Non-organic neurological diseases

5 Non-organic neurological diseases



Introduction


Many believe that the diagnosis of functional, and for that read non-organic or psychological, disease should be a diagnosis of last resort. Those advocating this approach adopt the view that one should never have functional illness as the number one diagnosis. They believe one should only entertain the possibility after all other potential diagnoses have been excluded. The problem with this concept is that it has the capacity to encourage ‘sick’ behaviour. It reinforces that there is something seriously wrong.


The need for an exhaustive list of investigations before broaching the topic of psychological illness suggests that the true diagnosis is beyond the doctor’s capacity to discern. It suggests that the label of ‘functional illness’ is a euphemism for medical ignorance or incompetence. This may be more worrying to the anxious patient than would be an early identification of the probable diagnosis of psychological illness.


It does not mean that the provisional diagnosis of non-organic disease should exclude investigation for alternative differential diagnoses. While a provisional diagnosis is the most likely answer, it is not the only possibility. The same applies to the provisional diagnosis of functional illness. Nevertheless, an early acknowledgement that the most likely diagnosis is non-organic serves to reinforce that the doctor retains clinical acumen, assuming that there are valid reasons for placing the ‘functional’ label as the most likely diagnosis.


To consider what some claim a diagnosis of last resort necessitates the clinician appreciating those features of non-organic diseases that justify placing them at the top of the diagnostic ladder. What follows in this chapter is the evidence upon which a diagnosis of non-organic disease can be suspected as the principal diagnosis.



Observation


In earlier chapters it was proposed that an astute receptionist may be invaluable in suspecting psychological illness. A patient may display a range of behaviours that lead to the suspicion of non-organic disease. A receptionist may note how the behaviour changes when the attending doctor is, or is not, in the waiting room. The way the patient walks into the room or excessive complaint of pain without attendant signs may raise suspicion. These features suggest malingering and patient complicity in the claim of symptoms and signs. The patient may benefit from a fraudulent claim, as might occur following an accident. An experienced general practitioner will be atuned to such behaviour, which will not be discussed further in this chapter.



History


As was stated earlier, the taking of an accurate medical history remains a fundamental tool of the neurological consultation. Within the context of functional illness, other than the case of a malingerer who wilfully aims to confound the picture, the patient usually is unaware of the possibility of a non-organic diagnosis. As with so many neurological diagnoses, including non-organic neurological presentations, the doctor must maintain a high index of suspicion. This is imperative if the diagnosis is to be identified as early as possible. Often the diagnosis of non-organic disease emerges because the history in these cases makes little sense, does not suggest a diagnostic label and confuses, rather than assists, the clinician.


Whenever the history fails to offer clinical diagnostic direction, the possibility of functional illness should arise. In these circumstances functional illness should not climb the diagnostic ladder, but merely be included among the potential diagnoses. It is part of the differential options but lacks credibility to be a principal choice. The provisional diagnosis should be based on positive factors, and confusion is far from positive, but may provide an important clue.


Having made the distinction, history is the tool that differentiates tension-type headache from migraine. Tension-type headache may well be a ‘front’ for non-organic disease. Particularly in societies in which physical fitness is a primary requirement, as is the case for members of the armed forces, patients often find it unacceptable to present with complaints of a psychological nature. Once tension-type headache becomes apparent, then the general practitioner is in an ideal position to seek and deal with the cause of the tension. The same applies to various complaints of pain. An example of this is the chest pain that accompanies da Costa’s syndrome, which is a left inframammary pain attached to stressful situations. It is unlike the pain that reflects ischaemic heart disease or chest infection. This should raise the red flag of probable psychological illness but this warning does not negate the need to investigate for both cardiac and pulmonary disease. An early suggestion that the primary diagnosis is most likely non-organic, allows a strengthening of the doctor–patient relationship and potential for mutual respect while the auxiliary investigations proceed.


The differentiation between epileptic seizures and non-organic, so-called pseudo-seizures, also referred to as ‘non-epileptic’ seizures, is based on meticulous history taking. There are some features that assist in the differentiation, including: whether the eyes were open or shut during the seizure (eyes are usually open during an epileptic seizure); what post-ictal features existed (people after a seizure are often confused, disoriented, fatigued and may complain of headache while those with non-organic seizures may not experience these symptoms); if there was tongue biting or biting of the buccal mucosa; as well as possible incontinence of urine and/or faeces. While none of these are pathognomic of true epileptic seizures, they add to the weight of evidence, which may differentiate between the two. Absence of features associated with epileptic seizures offers the doctor the opportunity to explore causes of functional illness. Raising this with the patient demonstrates an understanding of the subject matter and encourages trust and respect.


Within these scenarios the doctor can both reassure the patient that there is probably nothing organically wrong, while concurrently conducting the tests to prove this to be the case. Unlike the situation in which non-organic diagnosis is the diagnosis of last resort, early identification and intervention reduces the risk of the patient adopting the ‘sick’ role.


The doctor needs to explain the reason, based on the available evidence, as to why functional illness is at the top of the list of diagnoses. While the initial response may be disagreement, it reinforces the integrity of the doctor; as will be reinforced if later findings support the earlier supposition of non-organic disease. This allows the doctor and patient to build a relationship on trust, in which the intimacy of the relationship may permit the doctor to explore issues that might otherwise be off-limits. It may provide the portal to introduce psychological or psychiatric support.

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Jun 19, 2016 | Posted by in NEUROLOGY | Comments Off on Non-organic neurological diseases

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