Spontaneous CSF leak complicated by venous thrombosis and dural arteriovenous fistula.
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Adult↗
Biomedical subjects
M J Link
Publications and source records attributed to M J Link.
Meningioma radiosurgery: tumor control, outcomes, and complications among 190 consecutive patients.
OBJECTIVE: To determine local control (LC) and complication rates for patients with intracranial meningiomas who underwent radiosurgery. METHODS: One hundred ninety consecutive patients with 206 meningiomas underwent radiosurgery between 1990 and 1998. One hundred forty-seven tumors (77%) involved the cranial base. The median age at the time of radiosurgery was 58 years (range, 20-90 yr). There were 126 female patients (66%). One hundred twelve patients (59%) had undergone one or more previous operations (median, 1; range, 1-5). Twenty-two patients (12%) had either atypical (n = 13) or malignant (n = 9) tumors. The median prescription isodose volume was 8.2 cm(3) (range, 0.5-50.5 cm(3)), and the median tumor margin dose was 16 Gy (range, 12-36 Gy). The median imaging and clinical follow-up periods were 40 and 47 months, respectively. RESULTS: Overall survival rates for the entire cohort at 5 and 7 years were 82 and 82%, respectively; cause-specific survival rates at 5 and 7 years were 94 and 92%, respectively. The cause-specific survival rates at 5 years for patients with benign, atypical, and malignant tumors were 100, 76, and 0%, respectively (P < 0.0001). The 5-year LC rate was 89%, with 114 tumors (56%) decreasing in size. LC rates were correlated with tumor histological features (P < 0.0001); patients with benign tumors exhibited a 5-year LC rate of 93%, compared with 68 and 0% for patients with atypical or malignant meningiomas, respectively. No correlation was observed between radiation dose and LC rate. Twenty-four patients (13%) experienced treatment-related complications, including cranial nerve deficits (8%), symptomatic parenchymal changes (3%), internal carotid artery stenosis (1%), and symptomatic cyst formation (1%). Only six patients (3%) exhibited decreases in functional status that were directly related to radiosurgery. Tumor volume, tumor margin dose, or previous radiotherapy was not associated with the development of radiation-related complications. CONCLUSION: Radiosurgery is an effective management strategy for many patients with meningiomas. Patients with atypical or malignant tumors exhibit high recurrence rates despite the use of radiosurgery, and these patients continue to exhibit worse cause-specific survival rates despite aggressive treatment, including surgery, external-beam radiotherapy, and radiosurgery. Further study is needed to determine the tumor control and complication rates 10 years or more after meningioma radiosurgery.
Adult↗
Pilot study of bright-light therapy reflected toward the eyes for the pruritus of chronic liver disease.
OBJECTIVE: It is proposed that the pruritus of cholestasis is, in part, centrally mediated by endogenous opioid peptides. The expression of these peptides and their receptors on neurons displays a circadian rhythm, as does the scratching activity in patients with cholestasis and pruritus. Because light has regulatory effects on circadian rhythms via retinothalamic pathways, we hypothesized that bright-light therapy (BLT) reflected toward the eyes might alter the pruritus of cholestasis. To test this hypothesis, we studied the effect of BLT on this form of pruritus. METHODS: Eight patients with chronic liver disease of different etiologies and pruritus were studied in an open-label, pilot study of 8-wk duration. BLT (10,000 lux) was administered for up to 60 min twice a day. Pruritus was assessed subjectively by a visual analog scale from which a visual analog score (VAS) was derived, and objectively, by a scratching activity monitoring system that recorded hourly scratching activity (HSA). RESULTS: In seven of the eight patients studied, the mean HSA was lower during BLT. BLT was associated with a mean decrease in HSA of 32.2% (p = 0.123). The mean VAS for pruritus was lower in six patients during BLT; the mean VAS score derived from the eight patients studied decreased by 42% (p = 0.05) during treatment. CONCLUSIONS: The results of this short-term study suggest that the pruritus of cholestasis is responsive to bright light reflected toward the eyes and that in some patients, BLT may ameliorate this form of pruritus.
