bluuebunny/crossref_metadata_2025 huggingface dataset:
Posthemorrhagic Dilation of the Neonatal Fourth Ventricle
Authors: Gibson John Y. , Massingale Twila C. , Graves Glen R.
Published: February 2016

A retrospective review of 285 very‐low‐birth‐weight infants with periventricular‐intraventricular hemorrhage revealed that 20 infants developed posthemorrhagic dilation of the fourth ventricle. Evaluation of the survivors for 16 months (mean follow‐up period) showed a statistically significant increase in severe disability and in impaired cognitive development, compared with an equal number of control subjects matched for birth weight and grade of hemorrhage. These findings indicate that very‐low‐birth‐weight infants who develop dilation of the fourth ventricle following periventricular‐intraventricular hemorrhage have a greater likelihood of a poor outcome than those who do not have this complication. The predictive function of this sign appears to be independent of the grade of hemorrhage.
Progressive Brainstem Disease in a 32‐Year‐Old Man with a Pituitary Adenoma and Longstanding Diabetes Insipidus
Authors: Sanders Keith A. , Fetell Michael R.
Published: February 2016

A 32‐year‐old man who had unexplained diabetes insipidus for 14 years developed hypogonadism and was found to have a pituitary adenoma. Shortly thereafter he noted a progressive brainstem syndrome. Computed tomography and magnetic resonance imaging revealed lesions in the pituitary fossa and brainstem. Dr Keith A. Sanders discusses the differential diagnosis of these lesions, focusing on the significance of diabetes insipidus in a patient with a pituitary tumor, and the specificity of magnetic resonance imaging. Dr Michael R. Fetell discusses the histopathological findings and clinical pathological correlations in this unusual case.
Delayed Radiation Injury to the Optic Nerves
Authors: Carl Ellenberger
Published: February 2016

Until recently, diagnosis of delayed radiation‐induced injury to the optic nerves was based only on a visual deficit detected after cranial irradiation and an absence of direct optic nerve involvement by tumor. Now contrast‐enhanced magnetic resonance imaging (MRI) can demonstrate breakdown of the bloodbrain barrier in the optic nerves to provide stronger evidence for the diagnosis. This case illustrates that the MRI abnormality, and abnormalities of the ocular fundus, may precede visual symptoms. More precisely delivered radiation may prevent this complication.
Current and Future Technological Trends in Positron Emission Tomography
Authors: Karp Joel S. , Freifelder Richard
Published: February 2016

Current trends in positron emission tomography (PET) instrumentation are examined, with an emphasis on providing information suitable to the prospective PET user. Basic principles underlying PET are explained and information on performance measurements, techniques, and quantitation are given in order to allow the user to compare and contrast different types of PET scanners. These scanner designs are described. Specific examples are given and the combination of PET with other modalities is discussed.
Emergency Transcranial Doppler Assessment of Intracranial Vertebral Artery Dissection
Authors: Fredericks Ruth K. , McCormick George , Tegeler Charles , Troost B. Todd , Tesh Paul
Published: February 2016

Despite its risks, contrast angiography is the method of definitive diagnosis of vertebral artery dissection. This presents the case of a 49‐year‐old white man with ischemic symptomatology in the posterior circulation in whom transcranial Doppler sonography suggested vertebral dissection, leading to confirmation by emergency angiography and rapid institution of therapy.
Continuous Blood Flow Velocity Measurements in Obstructive Sleep Apnea Syndrome
Authors: Rieke Klaus , Poceta J. Steven , Mitler Merrill M. , Ley Larry R. , Torruella Ann K. , Adams Hans-Peter , Otis Shirley M.
Published: February 2016

Mean blood flow velocity was measured by transcranial Doppler (TCD) sonography in 15 patients with obstructive sleep apnea syndrome. Relative increases of mean flow velocity in the middle cerebral artery (MCA) during apneas were seen in all patients, and were related to the severity of desaturation (p < 0.05). Additionally, a relationship between mean flow velocity and both end‐tidal carbon dioxide pressure and oxyhemoglobin desaturation could be demonstrated, suggesting that cerebral blood flow is regulated by both parameters. After patients were treated with nasal continuous positive airway pressure, the mean flow velocity was normalized, demonstrating a beneficial effect of this treatment. Magnetic resonance imaging of the brain demonstrated abnormalities in 2 patients, raising the possibility that daytime neuronal dysfunction in sleep apnea patients may relate to increased mean flow velocity with secondary microvascular damage.
Multiple Cranial Nerve Palsies in a Patient 15 Years after Curative Therapy for a Pituitary Adenoma
Authors: Stechison Michael T. , Brogan Martha , Yates Allan J. , Yates Allan J.
Published: February 2016

Over a 3‐year period, a 31‐year‐old man developed multiple cranial nerve palsies consisting of diplopia, left‐sided facial numbness and weakness, and loss of the left corneal reflex. Fifteen years prior to presentation, he had undergone curative therapy for a prolactin‐secreting pituitary macroadenoma. The imaging studies were helpful in localizing the disease process, which correlated well with the clinical examination, and for focusing the differential diagnosis.
Differentiation Between Ischemic and Hemorrhagic Stroke by Transcranial Color‐coded Real‐time Sonography
Authors: Becker G. , Winkler J. , Hofmann E. , Bogdahn U.
Published: February 2016

