The only thing that I can disagree with in Jonathan Schott and Martin Rossor's article on the palmomental reflex in the December issue of Practical Neurology is their plea that I should stop scraping. I have found that the palmomental reflex can be made more specific for detecting brain damage by applying the orange stick or car key to the hypothenar rather than the thenar eminence. A positive palmomen...
The only thing that I can disagree with in Jonathan Schott and Martin Rossor's article on the palmomental reflex in the December issue of Practical Neurology is their plea that I should stop scraping. I have found that the palmomental reflex can be made more specific for detecting brain damage by applying the orange stick or car key to the hypothenar rather than the thenar eminence. A positive palmomental reflex sign is present if there is a mentalis twitch in at least seven out of ten successive scratches.
While I agree that the test has no role in the diagnosis of dementia or Parkinson's disease it may still have useful application in the investigation of psychosis and obsessional compulsive disorder. A positive quantitative palmomental reflex in a person under 60 would make me consider neuroimaging to look for structural cerebral abnormalities.
Similar caveats to those put forward by Schott and Rossor for the palmomental reflex apply to the glabellar tap (Myerson's sign). It is an accoutrement that impresses patients but is redundant in the evaluation of Parkinsonism. However, there are instances where it can be helpful. Some years ago I saw a woman of 45 who presented with physical fatigue. She had a hangdog posture, a monotonous voice, did not swing her arms when walking and had a sad face. She had seen several physicians already and carried the label of chronic fatigue syndrome. On examination she had a positive glabellar tap sign. When she returned for follow up a few months later she had developed a clear sequence effect (motor decrement) on finger tapping and I made a firm diagnosis of Parkinson's disease. Primitive reflex testing is quick and simple and may still have a place in the research screening of normal elderly people for neurological disease. I will continue to teach the palmomental reflex and the glabellar tap sign to medical students but emphasise the limitations highlighted by Schott and Rossor. Perhaps the Editors will consider a neuromythology series on useless research scales and operational criteria for the diagnosis of neurological disease when the physical signs series is completed?
We were interested to read the recent case study presented by
Rodrigues and Wild in the current edition of Practical Neurology where
they discussed "Psychogenic non-epileptic seizures in early Huntington's
disease"[1]. The authors gave an in-depth account of the clinical profile
of a 51-year-old male with early Huntington's disease (HD) who presented
with repeated episodes of repetitive, purposeless, c...
We were interested to read the recent case study presented by
Rodrigues and Wild in the current edition of Practical Neurology where
they discussed "Psychogenic non-epileptic seizures in early Huntington's
disease"[1]. The authors gave an in-depth account of the clinical profile
of a 51-year-old male with early Huntington's disease (HD) who presented
with repeated episodes of repetitive, purposeless, complex behaviours,
uncharacteristic of HD and discussed the process they followed before
diagnosing psychogenic non-epileptic seizures. Rodrigues and Wild then
went on to conclude that functional neurological symptoms and dissociative
phenomena are a common feature of early HD, particularly in the period
immediately post-diagnosis.
However, this is very different to our own clinical experience. Although
we have not prospectively undertaken a study to look specifically for
this, we have retrospectively analysed our cohort of over 700 patients
that we have seen over the last 20 years. Over this time we could only
identify two individuals who could be described as having a functional
neurological disorder. Furthermore, upon review of the literature we can
only find one case study reporting a psychogenic movement disorder in
preclinical HD [2] and a further case study of a psychogenic gait disorder
that was presented as a poster at the 2013 Sydney Movement Disorders
Conference.
