Letters to the Editor

384

The case shows how a lateral cervical
spine radiograph may be helpful in the diagnosis of patients with dysphagia and/or
sleep apnoea without neurological signs. In
view of the frequency of anterior cervical
osteophytes in the older population it is
imperative that other causes of dysphagia be
excluded; oesophageal perforation after
endoscopy in patients with large cervical
osteophytes has been reported' and barium
examination of the oesophagus may be
preferable.

Professor JD Parkes for allowing us to study
their patients.

iKALIDA ISMAIL

ROBERT HOWARD
SIMON LOVESTONE
Department of Old Age Psychiatry,
The Maudsley Hospital,
London, UK

Correspondence to: Dr Ismail, Departnent of
Old Age Psychiatry, The Maudsley Hospital,
Denmark Hill, London SE5 8AZ, UK.
Balldin J, Granerus AK, Lindstedt G, Modigh
K, Wallinder J. Predictors for improvement
after electro-convulsive therapy in a
Parkinsonian patient with "on-off" symptoms. Y Neural Transm 1980;49:133-5.
2 Anderson K, Balldin J, Gottpries CG, et al. A
double-blind evaluation of electro-convulsive therapy in Parkinson's Disease with the
"on-off" phenomena. Acta Neurol Scand

1

We are grateful to Mr Michael Saunders,
Chief Medical Technical Officer, Lung
Function Laboratory, Llandough Hospital,
for his assistance.

TAT HUGHES
CM WILES
Department of Medicine (Neurology),
of Medicine,
College
Wales
University of
Cardiff, UK
BW LAWRIE
Department of Radiology,
University Hospital of Wales,
Cardiff, UK
AP SMITH
Department of Chest Diseases,
Liandough Hospital,
Penarth, UK

1987;76:191-9..
3 Douyon R, Serby M, Klutchko B, Rotrosen J.
ECT and Parkinson's Disease revisited: a
"naturalistic" study. Am Psychiatry 1989;
146:1451-5.

phytes due to diffuse idiopathic skeletal
hyperostosis (DISH)

Lateral cervical spine radiograph showing
bridging mass of exuberant new bone formation
impinging on the posterior
pharyngeal wall.

Diffuse idiopathic skeletal hyperostosis
(DISH) may be an under recognised contributory factor to both dysphagia and
obstructive sleep apnoea.
A seventy-two year old man presented
with a 12 month history of intermittent
painless dysphagia. He had been aware of
the need to be careful when eating and
coughing after swallowing was a daily
occurrence. Liquids were more troublesome
than solids. He had not lost any weight.
In 1989 he had been diagnosed as having
obstructive sleep apnoea syndrome. Overnight impedance pneumography revealed
more than 40 episodes of apnoea per hour
and simultaneous oximetry showed a
corresponding fall in oxygen saturation to
80%. Treatment with noctumal continuous
positive airway pressure (CPAP) resulted in
improved sleep quality and daytime wakefulness. There was a history of ischaemic
heart disease and atrial fibrillation.
On examination he was 170 cm tall,
weighed 87 kg, and his neck circumference
was 46 cm. He was in controlled atrial
fibrillation. There were no neurological
signs but the tongue was large and the
oropharynx appeared small. Cervical spine
movements were limited in all directions.
In a timed test of swallowing' he coughed
violently after swallowing the first bolus.
After a pause he was able to drink 120 ml in
50 seconds (2-4 ml.s-1; normal >10 ml.s-1).
Over a two week period his swallowing
speed fluctuated between 6 ml.s-' and 20
ml.s-'; a double blind edrophonium test
had no effect on swallowing speed.
Videofluoroscopy examination showed
partial hold up of the bolus of contrast in
the mid-cervical region. Lateral cervical
spine radiographs showed a bridging mass
of exuberant new bone formation anteriorly
extending from C2 to C7, with a dividing
pseudofracture at the C3/C4 level
(figure). A boney canal stenosis was also
present from the C2 level downwards.
Radiographs of the thoracolumbar spine
showed areas of new bone formation bridging the vertebral bodies anteriorly. Despite
the extent of the new bone formation the
intervertebral disc spaces were relatively

