a registration strategy for T(1) and FIESTA MRIs.

METHODS

We conducted a retrospective study on 54 trigeminal neuralgia patients. All patients were scanned with T(1) and FIESTA MRIs. We evaluated 4 methods of registration: automatic image definition, superior-slice definition, middle-slice definition and inferior-slice definition. Target discrepancies were measured by deviations from an intracranial landmark on T(1) and FIESTA MR images.

RESULTS

The overall range in registration error was 0.10-5.19 mm using superior-, 0.10-1.56 mm using middle- and 0.14-2.89 mm using inferior-slice definition. Registration error >2 mm was observed in 11% of the patients using superior-, 4% using middle- and 7% using inferior-slice FIESTA MRI definition.

CONCLUSIONS

Among patients for whom FIESTA and T(1) MRI are used, registration based on middle-slice definition reduces registration error and improves targeting of the trigeminal nerve.

Microvascular Decompression vs. Gamma Knife Radiosurgery for Typical Trigeminal Neuralgia: Preliminary Findings

BACKGROUND

Patients with typical trigeminal neuralgia were treated by one neurosurgeon with either microvascular decompression (MVD) or Gamma Knife radiosurgery (GKRS) and were prospectively evaluated with a uniform protocol.

METHOD

GKRS was done with 75 Gy maximum to the cisternal trigeminal nerve near the pons. MVD was done without cauterizing or cutting the trigeminal nerve.

RESULTS

Twenty-four patients were treated with MVD and 61 with GKRS. Complete pain relief (no pain no medicines) occurred at 12 and 18 months in 68 and 68% of patients treated with MVD and 58 and 24% with GKRS (p = 0.089), and >or=90% pain relief (with or without medicine) at 12 and 18 months in 90 and 78% with MVD and 75 and 48% with GKRS (p = 0.171). There were no permanent complications.

CONCLUSION

Although many trigeminal neuralgia patients treated with either MVD or GKRS have pain relief, MVD is more likely than GKRS to result in complete pain relief.

Use of simulated annealing for optimization of alignment parameters in limited MRI acquisition volumes of the brain

Studies suggest that clinical outcomes are improved in repeat trigeminal neuralgia (TN) Gamma Knife radiosurgery if a different part of the nerve from the previous radiosurgery is treated. The MR images taken in the first and repeat radiosurgery need to be coregistered to map the first radiosurgery volume onto the second treatment planning image. We propose a fully automatic and robust three-dimensional (3-D) mutual information- (MI-) based registration method engineered by a simulated annealing (SA) optimization technique. Commonly, Powell's method and Downhill simplex (DS) method are most popular in optimizing the MI objective function in medical image registration applications. However, due to the nonconvex property of the MI function, robustness of those two methods is questionable, especially for our cases, where only 28 slices of MR T1 images were utilized. Our SA method obtained successful registration results for all the 41 patients recruited in this study. On the other hand, Powell's method and the DS method failed to provide satisfactory registration for 11 patients and 9 patients, respectively. The overlapping volume ratio (OVR) is defined to quantify the degree of the partial volume overlap between the first and second MR scan. Statistical results from a logistic regression procedure demonstrated that the probability of a success of Powell's method tends to decrease as OVR decreases. The rigid registration with Powell's or the DS method is not suitable for the TN radiosurgery application, where OVR is likely to be low. In summary, our experimental results demonstrated that the MI-based registration method with the SA optimization technique is a robust and reliable option when the number of slices in the imaging study is limited.

Where to locate the isocenter? The treatment strategy for repeat trigeminal neuralgia radiosurgery

PURPOSE

The purpose of this study is to investigate how the spatial relationship between the isocenters of the first and second radiosurgeries affects the overall outcome.

