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Biomedical subjects

L J Findley

Publications and source records attributed to L J Findley.

At least 55 records · Page 3Linked to original sources
PubMed1993

Assessing the impact of essential tremor on upper limb function.

We compared the impact of essential tremor on the performance of three manual tasks: drawing spirals, holding a cup full of water and a joystick-controlled tracking test. Tremor amplitude and frequency were measured by accelerometry during the tracking test, when holding the cup and whilst a standard posture was maintained. The inter-relationships between tremor amplitude, frequency and task impairment were then examined. The results showed that the amplitude and frequency of essential tremor (measured from the principal spectral peak) changed with different activities, with the mildest postural tremors changing most in frequency (by up to 4-5 Hz). The amplitude of tremor decreased in almost every case during the tasks, relative to posture, and this decrement was greatest for the most severe tremors. We also demonstrate that for practical purposes, such as routine clinical situations and therapeutic trails, the effect of essential tremor upon upper limb function can be usefully assessed by two simple complementary techniques: rating spirals and measuring the volume of water split from a cup. The impairments in carrying out these tasks and the tracking test were highly correlated with one another and also with the amplitude and frequency of postural tremor. The concept of tremor "suppressability" is introduced: the relative percentage decrease in the amplitude of a particular tremor during the performance of a specific task compared to that recorded whilst holding a standard posture.

Acceleration↗
PubMed1993

Comparison of propranolol LA 80 mg and propranolol LA 160 mg in migraine prophylaxis: a placebo controlled study.

Thirty patients with severe classical and common migraine participated in a double-blind placebo-controlled cross-over study of migraine prophylaxis with propranolol LA (long-acting) 80 mg once daily, or propranolol LA 160 mg once daily or placebo. Each treatment was given for two months. There were no significant differences between the three treatment periods in headache frequency, headache severity, nausea frequency or severity. There was a non-significant trend for reduced duration of headache with the two doses of propranolol. The possible reasons for this negative effect are discussed. The safety of propranolol and its lack of serious side effects were demonstrated.

Adolescent↗
PubMed1993

Modulation of postural tremors at the wrist by supramaximal electrical median nerve shocks in essential tremor, Parkinson's disease and normal subjects mimicking tremor.

The response of postural wrist tremors to supramaximal median nerve stimulation was examined in patients with hereditary essential tremor (n = 10) and Parkinson's disease (n = 9), and in normal subjects mimicking wrist tremor (n = 8). The average frequency of on-going tremor was the same in all three groups. Supramaximal peripheral nerve shocks inhibited and then synchronised the rhythmic electromyographic (EMG) activity of all types of tremor. The duration of inhibition ranged from 90 to 210ms, varying inversely with the frequency of on-going tremor. There was no significant difference in mean duration of inhibition or in the timing of the first peak after stimulation on the average rectified EMG records between the three groups. The degree to which supramaximal peripheral nerve shocks could modulate the timing of rhythmic EMG bursts in the forearm flexor muscles was also quantified by deriving a resetting index. No significant difference in mean resetting index of the three groups was found. These results suggest that such studies cannot be used to differentiate between the common causes of postural wrist tremors.

Adult↗
PubMed1993

Assessing tremor severity.

A clinical rating scale which measured the severity of tremor in 20 patients (12 with essential tremor and 8 with "dystonic" tremor) was assessed at specific anatomical sites for both inter and intra-rater reliability using four raters. The scores obtained with the scale were compared with the results of upper limb accelerometry, an activity of daily living self-questionnaire and estimates of the tremor induced impairment in writing and drawing specimens. The results show that, for the purposes of routine assessment and therapeutic trials, a clinical rating scale can produce reliable results which are a more valid index of tremor induced disability than standard postural accelerometry.

Activities of Daily Living↗
PubMed1993

Neurological or cardiological assessment of transient altered consciousness?