well preserved. Radiographs of the pelvis
showed irregular projections of bone from
the iliac crests and the lateral margins of the
ileum. The radiographic features were
typical of DISH. An MRI scan of the brain
stem and a CT scan of the brain were both
normal. A 75 g glucose tolerance test with
capillary bood suggested diabetes mellitus
with a fasting value of 7-1 mmolVl and a 120
minute value of 1 1-2 mmolIl.
The patient received advice from the
speech therapist and was able to reduce the
frequency of coughing by taking double
swallows for each bolus and slowing down
his eating. He did not wish to be considered
for any type of surgical intervention and
continues on CPAP at home. Follow up for
three years has revealed no other disorder.
In this case there is good radiographic
evidence to suggest that the limitation of
neck movement and the large anterior cervical osteophytosis were due to diffuse
idiopathic skeletal hyperostosis (DISH).
Forestier's original description of the
condition was confined to the spine but
many extraspinal manifestations have now
been described. The condition is common,
occurring in 6%-12% of a necropsy population, and impaired glucose tolerance is
often a feature.2
Although the patient had other features
that predisposed him to develop the sleep
apnoea syndrome including a large tongue
and neck circumference, the C2/C3 level is
a common site of obstruction in this condition.3 It seems highly likely that the boney
mass contributed to occlusion of the
oropharynx during sleep and videofluoroscopy suggests that it contributed significantly to the dysphagia; barium swallow
examination, indirect laryngoscopy, and
neurological investigation revealed no other
cause for the dysphagia.
Dysphagia is a recognised symptom of
cervical spine involvement in patients with
DISH. Obstructive sleep apnoea is an association not described before although cases
of stridor due to impingement of the osteophyte on the laryngeal vestibule have been
reported.4

Case report:

dysphagia and sleep

apnoea associated with cervical osteo-

Correspondence to: Dr TAT Hughes, Department of Neurology, University Hospital of Wales,
Heath Park, Cardiff CF4 4XN, UK.
1 Nathadwarawala KM, Nicklin J, Wiles CM.
capacity for
A timed test of swallowing
J

Neurol Neurosurg
neurological patients.
Psychiatry 1992;55:822-5.
Wiesner KB,
RF,
Shapiro
2 Resnick D,
Niwayama G, Utsinger PD, Shaul SR.
Diffuse idiopathic skeletal hyperostosis
(DISH) [ankylosing hyperostosis of
Forestier and Rotes-Querol]. Semin Arthritis
Rheum 1978;7:153-87.
V. Site of upper
3 Chaban R, Cole P, Hoffstein
airway obstruction in patients with idiopathic obstructive sleep apnea. Laryngoscope

1988;98:641-7.

4 Girgis IH, Guirguis NN, Mourice M.
in
Laryngeal and pharyngeal disorders
J

vertebral ankylosing hyperostosis. Laryngol
Otol 1982;96:659-64.
5 Wright RA. Upper oesophageal perforation
with a flexible endoscope secondary to
cervical osteophytes. Dig Dis Sci 1980;25:

66-8.

Horologagnosia: an impairment of the
ability to teli the time

We report a 57-year-old male patient who
had a right posterior stroke. A CT scan
indicated extensive hypodensity within the
territory of the right posterior cerebral
artery. There were also lacunes in the right
thalamus and corpus striatum bilaterally, as
well as small scattered lesions, predominantly within the peripheral areas of white
matter of the posterior frontal and parietal
lobes, consistent with ischaemic changes
due to small vessel disease. On admission to
hospital he presented with decreased sensation and muscle weakness on the left side of
his body, left homonymous hemianopia and
left-sided visuospatial neglect. Neuropsychological assessments during the first
three weeks after his admission to the
hospital showed well preserved language,
verbal reasoning, and verbal memory skills
(average range or above). On a relatively
easy picture recognition memory test he
also performed satisfactorily. Left-sided
visuospatial neglect was evident in his
performance on line bisection, cancellation,
and search tasks. He easily identified real
objects and line drawings of objects or