Therefore, we feel that the claim by Rodrigues and Wild is somewhat
misleading -that this is a common feature of early HD. In our experience a
significant proportion of patients experience psychiatric symptoms in
early HD which can take the shape of increased anxiety and
obsessional/compulsive type behaviours and as such patients can exhibit
repetitive stereotypic actions. They do not however, commonly present with
features that would be consistent with a psychogenic disorder and it is
important that the prevalence of such symptoms is not inflated. We
acknowledge that the behaviors presented in this case study as evidenced
by the video [helpfully included in the supplementary data], are not
consistent with anxiety or OCD, but we consider this to be a relative
rarity in HD. In our opinion, an HD patient presenting with physical,
cognitive or psychiatric features that are not consistent with the common
profile of the disease should be thoroughly investigated to rule out all
possible organic causes and only reluctantly should these symptoms be
attributed to a non-organic process.
References
1. Rodrigues, F.B. and E.J. Wild. Psychogenic non-epileptic seizures
in early Huntington's disease. Pract Neurol 2016.
2. Soltan, W., et al. Abnormal gait and bradykinesia in the preclinical
phase of Huntington's disease - psychogenic movement disorder? Acta
Neuropsychiatr 2011;23(6):315-7.
In his recent Neuromythology article1 on the Babinski sign, Professor
Kiernan repeats the oft quoted recommendation regarding the best method
for testing the plantar response, which is to:
'Run a car key (figure 1; or as some have suggested, a most expensive
motor car key...) along the lateral border of the sole.'
It will not surprise many readers of Practical Neurology to learn
th...
In his recent Neuromythology article1 on the Babinski sign, Professor
Kiernan repeats the oft quoted recommendation regarding the best method
for testing the plantar response, which is to:
'Run a car key (figure 1; or as some have suggested, a most expensive
motor car key...) along the lateral border of the sole.'
It will not surprise many readers of Practical Neurology to learn
that the author of this particular recommendation was the late Professor
Henry Miller and moreover that he was proscriptive with regard to the
precise type of ignition key. In his introduction to the book 'Remembering
Henry'1, reflecting on the remarkable life and career of one of the
undoubted pioneers of modern British neurology (and prolific music
critic), the late Lord Walton of Detchant wrote:
'Books could be (and probably will be) filled with quotations from
his tongue and from his fertile pen, some few of which were hallowed for
posterity as 'Henry Millerisms' in a popular medical journal. Who can
forget such comments as: 'The best instrument for obtaining the plantar
response is the ignition key of a Bentley'; or, 'Hemiplegic multiple
sclerosis is a rarity and is to be diagnosed only by me'?'
Henry George Miller (1913-1976) became Professor of Neurology at
Newcastle University in 1964. This was the second chair in neurology to be
established in the UK (Roger Gilliat having been appointed as professor of
clinical neurology at the Institute of Neurology, Queen Square in 1962).
He is best known for his work on multiple sclerosis (publishing the first
ever therapeutic trial in 19532) and accident neurosis. Henry was
successively Dean of Medicine (1966-1968) and Vice Chancellor (1968-76) of
Newcastle University, served as Secretary-General-Treasurer of the World
Federation of Neurology and Chairman of the medical panel of the MS
Society, and held visiting chairs in Australia, Canada and the USA.
References
1. Remembering Henry. LOCK S, WINDLE H (Editors). BMJ.
The Devonshire Press. 1977.
2. Acute disseminated encephalomyelitis and acute disseminated sclerosis;
results of treatment with ACTH. MILLER HG, GIBBONS JL. BMJ.
1953;2(4850):1345-1348
This sensitive review is very welcome, as in our experience, most
patients with functional disorders are told by specialists what they do
not have. I would be much more inclined to refer patients if this kind of
approach was more common. It is one reason why relatively few of the
patients we see in primary care are referred for specialist attention.
Specialists are seeing only the tip of the primary care functional
iceb...
This sensitive review is very welcome, as in our experience, most
patients with functional disorders are told by specialists what they do
not have. I would be much more inclined to refer patients if this kind of
approach was more common. It is one reason why relatively few of the
patients we see in primary care are referred for specialist attention.
