Lack of efficacy of levetiracetam in oromandibular and cranial dystonia.

OBJECTIVE: To determine the efficacy of levetiracetam in oromandibular or cranial dystonia. METHODS: We recruited seven subjects with oromandibular or cranial dystonia. Five completed the study, median age was 71 years (range 42-79 years), median disease duration was 12 years (range 2-30 years). Participants were randomized to receive levetiracetam or placebo and were then crossed over. They titrated up to a total daily dose of 4000 mg or the maximum tolerated dose over 3 weeks and maintained that dose for another 3 weeks. The primary endpoint was the percent change of the eyes, mouth, speech, and swallowing Burke-Fahn-Marsden (BFM) subscores from baseline to weeks 6 and 14. Additional endpoints included the BFM subscore at weeks 3 and 11, and the global dystonia severity (GDS) subscore at weeks 3, 6, 11, and 14, as well as all adverse side effects. RESULTS: The mean percent increase in the BFM subscore (placebo: 31.25%, levetiracetam: 12.16%) was not significantly different between the two arms according to the Friedman analysis. The Wilcoxon signed-rank test showed that these percent changes were not significant, indicating that there was no statistical clinical worsening in either arm. The mean percent change of the BFM subscore at weeks 3 and 11 and the mean percent change of the GDS subscore at weeks 3, 6, 11, and 14 were not significantly different between the two arms, and the Wilcoxon signed-rank test did not show statistical significance. CONCLUSION: Levetiracetam does not appear to be efficacious in patients with oromandibular or cranial dystonia.

The binding of organic ions to phospholipid bilayers.

The binding of organic anions and cations, mainly tetraphenylboride and tetraphenylarsonium, to phospholipid membranes has been studied using an NMR method. Binding is appreciable and is affected by cholesterol in the membrane and counterions in solution. The passage of the organic anions through the membrane has also been followed. These measurements indicate that it is naive to use organic anions to measure membrane potentials in a simple manner.

Anatomic considerations for computed tomography of the optic chiasm.

When the clinical distinction between lesions of the optic nerves or the chiasm is not apparent, computed tomographic scans should be performed at both 0 degrees and 25 degrees or 35 degrees to the orbital-meatal line (Reid's baseline). The former plane is preferable for the demonstration of the optic nerves or orbital structures, while the latter allows superior visualization of perichiasmatic structures.

Digital subtraction arteriography. A new method for evaluation of extracranial occlusive disease.

Digital subtraction arteriography (DSA) allows visualization of both the intracranial and extracranial vasculature following an intravenous injection of contrast medium. One hundred consecutive patients were evaluated using this modality. In 32, DSA was compared with conventional arteriography. The degree of internal carotid artery stenosis and/or occlusion shown by DSA was confirmed by conventional arteriography in 27 cases (84%). Abnormalities of the extracranial vasculature was demonstrated by DSA in 60% of patients with suspected cerebrovascular disease. Digital subtraction arteriography demonstrated significant stenosis or occlusion of the carotid arteries in 30% of patients in whom Doppler and radionuclide studies were normal. Digital subtraction arteriography is useful in evaluation of the extracranial vasculature in a variety of clinical conditions. In some instances it serves as a substitute for conventional arteriography. However, its exact place in evaluation of extracranial vasculature disease remains to be defined.

Digital subtraction angiography. Comparison of meglumine-Na diatrizoate with iohexol.

A slight improvement in image quality occurred with the use of iohexol when compared with meglumine-Na diatrizoate. There is less swallowing with iohexol, which gives better image registration when looking at the extracranial carotid arteries. A single significant tachycardia occurred with the ionic medium, but not with iohexol. Overall discomfort and minor adverse reactions were less with iohexol than with diatrizoate.

Xenon and krypton as radiographic inhalation contrast media with computerized tomography: preliminary note.

Computerized tomography (CT) scans of samples of the inert gases xenon and krypton inside a Lucite phantom, show these gases to be potentially useful inhalation contrast media with CT scanning of the chest.

Xenon inhalation as an adjunct to computerized tomography of the brain: preliminary study.

