assesment of simulation and exaggeration in ent expertise

8/14/2019 Assesment of Simulation and Exaggeration in Ent Expertise

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ASSESSMENT OF SIMULATION AND EXAGGERATION IN ENT EXPERTISE

R. BONIVER, M.D.; V. BONIVER, M.D.

INTRODUCTION:

In expertise, we have to obtain objective data from the patients complaints. Those, in certain

cases, are voluntary exaggerated, either because the subject has a temperament by which he always

tends to exaggerate his symptoms, or because he estimates to be injured in his integrity of its

physical status and to be entitled to a repair for which he will do the test in the way to have the best

advantages.

We shall consider three pathologies for which we are most frequently consulted in ENT:

- Hearing disorders

- Balance disorders

- Smell disorders

1.HEARING DISORDERS:

1.1 Hearing loss assessment.

The first evaluation of the patient with hypoacousia can be done easily without any instrument.

How does he understand the voice during the anamnesis?

Does he understand the whispered voice? Is it necessary to speak loud or very loud?

It is also important to observe the patient: does he have an auditory prosthesis? Is it open? Is it

working good? Is the battery good? How does he react to the questions?

In the case we suspect a hearing loss from one side or the other, the first measurement which can be

done to the consulting room of any doctor is a control of the hearing by a tuning fork. We use a

512 Hz tone to realize the Rinne and Weber tests.

In the Rinne test, the patient is asked to tell us whether the vibrating tuning fork seems louder when

it is held beside his hear (by air) or behind his hear directly on the mastoid bone (by bone). If the

fork is louder behind the ear, on the patients mastoid bone, his bone conduction is considered to be

better than his air conduction, and therefore has a conductive deafness.

In the Weber test, the tuning fork is placed on the patients forehead. Hes asked to indicate in which

ear the fork sounds louder. In a conductive hearing loss, the tone will sound louder in his bad hear.

In a sensory hearing loss, the tone will sound louder in his good hear.

_________________________________________________________________________________

R. BONIVER, M.D., Invited Prof. Liege University Belgium

rue de Bruxelles, 21B-4800 VERVIERS

BELGIUM

Email : r. [email protected]


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1.2 Audiometry

1.2.1 Pure tone audiometry consists to deliver via earphones pure tones of determined intensity

and frequency. In ideal conditions, the subject is placed in a sound-proof room and the tester

should be ideally outside of the room.

1.2.2 Speech audiometry will be carried out in double soundproof rooms. In a first examination,

the tester presents lists of words phonetically gauged, as the list of dissyllabic words of

Fournier for the French language to the patient.

One can measure the comprehension of the subject and determine some parameters, whose

principals are:

- The speech recognition threshold: Intensity at which 50% of the items are heard

correctly.

- The discrimination score is the percentage of understood words presented at 35 dB

above the speech recognition threshold.- The hearing capacity index (HCI) is the average percentage of understood words

presented at 40 dB, 55 dB and 70 dB. This test is useful in evaluating an auditory prosthesis.

These audiometric tests need the active participation of the subject.

In pure tone audiometry , whenever the subject exaggerates his handicap, the audiogram

doesnt fit with the responses he gave during the anamnesis. For example, with an average

of 80 dB loss on the audiogram, the subject cant understand the whispered voice.

Then, in suspected cases, the audiogram can be delivered in two sessions:

- Descending step: from loud to level of perception, decreasing by step of 5 dB.

- ascending step: from 0 dB to level of perception, increasing by step of 5 dB.

In the normal subject, the two levels of perception should be the same in the ascending and

descending pathways and should correspond to the discrimination level obtained during

speech audiometry.

1.2.3 When we suspect a functional hearing loss, further testing is necessary:

Historically, the following tests were used in simulation screening:

- Lombard or Voice-Reflex test- Azzi test

- Stenger test

- Bekesy audiometry

1.2.4 The DAF test (delayed auditory feedback test) introduced by Demanez (1) can detect

hearing losses of sizeable degree but not the minor exaggerations that can occur in medico-

legal situations.