Transcranial color‐coded real‐time sonography was applied to 20 patients with ischemic stroke and 28 patients with spontaneous intracerebral hemorrhage. In all patients the sonographic diagnosis corresponded closely to cranial computed tomography findings. Recent hemorrhages were visualized as a hyperechodense mass. The high contrast to minor echodense adjacent parenchyma led to a clear sonographic distinction. Older clots were characterized by a continuous decrease of echodensity and subsequently were interspersed by hypoechodense zones. In the acute stage of ischemic infarction, the vessel occlusion (17/20) and collateral vascular supply (1 0/20) could be depicted in the color‐B‐mode in two perpendicular planes and further verified by the Doppler mode. Brain edema was not visualized. Although in the acute stage no change of echo texture was observed within the infarction, hyperechodense regions (7/11) could be observed in some patients during the time course. Complications of intracerebral hemorrhage and ischemic stroke, such as disturbance of cerebrospinal fluid circulation, midline shift, and compression of adjacent territories, were depicted by transcranial color‐coded sonography. These preliminary results illustrate that transcranial color‐coded realtime sonography may be helpful in the early noninvasive differential diagnosis as well as long‐term follow‐up in patients with cerebrovascular disorders.
Sensory Level and Parietal Lobe Hemorrhage
Authors: Schmid F. , Bogousslavsky J. , Ghika J. , Bassetti C. , Regli F.
Published: February 2016

A 39‐year‐old woman with a right sensory level at T3 involving touch, pain, temperature, vibration, and position was found to have a small hemorrhage in the superior part of the postcentral gyrus. This case points out an unusual clinical presentation of parietal lobe lesion and provides clinicoanatomical correlation of the somatatopic organization of the sensory cortex. Furthermore, it confirms that sensory disturbance with a segmental level suggestive of a spinal cord lesion can be caused by a parietal lesion.
Dexamethasone and Brain Tumor Glucose Uptake; A Positron Emission Tomographic Study
Authors: Rozental Jack M , Levine Ross L , Levin Allan B , Nickels Robert J
Published: February 2016

Serial positron emission tomography scans with [18F]fluorodeoxyglucose (FDG) were acquired from 3 patients with malignant gliomas before and after 24 hours of dexamethasone administration (a total of 40 mg administered intravenously over 24 hours). Peak FDG uptake by the tumor decreased 10 to 20% in the posttreatment scans. The data suggest that at least some of the beneficial effects of dexamethasone on the signs and symptoms of tumor‐related increased intracranial pressure might relate to a direct acute effect on glucose metabolism.
Motor Activation by Single‐Photon Emission Computed Tomography: A Comparison of Xenon‐133 and Technetium‐99m HM‐PAO “Split‐Dose” Methods
Authors: Di Piero V. , Pantano P. , Ricci M. , Lenzi G. L.
Published: February 2016

Single‐photon emission computed tomography (SPECT) was used to investigate the feasibility of the technetium 99m‐hexamethylpropyleneamineoxime (99mTc HM‐PAO) split‐dose method to evidence changes in regional cerebral blood flow during a motor activation task, in comparison with a quantitative method using the inhalatory xenon‐133. Four subjects were studied twice with both methods, at rest and during finger opposition movements. On the activated cerebral hemisphere, a significant increase in regional cerebral blood flow was observed over the motor cortical areas. The average increases were + 28.1 ± 5.6% for the xenon‐133 method and + 12.3 ± 5.2% for the 99mTc HM‐PAO method. By using the linearization algorithm for the 99mTc HM‐PAO method, a mean increase of + 22.5 ± 8.9% was calculated. This study demonstrated that the split‐dose method allows the motor activation SPECT studies with 99mTc HM‐PAO to be done in a single session.
The Clinical Utility of Transcranial Doppler Ultrasound in Suspected Vertebrobasilar Ischemia
Authors: Kinsella Laurence J. , Feldmann Edward , Brooks Jamie M.
Published: February 2016

The impact of transcranial Doppler ultrasound (TCD) on the management of 107 consecutively referred patients with suspected vertebrobasilar ischemia was studied. Physicians who referred patients for TCD of the posterior circulation were interviewed before and after being given the results of the TCD examination. Management plans devised prior to knowledge of the TCD results were compared to those devised after TCD results were given. Management changed in 42% of the patients after TCD results were given, and there was a 58% reduction in the use of angiography (p = 0.04) and a 128% increase in the use of aspirin (p = 0.005). Changes in the use of anticoagulants and other diagnostic or therapeutic approaches were not significant. TCD appears to have a significant impact on the management of patients with suspected vertebrobasilar ischemia.
Disseminated Diffuse Sclerosis; A Variety of Multiple Sclerosis with Characteristic Clinical, Neuroimaging, and Pathological Findings
Authors: Anselmi Gregory , Masdeu Joseph C , Macaluso Claude , Donnenfeld Hyman
Published: February 2016

A 20‐year‐old man had a subacute onset of frontal lobe findings and seizures. Computed tomography and magnetic resonance imaging showed three large lesions with mass effect and ring enhancement. Histology and biochemistry confirmed a demyelinating process similar to myelinoclastic diffuse sclerosis but with multiple, noncontiguous lesions. This variety of multiple sclerosis (MS) with clinical, neuroimaging, histological, and treatment characteristics different from typical MS could be termed disseminated diffuse sclerosis.
In Vitro Validation of Color Velocity Imaging and Spectral Doppler for Velocity Determination
Authors: Eicke B. Martin , Tegeler Charles H. , Howard George , Bennett John B. , Myers Larry G. , Meads Dana
Published: February 2016