METHODS AND MATERIALS

We performed a retrospective study on 40 patients who had repeat gamma knife radiosurgery for trigeminal neuralgia. Only one 4-mm isocenter was applied in both first and second radiosurgeries, with a maximum radiation dose of 75 Gy and 40 Gy, respectively. The MR scan of the first radiosurgery was registered to that of the second radiosurgery by a landmark-based registration algorithm. The spatial relationship between the isocenter of the first and the second radiosurgeries was thus determined. The investigating parameters were the distance between the isocenters of the two separate radiosurgeries and isocenter proximity to the brainstem. The outcome end points were pain relief and dysesthesias. The median follow-up for the repeat radiosurgery was 28 months (range, 6-51 months).

RESULTS

Pain relief was complete in 11 patients, nearly complete (> or =90%) in 7 patients, partial (> or =50%) in 8 patients, and minimal (<50%) or none in another 14 patients. The mean distance between the two isocenters was 2.86 mm in the complete or nearly complete pain relief group vs. 1.93 mm in the others. Farther distance between isocenters was associated with a trend toward better pain relief (p = 0.057). The proximity of the second isocenter to the brainstem did not affect pain relief, and neither did placing the second isocenter proximal or distal to the brainstem compared with the first one. Three patients developed moderate dysesthesias (score of 4 on a 0-10 scale), and 2 other patients developed more significant dysesthesias (score of 7) after the second radiosurgery. Dysesthesias related neither to distance between isocenters nor to which isocenter was closer to the brainstem.

CONCLUSIONS

Image registration between MR scans of the first and second radiosurgeries helps target delineation and radiosurgery treatment planning. Increasing the isocenter distance between the two radiosurgeries treated a longer segment of the trigeminal neuralgia nerve and was associated with a trend toward improved pain relief.

Gamma knife surgery with a dose of 75 to 76.8 Gray for trigeminal neuralgia

Object. The author presents a large series of patients with idiopathic trigeminal neuralgia (TN) who were treated with gamma knife surgery (GKS), at a maximum dose of 75 to 76.8 Gy, and followed up in a nearly uniform manner for up to 4.6 years.

Methods. Two hundred ninety-three patients were treated and followed up for at least 6 months (range 0.4–4.6 years, median 1.9 years). At the final follow-up review, there was complete (100%) pain relief without medicines in 64 patients (21.8%), 90% or greater relief with or without small doses of medicines in 86 (29.4%), between 75 and 89% relief in 31 (10.6%), between 50 and 74% relief in 19 (6.5%), and less than 50% relief in 23 patients (7.8%). Recurrent pain requiring a second procedure occurred in 70 patients (23.9%). Kaplan—Meier analysis showed that 100%, 90% or greater, and 50% or greater pain relief was obtained and maintained for 3.5 to 4.1 years in 5.6 , 23.7, and 50.4% patients, respectively. Of 31 patients who described pain relief ranging from 75 to 89%, 80% of patients described it as good and 10% as excellent; of 17 patients who reported between 50 and 74% pain relief, 53% described it as good and none as excellent (p = 0.014). Dysesthesia scores greater than 5 (scale of 0–10, in which a score of 10 represents excruciating pain) occurred in four (3.2%) of 126 patients who had not undergone prior surgery; all these patients obtained either good or excellent relief from TN pain. There were 36 patients in whom the TN had atypical features; these patients were less likely to attain at least 50% or at least 90% pain relief compared with those without atypical TN features (p = 0.001).

Conclusions. Gamma knife surgery is a safe and effective way to relieve TN. Patients who attain between 75 and 89% pain relief are much more likely to describe this outcome as good or excellent than those who attain between 50 and 74% pain relief.

Repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia

BACKGROUND

Although gamma knife radiosurgery (GKRS) has been shown to be safe and effective for the treatment of trigeminal neuralgia (TN), there are few studies that report the results of a second GKRS.