Adult↗
Stereotactic radiosurgery for cavernous malformations.
OBJECT: The use of stereotactic radiosurgery to treat cerebral cavernous malformations (CMs) is controversial. To evaluate the efficacy and safety of CM radiosurgery, the authors reviewed the experience at the Mayo Clinic during the past 10 years. METHODS: Seventeen patients underwent radiosurgery for high-surgical-risk CMs in the following sites: thalamus/basal ganglia (four patients), brainstem (12 patients), and corpus callosum (one patient). All patients had experienced at least two documented hemorrhages before undergoing radiosurgery. Stereotactic magnetic resonance (MR) imaging was used for target localization in all cases. The median margin radiation dose was 18 Gy and the median maximum dose was 32 Gy. The median length of follow-up review following radiosurgery was 51 months. The annual hemorrhage rate during the 51 months preceding radiosurgery was 40.1%, compared with 8.8% in the first 2 years following radiosurgery and 2.9% thereafter. In 10 patients (59%) new neurological deficits developed that were associated with regions of increased signal on long-repetition time MR imaging performed a median of 8 months (range 5-16 months) after radiosurgery. Three patients recovered, giving the group a permanent radiation-related morbidity rate of 41%. Compared with 31 patients harboring arteriovenous malformations (AVMs) of sizes and in locations similar to those of the aforementioned CMs, who underwent radiosurgery during the same time period, the patients with CMs were more likely to experience radiation-related complications (any complication, 59% compared with 10%; p < 0.001; permanent complication, 41% compared with 10%; p = 0.02). CONCLUSIONS: It is impossible to conclude that radiosurgery protects patients with CMs against future hemorrhage risk based on the available data, although it appears that some reduction in the bleeding rate occurs after a latency interval of several years. The risk of radiation-related complications after radiosurgery to treat CMs is greater than that found after radiosurgery in AVMs, even when adjusting for lesion size and location and for radiation dose.
Adolescent↗
Gamma knife radiosurgery as a primary treatment for prolactinomas.
OBJECT: The purpose of this study was to estimate the efficacy of gamma knife radiosurgery (GKS) in controlling tumor growth and endocrinopathy associated with prolactinomas. METHODS: Between 1993 and 1997, 164 of 469 patients with pituitary adenomas treated by GKS harbored prolactinomas. The dose to the tumor margin ranged from 9 to 35 Gy (mean 31.2 Gy), and the visual pathways were exposed to a dose of less than 10 Gy. The mean tumor diameter was 13.4 mm. The mean follow-up time for 128 cases was 33.2 months (range 6-72 months). Tumor control was observed in all but two patients who underwent surgery 18 and 36 months, respectively, after GKS. Clinical cure was achieved in 67 cases. Clinical improvement was noted with a decrease in the hyperprolactinemia after GKS. Nonetheless, in 31 (29%) of 108 patients who were followed for more than 2 years no improvement in serum prolactin levels was demonstrated, although this could be normalized by bromocriptine administration after treatment. Nine infertile women became pregnant 2 to 13 months after GKS and all gave birth to normal children. There was no visual deterioration related to GKS. Five women experienced premature menopause. In these patients there was subtotal disappearance of the tumor and an empty sella developed. CONCLUSIONS: Gamma knife radiosurgery as a primary treatment for prolactinomas can be safe and effective both for controlling tumor growth and for normalization of prolactin hypersecretion. A higher margin dose (> or = 30 Gy) seemed to be associated with a better clinical outcome. Gamma knife radiosurgery may make prolactinomas more sensitive to the bromocriptine.
Humans↗
Honored guest presentation: therapeutic carotid occlusion.
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Balloon Occlusion↗
Gamma knife radiosurgery for skull base meningiomas.
