Acta psychiat. scand. (1978) 58, 61-66
Department of Psychiatry (Head: Prof. Sir Denis Hill),The Maudsley Hospital,
London, England

Psychomotor seizures, arterio-venous malformation
and the olfactory reference syndrome
A CASE REPORT

B. K. T o o m
A case history is reported of a 44-year-old man with a &year
history of psychomotor seizures. For the past year he had d e
scribed persistent olfactory hallucinations of an unpleasant nature
which he referred to himself. In many respects these symptoms
conform to the pattern observed in the olfactory reference syndrome, a recently described but apparently quite discrete psychiatric disorder; there were, however, certain atypical features. At
a later stage unilateral anosmia was noted. Radiological examination then demonstrated an arterio-venous malformation in the
right frontal lobe. The relationship between the malformation and
the psychomotor seizures, and the implications that each has for
the development of an olfactory reference syndrome are fully discussed.
Key words: Anosmia - arterio-venous malformations - automatisms

- hallucinations.

During the first third of this century descriptions of a syndrome characterized
by a persistent morbid preoccupation with personal odour at times approaching
levels of delusional intensity appeared in a number of case reports in the French
and German literature. Various descriptive titles were applied (Souchunofl (1906),
Birnbuurn (1915)) and classifications attempted (Reichurdt (1918), Muyer-Gross
(1932)), but a recognition of the syndrome as a discrete nosological entity was
delayed until the publication of a short series of case studies by Videbech (1967)
who introduced the term “olfactory paranoid syndrome”. A later survey (PrysePhillips (1971)) emphasized the distinctive characteristics of the syndrome: unlike schizophrenia the concern with body odours remains the dominant symptom throughout, the patient does not regard the smell as an imposition by some
external agency but holds himself solely to blame. His response is correspondingly contrite and apologetic. The olfactory reference syndrome, to use this
author’s terminology, may also be distinguished from depressive disorders in
which the affective disturbance is primary. As this extensive survey provides the
most detailed description of the syndrome, the title suggested by Pryse-Phillips
will be the one used here.
The case reported here is of interest partly because there are certain atypical
features which may reflect the presence of an underlying organic lesion, but also

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because it introduces the possibility that the development of an olfactory reference syndrome may in part be dependent on certain physical as well as psychological factors.
CASE REPORT
The patient, a 44-year-old male upholsterer, was first referred to a psychiatrist at the
age of 38 for the investigation of episodes of altered consciousness during which, according to eye witnesses, he would look blank, talk irrelevant, fumble with his hands
and o n occasions indulge in bizarre behaviour. Once he picked up a lighter and attempted t o set fire to the Black Jack table at a nightclub; another time he was found
unscrewing a door in a hotel bedroom for no apparent reason. At the time he seemed
unaware of what was going on. His only complaint was of amnesic spells, lnsting for
up t o 15 min and on two of these occasions he had been incontinent of urine. Such
episodes occurred every 1-2 months. There was n o previous record of psychiatric
illness in the patient or his family and his birth and upbringing were quite unexceptional. H e was described as an easy-going but rather egocentric man. He was
a t times inclined to drink rather heavily. He changed jobs frequently but was rarely
unemployed. He had been married and had two children but was now divorced.
No abnormality was found on examination. A diagnosis of temporal lobe epilepsy
was made and this was supported by EEG investigation. Although a routine waking
EEG was normal, a sleep recording showed numerous rhythmic sharp wave forms in
the mid-temporal regions bilaterally though more marked on the right. A brietalsphenoidal EEG showed the same sharp waves at the sphenoidal electrodes. Routine
haematological investigations, blood WR, plain chest and skull X-rays were all normal. Psychometric testing indicated a full scale IQ of 116 on the WAIS (verbal 118;
performance 110). Performance on the Wechsler Logical Memory test, Rey-Osterreith
test, Walton Black Modified Word Learning test and Wisconsin Card Sorting test, was
not impaired. His score on the Benton Visual Retention test was less than expected
taking his overall IQ into account, but this was not thought to be of any significance.
In view of the late onset of epilepsy the need for more detailed radiological investigation was discussed with the patient but permission for this was refused. He
was treated with combined anticonvulsants and the frequency and severity of the
attacks diminished although they never disappeared altogether. This state of affairs
persisted for 5 years.
Six months prior to the present admission a new symptom appeared. The patient
began t o notice that he gave off a peculiar, burning odour (like old leaves or an old
bonfire). This followed him around wherever he went and he assumed that he must
be responsible for it as no other explanation was forthcoming. His awareness of the
odour was to a considerable extent situationally determined; although he could from
time to time perceive it when he was alone, h e became immediately more aware of it
when he was in the presence of others, particularly if they were strangers. Moreover
if someone in his presence sniffed or sneezed he was instantly conscious of the
odour. H e began to watch for any suggestion on the part of others that they had
become aware of the smell and were offended by it. He felt that people were avoiding
him. H e said that when he entered a room someone would straight away open a
window. On one occasion, on entering a public house, the publican turned on the
extractor fan; he took this as indubitable evidence that the odour that he gave off
was also discerned by others and he took t o shunning all company and to drinking
by himself. He also began t o use an amount of deodorant that he later admitted
to be excessive in an attempt t o counteract the smell, although he did not attempt
to explain this in terms of failure of personal hygiene or biological function. H e
badgered his friends and relatives, demanding t o know if he smelt, and refusing to
believe them when they attempted to reassure him. With his brother he almost came
to blows on one occasion. Although prone to misjudge the actions of others, ideas of
reference, drawn from verbal sources, were notably absent. Snatches of overheard

