Workers who are at risk of passing out suddenly or who suffer from frequent fitting can be a danger to themselves and others. Occupational health teams can help manage these afflictions in order to minimise the associated risks. Colin Payton reports.
Occupational health practitioners are regularly asked to see workers who have suffered from what they describe as fits, faints, blackouts or turns of some other sort. It is vital to establish the true clinical nature of such episodes, whether or not they have involved a transient loss of consciousness (TLOC), and to determine the cause in order to advise employers on the afflicted member of staff's fitness for work.
It is also important to understand how underlying conditions are investigated, how they can be treated and how effective treatment can help workers to remain at, or return to, work. The most common causes of TLOC are seizures (provoked and unprovoked) and syncope (cardiac and non-cardiac); it is important to distinguish between these because seizures, generally speaking, have far greater implications on fitness for work. Other causes of TLOC include concussion following a head injury and intoxication, but these are less relevant to occupational health.
Epileptiform seizures, also referred to as fits or convulsions, are the result of a spontaneous abnormal electrical discharge in the brain. Around 10% of people experience a seizure at some time in their life (Berg et al, 1991).
They can be provoked or unprovoked. Provoked seizures are caused by brain injury or illness, or by metabolic problems. The most common causes are cerebrovascular disease, withdrawal from alcohol and drugs, trauma and tumours. There are many different types, not all of which cause loss of consciousness. A generalised tonic-clonic seizure, or grand mal seizure, is the most common, the most debilitating and the most likely to affect fitness for work. Epilepsy is a disorder where there is a tendency for recurrent unprovoked seizures, and is diagnosed after a patient suffers two or more.
A prodromal phase is uncommon but can be the first indication of an impending seizure. The patient experiences symptoms that are ill-defined, but also has a distinct feeling that a seizure is about to happen. This phase can last just a few moments or much longer, sometimes days. An aura is more common, and very brief, and includes physical symptoms such as butterflies in the stomach, paraesthesiae (pins and needles), a feeling that they can smell something familiar, difficulties with speech and a sensation of déjà vu. Consciousness is sometimes altered during the aura and the patient may be unresponsive to others' conversation. The patient then loses consciousness and falls abruptly, with an appreciable risk of injury.
It is important to understand how underlying conditions are investigated, how they can be treated and how effective treatment can help workers to remain at, or return to, work."
Their muscles go into spasm, in what is described as the tonic phase of the fit, and they sometimes cry out due to spasm of the respiratory muscles forcing air out of their lungs. This is followed by the clonic phase, which includes rhythmic jerking movements of the arms, leg and face. They sometimes bite their tongue and can lose control of their bladder and, occasionally, their bowels. When they wake up, they are confused and may then fall into a postictal sleep. Over the next 24 hours they may experience soreness and stiffness of their muscles due to the powerful repetitive jerking movements during the clonic phase. Patients may not have any recall and an eye-witness account, or even a video of an attack, can help to establish the clinical diagnosis.
Patients suffering symptoms suggestive of even a single, generalised seizure should always be investigated by a neurologist, via electroencephalography (EEG) and an MR brain scan, for an underlying cause. Sixty per cent of adults who suffer a single seizure will never have another; this figure rises to 90% when EEG results are recognised as normal. After two seizures, the two-year-recurrence risk rises to 70% (Annegers et al, 1986) and treatment with anti-epileptic drugs (AEDs) is normally started at this stage. This can be very effective and complete control of seizures is achieved in approximately 80% of patients.
Syncope is defined as a sudden transient loss of consciousness due to decreased cerebral blood flow, and is characterised by abrupt onset, brief duration and complete spontaneous recovery. It is common and is responsible for 1% to 3% of visits to emergency departments as well as 6% of all hospital admissions (White et al, 2000). It becomes more common as age increases. The most well-known type of syncope is vasovagal, in which there is triggering of a neural reflex leading to excessive autonomic activity that causes a drop in blood pressure, bradycardia and peripheral vasodilatation. Collapse is usually preceded by symptoms including lightheadedness, nausea and blurred vision, and the patient becomes sweaty and very pale. Collapse is not normally as sudden and dramatic as in a seizure, however, there can be jerking of the limbs due to cerebral hypoxia, which can lead to a misdiagnosis of epilepsy. In syncope, the jerking is usually very brief (no more than about 15 seconds) and tends to involve only the distal parts of the limbs. There is no postictal confusion or sleep, but the patient may feel tired or drained.