METHOD

Between May 22, 1998 and April 1, 2003, we treated 335 primary TN patients with GKRS. All received a maximum dose of 75 Gy to the cisternal trigeminal nerve. 45 patients with recurrent or persistent TN were treated with a maximum dose of 40 Gy at a second GKRS and were available for at least 6 months of follow-up.

RESULTS

Final pain relief (mean of 15 months after second GKRS) was 50% or greater in 28 of the 45 patients (62.2%). Patients who had no neurosurgical procedure prior to their first GKRS were more likely to have pain relief of 50% or greater following the second GKRS (p = 0.042). Significant new dysesthesias (score greater than 5 on a scale of 0-10) developed in 2 patients (4.4%).

CONCLUSION

Repeat GKRS has a good chance of relieving TN pain without complications and is more likely to relieve pain in those who did not have any procedure prior to their first GKRS.

Trigeminal Nerve-Blood Vessel Relationship as Revealed by High-resolution Magnetic Resonance Imaging and Its Effect on Pain Relief after Gamma Knife Radiosurgery for Trigeminal Neuralgia

OBJECTIVE

Blood vessel (BV) compression of the trigeminal nerve (Cranial Nerve [CN] V) is a common cause of trigeminal neuralgia (TN). High-resolution magnetic resonance imaging scans obtained during gamma knife radiosurgery (GKRS) in patients with TN may be used to analyze the BV-CN V relationship. Follow-up data from a large series of patients treated with GKRS for TN were used to provide information regarding the BV-CN V relationship and pain relief.

METHODS

T1-weighted, axial 1-mm-thick volume acquisition magnetic resonance imaging scans were obtained through the area of CN V at its exit from the brainstem after injection of 15 ml of gadolinium. The BV-CN V relationship on the symptomatic side that was treated with GKRS was categorized into the following groups: Group 1 (no close relationship), Group 2 (BV close to CN V but not touching it), and Groups 3 and higher (BV-CN V contact).

RESULTS

A total of 181 symptomatic nerves were studied in 179 patients with TN who were treated with GKRS. In BV-CN V Groups 1, 2, and 3 and higher, respectively, were 43 sides (24%), 31 sides (17%), and 107 sides (59%). In 100 sides where there was no surgical procedure before GKRS, 50% or greater pain relief was more likely in those with BV-CN V contact (51 [88%] of 58 sides) than in those without BV-CN V (29 [69%] of 42 sides) (P = 0.024). BV-CN V contact was observed more often in men (55 [69%] of 80 sides) than in women (52 [52%] of 101 sides) (P = 0.023) and more often in patients who had unilateral TN (104 [62%] of 169 patients) rather than bilateral TN (2 [20%] of 10 patients) (P = 0.016).

CONCLUSION

In patients who have not undergone previous surgery for TN, BV-CN V contact revealed by high-resolution magnetic resonance imaging may indicate a particularly favorable response to GKRS.

Gamma knife radiosurgery for trigeminal neuralgia: dose—volume histograms of the brainstem and trigeminal nerve

Object. The purpose of this study was to assess the relationship between the volume of brainstem that receives 20% or more of the maximum dose (VB20) and the volume of the trigeminal nerve that receives 50% or more of the maximum dose (VT50) on clinical outcome following gamma knife radiosurgery (GKS) for trigeminal neuralgia (TN).

Methods. Patients with TN were treated with a single 4-mm isocenter with a maximum dose of 75 Gy directed at the trigeminal nerve close to where it leaves the brainstem. The VB20 and VT50, as determined on dose—volume histograms, were correlated with clinical outcomes at 6 and 12 months, laterality, presence of multiple sclerosis (MS), and each other.