Radiosurgery has been proven to be a safe and effective management strategy for skull base meningiomas either primarily or for tumor recurrence or progression after prior microsurgical resection. With its steep radiation falloff, radiosurgery provides long-term tumor growth control without the complications associated with conventional fractionated radiation therapy. Stereotactic MR imaging has allowed better definition of the tumor margin for precise multiisocenter conformal dose planning, and our current radiation dose prescription has decreased the incidence of new cranial nerve deficits after radiosurgery to less than 10%. Tumor growth control after radiosurgery remains greater than 90%; patients with subsequent growth typically have tumor outside the irradiated volume or a histologic diagnosis of atypical or malignant meningioma. Still, longer follow-up is needed to ensure that tumor growth control remains permanent after radiosurgery. For patients with large tumors of the skull base, radiosurgery can be part of a staged approach with microsurgery. Initially, the tumor is debulked without an attempt at resection involving the cranial nerves or basal vessels. Radiosurgery can then be performed for the small remaining tumor volume with little risk of cranial nerve deficits. Such multimodality treatment should result in reduced patient morbidity, with long-term tumor control.
Adult↗
Hypomania interview guide (including hyperthymia): retrospective assessment version (HIGH-R).
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Bipolar Disorder↗
A comparison between endovascular and surgical management of basilar artery apex aneurysms.
OBJECT: The goal of this retrospective study was to evaluate endovascular treatment by means of Guglielmi detachable coils (GDCs) compared with surgical management for basilar artery (BA) apex aneurysms. METHODS: Forty-one patients presented with saccular BA apex aneurysms with angiographically definable necks that were judged suitable for either treatment. Of 20 patients who underwent surgery and 21 who underwent GDC embolization, 15 (75%) and 11 (52%), respectively, were treated in the acute phase after subarachnoid hemorrhage (SAH). Twenty-four (92%) of the 26 patients presenting with an SAH had a Hunt and Hess Grade III or better. Fifteen patients with unruptured or ruptured aneurysms more than 14 days post-SAH were treated electively. Patients in the endovascular and surgical treatment groups had aneurysms with comparable dimensions and configurations. Overall, 15 (75%) of the surgical patients and 20 (95%) of the patients in whom GDC embolization was performed had a good outcome (Glasgow Outcome Scale score of 4 or 5). Among those patients treated in the acute stage post-SAH, 11 (73%) of the surgical group and 10 (91%) of the endovascular group did well. Fourteen patients treated electively (93%) had good outcomes. There were two deaths (10%) in the surgical group and none in the endovascular group. Patients treated surgically were hospitalized twice as long and incurred twice the expenses of patients who underwent endovascular treatment (p<0.001). CONCLUSIONS: Endovascular GDC embolization of select BA apex aneurysms may be a competitive alternative to direct surgical clipping. Long-term follow up is needed to better define the natural history of the endovascularly treated aneurysm and to further evaluate the accuracy of these preliminary results.
Adult↗
Cervicomedullary compression: an unrecognized cause of vocal cord paralysis in rheumatoid arthritis.
Cervicomedullary compression (CMC) from traumatic, infectious, or congenital processes of the atlanto-axial joint is a known cause of vocal cord immobility. Cervicomedullary compression can also occur from destructive arthritic changes and inflammatory pannus formation at the occipito-atlanto-axial joint in patients with rheumatoid arthritis (RA). We present findings suggesting that CMC in patients with RA is an unrecognized cause of vocal cord immobility. Previously, vocal cord immobility in patients with RA has been assumed to be cricoarytenoid arthritis with joint fixation. We report 3 patients with RA and radiographically demonstrated CMC with vocal cord immobility. One patient had bilateral vocal cord immobility and airway obstruction; 2 patients had unilateral cord paralysis and contralateral paresis without airway compromise. All patients had myelopathy and neck pain in addition to brain stem symptoms. All patients underwent transoral-transpharyngeal decompression of the anterior craniocervical junction with subsequent posterior fusion. These patients demonstrated full return of vocal cord function within 3 months of decompression. We propose that CMC is a cause of vocal cord paralysis in patients with RA that may go unrecognized without appropriate imaging studies of the skull base and physician awareness of symptoms of occipito-atlanto-axial subluxation and/or basilar invagination with brain stem compression. Our results demonstrate that CMC in RA is a potentially reversible cause of vocal cord paralysis.