Color velocity imaging (CVI) is a new non‐Doppler ultrasound technique for vascular color flow imaging. Using information contained in the two‐dimensional B‐mode, gray‐scale image to determine velocity, CVI offers potential advantages over Doppler color flow imaging methods. In order to be used clinically, velocity determination with CVI must be validated by other current methods. A Doppler string phantom was studied with a Philips CVI ultrasound system. Velocity measurements were obtained by both CVI and duplex Doppler spectral analysis for constant string speeds from 10 to 200 cm/sec, at intervals of 10 cm/sec. Twenty separate estimates were obtained with each method, at each string speed. Linear regression assessed the relationship between estimated and actual string velocities, with CVI and spectral Doppler analysis yielding highly valid results (CVI = −0.713 + 1.000997 × phantom; r2 = 0.9979). At all string speeds tested, the averaged estimated and the actual velocities for both methods were within the 95% confidence estimates. The range for the CVI 95% confidence limits from the regression line varied from ± 1.07 cmjsec at the lowest speed of 10 cmjsec (11.6%) to ± 7. 72 cm/sec at 200 cm/sec (3.87%). Based on in vitro testing, CVI is as accurate as Doppler spectral analysis for the estimation of flow velocity.
Backache, Unsteady Gait, Incontinence, and Large Thoracic Epidural Mass
Authors: Maertens Paul , Snow Ruth , Boudreaux Carole , Bastian Frank , Weber Eric
Published: February 2016

Unsteady gait with frequent falls and urinary incontinence appeared over a period of a few days in a 6‐year‐old girl with a long history of backache. A large posterior epidural mass involved the lower thoracic vertebral canal and extended over several vertebral levels, suggesting a diagnosis of epidural hemorrhage with spinal cord compression. Examination of a surgical specimen led to a different diagnosis.
The Transcranial Doppler Standardization Project
Authors: Gomez Camilo R. , Brass Lawrence M. , Tegeler Charles H. , Babikian Viken L. , Sloan Michael A. , Feldmann Edward , Wechsler Lawrence R.
Published: February 2016

A project to pursue standardization of the performance and interpretation of transcranial Doppler studies was designed. Phase I consisted of a national survey of the current practice of transcranial Doppler in the United States. From 200 ultrasound laboratories surveyed about the use of transcranial Doppler, 60 completed questionnaires were returned. The results show that further standardization of transcranial Doppler performance and interpretation is necessary, and provide the foundation for phases II and III of the project.
Cerebral Perfusion Index
Authors: Alexandrov Andrei V. , Ehrlich Lisa E. , Bladin Christopher F. , Norris John W.
Published: February 2016

Single‐photon emission computed tomography (SPECT) and transcranial Doppler (TCD) ultrasound are of good prognostic value in acute stroke, and combined they may be an accurate way to determine a target group of patients with maximum therapeutic response. Seventy consecutive patients were studied (42 with middle cerebral artery strokes, 18 with transient ischemic attacks [TIAs]; 10 were excluded due to failure of insonation). Two SPECT studies were performed at 2.1 ± 1.2 and 13.8 ± 3.1 days after onset. Serial TCD studies were done at 10 hours and at the time of the SPECT studies. Neurological deficit was scored on admission and 2 weeks later (using the Canadian Neurological Scale). Cerebral perfusion index (CPI) was derived by multiplying the values for TCD and SPECT patterns. Positive correlation was obtained in all 16 patients in whom cerebral angiography was performed within the first 3 days after onset. The occlusive TCD pattern and absence of perfusion on SPECT were common in the stroke group (19/42 patients) and were never seen in those with TIAs. A normal TCD pattern and normal perfusion on SPECT were more common in the patients with TIAs (9/18 vs 8/42, p = 0.02; 5/10 vs 1/40, p = 0.0003). The occlusive TCD and SPECT patterns were associated with the highest mean infarction volume (147 ± 87 vs 19 ± 21, p < 0.0001) and all nonocclusive TCD and SPECT patterns were associated with the better short‐term outcome (43.2 ± 33.9 vs 92.4 ± 20.2, p < 0.0001). A tendency for hyperfixation of the tracer to be more common in cardioembolic stroke was found. The three grades of the initial CPI (1–5, 6–12, 15–20) were found to predict different degrees of short‐term outcome (good, medium, and poor). The TCD and SPECT combination (CPI) may prove to be a safe, fast, and reliable noninvasive substitute for angiography.
Magnetic Resonance Imaging in Intracranial Paracoccidioidomycosis
Authors: Magalhaes A. C. A. , Caramelli P. , Silva E. D. , Bacheschi L. A. , Lo L. S. , Menezes J. R. , Shikanai-Yasuda M. A. , Magalhaes A. , Polachini Ilydio
Published: February 2016

Paracoccidioidomycosis is a systemic mycosis, endemic in South and Central America, that affects the central nervous system (CNS) in almost 10% of patients. Neurological involvement includes two different clinical forms: meningeal and granulomatous, also known as the pseudotumor form. Five patients with biopsy‐proved systemic paracoccidioidomycosis and neurological complaints were studied by magnetic resonance imaging. CNS involvement was detected in all patients in the form of multiple round or lobulated lesions, predominantly hypointense on T2‐weighted images and ring or nodular enhancement on post‐gadolinium T1‐weighted images. The lesions were distributed diffusely, with a slight predominance in the supratentorial compartment, although infratentorial lesions were also observed, mainly in the cerebellum. Hypointense lesions on T2‐weighted images persisted in all 3 patients reexamined after treatment, whereas enhancing lesions on post‐gadolinium T1‐weighted images turned isointense in 2 patients. Magnetic resonance imaging is a sensitive method in documenting CNS paracoccidioidomycosis, most frequently as supratentorial and infratentorial multiple, round or lobulated hypointense lesions on T2‐weighted images.
Advantages of Color Doppler Imaging for the Evaluation of Vertebral Arteries
Authors: Bartels Eva , Flügel K. A.
Published: February 2016