Cardiac arrhythmias are a recognized cause of transient alteration of consciousness and unless suspected, a cardiac aetiology for apparent neurological symptoms may be overlooked. We retrospectively assessed the variation in the investigations of 122 patients who were referred to our hospital over a twelve month period for assessment of transient alteration of consciousness and we attempted to identify any factors which might have influenced the clinical outcome for these individuals. Eighteen patients were initially referred for cardiological opinion and 104 for neurological assessment. Sixty-one patients presented with syncope, 43 with seizures, and 18 with presyncope. A baseline electroencephalogram (EEG) was obtained in 104 (85%) and 65 (53%) were also subjected to a stress EEG. Cerebral dysrhythmia was documented in 14 patients. A standard electrocardiogram (ECG) was recorded in only 71 (58%) and sinus bradycardia (heart rate < 60/min) was observed in 34. Twenty-four hour (Holter) ECGs were recorded in only 58 (48%). Ventricular pauses (at least 1.84 seconds) and/or profound bradycardia (heart rate < 40/min) occurred during waking hours in 10 patients and were more likely to be detected in individuals who also exhibited bradycardia on standard ECG (8 patients) (p < 0.05). After six months, 35 (29%) of the 122 patients still lacked a diagnosis and although cerebral dysrhythmia had been diagnosed with equal frequency in the bradycardia and non-bradycardia groups, 21 (62%) of those with bradycardia were still symptomatic compared with 11 (30%) of the non-bradycardia group (p < 0.02). Our findings indicate that, at present, investigation of patients with transient altered consciousness lacks a coordinated approach and bradycardia may influence the diagnosis and morbidity of these individuals. We suggest that greater attention should be paid to possible cardiac causes of transient altered consciousness and that only under joint direction of a cardiologist and a neurologist can efficient and thorough investigation of these patients be realised.

Adolescent↗
PubMed1992

"Resetting" of postural tremors at the wrist with mechanical stretches in Parkinson's disease, essential tremor, and normal subjects mimicking tremor.

The response of postural wrist tremors to brief mechanical displacements was compared in two groups of patients, one with classical hereditary essential tremor (n = 18) and another with typical Parkinson's disease (n = 13). These groups were compared with an additional group of normal subjects mimicking wrist tremor (n = 9). The degree to which brief mechanical displacements of the wrist produced by torque pulses of three different sizes could modulate the timing of rhythmic electromyographic bursts in the forearm flexor muscles was quantified by deriving a resetting index, which could range between 0 (no phase resetting) and 1 (complete phase resetting). In all three groups of subjects studied, the resetting index varied significantly with the size of the mechanical perturbation and, in an inverse fashion, with the ongoing tremor amplitude. When due allowance for these factors was made, the difference in mean resetting indexes between the three groups of patients and subjects was reduced to the extent that no definitive statement could be made as to whether brief mechanical perturbations had more effect on essential tremor than parkinsonian tremor. The method is therefore unlikely to be useful in differentiating the common causes of postural wrist tremors.

Adult↗
PubMed1992

Primary orthostatic tremor: further observations in six cases.

The clinical and physiological features of six new patients with primary orthostatic tremor are described. We suggest that use of the term primary orthostatic tremor be confined to the clinical syndrome in which unsteadiness when standing is the predominant complaint and accompanied by characteristic electrophysiological findings of a rapid (frequency around 16 Hz), regular leg tremor which is not influenced by peripheral feedback, is synchronous between homologous leg muscles, and in certain postures of the upper limbs, between muscles of the arm and leg. The fast frequency of muscle activity in primary orthostatic tremor of the legs causes unsteadiness when standing (presumably due to partially fused muscle contraction) but only a fine ripple of muscle activity is visible. In contrast, the slower frequency of other leg tremors, for example essential tremor, results in obvious leg movement which is evident in many leg postures, is variable over time and can be reset by a peripheral nerve stimulus. Essential tremor and orthostatic tremor do not respond to the same therapies, suggesting differences in the pharmacological profiles of the two conditions. Accordingly, there are clinical, physiological and pharmacological differences between primary orthostatic and essential tremor. Whether these factors are sufficient to regard these tremors as separate conditions is discussed.

Adult↗
PubMed1992

Sumatriptan in the treatment of acute migraine with aura.

