The functional effects of head injury in the elderly

The nature of head injury in the elderly differs from that in younger adults. Fifty-four consecutive patients, aged 65 years or older admitted to a neurotrauma unit with head injury over a six-month period, were identified to determine the causes and medical and social consequences. Falls accounted for the great majority of cases, and alcohol consumption was an important contributory factor in males, while pedestrian road accidents were responsible for most deaths. A routine investigative screening procedure was evaluated. When visited after discharge, 72% of survivors had experienced a change in functional status with increased family involvement and use of community support services. This group was significantly older (p less than 0.01) than those whose status had not changed. A third of the survivors had changed their living circumstances at review. It is suggested that such patients could benefit from increased involvement of the geriatric services.

ICP monitoring--current status and future directions

Continuous monitoring of intracranial pressure (ICP) is now an accepted part of neurosurgical practice, used in the management of patients with severe head injury, coma-producing subarachnoid haemorrhage, hydrocephalus, intracranial infection and following hypoxic or ischaemic insults to the brain. The pressure is measured from the lateral ventricle or from the subarachnoid space, and each neurosurgical department should establish criteria for determining what level of increased ICP should be acted upon and how it should be managed. This review favours a three stage approach: a) determining that ICP is truly elevated and correcting any immediately remediable causes, such as airway obstruction, then b) first-line measures, which consist of hyperventilation, osmotherapy and controlled CSF drainage, then c) second-line measures, consisting of short-acting anaesthetic agents--thiopentone and gammahydroxybutyrate. Future refinements of ICP monitoring will include improved understanding and better methods of measuring intracranial pressure-volume relationships and more detailed analysis of intracranial pulse pressure and the pressure waveform, its changes with mean ICP and its relationship with the arterial pressure waveform.

Supratentorial pressures. Part II: Intracerebral pulse waves

Intracerebral pulse waves were recorded in cat and monkey while intracranial pressure (ICP) manipulations were performed. The intracerebral pulse waves appeared comparable to cerebrospinal fluid (CSF) pulsations. The wave forms were divided into multiple smaller waves, designated P1 to P4. The P1 component was primarily of arterial origin and was accentuated by increasing ICP unrelated to increased venous pressure, most commonly from a mass lesion. Bilateral carotid occlusion resulted in decreased amplitude of P1. Venous hypertension from jugular venous or sagittal sinus occlusion, on the other hand, accentuated waves P2 and P3 more than P1. This is consistent with a Starling resistor model of the cerebral venous system in which mass lesions may compress low-pressure veins and accentuate the arterial pressure-dependent P1 wave, whereas venous hypertension causes increased prominence of the later P2 and P3 waves.

Supratentorial pressures. Part I: Differential intracranial pressures

Dynamic supratentorial pressure changes may differentially alter tissue pressure and intraventricular fluid pressure. To evaluate these pressures, we used a floppy cuff intracerebral catheter and an intraventricular catheter in the cat and rhesus monkey. Baseline intraventricular pressures exceeded intracerebral pressure in both species. Intraventricular pressure was 3-4 mmHg in cats and 6-14 mmHg in monkeys, while the intracerebral pressure was in the range 0-4 mmHg in both. Saline injection into the spinal or cranial subarachnoid space resulted in a greater increase in ventricular fluid pressure, and the time for return to baseline was one and a half times longer in the intraventricular compartment. Jugular venous and abdominal compression resulted in a greater rise in the ventricular pressure than intracerebral pressure. Inflation of subdural balloons and intracerebral injection of silicone caused a differential pressure across the brain with the pressure being greatest in the ipsilateral hemisphere and lowest in the contralateral hemisphere. Rapidly evolving epidural masses produced varied results. We did not evaluate compensatory pressure changes in these animals. Those pressures that involve cerebrospinal fluid (CSF) dynamics alter intraventricular pressure more than tissue pressure. Alternatively, rapidly forming masses tend to increase tissue pressure near the mass more than intraventricular pressure.

Etiology and clinical course of missed spine fractures

A prospective study was designed to document course and outcome. Two hundred fifty-three patients with 274 spinal injuries were reviewed at the time of injury and discharge from hospital, as well as at 1, 2, and 5 years postinjury. Thirty-eight of these patients were identified who had been misdiagnosed at the initial assessment. Fracture location, cause of injury, neurologic deficit, and delay in diagnosis were all documented: 22.9% of cervical injuries, and 4.9% of the thoracolumbar injuries had a delayed diagnosis ranging from less than 1 day to 36 days. The causes of delayed diagnosis were: 1) failure to take X-rays, 2) fractures missed on X-ray, and 3) failure of patients to seek medical attention. Associated factors such as intoxication of the patient, multiple injuries, level of consciousness, or two levels of spinal injury contributed to the delayed diagnosis of these injuries. Certain "at-risk" populations for missed spinal injuries have been identified. In spite of delays in diagnosis, progression of an established neurologic deficit did not appear to occur in our study. However, the development of secondary deficits was significant in the delayed diagnosis group.

