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Biomedical subjects

H Schrader

Publications and source records attributed to H Schrader.

At least 19 recordsLinked to original sources
PubMed1992

Palatopharyngoglossoplasty in the treatment of patients with obstructive sleep apnea syndrome.

A new technique (palatopharyngoglossoplasty (PPGP)) has been developed for surgical treatment of patients with the obstructive sleep apnea syndrome (OSAS). In 20 operated patients 18 reported immediate marked improvement of daytime sleepiness, alertness and vigilance during the day, and of working capacity. However, polysomnography carried out pre- and postoperatively showed that only 10 patients were "cured", defined as 50% or more reduction in apnea/hypopnea index (AHI). Cephalometric analysis pre- and postoperatively indicated that nonresponders had a long and narrow posterior airway space, and we suggest that during sleep this part of the upper airway collapses before as well as after the operation. The discrepancy between the subjective improvement observed after PPGP and the postoperative reduction in AHI may be due to reduced/eliminated snoring and/or improvement in sleep quality after the operation.

Adult↗
PubMed1991

[Spinal puncture].

Explore the source record for details and available documents.

Contraindications↗
PubMed1991

"Hemicrania continua": a clinical review.

Hemicrania continua (HC) is a headache entity completely responsive to indomethacin. Since 1984, 18 cases have been described, 15 females and 3 males, i.e. a F:M ratio of 5.0. The finding of a female preponderance, like that in chronic paroxysmal hemicrania, is a new observation. HC is, in general, a unilateral headache in the sense that it sets in on one side and subsequently sticks to this side. In two cases, both sides might possibly be involved, when the pain was at its maximum. In another (somewhat dubious) case the headache was bilateral. The pain was continuous from the beginning in 8 of 18 cases (early stage ratio continuous: non-continuous = 0.8). Over time, the headache developed a continuous character in 16 of the 18 cases, producing a "continuous: non-continuous ratio" of 8:1. The intensity of pain generally was moderate and was not reported as excruciatingly severe by any patient. The autonomic involvement from a clinical point of view, was clearly less pronounced than that of other unilateral headaches, such as cluster headache and chronic paroxysmal hemicrania.

Adult↗
PubMed1991

Anterior perforations in lumbar discectomies. A report of four cases of vascular complications and a CT study of the prevertebral lumbar anatomy.

Four cases of vascular complications to anterior perforations during discectomy prompted a CT study to measure lumbar disc diameters and to evaluate the prevertebral anatomy. Fifty young adults who had been referred for low-back pain and/or sciatica but had not undergone operation were included. In five additional patients, prone versus supine CT examinations were compared. Six typical configurations of the vascular anatomy could be classified to explain the type of vascular complications occurring at the L3-4 and L4-L5 disc levels. The sagittal diameter of the three lowest lumbar discs varied from 33 to 56 mm, indicating the importance of this parameter as an intraoperative guideline for the spine surgeon. Air-filled intestines were observed anterior to the L5-S1 disc predominantly in the prone position. The possible relationship between this finding and postoperative discitis is discussed.

Adult↗
PubMed1990

[Delayed sleep phase syndrome. The most frequent cause of primary chronic insomnia?].

During the past four years the author has seen six cases of chronic persistent insomnia with onset in childhood. Four of these cases had delayed sleep phase syndrome, a disturbance in sleep-wake schedule characterized by the inability to fall asleep, and by continuous sleep of normal length later in the night. The article describes the case histories of two adolescent patients and experience from using chronotherapy. It appeared that chronotherapy was effective, but the demands on the sleep-wake schedule discipline were difficult to accept. It is suggested that delayed sleep phase syndrome may be the most frequent cause of chronic insomnia with onset in childhood.

Adolescent↗
PubMed1990

Subdural hematoma presenting as headache in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) affects the nervous system in 75% of cases (1). A female with several neurological manifestations in the case history presented with severe headache, psychiatric disturbances, and increasing paraparesis. She was found to have bilateral subdural hematomas, and after evacuation her neuropsychiatric symptoms, including headache, disappeared. It is speculated that the reported low incidence of subdural hematomas in SLE may be more apparent than real. On the basis of our case, we recommend repeated neuroradiological investigations to uncover this important, treatable and otherwise potentially fatal cause of headache.

Adult↗
PubMed1989

The significance of age, sex, and cerebrospinal fluid pressure in post-lumbar-puncture headache.

In this study of 300 neurological inpatients aged between 18 and 60 years the incidence of post-lumbar-puncture headache (PPH) was 37.3%. The more severe the headache, the more frequently it was associated with dizziness, nausea, vomiting, and tinnitus. If PPH occurred during the first day after lumbar puncture (LP), it was more severe, and lasted longer than PPH, which started later. The incidence of PPH and associated symptoms decreased with increasing age, and was much higher in females than males. The sex difference was nearly exclusively explained by a marked preponderance of PPH in females below 40 years of age, i.e. women in the fertile age. Furthermore, there was a decreased incidence of PPH and associated symptoms in patients with an initial higher than average cerebrospinal fluid (CSF) pressure (162 mm H2O). All these differences were statistically significant. Particularly high frequencies of PPH were found in young women with an initial CSF pressure lower than mean.

