Journal of Neuro-Ophthalmology, June 1999, Volume 19, Issue 2

Literature Abstracts

Journal of Neuro- Ophthalmology 19( 2): 112- 117, 1999. © 1999 Lippincott Williams & Wilkins, Inc., Philadelphia Literature Abstracts Steven A. Newman Literature Abstracts- The American Journal of Neuroradiology, 1997 Clinicoanatomic and Pathologic Correlations MR Changes in the Calcarine Area Resulting From Retinal Degeneration. Kitajima M, Korogi Y, Hirai T, Hamatake S, Ikushima I, Sugahara T, Shigematsu Y, Takahashi M, Mukuno K. AJNR 1997; 18: 1291- 5. Nine patients with retinal degeneration were studied with magnetic resonance ( MR) that were compared with those of 30 control volunteers. Calcarine fissures were significantly dilated in patients with retinal degeneration, suggesting relative atrophy of the calcarine cortex. The authors suggest transsynaptic neuronal degeneration as­sociated with retinal changes. Because it is well recog­nized that development of the primary visual cortex re­quires image input, it is probably not necessary to invoke transsynaptic degeneration to explain decreased cortical volume in patients with abnormal retinas. Representation of the Visual Field in the Striate Cor­tex: Comparison of MR Findings With Visual Field Deficits in Organic Mercury Poisoning ( Minamata Disease). Korogi Y, Takahashi M, Hirai T, Ikushima I, Kitajima M, Sugahara T, Shigematsu Y, Okajima T, Mukuno K. AJNR 1997; 18: 1127- 30. Goldmann visual fields were correlated with imaging studies in eight patients with Minamata disease compar­ing the calcarine cortical atrophy with the visual field defects. The central 10° of the visual field was repre­sented by 20% of the cortical surface, with 30° of vision represented by 50% of the total surface. The authors conclude that the visual field defects in Minamata dis­ease correlate well with MR findings of abnormalities in the striate cortex, consistent with the classic Holmes rep­resentation. This is somewhat at variance with results in more recent studies from the University of California, San Francisco, suggesting that the Holmes map under­estimates the cortical representation of the central visual fields. Test- Retest Analysis With Functional MR of the Ac­tivated Area in the Human Visual Cortex. Rombouts SA, Barkhof F, Hoogenraad FG, Sprenger M, Valk J, Scheltens P. AJNR 1997; 18: 1317- 22. Functional MR promises to provide additional data about areas of cortical activity associated with sensory and motor performance. Twenty- eight volunteers were analyzed by functional MR for visual cortical activation after light- emitting diode stimulation. This preliminary study indicates significant variability in the location of cortical activity among subjects. This variability empha­sizes the need for additional physiologic data to compli­ment anatomic understanding. Cyclopia: Craniofacial Appearance on MR and Three- Dimensional CT. Liu DP, Burrowes DM, Qureshi MN. AJNR 1997; 18: 543- 6. Holoprosencephaly may be associated with variations of cyclopia. A midline orbit contained two globes with separate lenses supplied by a single optic nerve. Proton MR Spectroscopy in Coats Disease. Eisenberg L, Castillo M, Kwock L, Mukherji SK, Wallace DK. AJNR 1997; 18: 727- 9. Magnetic resonance spectroscopy is likely to be the next technical development in MR imaging. A 4- year- old boy with a retinal detachment had a computed tomo­graphic ( CT) scan that showed a tiny calcification. Mag­netic resonance spectroscopy revealed a peak corre­sponding to lipid in the subretinal space, characteristic of the exudate of Coats disease. Globe Tenting as a Result of Head Trauma. Hrach CJ, Quint DJ. AJNR 1997; 18: 980- 2. 