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Biomedical subjects

O R Hubschmann

Publications and source records attributed to O R Hubschmann.

26 records · Page 2Linked to original sources
PubMed1980

Dorsal column stimulation: Effect on human cerebrospinal fluid and plasma catecholamines.

Plasma and cerebrospinal fluid catecholamines were measured in three patients with multiple sclerosis who had dorsal column stimulators placed at the T5-7 levels. Stimulation for 3 minutes and 20 minutes increased release of plasma norepinephrine, epinephrine, and dopamine, as well as norepinephrine into the cerebrospinal fluid. Neither dopamine nor epinephrine was released into the spinal fluid during or after stimulation. Percutaneous stimulation did not release catecholamines into the plasma or spnal fluid, suggesting that these findings were not simply related to sensory stimulation or stress. Plasma catecholamine levels were inconsistently correlated with pulse rate changes during and after stimulation but not with blood pressure, although the changes in pulse rate and blood pressure were relatively small compared to changes in plasma catecholamines. This study suggests that plasma catecholamines and spinal fluid norepinephrine reflect central activation of sympathetic nervous system pathways and are more reliable indicators of sympathetic activity than changes in cardiovascular function.

Adult↗
PubMed1980

Cortical cellular response in acute subarachnoid hemorrhage.

Acute subarachnoid hemorrhage (SAH) over the cerebral cortex causes single or multiple waves of cellular depolarization, which may occur in a self-propagating, reverberating fashion. This process is characterized by a massive K+ release and transient depression in electrocortical activity. The K+ levels in the extracellular space reach magnitudes known to substantially affect the membrane potentials of neurons and glia, and may cause a release of neurotransmitters from depolarized presynaptic terminals. The release of K+ may be the initial step in the development of cellular edema and, together with a multitude of other chemical and biochemical changes taking place at the cellular level, may underlie the loss of autoregulation. Cortical cells rather than blood vessels are the primary targets in the initial stages of SAH, and ischemia does not play a causal role in the pathogenesis of cellular dysfunction during this stage.

Animals↗
PubMed1980

Carotid ligation for recurrent ischemia due to inaccessible carotid obstruction. Examination of the rationale of this treatment.

Experiences with a patient with symptomatic obstruction to the carotid artery in its petrous segment are described. In spite of the severe stenosis of this vessel, complete arteriography demonstrated excellent perfusion of the symptomatic eye and hemisphere and an ample collateral reserve. Funduscopy confirmed the clinical impression that recurrent retinal and hemispheric ischemia in this patient was the result of microembolism rather than intracranial hemodynamic insufficiency. Consequently, extracranial-intracranial (EC-IC) bypass was believed to offer little benefit to this patient. Abrupt ligation of the internal carotid artery in the neck proved to be an effective method for arresting the embolic discharge from this vessel's inaccessible obstruction, and resulted in prompt and complete relief of ischemic symptoms. It is concluded that identifying the mechanism(s) responsible for recurrent ischemia past uncorrectable carotid obstructions is of paramount importance in order to establish the most appropriate treatment(s). Carotid occlusion is an effective surgical remedy for terminating microembolism from this vessel when it is diseased and incompletely obstructed, and should be considered in selected patients. The importance of angiographic evaluation of naturally occurring EC-IC anastomotic connections in addition to the assessment of intracranial collateral reserves in cases of carotid occlusion is also emphasized.

Brain Ischemia↗
PubMed1980

Twist drill craniostomy in the treatment of chronic and subacute subdural hematomas in severely ill and elderly patients.

The results of treatment of a group of severely ill and geriatric patients with chronic or subacute subdural hematoma using the twist drill craniostomy (TDC) with closed system drainage are presented. Of the 22 patients selected for this procedure because of the high risk of general anesthesia, 18 had a total removal of the hematoma with the first procecure, 1 required a second TDC, 1 required craniotomy, and the procedure failed in 2 patients. There was no mortality or significant morbidity associated with this procedure performed under local anesthesia, and there were no infections. The absence of mortality, the low incidences of incomplete removal or recurrence, and the rapidity of clinical results make this procedure superior to other surgical procedures or medical treatment in this specific group of patients.

Adult↗
PubMed1979

Gram-positive peritonitis in patients with infected ventriculoperitoneal shunts.

Patients with infected ventriculoperitoneal shunts may, in some situations, present with prominent abdominal signs and symptoms and no neurologic complaints. As a consequence, the correct diagnosis may be confused initially, and the appropriate therapy may be dangerously delayed. Definitive diagnosis is established by percutaneous tap of the shunt reservoir and analysis of the ventricular fluid. If the offending organism is gram-positive, externalization of the shunt combined with systemic and intraventricularly administered antibiotics, without laparotomy, is the treatment of choice. If gram-negative organisms are identified, exploratory laparotomy is indicated to rule out a ruptured viscus. In establishing the correct diagnosis and determining the appropriate therapeutic priorities, the co-operative efforts of the general, as well as the neurologic, surgeon are required.

Adult↗
PubMedDate not supplied

Computer analysis of motor performance.

Employing the techniques of electrogoniometry and force measurement, the authors devised a system that provides rapid, reliable, and objective evaluation of a motor task. Utilizing a high-speed minicomputer, various parameters of a motor task were recorded, analyzed, and displayed. This system was used to monitor recovery of motor function after surgery, during a drug regimen, and during electrical stimulation of specific sites in the central nervous system.

Central Nervous System↗