Aged↗
The role of radiosurgery and particulate embolization in the treatment of dural arteriovenous fistulas.
Over the past 5 years 29 patients with dural arteriovenous fistulas (AVFs) were treated by the authors using the Leksell radiosurgical gamma knife unit. Within 2 days after radiosurgery, 17 patients with AVFs that exhibited retrograde pial or cortical venous drainage (12 patients) and/or produced intractable bruit (eight patients) underwent particulate embolization of external carotid feeding vessels. The rationale for this treatment strategy was that radiosurgery was expected to cause obliteration of most fistulas after 12 to 36 months. In patients with bruit, ocular symptoms, or in those at risk for hemorrhage, treatment with embolization after radiosurgery kept the fistulas angiographically visible for radiosurgical targeting yet offered palliation of symptoms and temporary, partial protection from hemorrhage during the latency period. In 12 patients, preobliteration embolization immediately reduced (10 patients) or eliminated (two patients) retrograde pial venous drainage. To date, no lesion has hemorrhaged after treatment. Angiography 1 to 3 years posttreatment in 18 patients showed total obliteration of 13 fistulas (72%) and partial obliteration of five (28%). Radiosurgery, followed by embolization when retrograde pial venous drainage, intractable bruit, and/or major external carotid artery supply is present, appears to be a promising treatment for selected patients with symptomatic dural AVFs.
Adult↗
Pneumatic nerve root compression: epidural gas in association with lateral disc herniation. Report of two cases.
Extreme lateral disc herniations are increasingly recognized as a cause of lumbar nerve root compression syndromes. This disorder often presents major diagnostic and therapeutic challenges, especially in the presence of multiple degenerative changes and chronic back pain in elderly patients. The authors describe two patients with presentations and findings that have not been previously described in the literature. Both patients had histories of upper lumbar back and leg pain. Degenerative spine disease, gaseous degeneration of the intervertebral discs, and epidural gas in the lateral recesses were noted on imaging studies. However, because both patients had undergone prior epidural diagnostic and therapeutic procedures, the epidural gas in the lateral recesses could be attributed either to gaseous disc degeneration or to the previous intraspinal procedures. One patient was found to have a large, far lateral extruded disc fragment that contained air. The nerve root in the second patient was impaled by an unusual combination of a small extruded disc fragment as well as an air-filled sac that was surrounded by the walled-off fragment's capsule and which freely communicated with the gaseous degenerated disc space. The suspected mechanism of root compression is illustrated and discussed. The possibility of disc herniation should be seriously considered in cases of nerve root compression in which epidural gas is present, especially those associated with gaseous degenerated discs.
Aged↗
Spontaneous midbrain hemorrhage: report of seven new cases.
Spontaneous midbrain hemorrhage is a unique brain-stem vascular lesion. Sixty-six cases have been reported in the literature, to which we add seven. Of the total of 73 patients reviewed, most presented acutely (66%), but subacute (22%) and chronic onsets (12%) also occurred. Neuro-ophthalmologic abnormalities were found in 88% of patients. Some alteration of consciousness and headache occurred in most patients. Hemiparesis, hemisensory loss, and ataxia were less frequent manifestations. Vascular malformations were suspected or proved in 37% of patients, hypertension was present in 21%, and a bleeding diathesis was noted in 5%. No underlying cause was apparent in 37%. Most patients improved with supportive care only. At follow-up, 23% of patients had no neurologic deficits. In 51% of patients, minor neurologic deficits persisted, related chiefly to cranial nerves III and IV. Moderate deficits persisted in 16% of patients, and 5% of patients died.