112 LITERATURE ABSTRACTS 113 With 10 to 12 mm of redundant optic nerve, moderate acute proptosis usually does not cause a problem. If the proptosis is severe, however, there may be tenting of the globe posteriorly because of the inability of the optic nerve to stretch farther. In earlier articles, authors have suggested that this is an indication for acute orbital de­compression. A case of globe tenting due to trauma spon­taneously improved with conservative therapy over 4 days, suggesting that these patients may not require sur­gery. Comparison of Dynamic Contrast- Enhanced Gradi­ent- Echo and Spin- Echo Sequences in MR of Head and Neck Neoplasms. Escott EJ, Rao VM, Ko WD, Guitierrez JE. AJNR 1997; 18: 1411- 9. Standard MR spin- echo techniques provide excellent resolution of intracranial disease. Surgical planning, however, requires precise demarcation of tumor extent. In this study of 23 patients with tumors in the head and neck, dynamic gradient- echo techniques were compared with standard spin- echo imaging in a masked manner by three neuroradiologists. Dynamic gradient- echo images showed better or equal delineation of tumor extent in 21 of 23 patients. Adenosquamous Carcinoma of the Facial Bones, Skull Base, and Calvaria: CT and MR Manifesta­tions. Som PM, Silvers AR, Catalano PJ, Brandwein M, Khorsandi AS. AJNR 1997; 18: 173- 5. The. authors present a case of a 62- year- old woman with proptosis, decreased visual acuity, and evidence of bone destruction with a soft tissue lesion extending to involve the middle cranial fossa, cavernous sinus, and calvaria. Analysis of a biopsy specimen showed adeno­squamous carcinoma, an unusual variant of aggressive malignant disease that may involve the skull base. l l l l n Octreotide Scintigraphy in the Evaluation of Head and Neck Lesions. Whiteman ML, Serafini AN, Telischi FF, Civantos FJ, Falcone S. AJNR 1997; 18: 1073- 80. Octreotide scanning may detect neuroendocrine le­sions of the head and neck. Twenty- two patients with suspected lesions of the head and neck were studied with single photon emission CT images after receiving 6 mCi octreotide. Eighteen of the 22 patients had abnormal scans. Eleven paragangliomas were seen in 10 patients. Octreotide scans were also positive in metastatic medul­lary thyroid carcinoma, thyroid adenoma, Merkel cell tumor, and carcinoid. Proton MR Spectroscopy of Squamous Cell Carci­noma of the Extracranial Head and Neck: In Vitro and In Vivo Studies. Mukherji SK, Schiro S, Castillo M, Kwock L, Muller KE, Blackstock W. AJNR 1997; 18: 1057- 72. The authors investigated the ability of MR spectros­copy to differentiate tissue specimens of squamous cell carcinoma of the head and neck from normal tissue and cervical nodes with squamous cell involvement. The choline- to- creatine ratio was significantly increased in tumors compared with that in normal tissue. These analy­ses may have important clinical implications for recog­nition for squamous cell carcinoma involving the head and neck tissues. Heterotopic Brain in the Pterygopalatine Fossa. Kail-man JE, Loevner LA, Yousem DM, Chalian AA, Lanza DC, Jin L, Hayden RE. AJNR 1997; 18: 176- 9. Heterotopic brain outside the cranial vault has been reported within the orbit. This lesion is far less common than encephalocele or myelomeningocele. The authors report a case of heterotopic brain within the pterygopa­latine fossa. CT- Generated Porous Hydroxyapatite Orbital Floor Prosthesis as a Prototype Bioimplant. Levy RA, Chu TM, Halloran JW, Feinberg SE, Hollister S. AJNR 1997; 18: 1522- 5. Cranial imaging, particularly CT, can provide a tem­plate for generation of prosthetic replacement implants. Hydroxyapatite bioceramic was used to manufacture floor implants from previously acquired CT data. This combination of CT with computer- assisted design is likely to have an impact in creating systems to tailor bone replacement in the future. Atypical Skull Base Paragangliomas. Noble ER, Smoker WR, Ghatak NR. AJNR 1997; 18: 986- 90. Paragangliomas usually form along the carotid artery involving the sympathetic neural plexus. These can grow extensively causing destruction of the skull base. The authors present two cases of unusually large skull base paragangliomas with intracranial extension. J Neuro- Ophthalmol, Vol. 19, No. 2, 1999 114 LITERATURE ABSTRACTS