At 6 months excellent pain relief (no pain or required medicine) was achieved in 27 of 48 patients (p = 0.009) when VB20 was greater than or equal to 20 mm3 and in 25 of 78 when VB20 was less than 20 mm3, when all patients are considered. At 12 months excellent pain relief was achieved in 16 of 32 patients (p = 0.038) when VB20 was greater than or equal to 20 mm3 and in 14 of 52 when VB20 less than 20 mm3, when all patients are considered. When VB20 was less than 20 mm3 in MS patients, five of 21 had an excellent result at 6 months and two of 13 at 12 months. The VB20 was 20 mm3 or more in 38 of 64 on the right side and in eight of 41 on the left side (p < 0.001) in patients with TN and without MS. There is a difference between left and right dose—volume histograms even when the same isodose is placed on the surface of the brainstem.

The VB20 was 20 mm3 or more in 45 of 105 patients with TN and without MS but in only three of 21 patients with TN and MS (p = 0.014). There was an inverse relationship between VB20 and VT50 (p = 0.01).

Conclusions. Isocenter proximity to the brainstem, as reflected in a higher VB20, is associated with a greater chance of excellent outcome at 6 and 12 months. Worse results in patients with TN and MS may be partly explained by a lower VB20.

Gamma knife radiosurgery for primary management for trigeminal neuralgia

Object. The purpose of this study was to assess the efficacy of gamma knife radiosurgery (GKS) as the primary rather than secondary management for trigeminal neuralgia.

Methods. Eighty-two patients underwent GKS as their first neurosurgical intervention (Group A), and 90 patients underwent GKS following a different procedure (Group B). All GKS patients were treated with a maximum dose of 75 Gy. The single 4-mm isocenter was placed close to the junction of the trigeminal nerve and the brainstem. Six-month follow up was available for 126 patients and 12-month follow up for 84 patients.

Excellent (no pain and no medicine) or good (at least 50% reduction in pain and less medicine) relief was more likely to occur in Group A than in Group B patients 6 and 12 months following GKS for trigeminal neuralgia (p = 0.058). Excellent or good results were also more likely in patients with trigeminal neuralgia without multiple sclerosis (MS) (p = 0.042). The number and type of procedures performed prior to GKS, the interval between the last procedure and GKS, and the interval from first symptom to GKS (within Groups A and B) did not affect 6-month outcome. The interval between first symptom and GKS was shorter in Group A patients without MS (87 months) than in Group B (148 months; p < 0.004). There were no significant differences between Group A and B patients with regard to sex, age, or laterality.

Conclusions. Patients with trigeminal neuralgia who are treated with GKS as primary management have better pain relief than those treated with GKS as secondary management. Patients are more likely to have pain relief if they do not have MS.

Surgical treatment of trigeminal neuralgia

Patients with medically intractable trigeminal neuralgia characterized by paroxysmal, triggered, trigeminally distributed pain are excellent candidates for neurosurgical intervention, which can not only relieve the pain of trigeminal neuralgia, but also eliminate the unpleasant side effects of medicines used to treat it. The two major neurosurgical choices are percutaneous denervation and microvascular decompression (MVD). Percutaneous denervation is done best when the surgeon has available radiofrequency and glycerol and uses one, the other, or both depending on technical circumstances that pertain to each patient. The percutaneous denervation is less likely than MVD to cause death, stroke, facial weakness, or hearing loss, but more likely to be associated with recurrence or dysesthesias. Patients with multiple sclerosis, medical illness, or who are elderly are much better candidates for percutaneous denervation. For any patient, a number of other factors also must be considered before deciding on a particular procedure. These include response to previous interventions, ability to tolerate carbamazepine, risk tolerance for various complications, preference regarding duration of hospital stay and postoperative recovery, presence of pain outside the trigeminal distribution, and findings on a high resolution magnetic resonance imaging (MRI) scan.