Assessment of the vertebral arteries is often difficult with conventional duplex ultrasonography. This study of 60 patients aimed to determine the potential advantages of color Doppler imaging over conventional duplex ultrasonography in the evaluation of vertebral arteries, specifically three extracranial segments of these vessels. Both methods allowed visualization of the vertebral artery in the midcervical course (V2 and distal V1 segments) in all subjects. Color Doppler imaging appeared more effective for visualization of the VO and the proximal V1 segments (on the right side in 88% of patients and on the left side in 73%). Conventional duplex ultrasonography imaged the ostium on the right side in 80% of patients and on the left side in 65%, but was difficult and time‐consuming. Visualization at the atlas loop (V3 segment) was rarely successful with duplex sonography, whereas color Doppler imaging visualized the vertebral artery on the right side in 87% of patients and on the left side in 85%. Color Doppler imaging allows better visualization of the proximal and distal segments of the vertebral arteries, compared to conventional duplex ultrasonography.
Single‐Photon Emission Computed Tomography, Transcranial Doppler Ultrasound, and Cerebral Angioplasty for Posttraumatic Vasospasm
Authors: Lewis David H. , Eskridge Joseph M. , Newell David W. , Grady M. Sean , Winn H. Richard
Published: February 2016

Intracranial arterial vasospasm is an important consequence of subarachnoid hemorrhage. In posttraumatic patients, this phenomenon is becoming increasingly recognized with noninvasive techniques that evaluate (1) vascular stenosis, such as transcranial Doppler (TCD) ultrasound, and (2) regional cerebral blood flow, such as single‐photon emission computed tomography (SPECT). A posttraumatic patient developed symptomatic vasospasm that was detected by TCD and SPECT and then treated with percutaneous transluminal balloon cerebral angioplasty, which improved the symptoms. The anatomical and functional results of angioplasty were evaluated also by TCD and SPECT, which showed a reduction in the severity of stenosis and improved blood flow, respectively.
Acute Pancerebellar Syndrome During Recovery from Alcohol Withdrawal
Authors: Venkatesh Swamy , Venna Nagagopal , Sabin Thomas D.
Published: February 2016

An acute pancerebellar syndrome developed in a 40‐year‐old, alcoholic, malnourished woman while she was recovering from alcoholic hepatitis in the hospital. Brain magnetic resonance imaging showed a lesion in the pons and helped identify this syndrome as central pontine myelinosis despite the lack of typical neurological signs and fluxes of serum sodium levels.
Identification of Ventricular Enlargement and Estimation of Intracranial Pressure by Transcranial Color‐Coded Real‐Time Sonography
Authors: Becker G , Bogdahn U , Straßburg H‐M , Lindner A , Hassel W , Meixensberger J , Hofmann E
Published: February 2016

Transcranial color‐coded real‐time sonography (TCCS) was applied to 26 patients with ventricular enlargement to quantify the ventricular size and to estimate intracranial pressure. Intracranial pressures, as determined by lumbar, epidural, or ventricular tonometry, ranged from 6.5 to 55 cm H20 (8 patients had pressures > 18 cm H20). The widths of the third ventricle and the frontal horns of both lateral ventricles depicted by TCCS were compared to corresponding computed tomography data: TCCS and computed tomography findings correlated well for the third ventricle (r = 0.96) and for the right (r = 0.86) and left (r = 0.92) frontal horns. The capability of the septum pellucidum to undulate relative to the ventricular wall during short (20‐degree) rotatory movements of the head was related to intracranial pressure. In all patients with intracranial pressure below 17 cm H20, rotatory head movements induced septum pellucidum undulation; no lateral deflection of the septum pellucidum was found in patients with an intracranial pressure above 21 cm H20. Therefore, TCCS may be employed to quantify and follow‐up ventricular enlargement. Dynamic neurosonographic tests may allow a gross estimation of intracranial pressure.
Angle Correction in Transcranial Doppler Sonography
Authors: Martin Eicke B , Tegeler Charles H , Dalley Gary , Myers Lawrence G
Published: February 2016

Since the introduction of transcranial Doppler sonography in the early 1980s, flow velocity estimates have assumed a 0‐ to 30‐degree angle of insonation. Based on limited radiological and anatomical studies. such an assumption appeared justified, and seemed to confer only minimal potential for error due to the cosine function in the Doppler formula. The introduction of transcranial color duplex sonography allows the direct evaluation of this assumption and the effect on flow velocities. Fifteen healthy volunteers were studied bilaterally using a unilateral transtemporal approach from the right. Velocity measurements were taken from the middle, anterior, and posterior cerebral arteries. Flow velocities were obtained with and without angle correction (0 degree). After completion of the color duplex study, velocities were obtained with a conventional, “blind” Doppler transducer at corresponding depths. For all insonated vessels the average angle of insonation was around 30 degrees. However, there was a wide variability of individual angles of insonation (0–70 degrees) in specific vessels. In 74.5% of all vessels, the angle‐corrected flow velocity did not exceed the uncorrected velocity by more than 25%. In 14.5% the angle‐corrected velocity was 25 to 50% higher and in 10.8% it was more than 50% higher as compared to the uncorrected velocity. Thus, the angle of insonation was unpredictable and often higher than originally expected. Angle‐corrected velocities were higher than uncorrected values, and were more than 25% higher in about one‐fourth of the vessels studied. Understanding of the clinical importance of such differences requires further study.
Clinical Recognition of Granulomatous Angiitis of the Brain: Novel Magnetic Resonance Image
Authors: Arora Ravinder , White Harry H
Published: February 2016

