Physiological and psychological responses to stress in neurotic patients.
Summary 1.Exercise Response to work done on a bicycle ergometer Standard work : (6,750 ft.lb. of work per minute for five minutes).A significant difference between a group of normal controls and groups of neurotic patients with various diagnoses was obtained by measuring the post exercise pulse response (pulse area) , the post exercise oxygen uptake, and the blood lactate rise following exercise.Post-exercise ventilation showed no evidence of deficient ventilation; the volume per breath was approximately equal in controls, effort syndrome (E.S.), and anxiety states, but in both groups of patients more ventilation was necessary for the assimilation of 100 c.c. of oxygen than in the controls. Maximal work : (work to complete exhaustion).Twenty normal controls showed a significantly greater blood lactate rise following maximal work than did a group of 20 E.S. patients. It appeared that the E.S. patients gave up before a “physiological end-point” had been reached, or in other words, that the E.S. patients had an effort phobia.Arterial blood gas analysis gave no evidence of anoxaemia after maximal work ; nor was there any evidence of respiratory alkalosis resulting from hyperventilation after maximal work, judged by the blood pH and pCO 2 Light work : (4,500 ft.lb. of work per minute for one minute).A simple respiratory exercise tolerance test was devised using a closed circuit metabolism machine. Significantly greater ventilation post exercise was recorded in the group of E.S. patients compared with the controls. Minimal work : (pedalling against no resistance).A work situation without any real work being done was created by asking the subject to pedal the ergometer against no resistance. Respiratory tracings were obtained by using a closed circuit metabolism apparatus. The results showed a marked tendency in E.S. patients for irregular and/or excessive breathing to occur in a work situation.The reason for the poor exercise response in neurotic patients was studied, but no definite conclusions were arrived at. An attempt to create experimentally a poor exercise response in a normal control showed that paralysing the vagus by intravenous atropine resulted in a greatly increased post exercise oxygen uptake ; a much smaller rise resulted from voluntary hyperpnoea (simulating E.S. breathing), or the administration of adrenaline to the control before exercise. Neither muscle tension nor autonomic over-activity alone appeared adequately to explain the poor exercise response in neurotic patients. 2 and 3.Response to Pain and ColdBlood pressure and respiratory responses to these two external stimuli were studied. Significant differences between certain groups of neurotics and normal controls were obtained when the increased ventilation resulting from the stimulus was measured. The B.P. response to the two stimuli showed no significant difference between controls and neurotic patients. 4.Response to ExcitementThe emotional excitement of the initial interview was used as a stimulus, and pulse, respiratory, and B.P. readings taken at this time were contrasted with similar readings taken some weeks later under basal conditions. A possibly significant fall in pulse and B.P. readings occurred in certain groups of neurotic patients, but unfortunately no normal controls were available for comparison. 5.PersistenceBreath-holding and leg-raising tests were used, and both tests showed significant differences between groups of neurotic patients and normal controls. 6.Other FindingsThe enzyme choline esterase was found to be significantly higher in a group of E.S. patients when compared with a group of normal controls. It is suggested that blood choline esterase is higher in subjects with autonomic over-activity.Insulin tolerance tests done on E.S. patients gave generally normal results.We found no evidence of vitamin B1 deficiency in E.S. patients on quantitative testing (excretion and saturation test) . Vitamin C (excretion and blood level) appeared to be low, but no lower than we found in normal subjects at the same time of year (winter). 7.TreatmentThe above objective findings were used to guide our formulation of a treatment programme designed to combat effort intolerance in E.S. patients. Education of the patient to an understanding of the meaning of his symptoms is considered to be the most important aim. Twelve hours of physiological and psychological talks were given each month to the whole group of E.S. patients. Cures were not expected, but rather a change of attitude by the patient towards his symptoms—these which previously had been regarded as an illness were now accepted without anxiety as an understandable physical disability. The wider question of the psychiatric treatment of the neurosis itself is not discussed, as our concern is primarily with poor exercise response, and the symptoms related to this.