Neuropsychologia 42 (2004) 230–238

Belief and awareness: reflections on a case of persistent anosognosia
Annalena Venneri a,∗ , Michael F. Shanks b
a Cognitive Neuroimaging Research Unit, Department of Psychology, University of Aberdeen, King’s College, Aberdeen AB24 2UB, UK
b Department of Psychiatry, University of Auckland, Auckland, New Zealand

Received 2 January 2003; received in revised form 15 May 2003; accepted 24 June 2003

Abstract
Persisting anosognosia after acute lesions is relatively rare, and no case studies to date have reported functional scanning investigation of
this disorder. This is a case report of an 85-year-old right-handed Scottish woman, EN, who showed persistent anosognosia for hemiplegia
following a haemorrhagic stroke. Extensive damage in the right hemisphere caused left upper and lower limb flaccid hemiplegia and severe
left-sided neglect. Lack of awareness for her deficits was still present 2 years after the stroke, when neurological, neuropsychological, and
SPECT examinations were performed. Testing revealed severe left unilateral neglect and poor performance on verbal fluency tasks. EN
had age normal memory performance, and her object recognition and praxic abilities were preserved. She showed no global reasoning or
language problems apart from her abnormal beliefs. EN believed that she was able to walk and carry out several activities, in a context of
other disorders of belief. SPECT scan showed marked hypoperfusion in the right parietotemporal cortex and this extended to the associative
cortex in the right frontal regions.
The persistence of anosognosia in this patient cannot be explained by memory impairments or global cognitive decline. A possible
account might be that alteration in awareness was maintained by contingent right frontal and/or parietal dysfunction causing a suspension
or change in the ability to monitor and check the ‘real’ and especially to assess the veracity of mental contents.
© 2003 Elsevier Ltd. All rights reserved.
Keywords: Anosognosia; Hemiplegia; Neglect; SPECT; Persistent; Chronic; Reality monitoring; Delusions

1. Introduction
A failure of awareness of deficit or anosognosia is frequently reported following right hemisphere damage and
can also be seen in patients who have global cognitive
impairment from degenerative causes like Alzheimer’s disease (AD). Lack of awareness of functional decline in AD,
when this symptom makes its appearance, is persistent
and its severity increases with disease progression. When
anosognosia appears following an acute lesion it is usually
shortlived, in most cases involves unawareness of hemiplegia, and when the acute or post-acute state is over patients usually gain awareness of their condition. Persisting
anosognosia after acute lesions is less frequent, although a
few cases have been described (e.g. Berti, Ladavas, & Della
Corte, 1996; Berti, Ladavas, Stracciari, Giannarelli, &
Ossola, 1998; Cocchini, Beschin, & Della Sala, 2002;
Marcel, Tegnér, & Nimmo-Smith, in press). In the context
of global cognitive impairments anosognosia can be seen
∗ Corresponding author. Present address: Department of Psychology,
University of Hull, Hull, HU6 7RX, UK. Fax: +44-1482-465599.
E-mail address: annalena@abdn.ac.uk (A. Venneri).

0028-3932/$ – see front matter © 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/S0028-3932(03)00171-4

as an inevitable consequence of multiple and increasingly
severe cognitive failures, but the need for a theoretical
explanation seems both more necessary and potentially
achievable where this symptom appears in the absence of
global deficits. Several such theoretical accounts have been
put forward. These can be fairly divided into psychodynamic
or motivational theories (Weinstein & Kahn, 1955) and cognitive theories (Bisiach, Meregalli, & Berti, 1990; McGlynn
& Schacter, 1989). Pure psychodynamic theories, involving
for example denial or depression, are challenged to some
degree as comprehensive explanations of disturbances in
awareness by the more frequent link between anosognosia
and right hemisphere dysfunction. It is also perhaps hard
to understand how mechanisms of denial might be specific
to individual aspects of awareness when these disturbances
are dissociated in individual patients (Berti et al., 1996).
Motivational explanations are also less convincing given
the usual parallel resolution of the symptom and the acute
phase of brain damage, although it is conceivable that certain forms of brain damage might allow the appearance of
otherwise suppressed defence mechanisms.
The existing cognitive theories are numerous and
must attempt to account for the various syndromes of

A. Venneri, M.F. Shanks / Neuropsychologia 42 (2004) 230–238

anosognosia, and the different observed patterns of neurological and cognitive disturbance. No theory appears to
account for the phenomenon in all its forms, its association
with the right hemisphere, and the appearance of anosognosia as both a transient and occasionally as a persistent
symptom.
This paper reports a case of persisting anosognosia for
hemiplegia and left-sided neglect in the absence of global
mental deterioration. It is suggested that the associated
phenomena of false beliefs and misidentifications may
be integral components of persistent anosognosia in this
case. Similar mechanisms may be of importance, albeit
transiently, in association with more acute disturbances of
awareness. It is important for our argument, and not available in other published material, that functional as well as
structural imaging is available for analysis in this case.