Granulomatous angiitis of the brain is a rare form of vasculitis affecting small and medium‐size blood vessels. The most common initial symptoms include headache and confusion after age 45. The cerebrospinal fluid is almost always abnormal with lymphocytic pleocytosis and protein content over 100 μg/dl. Diagnosis may be supported by contrast‐enhanced magnetic resonance imaging findings of a hypointense granuloma surrounding a hyperintense blood vessel. Described herein is a previously unrecorded magnetic resonance image in an autopsied case of granulomatous angiitis of the brain.
Central Pontine Myelinolysis with Complete Recovery
Authors: Keilson Marshall J , Drexler Ellen , Miller Aaron E , Bruining Kersti
Published: February 2016

A 35‐year‐old woman made a complete clinical recovery after having central pontine myelinolysis despite persistence of a typical lesion on a magnetic resonance image 6 years after diagnosis.
Is Angle Correction Correct?
Authors: Giller Cole A
Published: February 2016

The use of the Doppler principle to measure blood velocity is efficiently exploited in clinical practice by precisely aiming a beam of ultrasound through a superficial “ultrasonic window” at the desired target. This allows insonation of otherwise obscure vessels, but it also results in a crucial limitation: The dependence of the velocity measurements on the angle between the ultrasound beam and the direction of blood flow. When a long segment of the vessel can be imaged in one plane, “correcting” the velocity by the appropriate factor (cosine of the angle) is now standard. The result is a more accurate measurement of true velocity, and normal and pathological ranges have been established using this straightforward adjustment.
Magnetic Resonance Imaging Functional Activation of Left Frontal Cortex During Covert Word Production
Authors: Rueckert L , Appollonio I , Grafman J , Jezzard P , Johnson R , Le Bihan D , Turner R
Published: February 2016

Six normal volunteers underwent 4‐T functional magnetic resonance imaging while performing a covert letter fluency task. An echo planar imaging sequence was utilized to detect activation based on deoxyhemoglobin contrast. All 6 subjects showed consistent activation in the frontal operculum and premotor and primary motor cortices. Activation was also detected in the supramarginal gyrus and the posterior part of the superior temporal gyrus. These results show that magnetic resonance functional neuroimaging can be used to investigate cerebral activity noninvasively during performance of complex cognitive tasks.
Quantitative Measurements of Blood Flow Velocity in Basal Cerebral Arteries with Transcranial Duplex Color‐Flow Imaging: A Comparative Study with Conventional Transcranial Doppler Sonography
Authors: Bartels Eva , Flügel K. A.
Published: February 2016

Transcranial duplex color‐flow imaging is a new diagnostic method that allows visual display of blood flow in the basal cerebral arteries. This method allows determination of and correction for the Doppler angle of insonation. Conventional transcranial Doppler sonography has no imaging component and assumes a 0‐degree Doppler angle for the calculation of flow velocities. The magnitude of the angle of insonation and the effect on flow velocity estimates have not been clearly defined. In order to evaluate the angle of insonation and the effect of angle correction on velocity readings, 50 patients referred for evaluation of cerebrovascular disease were studied. The mean age was 45 years (range, 24‐62 yr). All were examined with conventional transcranial Doppler and transcranial duplex color‐flow imaging. Specific vessels of the circle of Willis were identified by location, course, and direction of flow on color‐flow images and by depth, direction of flow, and transducer orientation with conventional Doppler sonography. Visually controlled measurements of the Doppler angle of insonation were made by color‐flow imaging. The data show that the mean angle of insonation was 33 degrees (± 15) in the middle cerebral artery, 35 degrees (± 17) in the anterior cerebral artery, 45 degrees (± 18) in the posterior cerebral artery, and 15 degrees (± 14) in the basilar artery. Angle‐corrected peak systolic flow velocities were higher in all vessel segments (middle cerebral = 15%, anterior cerebral = 18%, posterior cerebral = 30%, and basilar = 3%), compared to uncorrected velocity readings by conventional Doppler sonography. Colorflow imaging facilitates determination of the angle of insonation and angle correction of flow velocity estimates. These data suggest that the angle of insonation is greater than previously appreciated. Angle correction yielded higher average flow velocities in all vessels. The clinical importance of these higher, angle‐corrected velocities is not known.
Longitudinal Monitoring of Intracranial Arterial Stenoses with Transcranial Doppler Ultrasonography
Authors: Schwarze Jens J. , Babikian Viken , DeWitt L. Dana , Sloan Michael A. , Wechsler Lawrence R. , Gomez Camilo R. , Pochay Val , Baker Errol
Published: February 2016

The natural history of intracranial arterial stenoses remains relatively unknown. To monitor the progression of these lesions over time, the authors reviewed transcranial Doppler (TCD) laboratory reports at five hospitals for patients with angiographically documented intracranial arterial stenoses along the internal carotid artery distribution, and at least two TCD studies conducted more than 2 months apart. Twenty‐two patients (19 men and 3 women; mean age, 64 years) with 29 stenoses were identified. The findings were compared to reproducibility data obtained from 11 age‐matched control subjects with repeat TCD studies. During a mean follow‐up period of 21 months, peak systolic flow velocities corresponding to the areas of stenosis increased in 9 arteries with lesions, and new collateral flow patterns, indicating further hemodynamic compromise distal to the lesions, developed in 2; one of the latter also had increased corresponding velocities. Thus, 10 (35%) arteries with lesions had TCD evidence of progression. Flow velocities remained the same in 13 (45%) stenotic vessels and dropped in 2 (7%). Findings were considered inconclusive for 4 lesions (14%). These findings suggest that intracranial arterial stenoses are dynamic lesions, and that they can evolve and cause further reductions of the arterial diameters after relatively short periods of time. TCD can noninvasively detect their hemodynamic efects.
Hyperdense Basilar Artery An Early Computed Tomography Sign of Thrombosis
Authors: Ehsan Tajammul , Hayat Ghazala , Malkoff Marc D. , Selhorst John B. , Martin David , Manepalli Anantha
Published: February 2016