Specialists are seeing only the tip of the primary care functional
iceberg. Referral rates vary widely depending variously on levels of
experience, resilience, tolerance of uncertainty and access to peer or
specialist support.
One advantage GPs have over our specialist colleagues is that we get
to know our patients over many years - which is how long it may take to
discover the biography behind their functional symptoms. A second
advantage we have is a knowledge of their family and social context within
which they experience their symptoms enabling us to take a systemic
approach. We have more in common with Oliver Sacks- who rediscovered the
importance of narratives divulged slowly, and used to visit his patients
at home like his father, a London GP, than we do with our younger
neurological colleagues.
It's worth remembering that a clinical history is not narrative and
biography is not psychology. Stone warns against framing functional
neurological symptoms in psychological terms, which I would agree with -
mental illness, if it co-exists ought to be seen as a co-morbidity rather
than a primary cause. But Stone's approach is still biomedical and lacks
the systemic approach that time, continuity and contextual factors
illuminate. I recently invited older GPs to talk to trainees about their
favourite patients. Many described patients who were struck with their
functional symptoms for years, decades even - in a state of narrative
chaos, before something changed and they found some kind of peace with
themselves and were much better able to live with their symptoms. In
narrative medicine this is a shift from chaos to quest, where making sense
takes over from searching for a cure. There are many ways of making sense
of functional symptoms and my main concern about Stone's approach is that
usually it's most honest to admit we just don't (yet) know.
Title: Romberg's test has stood up to the test of time and should
remain standing
(Neuromythology: Letter to the Editor)
I was Interested to read Professor Martin Turner's article entitled
Romberg's test no longer stands up. In the article Professor Turner
describes the test as "the process of standing unsupported with the eyes
closed and feet together for 30 s" and asserts that "the positive result
is the p...
Title: Romberg's test has stood up to the test of time and should
remain standing
(Neuromythology: Letter to the Editor)
I was Interested to read Professor Martin Turner's article entitled
Romberg's test no longer stands up. In the article Professor Turner
describes the test as "the process of standing unsupported with the eyes
closed and feet together for 30 s" and asserts that "the positive result
is the patient falling to the floor" which he gives as one of his reasons
for abandoning the test. He further states that the test is "neither
highly sensitive nor specific for its original purported purpose".
Furthermore, along with the authors of previous reviews of the test which
he quotes,1,2 he denies Romberg the credit of having linked the positivity
of the test to a dorsal column lesion. I note that Professor Turner
does not reference the 2nd Edition Romberg's Manual, the original source
description3 of the test in and his description of the test or sign does
not corresponded with the original. Romberg3 describes his sign twice in
the Manual. In the second description, at the top of page 396 of Volume
2, Romberg states "If he [the patient with Tabes Dorsalis] is ordered to
close his eyes while in the erect posture, he at once commences to totter
and swing from side to side; the insecurity of his gait also exhibits
itself more in the dark". In the earlier description in Volume 1, on
pages 226-227, he says "I have observed that anaesthesia of the muscles
alone without loss of tactile power, invariably accompanies tabes
dorsalis. A simple experiment suffices to determine the fact. If the
patient is told to shut his eyes while in the erect posture, he
immediately begins to move from side to side, and the oscillations soon
attain such a pitch that unless supported he falls to the ground."