2. Case report
EN1 is an 85-year-old right-handed Scottish lady with a
history of hypertension, atrial fibrillation and asthma. She
was taking aspirin. In February and March 1999 she had
two transient ischemic attacks. In the first, she reported
mild and shortlived speech disturbance, while in the second, she had left upper limb paraesthesia which resolved
spontaneously after 1 h. During the second episode, her
case notes record that she felt that her arm was weakened
and difficult to move. By the time she was neurologically
examined, however, there were no focal signs. Warfarin
was prescribed after the first episode. In June 2000 she was
admitted to general medical care following a haemorrhagic
stroke, with extensive damage in the right hemisphere. The
MRI images, 3 days after the stroke, showed a haemorrhage measuring 2 cm × 3 cm × 3 cm involving the right
posterior temporal and parietal regions. The lesion was
surrounded by a rim of cerebral oedema, and there was
some effacement of the posterior horn of the right lateral
ventricle. Routine neurological examination indicated a
left-sided flaccid paralysis of the upper and lower limb.
There was a mild paresis of the left lower facial muscles,
which quickly resolved. She also had some difficulty swallowing with impaired tongue movements. She was mildly
dysarthric with severe left visuospatial neglect and profound
anosognosia for her hemiplegia and unilateral neglect. No
visual field defect was elicited. No specialist neurological
or neuropsychological assessments were carried out at this
time.
The patient had physical rehabilitation but remained unable to walk and was mobilised only with a wheelchair. She
was discharged after 4 weeks to permanent nursing home
care.
1 Patient’s initials have been changed to preserve anonymity and both
the patient and her relatives gave their consent to the present report.

231

2.1. Neuropsychiatric assessment
In November 2001, 17 months after the stroke, she was
referred for psychiatric assessment because of behavioural
problems. The nursing home staff reported her spontaneous
claims following admission that she was able to stand and
walk, and to look after herself. She accused staff of being
cruel, torturing and poisoning her and leaving her out in the
rain. At times she had requested that her mother be informed
of her whereabouts. She had discussed sexual matters with
her son in an inappropriate and disinhibited way.
EN presented as an alert and emotionally serene lady who
smiled readily and showed no language disorder. There was
no evidence of subacute confusion or alteration in the level
of consciousness at any point during the examinations. She
claimed that she lived in a new house in the city, although
she was presently visiting another city where her sister lived.
She had frequent visitors at home and was perfectly able to
travel by train between her present residence and that of her
sister. She continued to hold the belief that her left side was
fully functional and that she was physically independent.
At different times the staff reported she had said that either
her left hand or both of her hands had disappeared. Neuropsychiatric inventory was completed and the retrospective
assessment showed that she had frequent delusions, persistent apathy interspersed with frequent episodes of aggressive behaviour, all of moderate severity. There was evidence
of left-sided neglect and inattention. She was referred for
functional and structural brain scan and neuropsychological
assessment, because of concerns about more global cognitive decline due to progressive degenerative brain disease
together with a requirement to counsel and fully inform her
family and nursing staff about her symptoms. Risperidone
0.5 mg daily was prescribed with benefit for the hostility
and aggressive behaviours associated with paranoid beliefs.
2.2. Neuropsychological assessment
EN was tested in December 2001 and August 2002. On
both occasions comprehensive testing as detailed below was
carried out, including assessment of the persistent anosognosia. There were only minor differences in psychometric test scores and no changes in her behaviour or mental
state between examinations. Mini Mental State Examination
(Folstein, Folstein, & McHugh, 1975) showed that EN was
partially oriented in time and place. She knew the month
and the year, and the city and country where she lived. She
could readily understand and follow test instructions and
was very cooperative. She had no oral or written comprehension deficits nor grammatical comprehension deficits nor
expressive language problems. Her spontaneous speech was
well organised with good intonational contour, grammatical and logical structure and rich in information content. On
confrontation naming she showed no naming difficulties, although on two occasions she produced visual paraphasias
(e.g. thermometer → pen, compasses → stepladder). There

232

A. Venneri, M.F. Shanks / Neuropsychologia 42 (2004) 230–238

Fig. 1. EN’s spontaneous drawing of (a) a daisy; (b) a clock face and (c) copying a line drawing.