Noncontrast computed tomographic scans (CT scans) may show a hyperdense basilar artery before a brainstem infarct is visualized. This early sign should assist clinicians in confirming the diagnosis of basilar artery thrombosis. In a review of admission records of 750 patients with acute cerebrovascular disease from July 1991 to June 1993, at Saint Louis University Hospital, 20 patients were identified with clinical signs of nonlacunar, vertebrobasilar distribution infarction. Eight of these had pontomesencephalic ischemia. Their neuroimaging studies and medical records were evaluated. Four patients with acute clinical signs of pontomesencephalic infarction were found to have a hyperdense basilar artery on CT scans. The scans of 2 patients were excluded because of dolichoectasia; in the other 2 patients, the basilar artery appeared normal on the CT scan. The hyperdense basilar artery was detected within the early hours of neurological symptoms and often was the only detectable abnormality on the scan. In 3 patients extensive brainstem infarcts subsequently developed and they died. Basilar artery thrombosis was confirmed by pathological study in all these patients. In the fourth patient basilar artery occlusion and a large pontine infarct were evident by magnetic resonance imaging and angiography. A hyperdense basilar artery is a common feature on CT scans of patients presenting with an early clinical diagnosis of thrombosis. Untreated, the hyperintense basilar artery often portends a poor prognosis. Its ready recognition should guide further interventional studies and treatment.
Measurement of Anterior and Posterior Circulation Flow Contributions to Cerebral Blood Flow
Authors: Boyajian Robert A. , Schwend Raymond B. , Wolfe Mary M. , Bickerton Robert E. , Otis Shirley M.
Published: February 2016

Ultrasound‐derived volumetric flow analysis may be useful in answering questions of basic physiological interest in the cerebrovascular circulation. Using this technique, the authors have sought to describe quantitatively the complete concurrent flow relations among all four arteries supplying the brain. The aim of this study of normal subjects was to determine the relative flow contributions of the antenor (internal carotid arteries) and posterior (vertebral arteries) cerebral circulation. Comparisons between the observed and theoretically expected anterior and posterior flow distribution would provide an opportunity to assess traditional rheological conceptions in vivo. Pulsed color Doppler ultrasonography was used to measure mean flow rates in the internal carotid and vertebral arteries in 21 normal adults. The anterior circulation (Internal carotid arteries bilaterally) carried 82% of the brain's blood supply and compnsed 67% of the total vascular cross‐sectional area. These values demonstrate precise concordance between observations in vivo and the theoretically derived (Hagen‐Poiseuille) expected flow distribution. These cerebrovascular findings support the traditional conception of macroscopic blood flow. Further studies using ultrasound‐derived volumetric analysis of the brain's arterial flow relations may illuminate the vascular pathophysiology underlying aging, cerebral ischemia, and dementias.
Muscle Computed Tomography Features of Motor Neuron Disease in Late‐Onset GM2 Gangliosidosis
Authors: Streifler Jonathan Y. , Hadar Herzlia , Gadoth Natan
Published: February 2016

Late‐onset GM, gangliosidosis, a rare inherited neuronal storage disease, is characterized by a vanety of clinical manifestations. The common clinical picture comprises neuromuscular, spinocerebellar, extrapyramidal, cognitive, and psychiatric abnormalities. Details of the extent of muscle involvement have never been reported. Eight patients with this syndrome were evaluated for the existence and extent of motor neuron disease using routine electrodiagnosis and systematic evaluation of skeletal musculature by computed tomography. Motor neuron disease was present in each and every patient regardless of the clmical manifestations and to a degree beyond that suspected on neurological examination. Muscle imaging disclosed a diffuse wasting and fatty replacement of muscles with predilection of pelvic and thigh muscles, and especially the quadriceps group. It seems that progressive motor disability in this syndrome IS mainly due to motor neuron disease, as manifested by muscle atrophy, which can be easily demonstrated by muscle computed tomography.
Magnetic Resonance Imaging of Cauda Equina Syndrome in Ankylosing Spondylitis: A Case Report
Authors: Koenigsberg Robert A. , Klahr Jonathan , Zito Joseph L. , Patel Mahendra , Carsons Steven
Published: February 2016

A case of ankylosing spondylitis associated with massive dural ectasia is presented. Computed tomography and magnetic resonance imaging characteristics are shown, and possible causes are discussed.
Infratentorial Cerebral Cryptococcosis
Authors: Borresen Thor E. , Hunter David R.
Published: February 2016

In a nonimmunocompromised patient with cerebral cryptococcosis, unique magnetic resonance findings included abnormalities limited to the posterior fossa and cerebellar hemispheric edema, gyriform enhancement of the vermis and cerebellar hemispheres, and infratentorial plaquelike enhancement. Magnetic resonance findings in central nervous system cryptococcosis are discussed.
Hippocampal Volume Measurements Using Magnetic Resonance Imaging in Normal Young Adults
Authors: Honeycutt Nancy A. , Smith Charles D.
Published: February 2016