Craniocerebral Plasmacytoma: MR Features. Provenzale JM, Schaefer P, Traweek ST, Ferry J, Moore JO, Friedman AH, McLendon RE. AJNR 1997; 18: 389- 92. The authors reviewed the MR characteristics in two patients with isolated skull base plasmacytomas. These lesions were isointense with gray matter on T2- weighted images and diffusely enhanced after gadolinium admin­istration. The pattern was similar to that in meningiomas. In this particular case, CT scanning may have been use­ful in distinguishing the bone involvement seen in me­ningiomas from that in plasmacytomas. Intracranial Disease Cystic Pituitary Mass in Neurosarcoidosis. Sato N, Sze G, Kim JH. AJNR 1997; 18: 1182- 5. Cystic masses within the sella are presumed secondary to pituitary adenomas. In this unusual case, a patient with neurosarcoidosis had an intrasellar cyst extending into the suprasellar space. Hemorrhagic Arachnoid Cyst With Third Nerve Paresis: CT and MR Findings. Ide C, De Coene B, Gilliard C, Polio C, Hoebeke M, Godfraind C, Trigaux JP. AJNR 1997; 18: 1407- 10. Acute third nerve dysfunction in a 37- year- old patient was related to a nontraumatic hemorrhage arachnoid cyst. Specific characteristics on CT and MR led to the diagnosis of this unusual cause of ophthalmoplegia. The Variable MR Appearance of Primary Lym­phoma of the Central Nervous System: Comparison With Histopathologic Features. Johnson B A, Fram EK, Johnson PC, Jacobowitz R. AJNR 1997; 18: 563- 72. The authors sought to identify the MR characteristics in a series of 23 patients with primary central nervous system lymphoma. Sixty- one lesions in the 23 patients were isointense or hypointense on Tl- weighted images. Half were isointense or hypointense on T2- weighted im­ages. Forty- three ( 91%) of 47 lesions in 20 patients treated with intravenous gadolinium showed an increase in signal on Tl- weighted images. Thus, gadolinium is essential for assessment of suspected primary central nervous system lymphoma. Fast Fluid- Attenuated Inversion- Recovery MR of In­tracranial Infections. Tsuchiya K, Inaoka S, Mizutani Y, Hachiya J. AJNR 1997; 18: 909- 13. Fast fluid- attenuated inversion- recovery ( FLAIR) se­quences has become the imaging study of choice in de­tecting lesions of demyelinating disease. The authors in­vestigated the use of this sequence in 20 patients with infectious processes affecting the central nervous system. The FLAIR images demonstrated pathologic changes in intracranial infections better than, or as well as, proton density or T2- weighted sequences. The authors found, however, that abscess, meningitis, cysticercosis, and epi­dural empyema were more visible on contrast- enhanced Tl- weighted images. Systemic Disease with Ophthalmic Manifestations Abnormal Ocular Enhancement in Sturge- Weber Syndrome: Correlation of Ocular MR and CT Find­ings with Clinical and Intracranial Imaging Findings. Griffiths PD, Boodram MB, Blaser S, Altomare F, Bun-cic JR, Levin AV, Jay V, Armstrong D, Harwood- Nash D. AJNR 1996; 17: 749- 54. In this study, 15 patients with Sturge- Weber syn­drome were examined with CT and MR imaging. All patients had evidence of intracranial involvement which was bilateral in 4 and unilateral in 11. Seven of the 15 patients had abnormal ocular enhancement. Imaging studies detected choroidal hemangiomas in 7 of 8 pa­tients, found on funduscopic evaluation. Although the hemangiomas were seen on both CT scan and MR im­ages, MR was more sensitive, and the authors regard it as the imaging study of choice in patients with Sturge- Weber. Multiple Sclerosis Comparison of Magnetic Resonance Pulse Sequences in the Detection of Multiple Sclerosis Lesions. Yousry TA, Filippi M, Becker C, Horsfield MA, Voltz R. AJNR 1997; 18: 959- 63. The authors compared several imaging techniques in the detection of demyelinating lesions, including conven­tional spin- echo, fast spin- echo, fluid- attenuated inver­sion- recovery ( FLAIR), and turbo gradient spin- echo in seven patients with multiple sclerosis. Fast