Note firstly that there are arguably two parts to Romberg's test. The
first part, requires no time interval, on the contrary, a positive
Romberg's test is demonstrated by an increased sway that begins "at once"
or "immediately" after the eyes are closed. Furthermore, according to his
second description of the sign, a fall to the floor is not required and
only the now never-undertaken second part of the test, requiring darkness,
is potentially dangerous. Romberg's claim for specificity and
sensitivity is that "it invariably accompanies tabes dorsalis" and "it is
a symptom which I have not observed in other paralyses, nor in
uncomplicated amuarosis; since then [since he first said that he described
the sign 10 years previously], I have found it in a considerable number of
patients [with Tabes Dorsalis] .... and in no case have I found it
wanting." Romberg also states that "some patients mention the
circumstance [increased unsteadiness in the dark, while standing without
support] without being asked about it". It is also interesting that a
little later on in the same description, on page 397 of Volume 2, Romberg
says that as it progresses, "the necessity of employing the eyes becomes
more and more urgent; if he [the patient with Tabes Dorsalis] closes his
eyes, even while sitting, his body begins to sway to and fro" and he "is
no longer able to recognize the position of his own limbs and cannot tell
whether the right leg is crossed over the left, or the reverse". Since
this description of the disease was prior to the discovery of the
causative spirochaete, it quite possibly that Romberg (as well as other
19th century Neurologists) may have included other causes dorsal column
damage and large fibre neuropathy / neuronopathy and among his cases.
Romberg3, correlating the clinical features with the pathology, mentions
on the same page as his sign, that post-mortem findings "almost without
exception show the existence of partial atrophy of the spinal cord" and
that "the contents of the cords of the cauda equina have often been found
to have disappeared to such an extent that nothing but the empty
neurilemmatous sheaths seemed to remain". He further noted that "it is of
especial interest to observe that the posterior, sensory roots are
occasionally alone affected in conjunction with the posterior columns of
the spinal cord, the anterior motor columns and nerves retaining their
normal structure". To my mind, that counts as linking the positivity of
the test to a dorsal column lesion and indeed to a lesion of the sensory
roots and / or nerves which Professor Turner, incidentally, did not
mention as a cause of a positive Romberg's sign.
Sir William Gowers4 in the 1888 American Edition of his textbook cited
Romberg and his test as did the legendary Jean-Martin Charcot5 in his
Tuesday Lectures. It is interesting that Gowers4, referring to Romberg's
test states that "the effect of closure of the eyes is greatest when
sensation in the soles of the feet is defective, but does not depend on
this loss; it may be marked when sensation on the soles of the feet is
perfect". Although the current method of joint position testing in the
Hallux, referred to by Professor Turner, seems unlikely to have been
employed at the time of Gowers, it is certainly my experience that dorsal
column function or peripheral nerve proprioceptive sensory function can be
sufficiently impaired to cause "positive Rombergism" when concurrent
testing of joint position sense in the hallux on both sides is apparently
within normal limits. By way of explanation of this personal observation,
I would suggest that proprioception is likely to be a more complex
predominantly unconscious function of the nervous system, rather than the
simple transmission of the position of the distal phalanx of the hallux to
consciousness. Therefore, I disagree with Professor Turner's assertion
that simply testing joint position test in the Hallux is a substitute for
Romberg's test.
Before dismissing a test proposed by the one of the greatest Neurologists
of the 19th century who was author of the first systematic textbook of
Neurology ever written and who made numerous other seminal contributions
to our subject, I think we should be a little more circumspect. Wilson6
in his classic 1940 textbook also considered Romberg's sign useful and it
is considered an important part of the neurological examination in most
modern textbooks of Neurology. In my view, Romberg's Test is a very
useful part of the neurological examination, because it so beautifully
illustrates and confirms to the clinician and student alike, the degree to
which loss of proprioception contributes to ataxia and impaired balance in
any particular case (whichever of the limited number of underlying
pathophysiologies is responsible). A positive Romberg's test therefore
helps the clinician to attribute ataxia and / or impaired balance to
pathology in the dorsal column of the spinal cord, or in the peripheral
large nerve fibres destined for the dorsal columns, rather than to
pathology in the cerebellum. It is not dangerous and has stood the test
of time. I believe Romberg's test should remain part of the routine
neurological examination taught to all medical students and used by all
Neurologists. I believe that Professor Turner should stand down on this
issue and that Professor Romberg and his test remain upstanding.
References
1. Lanska DJ, Goetz CG
Romberg's sign. Development, adoption, and adaptation in the 19th century
Neurology 2000;55:1201-6.
doi:10.1212/WNL.55.8.1201
2. Pearce JM
Romberg and His Sign.