Adolescent↗
PubMed1988

Post-lumbar-puncture headache: the significance of body posture. A controlled study of 300 patients.

In this single-blind, randomized study of post-lumbar-puncture headache (PPH) in 300 neurologic inpatients the significance of body posture after lumbar puncture (LP) was evaluated. Immediate mobilization was compared with bed rest for 6 h (3 h prone followed by 3 h supine posture). Contrary to the widely held belief, this investigation did not show significant differences between recumbent and ambulant patients as to frequency of PPH in the total material (39% versus 35%) or when men (31% versus 29%) and women (48% versus 41%) were evaluated separately. Headache associated with nausea was significantly more frequent in the recumbent than in the ambulant patients both in the total material (23% versus 13%) and in women (35% versus 16%). Thus, immediate mobilization seems to be preferable after LP.

Adolescent↗
PubMed1986

Effects of continuously expanding intracranial lesions on vital physiological parameters. An experimental animal study.

The work described in this report confirms and extends the results described in a preliminary communication (Löfgren, J. and Zwetnow, N.N., Acta Neurol. Scand. (1970, 625) which examined the effects in cats of an expanding mass, in the form of an intracranial supratentorial balloon, on vital physiological parameters. In the present study, particular emphasis was placed on the possible significance of the rate of expansion of the mass in the range usually encountered in the clinical situation of intracranial haemorrhages. Results from the experiments on 37 cats and 8 dogs showed that changes in vital parameters appeared when the balloon had reached a volume of about 5% of the intracranial volume (the "reaction volume") while respiratory arrest occurred at an intracranial volume of about 10% (the "apnoea volume"). Both threshold volumes were independent of the rate of expansion within the range used. Alterations in EEG, heart rate, respiratory rate and systemic arterial pressure usually occurred simultaneously with the development of a transtentorial pressure gradient. When respiratory arrest occurred, the cerebral perfusion pressure was markedly reduced, usually to a value of about 30 mm Hg, suggesting that brain tissue ischaemia is an important component in the lethal mechanism underlying intracranial expanding lesions. It is proposed that the volume load tolerance of the organism towards an expanding intracranial lesion, as expressed by the reaction volume and the apnoea volume, may represent a biologically useful parameter potentially suitable for quantitative evaluation of adverse agents and therapeutic procedures.

Animals↗
PubMed1986

The treatment of accessory symptoms in narcolepsy: a double-blind cross-over study of a selective serotonin re-uptake inhibitor (femoxetine) versus placebo.

A randomized, double-blind cross-over trial was carried out in 10 patients with narcolepsy to evaluate the effect of 600 mg femoxetine versus placebo. In comparison to placebo, femoxetine treatment resulted in a significant decrease in both the number and severity score of cataplectic attacks per day. There were also significantly fewer attacks of sleep paralysis, whilst the effects on nightmare and hypnogenic hallucinations were minor. The frequency of sleep attacks decreased slightly during femoxetine treatment, but the overall estimated sleep time during the day and excessive daytime sleepiness remained un-affected. An ambulatory sleep recording for 48 h one week after the start of the femoxetine and placebo period showed that femoxetine treatment resulted in a significant decrease in the total time spent in REM sleep. The side-effects of femoxetine were restricted to transient nausea in 2 patients. It is concluded that femoxetine or other selective serotonin reuptake inhibitors may be a useful alternative for narcoleptic patients who experience troublesome side-effects with tricyclic antidepressants.

Adult↗
PubMed1985

Regional cerebral blood flow and CSF pressures during the Cushing response induced by an infratentorial expanding mass.

An experimental study was carried out in eight dogs to investigate whether the Cushing response (CR) during intracranial hypertension is due to pressure per se, tissue distortion, or ischemia in the brain stem. To minimize the effects of rostrocaudal displacement, intracranial pressure was raised by an expanding mass lesion located in the posterior fossa. Regional cerebral blood flow (rCBF) was measured with radioactive microspheres and compartmental cerebrospinal fluid (CSF) pressures were recorded during the CR which was induced by the continuous inflation at a constant rate of an infratentorial epidural rubber balloon in two groups of four dogs. In one group (A) rCBF was measured at the onset of the CR and in the other group (B) at the peak of the systemic blood pressure rise. In the animals of group A blood flow in the mesencephalon, pons and upper medulla oblongata was reduced from control values by 32%, 57% and 85% respectively. In group B blood flow in the same areas did not differ significantly from pre-inflation values. In contrast, the recorded balloon volume, which was assumed to be an index of mechanical distortion of the brain stem, varied considerably at the beginning of the blood pressure rise (from 2.5 to 4.7% of the calculated intracranial space). Similarly, CSF pressure in the posterior fossa at the onset of the CR also varied considerably (from 52 to 117 mmHg). Thus, the large quantitative variations meant that both absolute pressure and tissue distortion were poor predictors of the onset of the CR. The findings suggest that ischemia, rather than brain stem distortion per se or pressure by itself, is responsible for the initiation of the CR. The rise in blood pressure elicited during the CR seems capable of restoring blood flow in the brain stem back to control values.