spin- echo and FLAIR sequences substantially improved the detec­tion sensitivity of multiple sclerosis lesions compared with conventional spin- echo techniques. Turbo gradient spin- echo was inferior in terms of detection but had markedly reduced acquisition times, potentially of ben- J Neuro- Ophthalmol, Vol. 19, No. 2, 1999 LITERATURE ABSTRACTS 115 efit in those patients who could not tolerate longer ex­aminations. Serial Contrast- Enhanced MR in Patients with Mul­tiple Sclerosis and Varying Levels of Disability. Fil-ippi M, Rossi P, Campi A, Colombo B, Pereira C, Comi G. AJNR 1997; 18: 1549- 56. Fourteen patients with multiple sclerosis ( seven with absence of disability due to relapsing- remitting multiple sclerosis and seven patients with severe disability due to progressive disease) were studied with serial contrast en­hanced MR scans. Although equal numbers of T2- positive lesions were seen in both groups, the group with severe disability and progressive multiple sclerosis had far fewer enhancing lesions than did those with relaps­ing- remitting disease. Trials are planned for an increas­ing number of agents to influence the course of demye-linating disease, and it is important to recognize the po­tential for variability in MR findings in different disease forms. Computer- Assisted Quantitation of Enhancing Le­sions in Multiple Sclerosis: Correlation With Clinical Classification. Miki Y, Grossman RI, Udupa JK, Sama-rasekera S, van Buchem MA, Cooney BS, Pollack SN, Kolson DL, Constantinescu C, Polansky M, Mannon LJ. AJNR 1997; 18: 705- 10. In an effort to produce quantitative markers that cor­relate with disease activity in demyelinating disease, the authors have studied the utility of a computer- assisted method of quantitating enhancing lesions on MR scans in patients with multiple sclerosis. Patients were classified as having either relapsing- remitting ( n = 27) or chronic progressive ( n = 13) disease. There was a strong posi­tive correlation between the number of lesions and the total enhancing lesion volume. The enhancing lesion vol­ume was significantly greater in the relapsing- remitting disease than in the chronic progressive type. There was, however, no correlation between the disability status score and the number of enhancing lesions or total vol­ume. The utility of this parameter remains to be seen. Global Volumetric Estimation of Disease Burden in Multiple Sclerosis Based on Magnetization Transfer Imaging. Van Buchem MA, Udupa JK, McGowan JC, Miki Y, Heyning FH, Boncoeur- Martel MP, Kolson DL, Polansky M, Grossman RI. AJNR 1997; 18: 1287- 90. The authors report a semiautomated processing method based on magnetization transfer MR imaging in patients with multiple sclerosis. It is thought that this could help quantitate the extent of global disease seen on imaging studies. Single- Dose Gadolinium With Magnetization Trans­fer Versus Triple- Dose Gadolinium in the MR Detec­tion of Multiple Sclerosis Lesions. Van Waesberghe JH, Castelijns JA, Roser W, Silver N, Yousry T, Lyck-lama A, Nijeholt GJ, Ader HJ, Uitdehaag BM, Radue EW, Polman CH, Kappos L, Miller DH, Barkhof F. AJNR 1997; 18: 1279- 85. The efficacy of single- dose gadolinium analysis with magnetization transfer contrast was compared to that of triple- dose gadolinium in detecting enhancing lesions in 21 patients with multiple sclerosis. They found that triple- dose gadolinium is more effective than single- dose gadolinium even in combination with magnetization transfer contrast in detection of enhancing multiple scle­rosis lesions. Cerebrovascular Disease Cerebral Infarction in Patients With AIDS. Gillams AR, Allen E, Hrieb K, Venna N, Craven D, Carter AP. AJNR 1997; 18: 1581- 5. Patients with human immunodeficiency virus have multiple reasons for vascular insufficiency, including in­fectious processes and vasculitis. In this retrospective study of 71 patients with acquired immune deficiency syndrome, 22 infarcts were identified in 13 patients. Most of these ( n = 15) affected