Analgesia and sedation during percutaneous radiofrequency electrocoagulation for trigeminal neuralgia

Patient comfort during percutaneous radiofrequency electrocoagulation for trigeminal neuralgia provides better working conditions for the surgeon and makes the patient more willing to return if a second procedure is necessary. This study evaluates five different regimens for analgesia and sedation including the standard of fentanyl and droperidol (Group A) and four other regimens, each containing midazolam. In a sixth group, droperidol was assessed for its antiemetic effects. Patients were medicated as follows: Group B, low-dose midazolam (3.0 mg average); Group C, low-dose midazolam (2.5 mg average) and oral diazepam (7.5 mg average) just before the procedure; Group D, high-dose midazolam (5.5 mg average); and Group E, high-dose midazolam (5.1 mg average) and oral diazepam. Medications were titrated to induce mild sedation in Groups A, B, and C and heavier sedation in Groups D and E. All patients received fentanyl and small doses of intravenous methohexital just before the cannula penetrated the foramen ovale and before radiofrequency electrocoagulation. At least 2 weeks later, patients reported their level of discomfort during the procedure and their recollection of the procedure on a 0 to 10 scale. In another group of 96 patients, 1.25 mg of droperidol was given in addition to the medications described for Groups D and E. There was a statistically significant improvement in comfort in Groups C, D, and E and added amnesia in Groups D and E. Vomiting occurred in none of the patients medicated with droperidol and in 5 of 143 patients who did not receive droperidol.(ABSTRACT TRUNCATED AT 250 WORDS)

Bilateral trigeminal neuralgia

Bilateral trigeminal neuralgia occurred in 32 (11.9%) of 269 consecutive patients who were treated with radiofrequency electrocoagulation (RFE). This is a higher incidence than has been reported before and may be explained by the prospective nature of the present study, the long follow-up period, and the inclusion of patients with mild bilateral symptoms. Multiple sclerosis is the most common predisposing factor and occurred in 18% of those with bilateral trigeminal neuralgia. Although patients with bilateral trigeminal neuralgia were more likely to have had prior surgery than those with unilateral neuralgia, they did not have a higher recurrence rate following treatment. Percutaneous RFE of the retrogasserian rootlets and gasserian ganglion, with or without glycerol, is effective in managing patients whose pain is intractable to medical therapy. The preservation of most trigeminal sensory and motor functions, the low morbidity rate, and the ability to repeat the procedure are particularly advantageous for patients with bilateral involvement.

Trigeminal neuralgia and multiple sclerosis

In a series of patients with trigeminal neuralgia (TN) who were treated with radiofrequency electrocoagulation of the gasserian ganglion and retrogasserian rootlets, either alone or with glycerol, 16 patients with TN and multiple sclerosis (TNMS) are compared with 219 patients with TN without MS. Patients with TNMS were younger and more likely to have bilateral facial pain than those with TN alone. Probability of ipsilateral recurrence was calculated on the basis of Kaplan and Meier product-limit estimates and showed no significant differences in the two groups.

Treatment of lower extremity reflex sympathetic dystrophy with continuous intrathecal morphine infusion

Continuous intrathecal morphine infusion has been used in 3 patients with refractory lower extremity reflex sympathetic dystrophy syndromes. Two patients have experienced prolonged significant benefit.

Trigeminal nerve stimulation: short latency somatosensory evoked potentials

We have devised a technique to measure trigeminal somatosensory evoked potentials, stimulating the mentalis nerve at the mandibular foramen and recording the evoked early potential on the scalp at 3.2 msec. The early potential was easily recognized in all normal subjects and on the asymptomatic side of patients with facial pain. The latency of the early potential in normals was 1 to 2 msec less than half the latency of the mechanically induced jaw jerk. The early potential appeared simultaneously on both sides after stimulation of either the right or left mentalis nerve and may have its origin in deep brainstem structures, the Gasserian ganglion, or the trigeminal nerve. The technique is useful in documenting the functional integrity of peripheral and central afferent pathways of the trigeminal nerve.

