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Biomedical subjects

D R Fish

Publications and source records attributed to D R Fish.

At least 127 records · Page 7Linked to original sources
PubMed1991

Motor inhibition from the brainstem is normal in torsion dystonia during REM sleep.

The maintenance of axial atonia during REM sleep was monitored in 14 patients with primary torsion dystonia, 10 patients with secondary torsion dystonia, and 10 normal subjects using submental EMG and video EEG telemetry. The excitability of the corticospinal tract during REM sleep was also assessed using scalp magnetic stimulation in seven patients and three controls. During REM sleep dystonic patients had well maintained atonia evidenced by infrequent bursts of submental activity, no episodes of complex semi-purposeful behaviour and reduced motor responses to magnetic stimulation. These findings suggest that the inhibitory centres in the region of the locus coeruleus and their descending pathways to the spinal alpha motor neurons are intact in torsion dystonia.

Adolescent↗
PubMed1990

Sleep spindles in torsion dystonia.

Quantitative analysis of overnight sleep spindles was performed in 14 patients with primary generalized torsion dystonia, 10 patients with secondary torsion dystonia, 10 normal subjects, and 39 patients with other neurological disorders. Only 4 patients with torsion dystonia had increased numbers of sleep spindles, and only one of these had sleep spindles of an abnormal amplitude or duration. Sleep spindle abnormalities do not appear to be common in torsion dystonia, and are unlikely to be of pathophysiological significance in this condition.

Adolescent↗
PubMed1990

The clinical differentiation of seizures arising in the parasagittal and anterolaterodorsal frontal convexities.

The ictal clinical manifestations of 40 patients with frontal lobe epilepsy who became and remained seizure free after selective removal of the parasagittal or anterolaterodorsal convexities were studied. Seizures arising from the parasagittal region were characterized by a high incidence of somatosensory auras (60%) and by tonic and/or clonic motor behavior (100%) and never exhibited automatisms. Conversely, the anterolaterodorsal convexity group never showed somatosensory auras but often had warnings more typical of temporal lobe seizures, only displayed partial motor seizure activity in half the cases, and included a relatively high incidence of automatisms (30%). These clinical differences may be useful in the localization of frontal lobe epileptogenic foci. The manifestations of anterolaterodorsal convexity seizures may reflect frequent spread to the temporal lobe, whereas parasagittal convexity seizures often show initial ictal behavior, in keeping with seizure activity in that region. Early ictal unilateral head turning without other motor manifestations was seen in 3 of 10 patients in the parasagittal convexity group and in 9 of 30 patients in the anterolaterodorsal convexity group. In 11 of these 12 cases, the head turning was contralateral to the surgical removal.

Adolescent↗
PubMed1990

Influence of high voltage pulsed direct current on edema formation following impact injury.

Edema results in pain and may lead to reduced functional mobility. High voltage pulsed direct current (HVPC) has recently been advocated for edema control. The purpose of our study was to determine the effect of HVPC on edema formation in frogs. Hind limbs of 20 anesthetized frogs were injured by dropping a 450-g weight onto the plantar aspects of the feet. One hind limb of each frog was randomly selected to receive continuous 120-Hz HVPC at voltages 10% lower than those needed to evoke muscle contraction. Four 30-minute treatments were administered at 1.5-hour intervals beginning 10 minutes after trauma. Limb volumes were measured by water displacement. An analysis of variance for repeated measures and a Newman-Keuls post hoc test were used to determine the significance of treatment effects. The HVPC significantly (p less than .01) reduced edema formation. We hypothesize that HVPC may also be effective in controlling edema formation after impact injuries in humans. [Bettany JA, Fish DR, Mendel FC: Influence of high voltage pulsed direct current on edema formation following impact injury.

Animals↗
PubMed1990

Early evidence of endothelial vasodilator dysfunction at coronary branch points.