Eur Neurol 2005;53:210-13
doi:10.1159/000086732
3. Romberg MH
A Manual of The Nervous Diseases of Man 2nd Edition 1851 Volumes 1&2 226-
227,396-397.
Translated and edited by Sieveking EH, London: Sydenham Society
Reprint: Alabama: Gryphon Editions Ltd 1983:
4. Gowers WR
A Manual of Diseases of the Nervous System. American Edition P.289
Philadelphia: P.Blakiston, Son & Co 1888
Reprint: Alabama: Gryphon Editions Ltd 1983:
5. Charcot JM
Charcot the Clinician. The Tuesday Lectures
Excerpted and translated case presentations by Goetz CG P143
Raven Press New York 1897
6. Kinnier Wilson SA
Neurology Volume 1 P.494
London: Edward Arnold & Co 1947
"Provenance and peer review. Not commissioned, Externally peer
reviewed. This paper was reviewed by Martin Tuner, Oxford, UK."
Sir,
I read with much interest the review by Weerasinghe and Lueck on the
diagnosis of optic neuritis. The authors provide an extensive and detailed
analysis on the differential diagnoses and the management of the disease.
The importance of retinal electrophysiology is also acknowledged when
differentiating retinal disorders that can mimic optic neuritis.
Surprisingly, however, the diagnostic role of pattern-reversal Visua...
Sir,
I read with much interest the review by Weerasinghe and Lueck on the
diagnosis of optic neuritis. The authors provide an extensive and detailed
analysis on the differential diagnoses and the management of the disease.
The importance of retinal electrophysiology is also acknowledged when
differentiating retinal disorders that can mimic optic neuritis.
Surprisingly, however, the diagnostic role of pattern-reversal Visual
Evoked Potentials (VEPs) is not discussed, not even mentioned. VEPs can
assess visual pathway function at a millisecond time scale and no other
visual function measure shares this temporal sensitivity. More than 40
years ago Martin Halliday demonstrated a delay in the VEPs after an attack
of optic neuritis. Since then, a huge number of studies have provided
converging evidence about the importance of VEPs recording in optic
neuritis and Multiple Sclerosis (MS).
Doubtless, the clinical use of VEPs has changed over time and the advent
of magnetic resonance imaging (MRI) have reduced the use of VEPs in
clinical practice. However, even in the MRI era, an abnormal VEP in
unaffected eyes of patients with MS provides evidence for clinically
silent demyelinating lesions in the optic pathway. This, in turn, is
extremely useful in identifying dissemination in space and, therefore, in
establishing the diagnosis of MS.
In their review, the authors also fail to mention another important
electrophysiological test, i.e. the Pattern Electroretinogram (PERG). The
PERG is generated by the activity of the retinal ganglion cells. Taken
together, PERG and VEPs are useful to identify the site(s) of dysfunction
along the retinocortical pathway. In a typical case of optic neuritis PERG
and VEP recordings might not be necessary. However, these techniques can
still retain many roles: first, to show the magnitude of conduction block
of the optic nerve fibres in the acute stage of the disease. Secondly, to
demonstrate the optic nerve conduction delay due to demyelination. Third,
to follow remyelination, which is seldom correlated to an improvement in
visual acuity, through the shortening of VEP latency. Finally, to define
the eventual retrograde degeneration of ganglion cells, which is reflected
by an amplitude reduction of the PERG N95 peak. Moreover, when diagnosing
atypical optic neuritis, these neurophysiologic techniques should be
implemented as a part of a comprehensive assessment.