were no object recognition deficits, but her performance was
affected by poor eyesight.
Her short term memory was intact and she achieved repetition of seven digits forward and four digits backward.
Long term verbal memory was tested with a paired associate word task and she achieved a total score of 11/12, a
performance within the range of that achieved by a group of
normal Scottish individuals comparable to EN for age and
education. Her verbal long term memory was also tested using a prose memory task on which she scored 15/25, a score
within the normal range for her age. She was also given
a structured questionnaire which assessed susceptibility to
provoked confabulations (Cooper, Shanks, Venneri, unpublished). Her performance on this task was within local norms
for the memory components, but was within the pathological range for verbal invention. She was able to report personal events, the occupation of family members and their
whereabouts. She could identify and name them as well as
indicate their relation to her when shown their photographs.
She achieved scores well below those of age and education
matched controls both on semantic (17 items) and phonemic
(8 items) fluency tasks. Reasoning abilities were tested with
the similarities subtest of the WAIS III (Wechsler, 1997).
She scored 19/28 on this task, a score within the range of
age and education matched controls. Her ability to make
plausibility judgments was informally evaluated during assessment. EN showed no difficulties in this respect.
2.3. Assessment of neglect
She showed severe left-sided neglect while copying simple geometrical figures with omission of the left side of the
figures. Spontaneous drawing was also hampered by severe
spatial neglect. She drew only the right part of a daisy and

crammed all numbers in the top right quadrant of a clock
face (see Fig. 1a and b). She was able to name the objects represented in simple line drawings, but her copying of
these drawings was also affected by the presence of neglect
(Fig. 1c).
Both in spontaneous drawing and when requested to write
a sentence or her name, EN used only the far right side of
the sheet which had been positioned in front of her aligned
to her trunk midline.
The severity of her left-sided spatial neglect was tested
formally using the Albert test (Albert, 1973), the Bells test
(Gauthier, Dehaut, & Joanette, 1989), a letter cancellation
task and a line bisection task. On the Albert test she made
10 omissions in total, eight of which were in the left half and
only two were in the right half. She identified only six target
items, all on the far right side, on the Bells test. She also
marked two distractors placed in the same spatial region;
she was, however, aware of making these errors. Similar
findings were obtained on the letter cancellation task where
she omitted 38 out of 52 target letters in the right half and 52
out of 52 target letters on the left half. Most of the identified
target letters were placed in the bottom part of the right half
of the page. Severe neglect was also detected on the line
bisection task. She placed the mid point of different lines on
the right of the true midpoint and her error was greater with
longer lines. Her reading abilities were tested with single
words from 4 to 10 letters long. She read all words correctly
but one (photograph → monograph).
Left-sided spatial neglect was observable on both testing
occasions. She also showed a marked bias to the right in
both her trunk posture and face orientation. There were signs
of personal neglect for the left upper limb. A cushion had
been positioned by the nurses to support her left arm, which
had a severe flaccid paralysis. However, her left arm would

A. Venneri, M.F. Shanks / Neuropsychologia 42 (2004) 230–238

often slip from its original position and she would leave
it dangling, with no attempt to make it resume its original
position, no matter what activity she was engaged in and no
matter how awkward her position was.
2.4. Assessment of sensation and extinction
Visual, auditory and tactile extinction was tested. Extinction in the visual modality was severe, and only mild in the
auditory modality. During the assessment of tactile extinction it became apparent that EN had severe sensory deficits
in both her left upper and lower limbs. Sensory assessment
by routine neurological examination showed that she was
insensitive for touch over the upper and lower left limbs although she was able to feel pinprick, and she spontaneously
complained of discomfort in her left foot.

233

paralysis and asserted that only the functions of her left wrist
had been impaired. When her left leg was lifted and she was
invited to look at the limb and to see that she had no control
over it, she acknowledged this fact but could not explain
why she had lost control.
Her ability to use both unimanual as well as bimanual
objects was also investigated. She was requested to lift and
open a book. She took it with her right hand by its spine,
holding the book as if her left hand might contribute to the
action, but then failed to complete the task. She said that she
was unable to act as requested. Asked why, she could not
say. Similar behaviour was observed for all actions requiring
bimanual involvement (harmonica, stethoscope, etc.). Even
when repeatedly asked, she would insist that she did not
know why she was unable to execute the requested action.
She completed all unimanual activities successfully with her
right hand.

2.5. Assessment of anosognosia
2.6. Neuroimaging investigation
EN showed severe anosognosia for her hemiplegia on both
occasions, confirming the observation and reports by staff
in the nursing home. Hemiplegia was assessed by routine
neurological examination of the limbs. When asked to lift
her hands, she only lifted her right hand. When asked if she
could move her left arm she replied ‘Yes, I can move my
arm, but it is better if it is rested. The doctor told me to rest
it’. Similar behaviour was observed when asked whether she
could walk. She claimed she could walk. When challenged
by the examiner to go to the door to greet her visitors, she
replied ‘Yes, I could get up to meet them, but the doctor
says it would be better if I rested’. A formal questionnaire
(adapted from Feinberg, Roane, & Ali, 2000) was then used
to explore her awareness of her hemiplegia for the left upper
and lower limbs separately. This instrument allows a qualitative assessment of anosognosic symptomatology, rather
than a quantitative estimate. When asked whether she had
any weakness in her arms she acknowledged that her left
arm was weak but denied that it was causing any problems,
except when she had to be put in a hoist. Asked why she had
to be put in hoist, she replied that this was to avoid tiring
the staff when they were helping her. When challenged, she
acknowledged that she could not use her left arm as well as
before and that she was fearful about losing her ability to
use her arm properly. She claimed that sensation in her left
arm was normal. She acknowledged that her left arm had
been paralysed and when her left arm was lifted she agreed
that the limb appeared to be rather weak.
A similar interview was completed in reference to her left
lower limb. If asked about weakness in her legs she claimed
that there was none. EN maintained that her left leg was
not causing her any trouble. She claimed that sensation in
her left leg was normal and that the leg felt normal. She
acknowledged that she could not use it as well as before and
she was fearful that something might prevent her from using
it properly in the future. When asked whether her doctor’s
account of her leg being paralysed was correct, she denied