Intracoronary acetylcholine produces endothelium-dependent dilation of normal coronary arteries and paradoxical constriction of atherosclerotic vessels. Regional differences in endothelium-dependent vasomotion, however, have not been studied in relation to the nonuniform development of atherosclerosis. We compared the vasomotor response to increasing doses of acetylcholine of angiographically smooth coronary artery segments prone to atherosclerosis (coronary branch points) with segments remote from branch points (straight segments). In patients with entirely smooth coronary arteries and a dilator response to acetylcholine (group 1, n = 7), branch points and straight segments demonstrated equal and significant dose-dependent dilation to acetylcholine (14.7 +/- 8.9% and 12.3 +/- 12.7%, respectively; p identical to NS). In patients with early atherosclerosis as manifest by luminal coronary irregularities, the lowest dose of acetylcholine (10(-8) M) produced constriction at branch points and slight dilation at straight segments (-6.3 +/- 7.4% vs. +2.2 +/- 7.3%, p less than 0.05). At higher doses of acetylcholine, both branch point and straight segments constricted, but constriction remained more pronounced at branch points. Both branch point and straight segments, however, retained the ability to dilate to the non-endothelium-dependent agent, nitroglycerin. In a third group of patients with angiographically entirely smooth coronary arteries but without dilation to acetylcholine, constriction to acetylcholine again occurred first at branch points. Thus, coronary branch points demonstrate increased sensitivity to acetylcholine-induced constriction in patients with angiographic evidence of early coronary atherosclerosis and in middle-aged patients with smooth coronary arteries. These segments, however, retain the ability to dilate to nitroglycerin. Whether this early evidence of defective endothelium-dependent vasodilation predicts the later development of occlusive atherosclerosis is not yet known.

Acetylcholine↗
PubMed1990

High-voltage pulsed direct current: effect on edema formation after hyperflexion injury.

High-voltage pulsed direct current (HVPC) has been shown to retard edema formation after impact injury in frogs, but the effectiveness of HVPC in reducing edema after other forms of trauma has not yet been established. The purpose of our study was to determine the effect of HVPC after simulated sprains. Hind limbs of 20 anesthetized frogs were injured by hyperflexing ankles to 90 degrees. Four 30-minute treatments were administered at 1.5-hour intervals. One limb of each subject was randomly selected to receive cathodal 120-Hz HVPC at voltages 10% lower than those needed to evoke muscle contraction. Limb volumes were measured by water displacement. ANOVA with repeated measures, Newman-Keuls post hoc tests, and selected t-tests were used to determine significance of limb volume changes. HVPC retarded edema formation. HVPC was so effective (p less than .0001) that significant differences between treated and untreated limb volumes were evident after the first treatment (p less than .01), and these differences remained throughout a 17-hour posttreatment period.

Animals↗
PubMed1989

Changes in human alpha-motoneurone excitability following mechanical muscle stimuli.

Short mechanical stretches given to partially activated human abductor digiti minimi muscle (ADM) evoke early (M1) and late (M2) reflex responses. Transcranial magnetic brain stimuli were used to evoke compound muscle action potentials in ADM and hence to estimate motoneuronal excitability at various times after mechanical stimuli. There was no evidence that Ia volleys produce additional facilitation in motoneurones of muscles which are already voluntarily activated. However, the inhibitory phase between M1 and M2 was associated with a reduction in size of muscle responses from brain stimuli. This may reflect reduced Ia input, polysynaptic Ia inhibition or Renshaw inhibition.

Adult↗
PubMed1989

The natural history of late-onset epilepsy secondary to vascular disease.

Twenty-nine patients with late-onset epilepsy were followed prospectively for a mean period of 4.9 years; 14 had CT evidence of occult cerebral infarction and 15 had normal scans. The prognosis was similar in the 2 groups; 57% and 53% respectively became seizure-free. One patient in each group had a myocardial infarction and one patient with occult cerebrovascular disease had a stroke. A separate study was made of the prognosis of 24 patients with epilepsy following stroke (mean follow-up 5.9 years). Twelve of 12 patients with seizure onset within 2 weeks of the stroke became seizure-free, compared with 7/12 with more delayed onset. Late-onset epilepsy has a favourable prognosis, and excellent control should be expected if seizures commence within 2 weeks of stroke.