the basal ganglia area. Six patients had a history of cocaine or intravenous drug abuse, and five additional patients had evidence of con­comitant infections. Infarction secondary to multifacto­rial vascular occlusive disease is an additional patho­physiology underlying abnormal MR scans in patients with human immunodeficiency virus. T2 Shortening in the Visual Cortex: Effect of Aging and Cerebrovascular Disease. Korogi Y, Hirai T, Ko-mohara Y, Okuda T, Ikushima I, Kitajima M, Shigematu Y, Sugahara T, Takahashi M. AJNR 1997; 18: 711- 4. The authors reviewed T2- weighted calcarine cortical images in 72 neurologically normal subjects aged 35 to 92 years and in 32 patients with cerebrovascular disease ( age range, 54- 92 years). They noted a reduction T2 signal intensity within the sensory cortex increasing with age of more than 60 years thought to represent increasing iron deposition. Cerebrovascular disease, however, had J Neuro- Ophthalmol, Vol. 19, No. 2, 1999 116 LITERATURE ABSTRACTS no age- independent effect on the T2 signal in the visual cortex. Magnetic Resonance Angiography MR Angiography of Aneurysm Models of Various Shapes and Neck Sizes. Isoda H, Ramsey RG, Takehara Y, Takahashi M, Kaneko M. AJNR 1997; 18: 1463- 72. Time- of- flight MR angiography is useful in screening for intracranial aneurysms. Delineation depends on flow within the aneurysm, which varies with the size of the aneurysmal neck. In this study of four lateral and four terminal saccular aneurysms, shorter repetition time and larger flip angles showed a weaker signal intensity, par­ticularly in aneurysms with a wider neck. Longer repeti­tion times can improve resolution in MR angiography, although aneurysms with wider necks continue to be more difficult to delineate than those with a narrow neck. Intracranial Vascular Stenosis and Occlusion: MR Angiographic Findings. Korogi Y, Takahashi M, Na-kagawa T, Mabuchi N, Watabe T, Shiokawa Y, Shiga H, O'Uchi T, Miki H, Horikawa Y, Fujiwara S, Furuse M. AJNR 1997; 18: 135- 43. Magnetic resonance angiography using time- of- flight data is a convenient way of looking at the large vessels at the skull base. One recognized problem has been the overestimate of stenosis. In a retrospective study of 103 patients with MR angiography undergoing evaluation for possible intracranial vascular disease, four of five pa­tients with complete occlusions were correctly identified. Magnetic resonance angiography detected 14 ( 78%) of 18 cases of moderate and severe vascular obstructive disease. The authors point out that reviewing the source images reduces the tendency to overestimate stenosis in patients with greater than 50% occlusion. Interventional Neuroradiology Possible Role of Neuromterventional Techniques in the Diagnosis of Hemifacial Spasm. Yamashita K, Hojo M, Okamoto S, Kim C, Nakatsu S, Mishima H. AJNR 1997; 18: 287- 90. In the case of a 48- year- old- woman with hemifacial spasm, insertion of a microcatheter into the posterior inferior cerebellar artery immediately stopped the spasm. This suggests the intriguing possibility of neuromterven­tional treatment of hemifacial spasm. It is conceivable that reduction in the pulsatility of the vessel in contact with the root exit zone of the facial nerve may reduce or eliminate hemifacial spasm. Endovascular Treatment of Ophthalmic Segment An­eurysms With Guglielmi Detachable Coils. Roy D, Raymond J, Bouthillier A, Bojanowski MW, Moumdjian R, L'Esperance G. AJNR 1997; 18: 1207- 15. Twenty- six patients with 28 ophthalmic segment an­eurysms were treated with Guglielmi detachable coils. Complete occlusion could only be obtained in 14 aneu­rysms ( 50%). Success was significantly influenced by the size of the aneurysm's neck. Complete occlusion could be obtained in 76% of small neck aneurysms as opposed to 9% of aneurysms with a large neck. Covered Stent Placement for Neurovascular Disease. Singer RJ, Dake MD, Norbash A, Abe T, Marcellus ML, Marks MP. AJNR 1997; 18: 507- 9. Detachable coils cannot