Three-dimensional MRI scan and SPECT scan were acquired in August 2002. The MRI images showed the right
parietotemporal lesion demonstrated in the acute phase
post-stroke with resolution of oedema, and no extension
of the stroke. T2-weighted MRI images showed hyperintensities in deep and periventricular white matter in both
hemispheres (Fig. 2).
Functional brain scanning with 99 Tc HMPAO SPECT
showed that a large area of hypoperfusion in the right hemisphere involved not only the overtly damaged right parietotemporal structures, but also a significant part of the
right frontal lobe. In detail, the dorsolateral and ventral right
frontal cortex showed a marked reduction in blood flow affecting the primary motor cortex and the posterior part of
the middle and inferior frontal gyri (Fig. 3). These investigations were carried out while EN still showed anosognosia
and this symptom still persisted in December 2002 when the
patient’s carers were last contacted.
In summary, the case description shows that EN remained
anosognosic for left hemiplegia and hemianaesthesia 26
months after a right sided haemorrhagic stroke in the territory of the middle cerebral artery. Her neuropsychological
profile demonstrated a preservation of language, short term
and long term episodic memory, abstract reasoning, praxis
and object recognition. Semantic and autobiographical aspects of memory were also spared, as was face recognition.
She had no visuoconstructive deficits, although her actual
performance showed the influence of left unilateral visuospatial neglect. EN had reduced verbal fluency with more
pronounced impairment in the phonemic task. Her reading
and writing abilities were affected by mild neglect dyslexia
and dysgraphia. There was visual and auditory left extinction. Motor and sensory functions of the left upper and
lower limbs were lost.
The disturbances of awareness were to a degree dissociated in that she was unaware of her motor disability and how

234

A. Venneri, M.F. Shanks / Neuropsychologia 42 (2004) 230–238

Fig. 2. Axial T2-weighted MRI images showing the residual damage to the right parieto-temporal structures.

this affected her performance on spatial and motor tasks, but
she was aware of poor performance in some areas of cognitive functioning. For example, she was not aware of the
neglect component in any graphic or lexical production but
recognised her lack of artistic ability and poor handwriting.
She was also fully aware of poor performance on the fluency
tasks. There was no awareness of the profound anaesthesia
in the upper and lower limbs, but she sometimes showed
awareness of the left arm paresis. This deficit was acknowledged in response to specific questions, but in practice and
during object use she was anosognosic for upper limb function. Her avoidance of certain actions with a rationalisation
and her attempts to perform certain actions with her right
hand rather than left hand, however, raise the possibility that
EN might have had some implicit awareness of her inability
although she resisted full explicit acknowledgment.
These neuropsychological deficits were associated with
equally striking and persistent neuropsychiatric symptoms.
EN confabulated extensively on themes of active excursions
and bizarre acts of persecution. Some of these themes were
relatively stable including a conviction that her mother was
alive and concerned about the alleged transgressions against

her daughter by the staff. An equally stable belief was that
her surroundings were “home”, and she seemed able to entertain apparently conflicting versions of her current reality
as both persecuting institution and her familiar former home.

3. Discussion
To what extent do the existing theoretical models for
anosognosia offer a plausible explanation for EN’s lack of
awareness and the persistence of this symptom? What significance, if any, should be attached to the other abnormalities
in her mental state? Any explanation should try to account
for transient and persistent loss of awareness, the prevalence
of right hemisphere lesions and the patterns of dissociated
awareness described in the literature.
EN’s emotional reactivity without evidence of clinical depression, her alertness and the absence of global cognitive
decline sufficiently refute any argument for reduced awareness based on disturbance of these elements in her mental state. There are formulations of anosognosic symptoms
which point to the probability of profound sensory deficits

A. Venneri, M.F. Shanks / Neuropsychologia 42 (2004) 230–238

235

Fig. 3. T99 HMPAO SPECT images showing marked hypoperfusion in the area of the stroke, including the right parieto-temporal cortex and extending
anteriorly to involve the right middle and inferior frontal gyri.