1.2.5 Nowadays, several objective tests can be done and are helpful in assessing auditory function

in patients who are unable or unwilling to cooperate.

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The most common used tests are

- Acoustic reflex thresholds

- Otoacoustic emissions (OAE)

- Brain stem evoked-response audiometry (BERA or ABR)

- Cortical evoked-response audiometry (CERA)

1.2.5.1 Acoustic reflex threshold

- Normally, the reflex for pure tones is elected at about 90 dB above the hearing threshold.

For broad-band noise, it occurs at about 70 dB above threshold.

- In patient with cochlear damage, the reflex may occur at sensation levels less than 60 dB

above the auditory pure-tone threshold. (Metz recruitment)

- It is absent :

o in conductive losses

o in case of impairment of the VII-VIII reflex arch.

o In case of cophosis

1.2.5.2 Otoacoustic emissions

Evoked otoacoustic emissions may be conceptualised as an echo in response to a sound

stimuli. These emissions are generally absent in hearing loss greater than 30 dB from 500 to

2000Hz.

Then, if the subject has a hearing loss of 60 dB in pure-tone audiometry with normal evoked

otoacoustic emissions on the same ear, it is a functional hearing loss.

Otoacoustic emissions is not a tool to determine the degree of hearing loss by frequency,

even with the distorsion product emissions.

1.2.5.3 Brain Stem Evoked-Response Audiometry

The test measures electrical peaks generated in the brain stem along the auditory pathways.

Testing can be done with pure tones, broad-band noise or clicks. In any case, the brain stem

does not react to a determined frequency.

The measure is objective, consistent and approximate threshold levels can be determined. In

suspected cases of exaggeration, ABR testing is reliable. If the BERA gives you normal

peaks at 20 dB and the threshold on pure tone audiometry is 80 dB, it is a functional hearing

loss.

ABR are also useful in neurologic disorders. Absence or distorsion in latency of peaks, or

delays between peaks, can help localize lesions in the auditory pathways. For example, a

difference in latency between a patients two ears of greater than 0,3 ms is often related to an

acoustic neuroma. In multiple sclerosis, when the patient complains of bad hearing with

normal pure tone audiometry, the BERA can demonstrate increasing interwave latencies or

complete desynchronisation.

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1.2.5.4 Cortical Evoked-Response Audiometry (CERA) (Fig.1)

This method focuses on electrical activity at the cerebral-cortex level. The patient must be

kept aware with images projection or reading. It is a valuable tool in evaluating thresholds

frequency by frequency. The results in normal subjects are in correlation with pure toneaudiometry findings. (Boniver 2; 3; 4)

1.3 Tinnitus

Tinnitus is an otological condition in which sound is perceived without any external auditory

stimulation. It may be a whistling, ringing, roaring, buzzing, This challenging pathology is

difficult to assess in expertise. Tinnitus may be either objective or subjective. Objective tinnitus

is comparatively easy to detect and localize because it can be heard by the examiner using a

stethoscope. It may be caused by glomus tumor, palatal myoclonus and other conditions.

Subjective tinnitus is much more common by far. All the tests described above can be done inthe assessment of subjective tinnitus to recognise a causal relationship. Nevertheless, in a large

number of cases in which a normal patient with normal hearing complains of head noises,

functional tinnitus has to be considered. The expertise of a psychotherapist is helpful to

determine the problem with the patients that can sometimes have distressing proportions.

1.4 Conclusion

Actually, objective hearing tests are accurate and reliable to define the hearing threshold of the

patient with functional hearing loss.

These objective tests are of great value in expertise.

2. VERTIGO

2.1 It is important to rule out all the organic causes that can lead to vertigo and dizziness.

In case of head trauma, the most common cause of vertigo is the benign positional paroxysmal

vertigo (BPPV) which is related to the liberation in the endolymph of little particules, the otoconias,that move in certain position of the head and irritate the sensory cells of the ampulla of the semi-

circular canal, creating a sudden vertigo. Imbalance from a trauma, injury or intoxication can be

very variable.