There are a number of variants of vasovagal syncope, for example carotid sinus syndrome and situational faints. Carotid sinus syndrome is an extreme reflex response to carotid sinus stimulation. Symptoms can occur when patients have neck tumours or severe neck scarring, or can be produced by wearing a tight collar, shaving or even by turning the head. A situational faint is associated with, for example, urination, defecation, coughing and sneezing.
Orthostatic syncope occurs when a patient stands up and their blood pressure drops due to failure of the autonomic nervous system to adequately compensate for the change in posture. It is seen in frail, elderly patients, especially if they are dehydrated. It can also occur in patients on diuretics, beta-blockers and drugs for hypertension. It affects 5% of the population and 7% to 17% of patients who have been admitted to acute care in hospital (Frishman et al, 2003). Occupational health practitioners are less likely to come across this condition.
Cardiac causes of syncope
1. Cardiac arrhythmias: Heart block, supraventricular and ventricular tachycardias.
2. Structural cardiac and cardiopulmonary disorders: Ischaemic heart disease, valvular disease, hypertrophic obstructive cardiomyopathy, aortic dissection and other rare causes, such as primary pulmonary hypertension.
Investigation and treatment
After a single episode of syncope, and when there is a confident clinical diagnosis of vasovagal faint, no additional investigation is needed. However, further investigation is required:
- when there are repeated episodes that may be interfering with normal activities, including work;
- when patients are suffering injuries after they have fallen; and
- in workers such as commercial drivers or midwives and other occupations where syncope could put others at risk.
Cardiac arrhythmias and structural cardiopulmonary disorders should be excluded clinically with an ECG, a chest X-ray and, if necessary, an echocardiogram and a 24-hour or seven-day ambulatory ECG (holter) monitor test. If cardiac investigations prove negative, the next step is head-up tilt testing: the patient is strapped to a horizontal table that is gradually elevated to a vertical position while blood pressure and an ECG are monitored. A fall in blood pressure and pulse during the test will confirm the diagnosis of vasovagal syncope.
Treatment of recurrent syncope includes patient education to reassure that there are no more serious underlying conditions and to avoid trigger situations, such as dehydration or stress. Where syncope is stress related, stress management may help and drug treatment may be offered. Both fludrocortisone (Da Costa et al, 1993), which increases blood volume, and midodrine (Kaufmann et al, 2002), an alpha-adrenergic agonist that increases peripheral vascular resistance and venous return, can be effective.
Conditions that may appear syncopal in nature but do not actually involve transient loss of consciousness include psychogenic non-epileptic seizures (PNES), panic attacks, drop attacks and cataplexy.
Role of occupational health
Occupational health practitioners can support workers with epilepsy in a number of ways. They can provide employers with information on the effects of epilepsy. They can advise workers on transport to work: they may be entitled to a bus pass or a disabled person's railcard, or even get funding from the Government's Access to Work scheme for taxis if they can't use public transport. They can advise employers on reasonable adjustments. Some people suffer seizures upon waking from sleep and need to start work later. Sleep deprivation can trigger breakthrough seizures in people who normally have good seizure control. Advice on shift patterns, eg avoiding night shifts, may help to prevent this.
PNES features resemble those of true seizures and are frequently misdiagnosed as epilepsy; 20% to 30% of patients referred for investigation of refractory seizures turn out to have PNES. Resistance to treatment with AEDs, psychological triggers to the seizures and features of the seizures that are inconsistent with a diagnosis of epilepsy are the hallmarks of the condition. They are a type of somatoform disorder - a psychological condition that manifests with physical symptoms suggesting a medical disorder, and, more specifically, they are termed "conversion disorders". The other psychological conditions that produce physical symptoms are malingering and factitious disorder, but these conditions rarely give rise to PNES. The most important step in management is making the diagnosis and 50% to 70% of patients become free of PNES once diagnosis is established.