Volumetric analysis of brain magnetic resonance images (MRIs) measures structural changes associated with neurological and neuropsychiatnc disorders. Several studies investigated the hippocampus specifically, report1ng degrees of atrophy in such disorders. However, the range of normal hippocampal volumes must be known to assess atrophy. In tracings of T1 oblique slice and three‐dimensional MRis 1n 24 normal subjects reported here, the average volume of right and left hippocampus was 2.90 cm3 and 2.78 cm3, respectively. On paired analys1s, this difference was significant The literature Indicated these volumes are in the m1ddle of a wide range of hippocampal volumes (1.73–5.68 cml) 1n both MRI‐based and histology‐based studies. Th1s wide variation can be expla1ned by differing hippocampal boundary definitions; technical factors of image processing, segmentation, and display; sample heterogeneity; and interoperator differences.
Assessment of Intracranial Primary Collaterals Using Transcranial Color‐coded Real‐time Sonography
Authors: Martin P. J. , Smith J. L. , Gaunt M. E. , Naylor A. R.
Published: February 2016

Transcranral color‐coded sonography (TCCS) was used to assess primary wlllisian collaterals in 100 patients with extracranral iternal carotid artery (ICA) stenosrs. Their importance was determined during carotid endarterectomy (CEA) by transcranial Doppler measurement of blood flow velocity in the ipsilateral middle cerebral artery (MCAV) before and after carotid clamping. All patients had unilaterl CA disease of at least 60% stenosis. Twenty‐nine ICAs (14.5%) were occluded, 70 vessels (35%) were stenosed by 80 to 99%, 43 vessels (21.5%) were stenosed by 60 to 79%, and 53 ICAs had stenosis of less than 60% Temporal hyperostosis precluded TCCS in 15 patients (15%) Anterior cerebral/communicating artery collaterals were detected 1n 40 patients (49%) and posterror cerebral/communicating artery collaterals were detected in 22 patients (27%). No patients with ICA stenosis of less than 80% had established collateral pathways. Patients with willisian col laterals showed hrgher postclamp MCAVs as a proportion of the preclamp value during CEA (72% \62–81] median with 95% confidence interval) than did those without primary collaterals (46% \34=58\; p = 0.02) TCCS allows nonivasive assessment of intracranial primary collaterals whose functional importance is recognized during abrupt hemodynamic challenge. It may deterine which patients are at greatest risk of ischemia during cerebral revascularizatron.
Modification of LowFrequency Spontaneous Oscillations in Blood Flow Velocity in Large‐ and Small‐Artery Disease
Authors: zner H. Bä , Daffertshofer M. , Konietzko M. , Hennerici M. G.
Published: February 2016

During a 30‐m mute period, the blood flow velocity of both middle cerebral arteries (MCAs) was measured bilaterally in 27 patients with obstructive carotid disease (n = 18, large‐artery disease) or subcortical vascular encephalopathy (n = 9, smallartery disease) and in control subjects of similar age and sex distribution (n = 14) To identify low‐frequency spontaneous oscillations (LFSOs), MCA envelope curves were Fourier transformed with filter application to select low‐frequency spectra (0.01–0.05, 0.05–0.15, 0.15–0.50 Hz) To measure the extent of LFSO amplitudes, a coefficient of variation (CoV) was calculated. In addition, a coefficient of correlation (CoC) was calculated to assess LFSO bilateral synchron1c1ty. Normal ranges for CoV (mean = 5.38 ± 1.82%) and CoC (mean = 0.91 ± 0.06) were established in control subjects. In patients with large‐artery disease, a significant CoV reduction was observed Ipsilateral to the carotid lesion (CoV mean = 3.91 ± 1.10%, p < 0.05, Wilcoxon's test) with a contralateral compensatory mcrease (CoV mean = 5.68 ± 1.79%) In addition, a significant desynchronlzation of LFSOs was found in patients w1th large‐artery disease (CoC = 0.39 ± 0.35, p < 0.05). This was less obvious in patients with small‐artery d1sease, who demonstrated a marked bilateral reduct1on of LFSO activity (CoV mean = 3.60 ± 0.71%, p < 0 05) and CoC values. Presuming that LFSOs reflect cerebral blood flow fluctuations caused by phasic arteriolar dilation and contraction, CoV and CoC values indicate integrity versus compromise and exhaustion of arteriolar regulation or compromised vascular reserve capacity in patients with extensive obstructive disease and, for the first time, in patients with small‐artery disease too. This is important as no other method is presently available to record vasomotor function in the arteriolar network.
Functional Caudate Imaging in Symptomatic Huntington's Disease: Positron Emission Tomography Versus SinglePhoton Emission Computed Tomography
Authors: Martin W. R. W. , Hoskinson M. , Kremer B. , Maguire C. , McEwan A.
Published: February 2016

Functional neuroimaging with positron emission tomography previously demonstrated reduced caudate glucose metabolism in virtually all symptomatic patients with Huntington's disease (HD) Single‐photon emission computed tomography studies of brain blood flow also have shown caudate abnormalities in patients with HD. The present study compared these two functional imaging modalities in 6 patients with HD who had been symptomatic for fewer than 5 years. All patients had significantly impaired caudate‐thalamus and caudate‐whole‐slice glucose metabolism ratios as measured by positron emission tomography. However, only 3 had clearly abnormal caudate‐thalamus activity ratios and 2 had clearly abnormal caudate‐whole‐slice ratios on single‐photon emission computed tomography. These findings indicate that single‐photon emission computed tomography imaging of caudate blood flow is a less sensitive indicator of caudate dysfunction in early HD than is positron emission tomography imaging of caudate glucose metabol1sm.
Neoplastic Meningitis with Normal Neurological Findings Magnetic Resonance Imaging Results
Authors: Elliott Paul , Ku Ni Ni , Werner Mark H.
Published: February 2016