The efficacy of the selective 5HT1-like agonist sumatriptan in acute treatment of classical migraine (i.e. migraine with aura) was assessed in a double-blind, placebo-controlled, parallel group randomized trial. An oral dose of 200 mg was chosen on the basis of the efficacy rates achieved (70-85%) with 70-280 mg in open studies (1, 2). The dose of 200 mg was also chosen for the study because preliminary data from an oral pilot study indicated that efficacy increased with increasing dose up to 200 mg. Each patient was treated for a maximum of three separate attacks of migraine with aura within a three months' period. Three attacks were treated so that we could examine consistency of response across more than one attack. For attack 1, 200 mg sumatriptan was significantly more effective, safe and well tolerated than placebo at relieving headache 2 h after treatment was given (p = 0.023). In subsequent attacks, i.e. in attacks 2 and 3, there was no such significant effect of sumatriptan compared with placebo in relieving headache. This reduced efficacy of sumatriptan in the second and third attacks may be due to a high incidence of vomiting induced by the high dose of dispersible formulation and also by the bitter taste of the tablets. In addition, there was an increase in placebo response in attacks 2 and 3 compared to the first attack.

Acute Disease↗
PubMed1992

Effect of very-low-calorie diets with weight loss on obstructive sleep apnea.

To determine the effect of very-low-calorie diets (VLCDs) with weight loss on obstructive sleep apnea (OSA), we studied eight obese subjects with OSA, five males and three females. Subjects consumed a VLCD of 1760 kJ (420 kcal) (67% protein, 4% fat, 29% carbohydrate) or 3350 kJ (800 cal) (20% protein, 30% fat, 50% carbohydrate) with 100% of the recommended daily allowance of vitamins and minerals. Mean (+/- SD) values of weight and respiration before and after weight loss were, for weight, 153 +/- 37 and 132 +/- 29 kg (P less than 0.05); for BMI (kg/m2), 54 +/- 13 and 46 +/- 10 (P less than 0.05); for desaturations/h sleep, 106 +/- 50 and 52 +/- 45 (P less than 0.05); for apneas + hypopneas/h sleep, 90 +/- 32 and 62 +/- 49; for Pco2, 48 +/- 10 and 42 +/- 4 torr (P less than 0.05). Desaturation episodes/h and apnea + hypopneas/h improved in six patients. The most obese subject (female, BMI 81) who lost the most weight (47 kg) did not improve, nor did the subject who lost the least weight, 7 kg. The number of movements + arousals from sleep decreased in all patients (P less than 0.05). We conclude that VLCD with weight loss can produce improvement in OSA; subjects who lose a small amount of weight or subjects who are extraordinarily obese before and after weight loss may not improve.

Adult↗
PubMed1992

Parkinson's disease: the spectrum of disabilities.

The needs of people with Parkinson's disease (PD) go beyond the purely medical domain and often require collaborative management. A Panel Discussion at the "Hither neurology" Symposium included neurologists, a speech therapist, a geriatrician and a sociologist. Their discussion highlighted certain aspects of the disability and disadvantage associated with PD. The starting point was a video recording, "Parkinson's Disease: the personal view", in which the contributors were patients and carers. Topics covered included counselling at the time of diagnosis; subsequent access to clinics and to neurological advice; access to therapy; support in the community; fluctuating disability associated with "on-off" phenomena; driving; and sexual problems.

Adaptation, Psychological↗
PubMed1992

A case of factitious fever and 'epilepsy'.

We describe the case of a 23 year old male who presented with a history of intermittent pyrexia associated with apparent episodic loss of consciousness. During these events, thermometers placed in the rectum and axillae supported the elevated oral temperature readings. After numerous investigations including electroencephalography had excluded organic disease, the patient was observed applying a hot douche to his rectum prior to his temperature being recorded.

Adult↗
PubMed1992

Isolated tremor and disruption of the nigrostriatal dopaminergic system: an 18F-dopa PET study.