Computed tomography of disseminated meningeal and ependymal malignant neoplasms

We studied computed tomography (CT) scans of 50 patients with clinical signs and symptoms compatible with disseminated meningeal tumor, all documented by cerebrospinal fluid cytology, surgical biopsy or autopsy. Twenty-three patients also had nuclear scans, and 13 had cerebral angiograms. Represented in the series were patients with metastatic carcinoma, gliomas, and lymphomas. The characteristic CT findings included gyral enhancement without edema; sulcal and basilar cisternal obliteration and enhancement, and ependymal-subependymal enhancement. The correct diagnosis was made by CT in 28 of the 50 cases (56%).

Management of extracranial carotid stenosis and intracranial aneurysms

Twenty patients with extracranial carotid stenosis and intracranial aneurysms are reviewed. Fifteen of these patients had transient ischemic attacks (TIA's) and incidental aneurysms. The other five presented with symptoms referrable to an aneurysm, and angiography revealed significant carotid stenosis. None of the patients who presented with TIA's and underwent endarterectomy suffered subarachnoid hemorrhage. However, those patients who presented with symptoms referrable to an aneurysm and underwent endarterectomy seem to be at greater risk for subarachnoid hemorrhage.

BCNU and steroids in the viral-induced dog brain tumor

Schmidt-Ruppin strain of Rous Sarcoma was inoculated intracerebrally into 27 newborn beagle dogs. Fourteen days after viral inoculation, 13 of the dogs were given intravenous BCNU (1 mg/kg). The other 14 were given the same volume of intravenous saline in a randomized, double-blinded fashion. Ninety percent of all dogs developed intracranial tumors. Radionuclide (mercury 197) brain scans were done on each dog at 2-week intervals. Median survival was 113 days in the BCNU group and 115 days in the placebo group (P > .99). Unequivocally positive radionuclide brain scans were detected in 5 dogs treated with BCNU and in 2 of the controls. There were no gross or microscopic differences at autopsy between treated and nontreated animals. BCNU, as given in this animal brain tumor model, did not demonstrate any oncolytic effect. An improvement in sequential brain scans was detected in 2 other dogs in response to Dexamethasone, which was given in a double-blinded, cross-over controlled fashion. Computerized tomography clearly demonstrated the tumor in two cases.

Period of risk for recurrence in medulloblastoma

Ninety-nine patients with medulloblastoma who received surgery and radiotherapy, and had a statistically sufficient follow-up period were analyzed for factors influencing survival and the relevance of the "period of risk for recurrence" hypothesis. This postulate states that the period of risk for recurrence of a congenital tumor is equal to the age at presentation of illness plus 9 months' gestational time. The assumption is made that a tumor of embryonic origin will become manifest after a period of time determined by its inherent rate of growth and that tumor cells surviving treatment will multiply and present with recurrence in an equal period of time. Ten of 43 patients survived the period of risk, a presumed cure rate of 23%. None of these patients has subsequently developed evidence of tumor recurrence. Older patients at initial surgery had a somewhat greater survival rate for the first 5 years after treatment (10 of 26 older patients (38%) versus 15 of 54 younger patients (28%)), but by 10 years there was no appreciable difference in survival rates between those over 16 years of age and those younger. The beneficial effect of total neuraxis megavoltage radiotherapy is indicated by the improved 5-year survival rate from 9 of 41 patients (22%) to 16 of 39 patients (41%) with the newer techniques.

Adjuvant nitrosourea therapy for glioblastoma

An attempt was made to evaluate the potential advantages of chemotherapy in the treatment of 62 patients with glioblastoma. Twenty-four of the 62 patients received adjuvant nitrosourea chemotherapy with carmustine (BCNU), lomustine (CCNU), or semustine (methyl CCCNU) in addition to surgery and radiotherapy. Thirty-three of the 62 patients were involved in a controlled, prospective, randomly allocated study. Quality or quantity of survival was not prolonged in patients who received chemotherapy. Age greater than 64 years, a severe postoperative neurological deficit, or the onset of symptoms less than 12 months prior to surgery were associated with a worse prognosis. The valid evaluation of the effect of a form of treatment on survival in patients with glioblastoma is contingent on the regorous avoidance of preselected factors that may predispose the treated group to a more favorable prognosis.