The purpose of this study is to determine whether computerized tomography can distinguish between brain tissue and brain tissue containing dissolved xenon at physiologic concentrations. Xenon is an inert gas of high atomic number (54), and is highly soluble in tissue, particularly in fat. Its presence in the brain after inhalation is manifested by well known anesthetic effects. Phantom studies using xenon in equilibrium at atomospheric pressure with water, corn oil, and milk samples of varying known fat content, demonstrate that xenon is detectable in all cases with a steep linear increase in change of attenuation factor (EMI number) with increasing fat content. In the rhesus monkey xenon is readily detectable at 20% inhaled gas concentration, with linear detectable at 20% inhaled gas concentration, with linear increase of attenuation factor with increasing concentration. The possible application of our findings to the study of brain pathophysiology is discussed. Since xenon is a potent although safe anesthestic, caution in clinical application is advised.

Computerized intravenous arteriography: a technique for visualizing the peripheral vascular system.

A unique method of computerized fluoroscopic enhancement allows direct visualization of the entire vascular system by intravenous injection of standard contrast agents, thereby avoiding the need for arterial puncture or hospitalization. This technique has been used to satisfactorily visualize the intra- and extracranial carotid and vertebral arteries, the aortic arch and upper extremity vessels, the abdominal aorta and its branches, as well as lower extremity vasculature. Although the technique is still under development, occlusions, stenoses, ulcerated plaques, and aneurysms have been visualized. Qualitative evaluation of these studies indicates a promising correlation with standard arteriography. This technique has great promise as a method of diagnostic screening in the management of peripheral vascular disease.

Digital subtraction angiography and continuous-wave Doppler studies. Their use in postoperative study of patients with carotid endarterectomy.

Postoperative study of 40 patients who underwent carotid endarterectomy was performed using digital subtraction angiography (DSA) and transcutaneous continuous-wave Doppler (CWD) studies. The two techniques were comparable in defining recurrent stenosis in the reconstructed carotid arteries and progressive disease in the contralateral carotid artery. Digital subtraction angiography appeared to be more sensitive than the CWD method in detecting minor progression of carotid disease. Our data suggested that CWD and DSA have comparable ability to identify significant (greater than 50%) carotid artery stenosis in this group of patients. However, DSA provided more detailed imaging of the carotid system and may give enough information about progression of carotid disease to avoid preoperative arteriography in some patients.

A comparison of standard cerebral arteriography with noninvasive Doppler imaging and intravenous angiography.

Standard cervical carotid arteriography was performed on 36 patients and compared with results of noninvasive Doppler arterial imaging and intravenous angiography (IVA). The 72 carotid arteries were anatomically classified by standard angiograms as follows; group 1 (normal), 13 arteries; group 2 (wall disease [50% stenosis]), 14 arteries; group 3 (moderate stenosis [5-% to 75% stenosis]) 12 arteries; group 4 (severe stenosis [greater than 75%]), 15 arteries; and group 5 (complete occlusion), 18 arteries.

Computerized arteriography of the cerebrovascular system: its use with intravenous administration of contrast material.

A unique method of computerized image enhancement makes it possible to visualize the arterial system by intravenous (IV) injection of small doses of standard contrast agent. This technique has been used to study the intracranial and extracranial circulation of more than 100 patients. Occlusion, stenosis, aneurysmal change, plaquing, and ulceration can be identified by computerized IV arteriography. Failures (less than 10%) results from inadequate venous access, extravasation of dye, or patient motion. This technique avoids the need for arteriography. The major risk of IV arteriography is contrast medium reaction. There is a close correlation between IV and standard arteriographic images. Intravenous arteriography does not require hospitalization, is suited for repetitive testing, and has promise as a method of diagnostic screening for stroke prevention.

Radiologic evaluation of the cerebellopontine cistern and the internal auditory canal.

Radiologic evaluation of patients with unilateral sensorineural hearing loss depends on the quality of the computed tomographic (CT) scanner. Two scanners were evaluated in the present study: one utilizing thick collimation (10- and 13-mm sections) and the second utilizing thin collimation (1.5-mm sections). In both evaluations, intravenous contrast medium was used to exclude a cerebellopontine angle mass. If the cerebellopontine cistern is normal and there is clinical evidence of an intracanalicular lesion, air or metrizamide CT is used. When 10- and 13-mm sections are used, air provides the best contrast with overlapping sections. When 1.5-mm sections are used, coronal CT shows metrizamide in the internal auditory canal.

The vestibular aqueduct--tomographic evaluation in Meniere's disease--a preliminary report.