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conversation might arouse his suspicions but did not lead to more specific misinterpretations.
Over the same period he noted other disturbances in his sense of smell. From time
to time naturally perceived odwrs were experienced with an intensity that was quite
unexpected: a woman’s perfume or a smell of baking bread as he passed a bakery.
Pleasant odours were as likely to be enhanced as disagreeable ones. He also noticed
that at other times his sense of smell was definitely deficient and odours which he
would have expected to perceive went unnoticed. Still more remarkably he found
that on some occasions he perceived pungent odours which on further investigation
proved to be completely unfounded. On entering a public house he was overwhelmed
by the agreeable aroma of a Sunday joint in preparation. He complimented the landlord only to be informed that no cooking was taking place on the premises.
These symptoms became increasingly intrusive and eventually he reckoned that for
about one quarter of his waking hours he was acutely aware of powerful odours,
particularly those which he attributed to his own body. He continued to have occasional psychomotor seizures. These would occur without any warning and upon
recovery were experienced only as an unaccountable gap in time. At no point was
there an olfactory component and their occurrence was quite unrelated to the persisting disturbance in olfaction described above.
On examination the only abnormal finding was a virtually complete right-sided
anosmia for coffee, vanilla, camphor and aniseed. These substances when presented to
the left nostril were readily identified. Full neurological examination was negative.
No bruit could be detected over the front of the head and no abnormal scalp vessels
were to be seen. The optic fundi were normal.
Investigations. Routine haematological investigations, serum folate and B 12, liver

function tests, plain skull and chest X-rays and routine waking EEG showed no abnormality. A Gamma scan showed a large lesion in the medial and lower part of the
right frontal lobe and a carotid arteriogram showed an arterio-venous malformation
in the same area (Fig. 1). The psychometric tests confirmed results obtained on the
previous occasion.
Management. It was felt that, in the absence d any symptoms suggestive of an intra-

cranial haemorrhage, surgery was not justified. The patient was told that his olfactory
experiences were not based on any objective reality; in part they were due to the
presence of an abnormal circulation in a part of his brain and the effect this might
have on the way he perceived things. He showed some surprise but was willing to
accept this explanation. However, at follow-up 4 months later he admitted that he
still had some doubts and had continued to use an excessive amount of deodorant
to eliminate any unpleasant body odours.

DISCUSSION
This case report prompts a number of questions. Firstly does the syndrome described here meet the criteria for a diagnosis of olfactory reference syndrome
as defined by Pryse-Phillips (1971)? The diagnosis may be made on the basis
of positive criteria: olfactory hallucinations or delusions should be present and
should refer to an odour, usually unpleasant, which the patient believes to be
his own and for which he assumes responsibility. This should be the principal
complaint and the cardinal feature of the illness at its inception and throughout
its subsequent course. Other psychiatric conditions such as schizophrenia, affective disorders and temporal lobe epilepsy in which olfactory hallucinations
may occur should be excluded.
This patient’s symptoms conformed to the picture described above in most