Computerized tomography correlated with CSF protein concentrations

The authors present a case of hydrocephalus complicated by ventriculitis in which it was possible to correlate the numerical printout of sequential computerized tomograms (CT-Scans) with cerebrospinal fluid protein concentrations obtained by direct ventricular puncture. Different protein levels were unambiguously associated with changes in the absorption numbers on the scan but they did not bear a simple linear relationship to one another. The value of the numerical printout in diagnosis and follow-up is discussed.

Reliability of technicians in computerized and standard A-mode midline echoencephalography

✓ A prospective controlled study was done to evaluate technician reliability in measuring midline cerebral shifts by computerized (Midliner) and standard A-mode echoencephalography. Thirteen of 16 (81%) verified shifts were correctly predicted by the Midliner, while only five of 14 (36%) shifts were correctly noted by the standard echoencephalograms. Two false negatives occurred with 2 mm Midliner shifts. The computerized echoencephalogram is a simple and effective instrument for determining midline shifts even when used by minimally trained paramedical personnel, but its reliability is limited when it shows a 1.5 to 2 mm shift or an unsatisfactory tracing.

Subarachnoid infusion and shunt function. Technical note

✓ A simplified technique for subarachnoid cerebrospinal fluid infusion of Ringer's lactate is described and evaluated as a method for determining shunt patency. An infusion index (change in pressure divided by volume infused) of 11 or greater is highly suggestive of shunt occlusion while an index of 6 or less strongly suggests a patent shunt. Further accuracy results when a baseline index and pressure-volume-time curve are obtained at a time of known shunt patency and compared with subsequent infusions. Using these criteria, the proper evaluation of shunt patency has been made in 18 out of 19 verified shunt problems.

Thromboembolism and brain tumors

✓ The relationship between brain tumor location and thromboembolism was studied by a retrospective review of autopsy and clinical material. Patients with suprasellar tumors had a higher incidence of thromboembolic complications than those with tumors in other locations. An associated derangement of hypothalamic function is suggested as predisposing to thromboembolism.

Doppler ultrasound measurements of superior sagittal sinus blood velocity

✓ Transcutaneous Doppler recordings from the patent anterior fontanel were used to measure superior sagittal sinus blood velocity (SSSV). In 15 cases it ranged from 4.5 to 18.1 cm/sec. In five of these patients with no mass effect and normal intracranial pressure, the mean SSSV was 13.6 cm/sec. An independent arteriographic measurement of SSSV was 4.5 cm/sec in a hydrocephalic patient with elevated intracranial pressure whose Doppler measurement of SSSV was 6.6 cm/ sec. The Doppler technique may be used to diagnose sagittal sinus occlusion. SSSV tended to be low when CSF pressure was elevated, but the relationship was not constant.

Familial gliomas. Report of four cases

✓ A report of two more instances of familial gliomas is presented, in one instance glioblastomas in two brothers and in the other posterior fossa astrocytomas in first cousins.

Treatment of multiple intracranial aneurysms. Treatment of multiple intracranial aneurysms

✓ The authors report a series of 70 patients with 161 multiple intracranial aneurysms. There was no mortality in 23 patients in whom all aneurysms were treated intracranially. Unoperated aneurysms later caused morbidity or mortality in eight of 33 patients. The authors believe that patients who have had a subarachnoid hemorrhage should have four-vessel arteriography to identify all aneurysms, and that all surgically accessible aneurysms should be treated, preferably intracranially in good-risk patients who have no disabling neurological deficit.

Familial intracranial aneurysms

✓ Six cases of intracranial aneurysms are described in three families: two sisters, identical twins, and a mother and daughter. The cases suggest a hereditary basis for some intracranial aneurysms.