Unilateral asterixis: motor integrative dysfunction in focal vascular disease.

In three patients we found unilateral asterixis in limbs contralateral to a discrete lesion adjacent to the internal capsule. Etiology was vascular in each, with no metabolic or toxic disturbance. Unilateral asterixis bespeaks focal disease arising from lesions in the thalamus or internal capsule and is a sign of motor integrative dysfunction.

Brain SPECT with dipyridamole stress to evaluate cerebral blood flow reserve in carotid artery disease.

UNLABELLED: This is a preliminary study of SPECT brain scan using dipyridamole as a stress agent to assess cerebral blood flow reserve in six patients with severe carotid artery disease. METHODS: We performed SPECT scanning of the brain, with and without dipyridamole stress. Dipyridamole (0.57 mg/kg) was given intravenously 3 min before infusion of 99mTc-HMPAO. Patients were studied 30 min later using a rotating head gamma camera. The scans were analyzed qualitatively and semiquantitatively. An acetazolamide stress SPECT image was also obtained in two patients. RESULTS: All patients had at least 80% stenosis in one internal carotid artery, three of them also had contralateral carotid stenosis. The dipyridamole SPECT showed an increased region of hypoperfusion in the hemisphere ipsilateral to the severe carotid disease in four patients. That suggests poor perfusion reserve and the potential risk of regional ischemia. In four of six patients, side-to-side asymmetry increased from the baseline condition after injection of dipyridamole. The asymmetry index increased more after dipyridamole than after acetazolamide injection in two patients. CONCLUSION: This study suggests that dipyridamole stress SPECT is useful in assessing cerebral blood flow reserve. It demonstrates the region of poor vascular reserve in patients with severe carotid artery disease. Dipyridamole SPECT scans show more extensive hypoperfusion than acetazolamide in the two cases.

Disk edema in an overweight woman.

A 46-year-old extremely obese black woman presented with headaches, blurred vision, and visual obscurations. Her exam was notable for bilateral severe papilledema, retinal hemorrhages, and lethargy. Her CAT scan was normal, and a spinal tap revealed a very high opening pressure. Although this patient's presentation mimicked pseudotumor cerebri, the lethargy and retinal hemorrhages were atypical. Her hospital evaluation was notable for elevation of the serum bicarbonate level, and she was subsequently found to have hypoxia and hypercapnia on a blood gas. The patient was diagnosed as Pickwickian syndrome, with obstructive sleep apnea. Treatment of the pulmonary problem resulted in dramatic improvement in her eye findings and her lethargy, and optic nerve sheath fenestration was not necessary.

Determination of methyl methacrylate in surgical acrylic cement.

A methyl methacrylate cement used in hip surgery as well as in dentistry was identified and quantitatively analyzed for its monomer content in starting materials and in the finished cement by proton magnetic resonance spectroscopy. IR data indicated that the monomer continued to escape from the product after it had hardened. The presence of 21% methyl methacrylate monomer relative to the polymer was demonstrated at the time the cement normally would be inserted into the body.

Case report. Evolution of cerebral abscess: disparity between radionuclide and CT scans.

The course of frontal lobe cerebritis in a teenage boy was followed with serial radionuclide and CT scans. During treatment with high doses of dexamethasone and antibiotics, the radionuclide scans became normal, whereas the CT scans remained abnormal and ultimately demonstrated an encapsulated abscess that was successfully drained. In patients receiving steroid therapy, the radionuclide brain scan may not be a reliable technique in demonstrating an intracranial abscess.

Recognition of pseudoseizures.

Failure to recognize pseudoseizures is a common problem, affecting both epileptic patients who additionally have pseudoseizures and nonepileptic patients inappropriately called epileptic. Pseudoseizures most commonly mimic generalized tonic-clonic (GTC, "grand mal") seizures or complex-partial seizures. Several patients whose speudoseizures were not recognized are described. Adhering to logical principles of diagnosis for epilepsy, as for other medical problems, and remaining aware of basic beahvioral dynamics should eliminate the confusion between pseudoseizures and epileptic seizures.

Infrared identification test for scopolamine as the hydrobromide.

The method of preparation of scopolamine hydrobromide affects the infrared (IR) spectrum of the product. A column chromatographic procedure is used to both isolate the drug from tablets and injections and form the hydrobromide salt. This yields reproducible IR spectra and thus constitutes an identity test for scopolamine hydrobromide.

The "jerks": mass hysteria or epilepsy?

Hysterical "epidemics" of "epilepsy" are well known in Eastern and Western cultures. A unique situation in the United States in the 19th and 20th centuries was the American religious movement, the setting in which "the jerks" occurred. Descriptions of various types of "jerks," including dancing, barking, laughing exercise, running exercise, and singing exercise are described.

Identification tests for propantheline bromide.

A method is described for the isolation and identification of propantheline bromide from bulk drug substances and dosage forms, both alone and in combination with other drug substances. The method permits the specific identification of the intact drug substance, using both infrared spectroscopy and thin layer chromatography.

Infrared spectrophotometric analysis of medicinal gases for trace impurities.

The feasibility of examining medical gases for trace impurities, using an infrared spectrophotometer in conjunction with a 10 m gas cell, was investigated. Many of the impurities for which the USP includes limits were detected and measured at concentrations at or below those permitted by the USP; these include sulfur dioxide, carbon dioxide, carbon monoxide, and water. However, others (hydrogen sulfide, nitric oxide, and nitrogen dioxide) were not detected at these levels by this technique. Methane was found at low levels in some samples.

Infrared identification of maleic acid in pharmaceutical maleate salts.

Difficulties are encountered in the USP melting point identification test for maleic acid extracted from chlorpheniramine maleate. A general procedure is described for the isolation and infrared identification of the maleic acid moiety of pharmaceutical salts from drug substances or dosage forms. This procedure permits the concurrent infrared identification of the amine moiety.

Predilection of brain metastasis in gray and white matter junction and vascular border zones.

BACKGROUND: The purpose of this study was to asses the importance of the vascular border zone and the gray and white matter junction on the distribution of brain metastases. METHODS: We reviewed the medical records, computed tomography (CT) of magnetic resonance imaging (MRI) of 105 patients with secondary brain tumors. The metastatic lesions noted on CT scans of MRI ere matched with a predetermined standard sheet containing axial images with shading on the border zones. To be included in the border zones, the center on more than 50% of the lesion had to be situated within these zones. RESULTS: Among 100 evaluable patients, there were 302 metastatic brain lesions. Of the 302 lesions, 210 lesions were 2 cm or smaller in greatest dimension and located in the cerebral and cerebellar hemispheres. The major vascular border zones were the site of predilection for 103 lesions (62%) although the border zones constitute only 29% of the area. Gray and white matter junction was the preferred site for 135 lesions (64%). CONCLUSION: The results demonstrated that brain metastasis occurs in the vascular border zone regions and the gray and white matter junction more frequently than previously recognized, and also supported the notion that metastatic emboli tend to lodge in an area of sudden reduction of vascular caliber (gray/white matter junction) and in the area most distal vascular field (border zone).

The analysis of pharmaceuticals by combined gas chromatography-mass spectrometry. I. The analysis of a medicated aerosol spray.

A medicated aerosol product was qualitatively analyzed by combined gas chromatography-mass spectrometry. The data were processed by a minicomputer. Ten of the 11 peaks in the gas chromatogram were identified with the assistance of the National Institutes of Health/Division of Computer Research and Technology/Chemical Information System mass spectral search system. The unidentified peak is probably a member of the terpene class. The aerosol propellants were also partially analyzed by infrared spectrophotometry.