It is important to keep in mind that the balance is the result of miscellaneous informations collected

in the vestibular nuclei arising from proprioceptive, visual, vestibular, cortical and emotional

pathways. The cerebellum is regulating the vestibular nuclei.

All these informations are integrated and sent to the motor pathways to control eye movement,

static and dynamic posture.

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2.2 The assessment of the dizzy patient:

- Anamnesis

- Physical examination

- How he stands

- How he walks- Otoscopy

- Audiology testing

- Pure-tone audiometry

- Acoustic reflex

- Otoacoustic emissions

- BERA

- Vestibular testing

- Oculomotor examination

- Clinical vestibular evaluation

- Index deviation and Romberg

- Spontaneous nystagmus and positional nystagmus

- Rotational testing with ENG/VNG control

- Caloric testing with ENG/VNG control

- Vestibular evoked myogenic potentials (VEMP)

- Posturography

ENG = electronystagmography

VNG = videonystagmography

2.3. Recurrent paroxystic vertigos can occur : (Boniver 5)

2.3.1 The most frequent are the benign positional paroxystic vertigos secondary to

canalolithiasis.

2.3.2 Other conditions such as Mnires disease, syncope, vestibular migraine or vascular

lesion as for example the subclavian artery steel syndrome, are possible.

2.4 In some patients victim of injury, psychogenic vertigo can occur:

- Either provoked by a persistent vertiginous sensation linked to well-known organic

lesion but unexplained to the patient that last for months.

- Either induced by the posttraumatic stress.

2.4.1 The interpretation of the dizziness is linked to several factors:

* The knowledge of the affection: Why, How.

* The interpretation of this knowledge

* The previous state of mind of the patient

Personality disorder

Anxiety

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Psychiatric disorder (schizophrenic, bipolar, Hysteric,)

The relationship with the physician

(danger of multiple examinations in expertise without a real relation with

the patient)

2.4.2 Vertigo ca also be a symptom in different psychiatric disorders. The list according to theDSM-IV classification was published by Brandt in 1996 :

* Vertigo as an associated symptom

Schizophrenia

Paranod Personality Disorder

Major Depressive Disorder

Dysthymic Disorder or Depressive Neurosis

Generalised Anxiety Disorder

Conversion Disorder or Hysterical Neurosis Conversion Type

Hypochondriasis Somatoform Disorder

Depersonalisation Disorder

Factitious Disorder with predominantly Physical Signs and Symptoms

Adjustment Disorders unspecified (with Physical Complaints)

* Vertigo as a defined syndrome

Panic Disorder with Agoraphobia

Agoraphobia without History of Panic Disorder

Acrophobia

* Impact of the psychological status on the organic vertigo

Predisposed Personalities

Evidence of Psychiatric Disorder

Voluntary exaggeration of existing Symptoms

Simulation

2.4.3 The frequency of psychogenic vertigo is not well described in the neuropsychiatryliterature. In a cohort of 1370 patients complaining of vertigo, Brandt (6) demonstrated

15 % of postural phobic vertigo.

When the otoneurological examination is normal, a psychiatric work out is then

necessary in case of suspected psychogenic vertigo.

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2.5. Conclusion

The accurate exploration of the dizzy patient is able to find out in the majority of the cases

the organic lesion of the disease.

The intense and paroxystic vertigo with rotational sensation is always from the labyrinth orsometimes secondary to an acute brainstem lesion but then associated issued with other

neurologic symptoms.

The balance disorders are dependent of many factors. Some of them are psychologic.

When the otoneurologic examination is normal, it is further necessary, in some cases, to ask

for a neuropsychiatric evaluation of the patient.

3. THE OLFACTION

3.1. Introduction:

The smell loss is frequent in head trauma with anteroposterior impulse which create a laceration of

the olfactive fibers or contusion of the olfactive bulb at the skull base. Up to these last years, it was

difficult to do an objective testing of these patients.

Actually, the tests we use nowadays can confirm the complete loss of smell (anosmia).