Animals↗
PubMed1985

Effects of prolonged supratentorial mass expansion on regional blood flow and cardiovascular parameters during the Cushing response.

To clarify the central nervous and the cardiovascular mechanisms mediating the Cushing response (CR) during intracranial hypertension, the effects of continuous and prolonged expansion of an epidural supratentorial balloon was studied in six dogs. Regional cerebral blood flow, cardiac output, extracerebral tissue blood flow and regional vascular resistance were measured with radioactive microspheres before and during the CR while heart rate, arterial blood pressure and ECG were continuously recorded. The results showed that balloon expansion led progressively to cerebrospinal ischemia beginning in the cerebrum and progressing to the pons, medulla oblongata and spinal cord in an orderly rostro-caudal fashion. This progressing ischemia was closely associated with patterned and stereotyped changes in cardiovascular indices. Thus, respiration ceased, heart rate decreased, blood pressure increased and cardiac output fell when the ischemia appeared in the lower pons. Further advancement of the ischemic front to the lower medulla oblongata led to an abrupt switch-over from bradycardia to tachycardia, which persisted until the experiment was terminated. Since bradycardia disappeared when ischemia reached the vagal cardiomotor nucleus, the initial bradycardia appeared to be the result of increased vagal discharge. When ischemia reached the pons, the mean arterial pressure rose to a maximum of 245 mm Hg (+/- 45) but then fell progressively when the ischemia reached the spinal cord. The decrease in cardiac output persisted throughout the CR and was associated with decreased flow in most extracerebral organs. Exceptions were the heart muscle and the adrenal medulla in which blood flow increased considerably. Changes in regional vascular resistance reciprocated the changes in flow. These results suggest that the vasomotor component of the CR is brought about entirely by peripheral vasoconstriction.

Animals↗
PubMed1985

Influence of blood pressure on tolerance to an intracranial expanding mass.

In 3 groups of 4 dogs with normotensive, induced-hypotensive and induced-hypertensive blood pressure respectively, continuous expansion of an extradural supratentorial balloon led to respiratory arrest at inflation volumes which increased with increasing blood pressure. This positive correlation between the volume tolerance to an expanding lesion and blood pressure was also found in similar experiments on 4 hypotensive and 4 hypertensive cats. Monitoring cerebrospinal fluid pressures in the cerebral lateral ventricles, in the posterior fossa and in the spinal subarachnoid space showed that absolute pressures in the various compartments as well as the intercompartmental pressure gradients at the moment of respiratory arrest were increased in proportion to the level of the systemic arterial pressure in each case. These observations do not support current concepts that brain-stem distortion alone or that stimulation of baroreceptors in the posterior fossa are responsible for eliciting the Cushing response. The fact that the supratentorial perfusion pressure was the only parameter which did not differ significantly under the different experimental conditions suggests that the mechanism responsible for the respiratory arrest is local brain tissue ischemia, probably near the tentorial incisure. The magnitude of gain in volume tolerance, when mean arterial pressure was varied from 60 mmHg to 190 mmHg, was 87% suggesting that the blood pressure may have a critical role in an intracranial lesion. These findings have clinical implications.

Animals↗
PubMed1985

Regional cerebral blood flow and CSF pressures during Cushing response induced by a supratentorial expanding mass.

In order to delineate the critical blood flow pattern during the Cushing response in intracranial hypertension, regional cerebral blood flow was measured with radioactive microspheres in 12 anesthetized dogs at respiratory arrest caused either by expansion of an epidural supratentorial balloon or by cisternal infusion. Regional cerebrospinal fluid pressures were recorded and the local cerebral perfusion pressure calculated in various cerebrospinal compartments. In the 8 dogs of the balloon expansion group, the systemic arterial pressure was unmanipulated in 4, while it was kept at a constant low level (48 and 70 mm Hg) in 2 dogs and, in another 2 dogs, at a constant high level (150 and 160 mm Hg) induced by infusion of Aramine. At respiratory arrest, regional cerebral blood flow had a stereotyped pattern and was largely independent of the blood pressure level. In contrast, concomitant pressure gradients between the various cerebrospinal compartments varied markedly in the 3 animal groups, increasing with higher arterial pressure. Flow decreased by 85-100% supratentorially and by 70-100% in the upper brain stem down to the level of the upper pons, while changes in the lower brain stem were minor, on the average 25%. When intracranial pressure was raised by cisternal infusion in 4 dogs, the supratentorial blood flow pattern at respiratory arrest was approximately similar to the flow pattern in the balloon inflation group. However, blood flow decreased markedly (74-85%) also in the lower brain stem. The results constitute another argument in favour of the Cushing response in supratentorial expansion being caused by ischemia in the brain stem. The critical ischemic region seems to be located rostrally to the oblongate medulla, probably in the pons.

Animals↗