The binding of Ca2+ to Ca2+-transporting microsomes derived from bovine uterine sarcoplasmic reticulum

An obligatory early step in the transport of calcium across the internal membranes of smooth muscle cells is the binding of calcium to the Ca,Mg-ATPase. The characterization of calcium binding to sarcoplasmic reticulum from smooth muscle has not been reported. Calcium binding to a bovine myometrium preparation was investigated using Scatchard analysis and a computer program utilizing weighted least squares curve fitting and an exact mathematical model of binding. This permitted objective measurement of goodness of fit and showed that best fit was obtained using a two site model. Magnesium did not change the affinity for calcium of the two sites; but reduced the number of low affinity sites to half.

CT guided functional stereotaxic surgery

One of the major problems in stereotaxic surgery is to identify the brain target. Since these do not show on any of the usual radiological studies they have to be located with reference to observable structures. Initially bony landmarks were used but later either positive or negative contrast ventriculograms were found to be more accurate. Often this involves additional needling of the brain or a spinal puncture with the added mortality and morbidity associated with these procedures. We have extended the use of CT guided stereotaxic surgery to functional conditions by measuring the target position in relation to the third ventricle and the AC-PC line as seen on the unaugmented CT scan. Our experience with 27 procedures in 23 patients (9 movement disorders, 13 pain and 1 insertion of depth electrode) would indicate it is at least as accurate as other techniques. The surgical time is usually shorter and patient tolerance is better.

Sex hormone receptors in intracranial tumours and normal brain

Fifty-four intracranial neoplasms (29 meningiomas, 16 gliomas, seven acoustic neuromas and two cerebral metastases) and nine specimens of normal brain were evaluated for specific progesterone and oestrogen receptor proteins using a dextran-coated charcoal assay and Scatchard plot analysis. Sixteen meningiomas (55%) were progesterone receptor (PgR) positive (median 52; mean 120; range 10-486 fmol mg-1 cytosol protein), whilst all were oestrogen receptor negative (ER-). Two (28%) of the acoustic neuromas contained small amounts of PgR protein, but all seven were ER-. None of the gliomas, cerebral metastases or specimens of normal brain contained ER or PgR protein. Analysis of PgR status and clinicopathological data suggest that there is no predictive correlation between PgR status and the patients age, sex, reproductive status, tumour histology or tumour behaviour. These results again suggest that in meningiomas PgR proteins are not modulated by oestrogens acting through ER. This finding may explain the failure of antioestrogen therapy to influence the growth of meningiomas. The significance of PgR protein in intracranial meningiomas is discussed with respect to tumour heterogeneity and implications for research with gene probes.

Interrelationships among stabilities of important agronomic traits in sugarcane

The stability-variance statistic, ĝs i (2) , measures the contribution of the i(th) genotype to genotype x environment interaction. In addition to the knowledge of cultivar stability for an agronomic trait, information on whether stability of one trait can be used to predict stability of another should be useful to breeders. Three separate groups of data, respectively involving CP 79 series, CP 80 series, and CP 81 series experimental clones of sugarcane (Saccharum spp.) were used in this study. Rank-correlation coefficients (rs) between ranks of genotypes for ĝs i (2) 's for paired traits indicated in both plant-cane and ratoon crops that stability of tons per hectare of sugar can be predicted from the stability of tons per hectare of cane (THC) and also, to a lesser extent, from the stability of stalk number. The stability of THC also can be reasonably well predicted from the stability of stalk number. Brix stability may give some indication of the stabilities for percentage sucrose and sugar concentration (SC). The ĝs i (2) 's for percentage sucrose and SC were almost identical in the CP 79 and CP 81 series (rs varied from 0.93, P<0.01, in plant-cane crop for CP 79 series to 0.98, P<0.01, in plant-cane crop for CP 81 series). Whether correlations were based on ĝs i (2) 's estimated across locations within crops or across crops, the magnitude of rs was about the same. Means of various traits were not correlated with their respective ĝs i (2) 's (for CP 81 series), indicating that identification and selection of high-yielding sugarcane genotypes with a relatively high degree of stability of performance across test environments should be possible.