Unfortunately, it is still a challenging procedure to detect the little variation of smell (dysosmia).

Even in a normal subject, the sense of smell is variable, depending on various conditions: ,

digestion, hormonal, metabolic disorder, smoking,

The testing must be completed with a detailed interrogatory to have the maximum level of success

in defining the diagnosis of anosmia or hyposmia.

3.2. the UPSIT test

Different psychometric tests to evaluate the sense of smell are available.

The UPSIT (University of Pennsylvania Smell Identification Test) test we use is based on thepresentation of 40 different micro crystallised substances that can be released by scratching with a

neutral pencil. All the odours are familiar.

For each item presented, the subject has to choose one between 4 different proposals.

The odorous substances that are presented have been selected on different criteria: pleasant and

repulsive, pure or mixed flavour (chocolate), trigeminal sensitive (menthol) to detect simulators.

The examiner is compelling the good responses and the score is reported in a board according to the

age and sex of the patient. The score is a percentile and the patient is classified as normosmic,

microsmic, anosmic or suspected simulator.

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3.3. The measurement of the time related respiratory flow

In this method, we record the variation of nasal air flow with an anterior rhinomanometer and some

different olfactive substances are introduced in the airflow channel. (Melon and Boniver, 1972,

unpublished-fig 2).

Four flavours are tested after a normal air test recording: eau de rose, lavander, pyridine, ammoniac

30%.

We observe the variations of the respiratory rhythm induced by the presentation of the different

flavours.

This test is reliable to detect an anosmic: the smell of pyridine is so intense that only the true

anosmic patient can breathe it. If the patient block his respiration with pyridine, he still can smell.

3.4. Olfactory Evoked Potentials

The olfactometer can stimulate the olfactive fibers and the nasal mucosa with the diffusion of

different odorous substances. The patient sits and is administred by a nasal tube during twenty to

forty minutes different flavours, some purely olfactive, some sensitive (trigeminal sensitive).

The patient must be relaxed and not disturb.

The computer analyses the results and can tell if the patient has a normal sense of smell. But it is

not reliable to detect the quality of the olfaction of an individual subject.

This objective test is time consuming and is actually developed by Rombaux at the University of

Louvain in Belgium.

CONCLUSION

The development of new technique and the use of more powerful computer assisted technology lead

us to reach the diagnosis of most disease more and more objectively.

No doubt, it will be even better in the future.

The simulator has a particular psychologic profile that the examiner has to take in account and it

needs a lot of patience and tact to tests these patients.

Simulating is a lie, a fraud, and all fraud must be revealed. It is in fact our opinion.

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BIBLIOGRAPHY

1 DEMANEZ J.P., DITTRICH F.L., LEDOUX A. DAF Test : a new recording and analysing

device. International Audiology. 1966, V ; 91-96.

2 BONIVER R. Intrt de ltude des potentiels voqus corticaux en expertise. Acta Oto-Rhino-Laryngologica, 1982, 36 : 377-381.

3 BONIVER R. Cortical electric response audiometry (slow vertex response) in forensic

audiology. Acta Oto-Rhino-Laryngologica Belgica, 1994, 48 : 357-361.

4 BONIVER R. Slow auditory evoked potentials. The end of malingering in Audiology.

International Tinnitus Journal. 2002, 8 : 58-61.

5 BONIVER R. Les vertiges paroxystiques rcidivants. Revue Mdicale de Lige, 2004; 59: 5:

326-330.

6 BRANDT Th. Phobic postural vertigo. Neurology. 1996, 46:1515-1519.

7 BRANDT Th. Psychiatric disorders and vertigo, in Vertigo its multisensory syndrome.

Springer Verlag Ed. 2000, ISBN 3-540-19934-9, 455-468

8 ROMBAUX Ph., COLLET S., ELOY Ph., LEDEGHEM S., BERTRAND B.

Smell Disorders in ENT Clinic.

B-ENT, 2005, Suppl. 1, 97-109.

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assesment of simulation and exaggeration in ent expertise

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