Frontal and off-lateral complex motion tomography was performed in 72 consecutive patients selected for endolymphatic sac surgery for episodic vertigo or sensorineural hearing loss. They were selected for this operation because of a fluctuating hearing loss. The morphology and visualization of the vestibular aqueduct and the degree of periaqueductal pneumatization were correlated with surgical results and the presence of bilateral disease. The surgical results were evaluated with use of the classification of the American Academy of Ophthalmology and Otolaryngology. Computer analysis was performed on the data for vestibular aqueduct radiographic anatomy and surgical results or bilateral disease. There was no correlation between visualization or morphology of the vestibular aqueduct and surgical results or presence of bilateral disease.

Bilateral homonymous hemianopia.

Bilateral homonymous hemianopia occurred in 15 patients seen during a four-year period. Persons with this visual deficit had similarly shaped visual field defects on corresponding sides of the vertical midline for each eye, equal visual acuity which is generally normal, and normal pupil and fundus examinations. The most common causes of the bilateral posterior cerebral artery insufficency were arteriosclerosis (40%), uncalherniation (20%), and migraine (13%).

Iohexol for cervical myelography via C1-C2 puncture: study of efficacy and adverse reactions.

Cervical myelography with iohexol via C1-C2 puncture was performed in 30 patients in two medical centers using a concentration of 240 mg l/ml. The study demonstrated iohexol to be a safe contrast medium without significant changes in neurologic and physical examination, vital signs, electrocardiogram, or hematologic or blood chemistry parameters. Fifteen patients had electroencephalograms (EEGs); two were abnormal. In one patient the baseline EEG demonstrated nonspecific slow waves in the temporal regions bilaterally that remained unchanged after myelography. In the second patient, transient changes in the left hemisphere during either hyperventilation or photic stimulation on postmyelographic EEG had not been present on the baseline recording. The relation of these changes to the drug remains unclear. Iohexol was found to be an efficacious myelographic contrast agent, with good to excellent myelograms in 93% of cases. Headache occurred in 13% and nausea in 3%.

Clinical comparison of metrizamide and iopamidol for myelography.

A double-blind parallel comparison of iopamidol and metrizamide for myelography was performed in 36 patients. Sixteen adverse reactions were noted in 10 patients who received metrizamide. Six adverse reactions were reported in five patients who received iopamidol. There was no appreciable difference in the radiographic opacification.

Limitations of intravenous digital subtraction angiography.

Eighteen digital subtraction angiography (DSA) examinations were retrospectively evaluated for factors that led to their erroneous interpretation. Overlapping vessels obscured pathologic conditions in five cases. In four cases the lesions were not adequately profiled by the DSA projections. Eight lesions were rendered inconspicuous by misregistration artifacts attributable to motion, either from swallowing or from pulsation of vessel walls. One diagnostic error was caused by poor opacification from a degraded contrast bolus secondary to low cardiac output.

Intravenous video arteriography of the intracranial vasculature: early experience.

A computerized fluoroscopic apparatus developed by members of the University of Wisconsin Medical Physics Section was used for 12 months to perform intravenous video arteriography. In previous papers, the apparatus was described and its use was illustrated for performing time subtraction intravenous video arteriography of the extracranial carotid arteries, the arteries of the abdomen and extremities, as well as angiocardiography. In this report, the use and current limitations of this technique for evaluation of the intracranial vasculature are described and illustrated.

Clivus epidural hematoma: a case report.

An acute traumatic epidural hematoma extending from the odontoid process to the dorsum sella is described. The mechanism for the formation of an extradural hematoma in this unusual location seems to be related to age and a severe hyperflexion injury.

Diagnosis of vertebral fractures. A comparison of conventional radiography, conventional tomography, and computed axial tomography.

Thirty patients with acute thoracic, lumbar, or thoracolumbar fractures, dislocations, or fracture-dislocations were evaluated with standard radiographs, conventional polytomography, and computerized axial tomography. The resulting ninety studies were coded, randomized, and independently interpreted by three radiologists. The diagnostic accuracy of the interpretations based on the computerized tomography scans combined with standard radiographs equaled that of the interpretations based on just the tomograms in the evaluation of fractures of posterior elements. In addition, computerized tomography was superior to the other methods in demonstrating impingement on the neural canal as well as injuries to other organ systems. Also, when compared with conventional polytomography, computerized tomography could be completed with less risk to the patient (no changes in position and ten times less radiation). We concluded that computerized tomography should replace conventional polytomography as the initial study to augment standard radiographs in the assessment of thoracic and lumbar fractures. Conventional polytomography should be reserved for patients in whom precise evaluation of the pars interarticularis is deemed necessary.