Letters to the Editor

photographs of certain famous faces. His
performance on the fragmented letters test'
of visual perception was, however,
impaired. On the cube analysis test' of visuospatial analysis his performance suggested
that he was able to integrate stimuli (cubes)
into spatial (three dimensional) schemas
but he obtained a low score apparently due
to omissions associated with neglect. He
was able to draw a cube (without a model),
making only slight mislocations of certain
lines depicting depth.
From the time of his admission to the
hospital our patient presented with a profound difficulty in telling the time from a
clock (or a watch), even when the clock
showed a simple "on the hour" time. We
investigated this impairment in two experimental sessions, two weeks and four weeks
after his admission. In each session the
following four conditions were used, involving time telling or clock setting for eight
different "on the hour" times, chosen to
represent equally the numbers on the left
and right hand side of the clock. Each of
eight "on the hour" times was presented
twice in a random order. (1) The patient
was shown a drawn clock face (diameter
12-5 cm) indicating an "on the hour" time.
He was asked first to name the time, then to
report the position of the clock hands and,
finally, to tell the time depicted on the
clock. His performance was scored as
correct if he gave the appropriate answer
before or after identifying the positions of
the clock hands; his scores in the two
sessions were: 3/16 and 0/16 (correct).
(2) He was shown a drawn clock face minus
the hands on which he was required to
insert the hands to depict a verbally given
on the hour time; he scored 16116 (correct)
in both sessions. (3) The positions of the
hands for an on the hour time were
described verbally to the patient who was
then required to say what that time was; his
scores in the two sessions were 4/16 and
6/16 (correct). (4) He was given the time
verbally and was then asked to say in which
positions the hands should be; his scores
were: 16/16 and 15/16 (correct). The
results from these experiments clearly indicate a dissociation between his virtually
errorless performance in conditions (2) and
(4) where the response involved clock setting and his very poor performance in condition (1) where the response involved time
telling from the clock face. His deficit in
condition (1) occurred despite consistently
accurate and unhesitating identification of
the positions of the hands. When he was
shown a clock face and asked to name the
time, he seemed rather bewildered and
reluctant to respond to the question. With
encouragement he would refer to the "12"
to which the long hand was pointing as the
hour and the number to which the short
hand was pointing as referring to the number of minutes to, or past 12 o'clock. For
example, he would refer to "eight o'clock"
as "eight minutes to 12" or "eight minutes
past 12" and to "four o'clock" as "four
minutes to 12" or "four minutes past 12".
In condition (3), in which he was asked to
tell the time on the basis of verbal information about the positions of the hands, his
performance was better than in condition
(1) but still impaired. By contrast, in conditions (2) and (4) he would respond readily
and accurately, by setting the clock or giving verbally the positions of the short and
long hands in the appropriate positions.

385

Three weeks after the second experimental
session his performances in conditions (2),
(3), and (4) were virtually perfect and half of
his responses in condition (1) were correct.
Deficits in telling the time from a clock
face have previously been reported in association with visuospatial neglect2 and it
would be reasonable to argue that inattention to the left-hand-side underlay our
patient's inability to recognise the time on a
clock face. Against such an explanation
would be the fact that consistently, readily,
and without prompting he located accurately the numbers on the left-hand-side of
the clock. He was also able to set the time
on demand normally, a task that necessitates accurate search of the left-hand-side.
Indeed, his satisfactory performance on
other tests that are dependent on accurate
recognition of (non-degraded) visual stimuli
suggested that his visuospatial neglect was
task specific-that is, it was mainly manifested when stimulus arrays were meaningless (for example, cancellation tests)
rather than when stimuli were continuous
or meaningfully integrated (for example,
pictorial material depicting animals, objects,
and, presumably, a clock face).3 A particularly striking finding was that he could not
identify the time from a clock face on which
he himself had only just correctly inserted
the hands to depict a specified time. This is
akin to certain well established and apparently counter-intuitive neuropsychological
syndromes involving other kinds of symbolic activity, such as dyslexia without dysgraphia and selective impairment of
auditory comprehension of words in the
presence of preserved ability to produce
them on demand, or vice versa.4 Our data
suggest that in the "telling the time" task
our patient was unable to access factual
knowledge about clocks and time, despite
the fact that he had available to him all the
relevant information. Exploration of his
ability to represent visuospatial relations
intemally was not possible within the time
before his recovery. It is, however, relevant
to add that at the time of the first set of
experiments he was able to navigate us in a
car through a fairly complex route in North
London. This finding would normally contradict a significant distortion of visuospatial
representations.
As far as we know, this form of transient
specific time telling deficit, in the context of
accessible information about the positions
of the hands on a clock face and intact
ability to set the time on demand, has not
previously been reported. We would like to
suggest that this deficit be referred to as
"horologagnosia" (from the Greek meaning
an impairment of the ability to tell the