and sensory inattention leading to lack of central feedback
and therefore an inability to experience the paretic limbs
(Heilman, Barrett, & Adair, 1998). While this might contribute to explanation in some cases, EN indicated discomfort from a tight fitting shoe on her left foot while engaged
in a drawing task. Neurological examination demonstrated
a lack of acknowledged epicritic skin sensation in the left
limbs, but she was sensitive to pinprick and so there may
have been sparing of elements of the protopathic sensory
pathways related to the perception of pain or discomfort.
There are no published case studies bearing on the incidence of such sensory dissociations in cases of anosognosia. In a wider sense, the argument from impaired sensory
feedback finds difficulty in accounting for lack of aware-

ness in other cognitive domains of, for example, memory or
reasoning.
EN’s persistent anosognosia was associated with concurrent phenomena of lifestyle as well as examination triggered
confabulations and with other reality dysfunctions. These
included delusions based on autobiographical memory failures, place misidentification with double orientation and
persecutory delusional beliefs about staff members and their
intentions. Similar neuropsychiatric symptoms have been argued, on the basis of case and cohort studies in AD, to arise
from regional neuropsychological failures in a context of disturbances in reality monitoring due to right hemisphere dysfunction (Feinberg & Shapiro, 1989; Förstl, Almeida, Owen,
Burns, & Howard, 1991; Mizukami, Yamakawa, Yokoyama,

236

A. Venneri, M.F. Shanks / Neuropsychologia 42 (2004) 230–238

Shiraishi, & Kobayashi, 1999; Shanks & Venneri, 2002;
Staff et al., 1999). Such symptoms are seen with highest
frequency in patients with right frontoparietal dysfunction.
EN did demonstrate some of the other behavioural changes
which have been associated with frontal lobe dysfunction
including occasional disinhibition and socially inappropriate
behaviours together with apathy and loss of realistic motivation. Reduced verbal fluency was also recorded, but no
other components of a formal dysexecutive syndrome.
SPECT examination showed an area of hypoperfusion in
the right frontal lobe extending beyond the precentral cortex into lateral and orbital associative cortex. It is difficult
of course to be certain in someone of this age whether the
extended regional deficit demonstrated by rCBF measurement is wholly related to the stroke event. There is always
the possibility that asymptomatic microvascular and/or degenerative brain disease (even developmental deficits) might
contribute to the functional impairments following stroke.
Her MRI also showed high grade white matter hyperintensities in both hemispheres. These white matter changes might
have contributed, speculatively, to an overall reduction in
cerebral reserve, but there was no indication of global cognitive decline, as might be expected if diffuse vascular brain
disease were an important aetiological factor. Brain ageing
may well be a contributory factor in this patient, but instances of confabulation and somatoparaphrenia can also be
observed in younger populations.
When these neuropsychological, neuropsychiatric and
neuroimaging findings are taken into account, it is reasonable to consider whether existing cognitive theories or modifications of them might offer some explanatory hypothesis
accounting for this patient’s symptoms. Most cognitive theories invoke higher order systems whose damage might lead
to anosognosia. These conjectured systems might either be
integral with the functional domain for which awareness
has been lost (i.e. modular Bisiach et al., 1990) or superordinate and centralised, able to influence awareness across
a range of sensorimotor and cognitive functions (McGlynn
& Schacter, 1989). In the latter case, even the invocation of
partial disconnection cannot account for the clinical observation of patients with loss of awareness for some symptoms but not for others. Neither modular nor centralised
hypotheses seem to explain why the greatest proportion of
left hemiplegic patients do not show anosognosia.
An attempted hypothesis at this level of cognitive functioning might be informed by theories of self monitoring
and reality monitoring. The argument would likely find
support from findings made in studies assessing the role of
the right frontal lobe in the retrieval and monitoring of self
related memories, as well as those evaluating the function
of the right hemisphere in verifying the truthfulness of
recollections (Craik et al., 1999; Fletcher, Shallice, Frith,
Frackowiak, & Dolan, 1998; Metcalfe, Funnell, &
Gazzaniga, 1995; Schacter, Curran, Galluccio, Milberg, &
Bates, 1996; Shanks & Venneri, 2002; Venneri, Shanks,
Staff, & Della Sala, 2000). It is worth considering in the first