Qualities and locations of stimuli and responses affecting discrimination learning of chinchillas (Chinchilla laniger) and pigeons (Columba livia)

Chinchillas and pigeons were used as subjects in separate experiments to study interactions among stimulus and response characteristics in discrimination learning. Both the stimuli and the responses could differ with respect to their "quality" and their "location." Bright versus dim lights and upper versus lower lights served as the stimulus qualities and stimulus locations for the chinchillas, respectively. Red versus green lights and upper versus lower lights served as the stimulus qualities and stimulus locations for the pigeons, respectively. Respond versus no-respond and respond-left versus respond-right served as the response qualities and response locations, for both species, respectively. In both experiments, response-quality performance was superior when the discriminative stimuli differed in quality than when they differed in location, whereas response-location performance was superior when the discriminative stimuli differed in location than when they differed in quality. These results were interpreted within the framework provided by a general law of learning, that is, the "quality-location hypothesis."

The effects of dialysis on brain water and EEG in stable chronic uremia

Cerebral edema in uremic animals and humans, as well as an EEG deterioration in humans, has been reported after dialysis. Both are manifestations of the dialysis disequilibrium syndrome (DDS). This study was designed to analyze the changes induced by dialysis in the EEG pattern (spectral analysis), in the cerebral hydration, and ventricular size (computed tomography [CT] of the brain) in a group of 11 stable uremic patients. They volunteered for a randomized crossover study of 4 months each of standard hemodialysis (HD) and hypertonic hemodiafiltration (H HDF). H HDF is a dialysis technique that is shorter and more efficient than HD. An EEG recording, a CT scan of the brain, and blood biochemistry were performed before and after a HD (four hours, blood flow rate 250 mL/min) and a H HDF run (three hours, blood flow rate 400 mL/min). Approximately 6 weeks of stabilization on each treatment were allowed before these studies. No difference was found in the density of seven specific brain structures (base and apical cuts), when comparing pre- v post-HD, pre- v post-H HDF, pre- HD v pre-H HDF, and post-HD v post-H HDF. Furthermore, no difference was evident either in the bicaudate diameter of the lateral ventricles or in the transverse diameter of the third ventricle. In addition, no significant in-between- and within-treatment difference was observed when analyzing the EEG% power (3-7/7-13 Hz) data. In conclusion, this study shows neither a postdialysis change in brain density and ventricular size nor a postdialysis EEG deterioration in a group of stable uremic patients undergoing both a rapid and a standard dialysis treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormal temporal lobe response in Alzheimer's disease during cognitive processing as measured by 11C-2-deoxy-D-glucose and PET

Elderly controls and probable Alzheimer's disease patients underwent serial positron emission tomography (PET) studies during a baseline condition and while performing a verbal memory task. For the temporal lobes, all 7 Alzheimer patients demonstrated a relative shift in glucose metabolic rates to the right hemisphere during the memory condition relative to baseline, and 5 of 7 controls showed a shift to the left hemisphere. Baseline absolute regional metabolic rates replicate previous findings and were somewhat less useful than the memory challenge in differentiating patients from controls. These results indicate that a temporal lobe abnormality in Alzheimer's disease is related to memory performance.

The response of suprachiasmatic neurons of the rat hypothalamus to photic and nicotinic stimuli

Single neurons in the suprachiasmatic nucleus (SCN) and surrounding hypothalamic nuclei of the rat were characterized functionally and pharmacologically. Photically responsive neurons of the SCN typically exhibited a similar response to intravenous nicotine. The response to nicotine was antagonized by the nicotinic blocker, mecamylamine. Nicotinic blockade either eliminated or even reversed the sign of the photic response during subsequent photic stimulation. This constellation of results was not seen in neurons of adjacent hypothalamic regions.

What follows diagnosis by computed tomography of solitary brain tumour? Audit of one year's experience in South East Scotland

The referral rate to neurosurgeons after diagnosis by computed tomography (CT) of solitary brain tumour (SBT) was audited for South East Scotland in 1985. 142 patients had SBT diagnosed by CT, but histological confirmation by biopsy or open operation was sought in only 67. Among these the CT diagnosis of glioma proved to be incorrect in 3 of 44 cases and that of solitary metastasis in 4 of 8 cases. Since CT diagnosis of SBT is not fully reliable, biopsy should be considered in all cases.