Of note, the visual pathway can now be more precisely evaluated in detail
by means of new neurophysiological tests (multifocal VEPs and ERG). These
techniques provides higher sensitivity and specificity in detecting
abnormalities in visual function in optic neuritis and MS
We welcome debate around this emerging condition. We all recognise a
situation when as clinicians we have had a strong feeling that a patient
has a functional complaint from early on in the consultation. However, the
differential diagnosis for Functional Cognitive Disorder is
neurodegenerative dementia which itself affects behaviour and personality
and could, therefore, influence many of the cues clinicians pick up on
wh...
We welcome debate around this emerging condition. We all recognise a
situation when as clinicians we have had a strong feeling that a patient
has a functional complaint from early on in the consultation. However, the
differential diagnosis for Functional Cognitive Disorder is
neurodegenerative dementia which itself affects behaviour and personality
and could, therefore, influence many of the cues clinicians pick up on
when "divining" a functional diagnosis.
Anecdotally, we have seen patients in our clinic diagnosed with a
functional disorder at other centres whom we have subsequently discovered
to have definite neurodegenerative disease. As an example, we were
referred a patient thought to have a psychiatric disorder and functional
left leg movements. After a detailed assessment including CSF biomarkers
and SPECT scanning, we suspected organic disease. His positive C9orf72
genetics have recently demonstrated he suffers from a genetic form of
Frontotemporal dementia and we believe that this altered his behaviour
such that he manifested a functional syndrome at the start.
Preceding medical events such as general anaesthesia or chemotherapy can
be triggers for health anxiety or FCD, but could also be a source of
cognitive symptoms. General anaesthesia (particularly if performed for
cardiac indications) is a risk factor for hypoxic or ischaemic brain
damage (which if focal can present with isolated cognitive deficits).
Chemotherapy agents can cause neurological complications (e.g.
methotrexate encephalopathy); their use also implies a history of
malignancy with consequent risk of tumour recurrence and direct or
indirect neurological complications.
Establishing the aetiology of cognitive complaints is the key challenge in
the memory or general neurology clinic. Large-scale research studies
suggest there is a continuum between Subjective Cognitive Impairment
(where individuals report cognitive symptoms but perform normally on
testing), MCI and dementia2. Given treatments may be effective only in the
earliest stages, identifying prodromal dementia will in the future be
increasingly important. Distinguishing incipient dementia at the Mild
Cognitive Impairment (MCI) phase from Functional Cognitive Disorder (FCD)
can be difficult, but is of vital importance to ensure patients receive
appropriate prognostic information including reassurance where necessary
and are entered into clinical trials where appropriate. This distinction
becomes particularly tricky in high-functioning individuals, and those
with co-morbid psychiatric conditions. The clinical history is very
useful, and conversational analysis has been successfully used to
differentiate dementia from FCD1. However we would counsel against solely
using the clinical history to distinguish FCD from incipient dementia at
the MCI phase. We know that anxiety, depression and abnormal behaviour may
occur in early dementia all of which might confound use of a clinical
history to differentiate incipient dementia from FCD.
Neuropsychology assessments are very useful in this context- they can
reveal patterns of deficits that are not consistent with organic
pathology, deficits out of keeping with FCD, or highlight significant
psychiatric symptoms warranting referral to psychiatry or psychology
services. Neurologists are often not trained in identifying psychiatric
disorders, therefore a structured neuropsychology assessment including
questionnaires looking for symptoms of depression or anxiety can often be
very helpful.
The authors would regard neuroimaging as an essential part of the
assessment, as recommended by NICE3. Even a patient with a 'classic' FCD
history may be harbouring structural brain pathology. To give a clinical
example, a 56 year old man presented to our general neurology clinic with
intermittent word finding difficulties during conversations and when
typing. He had a history of anxiety disorder, and his language appeared
normal during the consultation and on formal assessment. Neurological
examination was normal, and a functional cause was suspected. However on
MR imaging a large glioblastoma multiforme was found. Not performing
neuroimaging risks missing individuals with a strategic infarct,
malignancy or other structural pathology. Whilst such cases are not
common, missing such a diagnosis would have very serious consequences for
the patient.