We measured striatal 18F-dopa influx constants (Ki) for 20 patients with isolated, predominantly postural, tremor (eight familial, 12 sporadic) and 11 with predominantly rest tremor. Results were compared with 30 controls and 16 Parkinson's disease (PD) patients. The eight familial essential tremor (ET) patients had normal striatal 18F-dopa uptake. Two of the 12 sporadic postural tremor patients had subnormal putamen 18F-dopa Ki, one (who later became akinetic) falling in the PD range. The mean putamen 18F-dopa uptake of the 11 rest tremor patients was reduced to PD levels (51% of normal). Our findings argue against an association between ET and PD, but support the existence of a "benign" tremulous variant of PD. The presence of low-amplitude rest tremor, cogwheel rigidity, reduced arm swing, and short tremor duration was not a useful predictor of nigral dysfunction in patients with postural tremor. In contrast, patients with predominantly rest tremor, particularly with onset in the leg, consistently showed reduced putamen 18F-dopa uptake.

Adult↗
PubMed1992

Driving performance and automobile accidents in patients with sleep apnea.

Patients with untreated obstructive sleep apnea have poorer driving performance than patients without sleep apnea. This poor driving has been demonstrated by studies on a wide variety of driving simulators. Patients with sleep apnea show a significant improvement in driving performance after successful treatment of their apnea with nasal CPAP. After treatment with CPAP, their driving performance is similar to control subjects. Several studies show that patients with untreated sleep apnea are poor drivers and have two to three times more auto accidents than other drivers. These studies reveal that almost one quarter of these patients report frequently falling asleep while driving. Patients with severe sleep apnea or those who perform poorly on driving simulators may be at highest risk of auto accidents. Automobile accidents involving patients with sleep apnea may lead to severe injury or death. Patients, individual physicians, and the medical profession have responsibilities to help prevent these accidents. Finally, more study is needed to improve patient care, protect drivers, and formulate a fair and rational policy concerning drivers with sleep apnea.

Accidents, Traffic↗
PubMed1991

Progressive loss of speech output and orofacial dyspraxia associated with frontal lobe hypometabolism.

Three patients are described with slowly progressive loss of speech and dysarthria associated with orofacial dyspraxia, initially with intact written language, who subsequently developed more widespread cognitive abnormalities. Positron emission tomography (PET) revealed bifrontal hypometabolism in all of the patients, most marked in the inferior and lateral portions of both frontal lobes, with some extension into the parietal and temporal cortices in one case. These patients may represent a further example of focal progressive cortical degeneration.

Aged↗
PubMed1991

First single lung transplant in Virginia.

Lung transplantation is now established as a clinical reality for patients with irreversible, lethal pulmonary conditions. We report the first successful application of this treatment modality in Virginia.

Humans↗
PubMed1991

Drivers with untreated sleep apnea. A cause of death and serious injury.

Three patients with untreated sleep apnea fell asleep while driving and caused serious automobile accidents. One person died, another became permanently paraplegic, and the three patients with sleep apnea were seriously injured in these crashes. This sequela of sleep apnea is not surprising, since subjects with sleep apnea may be poor drivers with a high accident rate and a high incidence of "near-miss" vehicular incidents. Because drivers with untreated sleep apnea may cause a large number of preventable automobile accidents, physicians have specific duties involving these drivers. First, physicians must try to identify impaired drivers with sleep apnea before they have an accident; routinely asking patients about loud snoring and hypersomnolence may help identify these impaired drivers. Second, physicians must consider the diagnosis of sleep apnea when examining patients who fall asleep while driving. Next, physicians must warn their patients with sleep apnea about the risks of driving with untreated sleep apnea. Finally, physicians must treat any seriously impaired driver with sleep apnea and keep these patients from driving until they can receive successful treatment.

Accidents, Traffic↗
PubMed1990

Preliminary report: activation of the cerebellum in essential tremor.

Several images of cerebral blood flow were recorded during inhalation of carbon-15-labelled carbon dioxide by positron emission tomography in four patients with essential tremor and four normal controls. Unilateral involuntary postural tremor in essential tremor patients was associated with blood flow significantly greater than that at rest in the contralateral sensorimotor cortex, both lateral premotor regions, and both cerebellar hemispheres. Of these regions, only the cerebellum was not activated in normal controls holding a posture without tremor or in essential tremor patients undergoing passive wrist movement. The increased flow in the cerebellum therefore seems to represent neural activity involved in tremor generation. It is proposed that essential tremor is due to oscillation within cerebello-olivary pathways, relayed by way of the thalamus and motor cortex to the spinal cord.

Administration, Inhalation↗