Adolescent↗
Prewhitening for intelligibility gain in hearing aid arrays.
In this article, prewhitening multimicrophone data prior to use in an optimum spatial-filter preprocessor for a monaural hearing aid is considered. Considering preprocessor capabilities, interference signal spectral content and intelligibility, it is argued that prewhitening is advantageous. This advantage is illustrated via simulation of a head worn array. Also, an effective procedure for the design of (prewhitening) digital filters is presented. The effectiveness of this filter design technique is shown by presenting several prewhitening filter design examples.
Acoustic Stimulation↗
Tumor localization in nude mice bearing human breast carcinoma xenografts using 111In-DTPA conjugates of monoclonal antibodies.
Biodistribution of monoclonal antibody T43 and its F(ab')2 111In-DTPA conjugates were determined in nu/nu mice bearing human breast tumor and rat pituitary tumor xenografts. T43 localized in the target tumor with tumor/blood ratios of 3.9 (P less than 0.01) and 4.5 (P less than 0.05) at 48 and 72 h, respectively. T43 F(ab')2 fragments localized with tumor/blood ratio of 14.2 (P less than 0.1) at 72 h. Tumors as small as 4 mm were detected without computer subtraction technique. These studies suggest that T43 and T43 F(ab')2 might be useful reagents in radioimaging.
Animals↗
Efficacy of brief, intense light exposure for treatment of winter depression.
A high-intensity fluorescent lighting system, tilted downward toward the head, and emitting negligible levels of ultraviolet radiation, was tested under two random crossover protocols in winter-depressed patients: 30-minute sessions at (a) 3,000 lux vs. 10,000 lux in early morning, and (b) morning vs. evening sessions at 10,000 lux. Judgment of clinical remission was based jointly on relative and absolute score improvements on a Structured Interview Guide for the Hamilton Depression Scale--Seasonal Affective Disorder Version (SIGH-SAD) and a set of supplementary atypical-vegetative items. Data are presented for 24 subjects who showed relapse upon withdrawal. An overall remission rate of 75 percent was found for morning light at 10,000 lux. The rates for evening light (25%) and 3,000 lux morning light (19%) were significantly lower. The remission rate for morning light treatment of 10,000 lux for 30 minutes approximately equalled 2,500 lux treatment for 2 hours (data from our earlier studies), suggesting a reciprocity between dosing dimensions of intensity and duration. No pathological changes were revealed by ophthalmological examinations given after 2 to 6 weeks of daily treatment.
Affect↗
Effects of magnesium sulfate on pentylenetetrazol-induced status epilepticus.
The use of magnesium sulfate (MgSO4) as an anticonvulsant is controversial. Status epilepticus was induced in 0.5% halothane-anesthetized Wistar rats with a threshold (90 mg/kg) or suprathreshold (200 mg/kg) dose of intravenous (i.v.) pentylenetetrazol (PTZ) under stereotactic hippocampal depth electrode monitoring. Fifteen minutes after seizure induction, the maximum hemodynamically tolerated dose of MgSO4 (10 mg/kg/min in 22 min) was administered i.v. MgSO4 was ineffective in altering seizure discharge. A subgroup of nine animals received hypertonic mannitol before MgSO4 to open the blood-brain barrier (BBB) to facilitate Mg2+ CNS penetration. Again MgSO4 was ineffective in attenuating epileptic activity. These results support the contention that MgSO4 is not an effective treatment for status epilepticus. We hypothesize that because Mg2+ blocks Ca2+ influx into the neuron through the N-methyl-D-aspartate (NMDA) receptor-operated calcium channel in a voltage-dependent manner it would be ineffective in neurons that are continuously depolarizing as in status epilepticus.
Animals↗