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respects. But in two important details they differ. The content of the hallucination and the interpretation placed upon it varied; most commonly the perceived odour was unpleasant, was referred to the patient’s own body and became marked during stressful circumstances. Occasionally, however, the hallucination occurred in an emotionally neutral situation, concerned odours which
were not necessarily disagreeable and which were referred by the patient to the
outside world. Although the latter type of experience is not a feature of the
olfactory reference syndrome it is also highly atypical of the other conditions
in which olfactory hallucinations occur. The patient experienced the hallucination as a normal and thoroughly commonplace event and placed no special
significance upon it. It was only the response of others who did not share his
experience that led him to recognize its unusual nature. In this the characteristics
of the phenomenon differ from olfactory hallucinations which occur in schizophrenia and temporal lobe epilepsy. The patient also noticed that on occasions
his sense of smell was quite deficient. The possibility that this unusual feature
may be related to the presence of an underlying organic lesion will be commented on later.
In other, perhaps less distinctive ways, this patient’s history departs from the
classical description of the olfactory reference syndrome. Numerous authors
have commented on the premorbid personality and their observations have shown
a remarkable consistency. Such patients are notable for their moral scrupulousness but also for their keen sense of failure (Landis & Bolles (1946), Schneider
(1959)). Langfeldt (1951) has referred to the “Sensitive-Reaction type” and has
suggested a constitutional basis. In this patient’s history there is evidence of a
somewhat turbulent personality, an unstable work record, a broken marriage
and a tendency to drink heavily, but little to suggest the presence of character
traits of the kind described above. On the contrary he was said to be of a carefree, easy-going disposition although somewhat egocentric. Finally his ready acceptance of the explanation of his symptoms is very much at variance with the
intractable beliefs held by patients with the olfactory reference syndrome. However, it must be admitted that some reassurance was required from time to time
as his doubts were prone to return.
However, notwithstanding these reservations, a diagnosis of olfactory reference
syndrome, albeit with some atypical features, comes closest to summarizing the
psychiatric symptoms reported here. In that case three separate diagnoses have
been made: olfactory reference syndrome, psychomotor epilepsy and a frontal
arterio-venous malformation. Are these conditions aetiologically independent of
one another or are they in some way related? There are grounds for supposing
that the psychomotor seizures are symptomatic of the vascular malformation.
It is recognized that lesions of the frontal lobes may produce features more
commonly associated with temporal lobe pathology (Schneider et al. (1961)).
Hill & Driver (1962) have drawn attention to the fact that ictal automatisms
may be initiated by epileptic foci in the frontal and orbito-frontal areas. Moreover epilepsy is not uncommonly a first manifestation of arterio-venous malformations. However, the relevance of these two conditions for the later development of an olfactory reference syndrome is more speculative. Expanding lesions,

A

Fig. 1. Subtraction carotid angiography showing an arterio-venous malformation in the
right frontal lobe. A , arterial phase of filling. B, venous phase o f filling.

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particularly olfactory groove meningiomas, may cause olfactory symptoms
through pressure on the olfactory nerve but this usually takes the form of varying degrees of anosmia, or less commonly, parosmia. No cases have been described with olfactory hallucinations, or of olfactory delusional syndromes. This
patient experienced, in addition to a persistent and disagreeable odour which
he referred to himself, fleeting disturbances of olfactory perception which he
attributed to sources outside himself and which were lacking in personal significance. That such symptoms could have an organic basis seems worth considering. If this was so their ephemeral nature suggests that they may be caused by
ischaemia due to local vascular shunting rather than by a direct pressure effect.
Occasionally he noticed that his sense of smell was deficient. This is in accordance with the finding of unilateral anosmia and is likely to have an organic
explanation.
Whether such a structural lesion could also be responsible for the psychiatric
symptoms more typical of the olfactory reference syndrome is uncertain. Previous surveys (Videbech (1967), Pryse-Phillips (1971)) have not described any
cases in which an organic aetiology was considered likely: on the other hand it
is unusual for such patients to undergo extensive neuro-radiological investigation.
Even so such an association must be considered distinctly uncommon.
It is worth considering whether certain forms of prior perceptual experience
may directly influence the development of the psychotic illness. Following this
approach Pond (1962) has suggested that the ictal experience of temporal lobe
epilepsy may lead in time to emergence of chronic paranoid hallucinatory psychosis. This is unlikely to be the case here as the description of the ictal events
lack any olfactory component. Of more relevance to this case are the observations of Orbach e f al. (1952) that colostomy patients may develop olfactory
paranoid syndromes which in many ways resemble the olfactory reference syndrome. Therefore rather than postulate the coincidental development of two
uncommon disorders, each containing as its predominant symptom an abnormal
olfactory experience, a further possibility may be considered, that the disturbance
of olfactory function brought about by the arterio-venous malformation is capable of providing a biological substrate favourable to the development of the olfactory reference syndrome. Such an explanation assumes some degree of innate predisposition to psychotic illness but less than is usually the case in the
olfactory reference syndrome. This would be consistent with the presence of
certain atypical features, namely the uncharacteristic premorbid personality and
the late age of onset.
ACKNOWLEDGEMENTS
I wish to acknowledge the help given by Dr. L. A. Lishman in the preparation of this
report. Thanks are also due to Prof. C. D. Marsden, Mr. J . J . Maccabe and Dr. R. D .
Hoare for their valuable help and advice.

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Hill, D., & M . V .Driver (1962): Electroencephalography. In Brain, W. R . (ed.): Recent
5 ACTA PSYCH 58:l

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advances in neurology and neuropsychiatry. Churchill, London, pp. 169-238.
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182-213.
Received December 21, 1977

B. K . Toone, M.B.B.S.
The Maudsley Hospital
Denmark Hill
London SE5 8AZ
England