Changes in the cerebrospinal fluid pulse wave spectrum associated with raised intracranial pressure

The frequency spectrum of the cerebrospinal fluid (CSF) pulse and the amplitude transfer function between arterial and CSF pressures were measured from the cisterna magna of anesthetized, artificially ventilated cats when the intracranial pressure (ICP) was raised by saline infusion. The spectrum of CSF pulsation was composed of a fundamental and three higher harmonic waves. The amplitude and the amplitude transfer function of each spectral component revealed significant positive correlation with ICP and negative correlation with cerebral perfusion pressure (CPP). Both the amplitude and the transfer function of the fundamental CSF pulse wave showed an exponential correlation with ICP and CPP. A distortion factor of the CSF pulse wave, a measure of its difference from a simple sine wave, was calculated from the spectral components. This showed that distortion of the CSF pulse wave was rapidly and progressively reduced as the ICP rose to 50 mm Hg and then was reduced less thereafter.

Clinical usefulness of the palmomental reflex

The palmomental reflex was elicited, unilaterally or bilaterally, in 28% of a series of 121 patients with neurological disorders. There was no significant variation in the prevalence of the palmomental reflex with the age and the sex of patients, with the cause of the neurological disorder, or with the site of cerebral lesions. However, the reflex was found to be significantly more common among patients with signs of focal or generalized brain dysfunction than among patients with normal cerebral function (P less than 0.001). The side of the body on which the reflex was elicited was no indication of the side on which the cerebral lesion was situated. In three patients, who were examined on several occasions, the reflex disappeared as the psychomotor function of the patients improved. On the basis of the results, the nature of the palmomental reflex and the reasons why its presence is difficult to interpret are discussed.

Use of connected discourse tracking to train functional speech skills

The connected discourse tracking procedure was adopted for use as a production training task for profoundly hearing-impaired children. A clinician served as the receiver and 5 children with profound hearing losses each served as the sender for 16 tracking sessions. There were individual differences among the children in their ability to convey the connected discourse to the clinician over time. The increase in comprehension of each subject's speech during the last session relative to the amount of information understood during the first session ranged from 0 to 48%. Two independent observers were used during the first and last sessions to verify the tracking results obtained by the clinician (the primary receiver). There were differences in words tracked per minute among the three receivers with the primary clinician achieving higher tracking rates than the other two. The children learned how to use discourse strategies when they were not understood and they were highly motivated by the task. The results indicate that it is feasible to incorporate the procedure in a speech training program for hearing-impaired children.

Brain water measured by magnetic resonance imaging. Correlation with direct estimation and changes after mannitol and dexamethasone

Brain water content was measured in tissue samples taken at operation from 19 patients with intrinsic cerebral tumours imaged preoperatively by magnetic resonance. A high correlation (r = 0.94, p less than 0.0001) between white matter water content and the longitudinal relaxation time (T1) enabled water content to be estimated from T1 to within 4%. 11 patients received dexamethasone and improved clinically but their T1, and thus brain water content, was unchanged an average of 6 days later. Intravenous infusion of 20% mannitol in 11 patients significantly reduced T1 in oedematous white matter and tumour within 15 min of administration, and by 30 min the T1 of oedematous white matter had fallen to a mean of 32.4 (SEM 7.1) ms, corresponding to a reduction in water content of 1.4 (0.3)%.

Horse riding and head injury: admissions to a regional head injury unit

A retrospective survey has been carried out of 59 patients who suffered head injury related to horse riding out of 7172 cases of head and spinal injury admitted to a regional head injury unit in the 5-year period 1980-85. Most (85%) were female, against the usual 80% male predominance of head injury, 56 were minor injuries and 3 severe, of whom 2 died. Skull fracture was present in 10 patients (17%) of whom at least 5 had been wearing headgear at impact, and scalp trauma was noted in 22 (37%) with a predominance of occipital injuries. All the severely injured cases had an occipital skull fracture. One fifth of the patients suffered additional significant injuries. While most patients (90%) made a good recovery, 2 remained moderately and one severely disabled. Horse riding posed a significant risk of head injury to the population of riders, mainly young women. This survey suggests that the wearing of amateur riding headgear does not adequately protect the rider from scalp and skull injury, particularly in the occipital region.

Fat embolism: a clinical diagnosis

Fat embolism causes a distinctive clinical syndrome usually seen in trauma victims with long bone fractures. Clinical findings include hyperthermia, respiratory distress, petechiae and retinal fat emboli. Neurologic changes include decreased sensorium, decerebrate posturing and seizure activity. Chest radiographs commonly demonstrate bilateral fluffy infiltrates. Laboratory abnormalities include hypoxemia, respiratory alkalosis, anemia and hypocalcemia. Treatment consists of general supportive care with vigorous pulmonary therapy. Most patients have a good recovery.