safely be packed into wide-necked aneurysms. If endovascular stents could be suc­cessfully navigated into the paraclinoid section, addi­tional side- mouthed aneurysms could be successfully treated. In this case report, a patient with a giant para­clinoid aneurysm was treated with a Gortex- covered Pal-maz stent to occlude the cervical internal carotid artery. In a second patient, a hooded stent occluded a high- flow vertebrojugular fistula. Embolization of Dural Cavernous Fistulas via Supe­rior Ophthalmic Vein Approach. Quinones D, Duck-wiler G, Gobin PY, Goldberg RA, Vinuela F. AJNR 1997; 18: 921- 8. When the inferior petrosal and other skull base venous accesses are not available to treat dural cavernous fistu-lae, direct approach through the superior ophthalmic vein is often possible. The authors reviewed 12 patients treated directly through the superior ophthalmic vein at the University of California Los Angeles Medical Center over 3 years. Embolization was successful in 12 of 13 patients with complete angiographic occlusion of the fis­tula. One patient had a suture granuloma and another had transient cavernous sinus syndrome with sixth nerve palsy. One patient had late recurrence of the fistula. J Neuro- Ophthalmol, Vol. 19, No. 2, 1999 LITERATURE ABSTRACTS 117 Direct Endovascular Thrombolytic Therapy for Du-ral Sinus Thrombosis: Infusion of Alteplase. Kim SY, Suh JH. AJNR 1997; 18: 639- 45. Dural sinus thrombosis can increased intracranial pressure. Interventional neuroradiologic techniques af­fords the opportunity of direct placement of thrombolytic agents. In nine patients treated with alteplase rapid thrombolysis was achieved in all. Complications were minimal, including oozing at the femoral puncture site and one pelvic hemorrhage. Directly administered thrombolytic therapy is an additional means to lyse clots in the cerebral venous outflow system. Dissecting Aneurysms of AH Four Cervicocranial Ar­teries in Fibromuscular Dysplasia: Treatment With Self- expanding Endovascular Stents, Coil Emboliza­tion, and Surgical Ligation. Manninen HI, Koivisto T, Saari T, Matsi PJ, Vanninen RL, Luukkonen M, Hernesniemi J. AJNR 1997; 18: 1216- 20. In a patient with cervicocranial fibromuscular dyspla­sia, a ruptured dissecting distal vertebral artery aneurysm was treated with clip ligation of the parent vertebral ar­tery. Additional dissecting extracranial aneurysm of the internal carotid arteries were treated with self- expanding stents. Intravascular stents have had limited use intracra-nially because of technical difficulties of placement, but they are already in use in extracranial applications. Dural Arteriovenous Fistulas of the Marginal Sinus. McDougall CG, Halbach VV, Dowd CF, Higashida RT, Larsen DW, Hieshima GB. AJNR 1997; 18: 1565- 72. Interventional neuroradiologic techniques offer new options for patients with dural arteriovenous fistulae in­volving the marginal sinus. In 1 of 14 patients treated at the University of San Francisco, California, transient hy­poglossal nerve palsy developed. There were no other serious complications. This outcome may be compared with the potential serious consequence if marginal sinus dural arteriovenous fistulae are untreated. Two patients had previous intracranial hemorrhage and one had ataxia. Stereotactic Radiosurgery Cerebral Arteriovenous Malformations: The Value of Radiologic Parameters in Predicting Response to Ra­diosurgery. Meder JF, Oppenheim C, Blustajn J, Nataf F, Merienne L, Lefkoupolos D, Laurent A, Merland JJ, Schlienger M, Fredy D. AJNR 1997; 18: 1473- 83. Serial posttreatment MR images in 102 patients with arteriovenous malformations treated with radiosurgery were reviewed. Response to treatment seemed to corre­late with depth within the parenchyma and specific an-gioarchitecture. Size has been recognized as a predictive factor. These additional two parameters may also prove useful in predicting successful occlusion by stereotactic radiosurgery. J Neuro- Ophthalmol, Vol. 19, No. 2, 1999