Aged↗
PubMed1988

A new method for the quantitative analysis of sleep spindles during continuous overnight EEG recordings.

Sleep spindles are one of the most characteristic EEG transients of sleep. Quantitative analysis of sleep spindles may be of value in the study of involuntary movement disorders, depression, and sleep disorders, but this is difficult to perform manually. Phase-locked loop based devices have previously been used to analyse preselected periods of artefact-free non-REM sleep. We have developed a device of this type that provides reliable quantitative analysis of sleep spindles during continuous overnight EEG recordings. The number of sleep spindles detected by the device during overnight recordings correlated well with the mean of two independent human observers and measurements of the amplitude and duration of individual sleep spindles were similar to those obtained by visual analysis. The general applicability of the device was demonstrated by studying 61 patients with a range of neurological disorders.

Electroencephalography↗
PubMed1988

Respiratory arrest: a complication of cerebellar ectopia in adults.

Two adult patients are described with cerebellar ectopia whose presentation at diagnosis was respiratory arrest. Following surgical decompression both patients become self ventilating and now lead independent lives. Cerebellar ectopia is a potentially remediable condition and should be considered in patients with unexplained respiratory arrest.

Arnold-Chiari Malformation↗
PubMed1987

Regional cerebral blood flow of patients with focal epilepsy studied using xenon enhanced CT brain scanning.

Stable xenon-enhanced X-ray computed tomography (XeCT) was used to measure the regional cerebral blood flow (rCBF) of 12 patients with drug resistant partial epilepsy and a marked unilateral focus on electroencephalography (EEG). Interictal mean rCBF of fixed regions of interest (ROIs) was reduced by 25% in the cortex of the epileptogenic cerebral lobe compared with the same regions on the contralateral side (p less than 0.02). Six control scans showed a mean side to side cortical difference in rCBF of 14%, whereas the epileptogenic focus was associated with a reduction in the cortical rCBF of greater than 30% in six out of the 12 patients. In an additional patient with partial epilepsy XeCT demonstrated significant focal hypoperfusion when interictal EEGs and conventional CT scans showed no abnormalities.

Adult↗
PubMed1986

The use of impedance cardiography in heart failure.

The suitability of the impedance cardiograph for studying patients with cardiac failure in a District General Hospital was assessed over a 12-month period. Over 200 recordings were made from 60 patients. Stroke volume, using the derived formulation of Kubicek and his colleagues, and the Heather Index (a measure of cardiac contractility) were calculated in each case. Serial recordings provided an objective assessment of the efficacy of treatment. An abnormal diastolic O wave was found in the majority of patients. This may indicate an excessive accumulation of blood in the thorax as a result of myocardial dysfunction.

Cardiography, Impedance↗
PubMed1985

Sources of goniometric error at the elbow.

We assessed accuracy and potential sources of error in goniometry by using a photographic reference standard. Forty-six physical therapy students measured elbow positions using plastic or steel goniometers following three protocols: ALIGN, in which the investigator's elbow was splinted and bony landmarks were prelabeled; ASSIGN, in which the elbow remained splinted but labels were removed; and PROM, in which raters measured full passive flexion of the elbow. F ratios of variances indicated that alignment of goniometer, identification of landmarks, and variations in manual force during PROM contributed to goniometric error and that accuracy of joint angle measurement by photography (s +/- 0.7-1.1 degrees) was greater than by standard goniometry (s +/- 2.4-3.4 degrees). Analysis of variance and post-hoc test results unexpectedly indicated that all but one goniometric mean differed statistically (p less than .05) from associated photographic means. Small systematic errors in alignment of goniometers and identification of reference landmarks may have accounted for these differences. The results indicate that relatively inexperienced raters should be able to use goniometers accurately to measure elbow position when given standardized methods to follow.

Analysis of Variance↗