Neoplastic meningitis, an unusual complication of systemic cancer, is becoming more common as cancer patients live longer. Although leptomeningeal metastases from solid tumors are usually associated with multifocal neurological signs, the authors report on 4 patients who presented with normal findings on neurological exammation. One man had severe headache and complex partial seizures. Magnetic resonance imaging (MRI) of the bram revealed gadolmium enhancement of multiple cranial nerves. Cerebrospinal fluid (CSF) cytology was positive for melanoma. One woman presented with severe migratory retroorbital headaches. MRIs of the brain with and without gadolinium appeared normal CSF cytology was positive for pulmonary adenocarcinoma. One man presented with morning headache, and a woman presented with back pain. Both had CSF cytologies positive for lymphoma. Neoplastic meningitis can occur without abnormalities on neurological or MRI examinations. Lumbar punctures should be performed on cancer patients with severe, unusual, or prolonged headaches.
Cranial Arteriopathy in Familial Vogt‐KoyanagiHarada Syndrome
Authors: Ryan Stephen J. , Pettigrew L. Creed
Published: February 2016

A 59‐year‐old woman with Vogt‐KoyanagiHarada (VKH) syndrome presented with transient ischemic attacks. Magnetic resonance angiography showed multiple areas of stenosis affecting the intracranial portions of both internal carotid arteries. Conventional angiography confirmed these abnormalities and also demonstrated tapering stenosis of the extracran1al segment of the left internal carotid artery. This patient and her similarly affected daughter represent the first reported association between cranial arteriopathy and intergenerational passage of VKH syndrome.
Traumatic Abducens Nerve Paresis in a Child
Authors: Freeman Jerome W , Free Thomas W , Bunger Paul C.
Published: February 2016

Trauma is a frequent cause for a bducens (sixth) nerve paresis in a child, usually att ributed to injury along the nerve's course. An unusual focal lesion of the sixth nerve nucleus is described.
Rapid Decompression of Congenital Hydrocephalus Associated with Parenchymal Hemorrhage
Authors: Bass Thomas , White Larry E. , Wood Richard D. , Werner Alice L. , Schinco Frank P.
Published: February 2016

A newborn boy with congenital hydrocephalus was diagnosed with aqueductal stenoSIS using magnetic resonance Imaging. Low‐resistance ventrrculoperrtoneal shunt placement was followed by clmical deterroratlon Repeat imagrng studies revealed a collapsed cortical mantle with subdural hemorrhage. In addition to subdural blood, often associated with marked cerebral conformational changes, extensive lntraparenchymal hemorrhage was seen. For extreme congenital hydrocephalus, ventrlculoperrtoneal shunts with greater resistance to flow than the currently used neonatal shunt deVIces may be indicated, to allow a more gradual ventrrcular decompression.
Transcranial Doppler Detection of Middle Cerebral Artery Emboli Before and After Surgical Closure of a Patent Foramen Ovale
Authors: Doherty Elizabeth A.
Published: February 2016

This report describes the use of a combination of contrast transthoracic echocardiography and transcranial Doppler to detect emboli to the cerebral circulation in a patient with patent foramen ovale.
Transient Ischaemic Attacks of the Brain and Eye
Authors: Sperling Michael R.
Published: February 2016

Transient ischemic attacks are an important and common neurological problem. As harbingers of stroke and markers of vascular pathology, they paradoxically serve the useful purpose of identifying patients at increased risk of permanent injury. Consequently, they have been the subject of much study (sadly, mostly uncontrolled study).
SPECT Imaging of Stroke
Authors: Masdeu Joseph C. , Brass Lawrence M.
Published: February 2016

‐photon emission computed tomography (SPECT) is a helpful tool for the management of stroke patients. Brain perfusion SPECT can help differentiate an ischemic event from peri‐ictal phenomena such as Todd's paresis. Initial data suggest that SPECT may be useful in prognosticating the likelihood of an early stroke after a transient ischemic attack and in distinguishing lacunar from cortical stroke. After an acute stroke, early SPECT depicts the area of ischemia with greater accuracy than either computed tomography or magnetic resonance imaging. When the perfusion defect is large, the likelihood of hemorrhagic complications or herniation increases. Reperfusion of an arterial territory after thrombolysis can be documented more conveniently with SPECT than with angiography. SPECT before and after the inJection of acetazolamide has been used to assess the vascular reserve in patients with severe stenosis of the proximal vessels of the cerebrovascular tree. Combined with transcranial Doppler studies, SPECT is used to document ischemia after subarachnoid hemorrhage. It has also been used to assess the effect of arterial ligation intended to treat arteriovenous malformations or aneurysms on brain perfusion and to evaluate ischemia secondary to pressure from an intracranial hemorrhage.
SPECT Perfusion Imaging in the Diagnosis of Dementia
Authors: Jagust William J. , Johnson Keith A. , Holman B. Leonard
Published: February 2016

Single‐photon emission computed tomography (SPECT) imaging has provided the practicing clinician with a method of studying brain function in patients with dementia. A large and growing number of papers report the experiences of a number of laboratories in the use of this technique in the evaluation of demented patients. Studies from several laboratories comparing patients with Alzheimer's disease to control subjects report sensitivity and specificity of SPECT perfusion imaging to be in the 80% vicinity. In addit1on, a number of studies suggest that the dementias that show the greatest similarities in perfusion patterns to Alzheimer's disease are multi‐Infarct dementia and dementia associated with ParkinSon's d1sease. Although considerable data exist to guide the physician, a rigorous scientific approach to studying patients in a prospective, unselected clinical sample, with autopsy confirmation of the diagnosis, is needed to define clearly the utility of the technique in diagnosing dementias.