place, therefore, whether cognitive disturbances suggesting
a wider dysfunction of frontal lobe functions are observed
either transiently or chronically in association with neurologically defined lack of awareness. Similarly, it may be relevant if the brain damage and dysfunction identified in cases
of anosognosia might in some instances extend beyond the
lesion in the motor cortex to compromise frontal lobe function and contribute to related disturbances of normal consciousness, particularly when the disorder of awareness is
persistent.
The most straightforward point to make is that in all cases
of anosognosia for hemiplegia there will be direct or indirect
damage to the motor cortex in the frontal lobe. This must,
from neurological reasoning, involve a significant part of the
precentral gyrus and/or its subcortical connections and associated subcortical structures that even if structurally spared
must be functionally damaged. In the acute phase following
stroke, there is likely to be, at the least, a more anterior
and ventral region of oedema and parenchymal reaction encroaching on the associative cortex of the frontal lobe. This
raises the possibility that in transient cases of anosognosia
for hemiplegia, there might be a more extensive or regionally significant frontal dysfunction dependent on individual
variation in the local consequences of acute brain lesion either directly or via disconnection. The extent of any frontal
lobe dysfunction has rarely been assessed in acute stroke patients with anosognosia for hemiplegia either by functional
imaging, or by the appropriate detailed neuropsychological
assessment. Evaluation of frontal lobe function following
stroke has been problematic because of lack of test specificity, conflicting findings and the challenge of determining
which frontal function might be most closely involved in the
development of anosognosia. Conventional psychometric
measures may not be appropriate for the detection of subtle
deficits related to abnormal reality judgements. In this respect single case studies are perhaps of limited value without
the kind of neuroimaging evidence available in this case,
but the detailed study of individual patients may generate
working hypotheses for future research. One report records
anosognosia and confabulation in a patient with right frontal
hypometabolism after a stroke in the area of the right anterior choroidal artery (de la Sayette et al., 1995). Functional
neuroimaging findings are available in degenerative brain
disease, but these conditions are clearly different in their
clinical presentation and determinants. In AD the appearance of anosognosia has been associated with a reduction in
right frontal regional cerebral blood flow (Starkstein et al.,
1995) and with neuropsychiatric symptoms (Migliorelli
et al., 1995).
The association between loss of awareness of hemiplegia and right hemisphere dysfunction has also been examined using the Wada technique. Some authors have found
that unawareness of hemiplegia is preferentially associated
with anaesthesia of the right hemisphere while others claim
that anosognosia can be observed with induced dysfunction of either hemisphere (see Heilman et al. (1998) for a

A. Venneri, M.F. Shanks / Neuropsychologia 42 (2004) 230–238

review). Most of the subjects tested for anosognosia with the
Wada technique had neurological disorders, but they were
not typical of the older patients who most often present
with stroke and loss of awareness, and are likely to have associated vascular and degenerative brain disease (Koyama,
Mochizuki, Mitsui, & Marui, 1998; Mineura et al., 1995).
The finding that patients undergoing the Wada procedure
showed no consistent association between anosognosia and
confabulation on a test of simple sensory discrimination
(Lu et al., 1997) might, therefore, be set against the finding
that lack of awareness and confabulation tend to associate
in a more representative population after stroke (Feinberg,
Roane, Kwan, Schindler, & Haber, 1994), although double
dissociations can also be inferred from case descriptions reported in the neuropsychological literature. More generally,
the suspension of hemispheric functions may not be strictly
comparable to the regional dysfunctions seen in clinical
practice.
When it has been possible to study the rarer chronic forms
of anosognosia for hemiplegia, it is significant that such patients often have extensive right frontoparietal and subcortical lesions (e.g. Berti et al., 1998), and were reported to
show verbal inventions about capacity for activity as well as
more bizarre beliefs on the topic of their paralysed limbs.
In this respect, lesions and degenerations involving the
frontal and parietal lobes of the right hemisphere have been
associated with distinctive disorders of memory retrieval,
visuospatial processing, veridical assessment and reality
monitoring (e.g. Rapcsak, Polster, Comer, & Rubens, 1994;
Venneri et al., 2000). Right sided frontoparietal brain damage has also been more commonly aligned with a range
of neuropsychiatric symptoms including confabulation,
delusions based on autobiographical memory falsifications,
delusional misidentification syndromes and persecutory
states (e.g. Binetti et al., 1995; Conway & Tacchi, 1996;
Ellis, 1994; Shanks & Venneri, 2002; Venneri et al., 2000).
The evidence presented supports a conclusion that EN had
a significant deficit involving the associative right frontal
cortex in addition to the precentral gyrus. The content of
EN’s many confabulations about activities logically implies,
at the highest cognitive level, the lack of explicit awareness of disability demonstrated by the neurological and neuropsychological examinations. Loss of awareness following
stroke would seem to entail a, usually transient, disturbance
in the structure of normal consciousness and the experiential content seems often to include a process of “filling in”
manifest as confabulation. This alteration in awareness may
be supported by contingent right frontal and/or parietal dysfunction causing a suspension or change, albeit often partial,
in the ability to monitor and check the ‘real’ and especially
to assess the truth of mental contents. In acute and milder
cases these disturbances would likely fall short of the more
florid and established reality distortions seen in EN. Failures
in reality monitoring/checking from this frontal impairment
are known to facilitate the appearance of abnormal beliefs
whose content is then determined by emotional and moti-