time).
We thank Dr S W Clarke, consultant physician,
for permission to investigate the patient. We also
thank Dr A R Valentine, consultant neuroradiologist, for radiological advice.
L D KARTSOUNIS
The National Hospital for Neurology,
and Neurosurgery, Queen Square,
London WCIN3BG, UK
H CREWES
Free
Royal
Hospital, Pond Street,
London NW3, UK
1 Warrington EK, James M. The visual object

and space perception battrey. Bury St
Edmunds: Thames Valley Test company,

1991.
2 Diller L, Weinberg J. Hemi-inattention in
rehabilitation: The evolution of a rational

remediation program. In: Weinstein EA,
Freidland RP, eds. Advances in neurology.

Vol. 18. New York: Raven Press, 1977:6382.
3 Kartsounis LD, Warrington EK. Unilateral
visual neglect overcome by cues implicit
in stimulus arrays. J Neurol Neurosurg
Psychiatry 1989;52:1253-9.
4 Goodglass H, Klein B, Carey P, Jones K.
Specific semantic word categories in aphasia. Cortex 1966;2:74-89.

The coin-in-the-hand test: a new "bedside" test for the detection of malingering in patients with suspected memory
disorder
The detection of malingering is an important area of clinical neuropsychological
practice, especially in medicolegal settings
where it is often necessary to exclude simulation or exaggeration of poor performance.' 2 A number of tests have been used
by clinicians and researchers to examine the

issue of assessment of malingering during
memory functioning, including the Rey 15item visual memory test3 and the symptom
validity test.4
It is likely that no single test in itself will
be sufficient to prove the presence of malingering, and there remains a critical need for
further tests to be developed, especially
those that are simple and brief to administer
and that have relatively high face validity. I
describe a simple, brief test designed to
detect the presence of malingering in
patients who are suspected of simulating
poor memory performance. Some of the
tests that have so far been developed, such
as the Rey 15-item test, may still give
impaired performance in some neurological
patients with genuine severe memory disorder.5 I therefore sought to provide
comparative performance on this new test
from a group of densely amnesic patients.
Two suspected malingerers were
included, both of whom were taking part in
medicolegal proceedings and were suspected of simulating poor memory functioning. An amnesic group of five patients
was also examined, all of whom had had
herpes simplex encephalitis, and were left
with a dense amnesia.
The suspected malingerers showed variable, usually low, test scores on general
neuropsychological tests, and it was both
their clinical presentation and anomalies in
test scores that prompted their inclusion in
this study. As they both performed at
chance level on the test of malingering
described later, the reliability of their other
neuropsychological test scores must be put
in question. For the purposes of this paper,
therefore, I have simply presented a brief
clinical profile for each case, and the reasons why each case was included in the

study.
Case 1 was a right-handed woman in her
40s, who had been working in a professional job. She was involved in an accident,
and was claiming compensation for significant psychological and memory difficulties
that she considered were present after the
accident. She had patchy memory loss for
events around the time of the accident, and
it was uncertain if this reflected a period of
traumatic amnesia or if it was due to a
shocked state that resulted from the accident. She indicated that her memory for the
day of the event was clearer than her memory for the three to four weeks after the
accident. A skull radiograph was reported as
normal, a CNS examination showed no