Biomedical subjects

B Magnaes

Publications and source records attributed to B Magnaes.

70 records · Page 4Linked to original sources

PubMed1977

Functional myelography with metrizamide in the diagnosis of lumbar spinal stenosis.

Metrizamide (Amipaque) as a contrast medium for functional lumbar myelography was evaluated in 63 patients. It was found well suited, the adverse effects being insignificant. Good correlation was found between the clinical and the myelographic diagnosis. An a.p. diameter in extension of less than 8 to 10 mm (true value 5.5-7.0 mm) was found only in patients with considerable complaints and in whom operation was indicated.

Adult↗

PubMed1977

Controlled overpressure cisternography to localize cerebrospinal fluid rhinorrhea.

Cerebrospinal fluid (CSF) rhinorrhea is often intermittent, thus complicating the cisternographic localization of the leakage. In four patients studied, this difficulty was overcome by lumbar infusion of artificial CSF to which a bolus of radionuclide was added. The tracer was moved in bulk to the basal cisterns, and the rise in CSF pressure elicited a profuse rhinorrhea. Sequential imaging was started during the infusion, and prompt identification of the site of leakage was easily obtained. Special precautions must be followed when this technique of overpressure is used.

Cerebrospinal Fluid Rhinorrhea↗

PubMed1976

Body position and cerebrospinal fluid pressure. Part 1: clinical studies on the effect of rapid postural changes.

Cerebrospinal fluid (CSF) pressure was recorded in 149 patients and arterial blood pressure (BP) in 11 patients while moving between lateral and sitting positions. Rapid tilting initiated waves in BP and CSF filling pressure. The postural CSF pressure wave manifested itself either as a transient or as a stationary wave similar to a plateau wave. When patients sat up, transient waves had amplitudes up to 550 and stationary waves up to 1000 mm H2O. When they lay down, transient waves had amplitudes up to 800 mm H2O. Stationary waves were found only among patients with elevated intracranial pressure and a diseased brain. The waves were mainly caused by changes in cerebral blood volume probably reflecting the postural BP wave and brain autoregulation. Most patients with stationary and large transient waves also manifested clinical symptoms. These symptoms were aggravated when a craniospinal block developed in the sitting position, and were reduced or avoided when the tilting was performed slowly over 2 to 3 minutes.

Blood Pressure↗

PubMed1976

Body position and cerebrospinal fluid pressure. Part 2: clinical studies on orthostatic pressure and the hydrostatic indifferent point.

Lumbar cerebrospinal fluid (CSF) pressure was recorded in 116 adult neurosurgical patients in the lateral and sitting positions. The level of zero CSF pressure while in the sitting position (ZPS) and hydrostatic indifferent point (HIP) for lateral and sitting positions were determined and referred to the craniospinal axis. In control patients ZPS was located mainly at the upper cervical region, and showed nearly the same variation and frequency distribution as CSF pressure in the lateral position when efforts were made to reduce sources of error and there was no orthostatic change in CSF filling pressure. Under these circumstances ZPS may be used as a variable comparable from one subject to another. In control patients the HIP was located between C-6 and T-5. In 25 hydrocephalic patients, shunting resulted in a mean caudal shift of ZPS of 244 mm, and a mean pressure fall of 126 mm H2O in the lateral position. This difference was due to a caudal shift of HIP on shunting. A caudally located ZPS was found in patients with complete cervical subarachnoid block. Prevention and treatment of CSF leakage cranial to HIP is discussed.

Blood Pressure↗

PubMed1976

Testing cerebrospinal fluid shunt capacity and adequacy by the lumbar route in adults.

The pressure of the cerebrospinal fluid with the patient in a lateral position, the level of zero pressure in sitting position, and the infusion cisternography were evaluated as a test for determining shunt function. The lumbar infusion test gave information about shunt capacity, while the opening pressure in lateral and sitting position reflected shunt adequacy. A reduction in shunt capacity preceded the rise of the opening pressures when the shunt capacity preceded the rise of the opening pressures when the shunts became inadequate. Cisternography was relatively reliable in determining shunt adequacy when shunt capacity was near its high or low extreme, but unreliable in the middle ranges. In non-communicating hydrocephalus, the lumbar infusion test resulted in a correct conclusion as to shunt capacity provided the subarachnoid space was patent and the test was terminated before the ventricular system was empty.

Adult↗

PubMed1976

Infusion cisternography.

A source of error in cerebrospinal fluid (CSF) infusion tests is leakage at the dural puncture site. The addition of a bolus of radionuclide to the infusion fluid was helpful in detecting the existence of leakage as shown by increased infusion pressure in six of eight patients studied with and without scintigraphic evidence of leakage. Comparison of CSF dynamics in 26 patients studied by infusion cisternography and conventional cisternography showed similar patterns, suggesting no alteration of CSF dynamics by the artificial CSF infusion. Combining the two tests, therefore, resulted in simple identification of the leakage and saved the patient time and discomfort.

Cisterna Magna↗

PubMed1975