237

vational factors as well as by specific regional dysfunctions
(Shanks & Venneri, 2002; Venneri et al., 2000).
In this case at least, therefore, there may be a barrier to
the natural awareness of hemiparesis as part of a wider syndrome of reality monitoring failures which also have allowed
the development of other abnormal beliefs. The content of
these false beliefs often seems psychogenically driven and
either gainful for the patients or explicative in terms of their
changed appreciation of their environment. The neuropsychiatric symptoms may be viewed, therefore, as integral with
whatever mechanisms are promoting persistent anosognosia,
and this approach might have heuristic value for the interpretation of other similar cases and for future research.
This hypothesis could be tested by studies of reality assessment and susceptibility to provoked confabulation in
acute or subacute stroke patients with and without lack of
awareness. Cases of hemiparesis with anosognosia might
show a more extensive or subregionally relevant disorder
of frontal lobe function, and this also could be assessed by
functional brain imaging. Detailed evaluation of the idea
that frontal dysfunction may be an embedded factor in the
genesis and maintenance of lost awareness after stroke will,
therefore, require data from the study of both transient and
persistent cases with or without demonstrable frontal involvement. The present case, however, offers evidence that
a functional lesion extending into the associative cortex of
the right frontal lobe, as shown by the rCBF pattern, can
lead to distinctive neuropsychological and phenomenological changes in chronic anosognosia. These features suggest
the probable contribution of such regional dysfunction (either transient or persistent) in the genesis and endurance of
anosognosia.

Acknowledgements
The authors thank Alison D Murray and Howard G Gemmell for making the MRI and SPECT images available. They
also thank Anthony Marcel for his careful review of this
paper and his valuable comments, many of which have significantly improved the content and argument presented.

References
Albert, M. L. (1973). A simple test of visual neglect. Neurology, 23,
658–664.
Berti, A., Ladavas, E., & Della Corte, M. (1996). Anosognosia
for hemiplegia, neglect dyslexia, and drawing neglect: clinical
findings and theoretical considerations. Journal of the International
Neuropsychological Society, 2, 426–440.
Berti, A., Ladavas, E., Stracciari, A., Giannarelli, C., & Ossola,
A. (1998). Anosognosia for motor impairment and dissociations
with patients’ evaluation of the disorder: theoretical considerations.
Cognitive Neuropsychiatry, 3, 21–44.
Binetti, G., Padovani, A., Magni, E., Bianchetti, A., Scuratti, A., Lenzi,
G. L., & Trabucchi, M. (1995). Delusions and dementia: clinical and
CT correlates. Acta Neurologica Scandinavica, 91, 271–275.

238

A. Venneri, M.F. Shanks / Neuropsychologia 42 (2004) 230–238

Bisiach, E., Meregalli, S. & Berti, A. (1990). Mechanisms of production
control and belief fixation in human visuospatial processing: clinical
evidence from unilateral neglect and misrepresentation. In M. L.
Commons, R. J. Hernstein, S. M. Kosslyn & D. V. Munford (Eds.),
Computational and clinical approach to pattern recognition and
concept formation: quantitative analysis of behaviour (pp. 3–21).
Hillsdale, NJ: Lawrence Erlbaum Associates.
Cocchini, G., Beschin, N., & Della Sala, S. (2002). Chronic anosognosia: a
case report and theoretical account. Neuropsychologia, 40, 2030–2038.
Conway, M. A., & Tacchi, P. C. (1996). Motivated confabulation.
Neurocase, 2, 325–339.
Craik, F. I. M., Moroz, T. M., Moscovitch, M., Stuss, D. T., Winocur, G.
W., Tulving, E., & Kapur, S. (1999). In search of the self: a positron
emission tomography study. Psychological Science, 10, 27–35.
de la Sayette, V., Petit-Taboue, M. C., Bouvier, F., Dary, M., Baron, J. C.,
& Morin, P. (1995). Infarction in the area of the right anterior choroidal
artery and minor hemisphere syndrome: clinical and metabolic study
using positron-emission tomography. Revue Neurologique Paris, 151,
24–35.
Ellis, H. D. (1994). The role of the right hemisphere in the Capgras
delusion. Psychopathology, 27, 177–185.
Feinberg, T. E., Roane, D. M., & Ali, J. (2000). Illusory limb movements
in anosognosia for hemiplegia. Journal of Neurology, Neurosurgery
and Psychiatry, 68, 511–513.
Feinberg, T. E., Roane, D. M., Kwan, P. C., Schindler, R. J., & Haber,
L. D. (1994). Anosognosia and visuoverbal confabulation. Archives of
Neurology, 51, 468–473.
Feinberg, T. E., & Shapiro, R. M. (1989). Misidentification-reduplication
and the right hemisphere. Neuropsychiatry, Neuropsychology and
Behavioral Neurology, 2, 39–48.
Fletcher, P. C., Shallice, T., Frith, C. D., Frackowiak, R. S. J., & Dolan,
R. J. (1998). The functional roles of prefrontal cortex in episodic
memory. II. Retrieval. Brain, 121, 1249–1256.
Folstein, M. F., Folstein, S. E., & McHugh, P. R. (1975). Mini-mental-state:
a practical method for grading the cognitive state of patients for the
clinician. Journal of Psychiatry Research, 12, 189–198.
Förstl, H., Almeida, O. P., Owen, A. M., Burns, A., & Howard, R. (1991).
Psychiatric, neurological and medical aspects of misidentification
syndromes. A review of 260 cases. Psychological Medicine, 21, 905–
910.
Gauthier, L., Dehaut, F., & Joanette, Y. (1989). The Bells test: a
quantitative and qualitative test for visual neglect. International Journal
of Clinical Neuropsychology, 11, 49–54.
Heilman, K. M., Barrett, A. M., & Adair, J. C. (1998). Possible
mechanisms of anosognosia: a defect in self-awareness. Philosophical
Transactions of the Royal Society of London B Biological Sciences,
353, 1903–1909.
Koyama, T., Mochizuki, T., Mitsui, N., & Marui, A. (1998). Preoperative
magnetic resonance angiography findings and postoperative
neurological complications in 93 cases of CABG with cardiopulmonary