Drop attacks are spontaneous falls while standing or walking, without loss of consciousness. The onset is abrupt, there is rapid complete recovery and the patient has normal recall of the event. They are a common cause of falls in the elderly.
Panic attacks are brief periods of intense feelings of fear or apprehension that reach a peak within 10 minutes. The effects vary and the "Diagnostic and Statistical Manual of Mental Disorders" diagnostic criteria include shortness of breath, choking, chest pain, feeling dizzy or faint and a sense of impending death. Those who haven't previously experienced attacks can think they are suffering acute physical or psychological emergencies and will often call an ambulance.
Cataplexy is sudden muscular weakness found in a high proportion of patients with narcolepsy. The weakness can affect just a few muscles and can cause patients to drop things, the head to fall forwards, slurred speech or ptosis (drooping of the upper or lower eyelid). Sometimes it can cause complete paralysis and, therefore, collapse. It is triggered by strong emotion - especially positive emotions such as laughter - and usually lasts from only a few seconds to a few minutes. Other triggers include stress, fatigue and sleepiness. It does not cause loss of consciousness and the patient stays alert, although is unable to respond.
Fitness for work after collapse
Common, or vasovagal, syncope is unlikely to interfere with work unless it is happening frequently and with so little warning that the patient is suffering injuries when they fall. Sufferers may be no more at risk of injury at work in an office than they would be in their own home or in the street, but will be at considerably greater risk if they work on a building site, for example. Fainting on a regular basis is likely to affect productivity and can also take up a lot of colleagues' time as people will need looking after; it can also be distressing and quite frightening for others. However, employees should be able to return to work once vasovagal and cardiac syncope is effectively treated, or when they learn to avoid the triggers for carotid sinus syndrome or situational faints.
Seizures can have a much greater impact if they happen at work. An employee who has suffered a single seizure is at risk of further seizures and potentially at risk while working. After a single seizure, the two-year risk of recurrence is 32% to 57%, depending on the underlying cause (Berg et al, 1991). The type of work is also an important factor - drivers, pilots, offshore workers and those who work in kitchens, in isolated settings, with unguarded machinery, with high-voltage electricity, near open water and at heights should not continue to work without restrictions.
Drivers of small vehicles are prohibited from driving for one year after a seizure. They can reapply for their licence after that time, whether they have started AEDs or not, but if they suffer another seizure, they will incur a further one-year ban. Bus and lorry drivers have little chance of regaining their licences after a seizure - they would have to be seizure-free for 10 years and must not have taken AEDs during that period.
An employee who has suffered a single seizure is at risk of further seizures and potentially at risk while working."
Those who provide care to others, such as childminders and healthcare workers, may face restrictions. However, this would depend on the nature of their duties. For certain types of doctors, a risk of seizure would not prevent them from safely carrying out their duties. However, for nursing staff involved in manual handling of patients, it is more difficult. For surgeons and midwives, seizures could put adult patients and newborn babies at significant risk.
Effective treatment with AEDs reduces the risk of further seizures, and restrictions on some workers can be lifted after they have been fit-free for 12 months.
People with epilepsy experience prejudice and discrimination in employment, leading to high unemployment rates and economic and social disadvantage (Elwes et al, 1991). The Equality Act 2010 considers the effects of long-term medical conditions (without treatment) on normal day-to-day activities. It is therefore likely that workers with epilepsy would be protected by the Act. It is unlikely that the Act would cover someone after a single seizure and that people with vasovagal syncope would be covered, unless their symptoms were extreme. Non-syncopal conditions may be covered if they are longer term, for example cataplexy.
Colin Payton is a freelance writer and a consultant occupational physician at the Royal United Hospital in Bath.
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