bypass. Japanese Journal of Thoracic and Cardiovascular Surgery, 46,
1247–1252.
Lu, L. H., Barrett, A. M., Schwartz, R. L., Cibula, J. E., Gilmore, R.
L., Uthman, B. M., & Heilman, K. M. (1997). Anosognosia and
confabulation during the Wada test. Neurology, 49, 1316–1322.
Marcel A. J., Tegnér R. & Nimmo-Smith, I. Anosognosia for plegia:
specificity, extension, partiality and disunity of bodily unawareness.
Cortex, in press.
McGlynn, S. M., & Schacter, D. L. (1989). Unawareness of deficits in
neuropsychological syndromes. Journal of Clinical and Experimental
Neuropsychology, 11, 143–205.
Metcalfe, J., Funnell, M., & Gazzaniga, M. S. (1995). Right-hemisphere
memory superiority: studies of a split-brain patient. Psychological
Science, 6, 157–164.
Migliorelli, R., Teson, A., Sabe, L., Petracca, G., Petracchi, M., Leiguarda,
R., & Starkstein, S. E. (1995). Anosognosia in Alzheimer’s disease: a
study of associated factors. Journal of Neuropsychiatry and Clinical
Neuroscience, 7, 338–344.
Mineura, K., Sasajima, H., Kikuchi, K., Kowada, M., Tomura, N., Monma,
K., & Segawa, Y. (1995). White matter hyperintensity in neurologically
asymptomatic subjects. Acta Neurologica Scandinavica, 92, 151–
156.
Mizukami, K., Yamakawa, Y., Yokoyama, H., Shiraishi, H., & Kobayashi,
S. (1999). A case of psychotic disorder associated with a right
temporal lesion: a special reference to magnetic resonance imaging
and single photon emission computed tomography findings. Psychiatry
and Clinical Neuroscience, 53, 603–606.
Rapcsak, S. Z., Polster, M. R., Comer, J. F., & Rubens, A. B. (1994). False
recognition and misidentification of faces following right hemisphere
damage. Cortex, 30, 565–583.
Schacter, D. L., Curran, T., Galluccio, L., Milberg, W. P., & Bates, J.
F. (1996). False recognition and the right frontal lobe: a case study.
Neuropsychologia, 34, 793–808.
Shanks, M. F., & Venneri, A. (2002). The emergence of delusional
companions in Alzheimer’s disease: an unusual misidentification
syndrome. Cognitive Neuropsychiatry, 7, 317–328.
Staff, R. T., Shanks, M. F., Macintosh, L., Pestell, S. J., Gemmell, H.
G., & Venneri, A. (1999). Delusions in Alzheimer’s disease: SPET
evidence of right hemispheric dysfunction. Cortex, 35, 549–560.
Starkstein, S. E., Vazquez, S., Migliorelli, R., Teson, A., Sabe, L., &
Leiguarda, R. (1995). A single-photon emission computed tomographic
study of anosognosia in Alzheimer’s disease. Archives of Neurology,
52, 415–420.
Venneri, A., Shanks, M. F., Staff, R. T., & Della Sala, S. (2000). Nurturing
syndrome: a form of pathological bereavement with delusions in
Alzheimer’s Disease. Neuropsychologia, 38, 213–224.
Wechsler, D. (1997). Wechsler Adult Intelligence Scale (3rd ed.). San
Antonio: The Psychological Corporation.
Weinstein, E. A. & Kahn, R. (1955). Denial of illness. Springfield, IL:
Charles C. Thomas.