The authors agree that investigations such as SPECT, CSF biomarkers and
autoantibodies should be used selectively, but these can be helpful in
difficult cases. We plan to explore further the additive clinical value of
each of these tests.
Discovering the aetiology of cognitive symptoms often requires us to
operate at the limits of current knowledge about how the brain guides
behaviour. We do not believe we are at the point where we can always offer
certainty to a patient. However, we find it possible to reassure patients
effectively even when we represent this uncertainty to them. If we suspect
functional cognitive disorder, we introduce the concept at the first
consultation and offer reassurance saying we will do further tests and
follow up to rule out rarities. We find this is actually quite effective
as a means of reassurance, perhaps more so than being entirely dogmatic
that there cannot be organic pathology as most patients will know it is
more or less impossible to prove a negative in neurology. Overall we feel
that whilst we might strongly suspect FCD clinically at the first
consultation, it is unwise in almost all cases to make a firm diagnosis of
FCD without appropriate investigations. Even after diagnosis and initial
management of FCD, a period of clinical follow up can be informative. It
is only such follow up that has allowed us to begin to understand critical
components of FCD and to summarise clinical features of the condition.
References
1. Elsey, C., Drew, P., Jones, D., Blackburn, D., Wakefield, S., Harkness,
K., Venneri, A. & Reuber, M. Towards diagnostic conversational
profiles of patients presenting with dementia or functional memory
disorders to memory clinics. Patient Educ. Couns. pii: S0738, (2015).
2. Garcia-ptacek, S., Cavallin, L., Kramberger, M. G., Winblad, B., Jelic,
V. & Eriksdotter, M. Subjective Cognitive Impairment Subjects in Our
Clinical Practice. 419-430 (2014). doi:10.1159/000366270
3. NICE. Dementia diagnosis and assessment. (2015).
Pennington and colleagues review of Functional Cognitive Disorder
(FCD) [1] is very welcome to guide practice in a complex condition that is
presenting increasingly to general and cognitive neurology clinics.
However, in our view Pennington's presumption towards specialist
assessment, investigation and surveillance is unnecessary and misses an
opportunity to provide patients with a prompt diagnosis, explanation and
reas...
Pennington and colleagues review of Functional Cognitive Disorder
(FCD) [1] is very welcome to guide practice in a complex condition that is
presenting increasingly to general and cognitive neurology clinics.
However, in our view Pennington's presumption towards specialist
assessment, investigation and surveillance is unnecessary and misses an
opportunity to provide patients with a prompt diagnosis, explanation and
reassurance and immediate treatment for the FCD and/or significant
relevant co-morbidities e.g. depression, chronic fatigue syndrome (CFS).
In particular, we cannot agree with Pennington's comment that "Functional
cognitive disorder should be diagnosed only after excluding other causes
of cognitive decline as far as possible". We believe that clinicians
should aim to make a positive "rule in" diagnosis of FCD, exactly as
proposed for other functional disorders [2] and that this can be done in
the context of the general neurology clinic.
Pennington et al rightly point out features in the history that suggest
FCD but in our view they underestimate their significant diagnostic value.
Additional positive features for FCD in our experience are a high number
of presenting symptoms, the patient's emotional response to the symptoms
being more distressing than the actual consequences of any cognitive
lapses, co-morbid mood disorders, chronic pain or fatigue and recent
relevant life events including physical illnesses such as mild traumatic
brain injury, anesthesia or chemotherapy exposure.
Brief cognitive instruments (such as MoCA, ACE) are of limited value in
this context and have an opportunity cost in a 30 minute general neurology
consultation. Instead we suggest listening for particular features in the
patient's spontaneous speech that point towards FCD. A richly detailed
history in which multiple examples of cognitive lapses are described, and
in which events are precisely located in time, the patient's ability to
reference an earlier part of the consultation [4], and normal expressive
language (e.g. the absence of word finding pauses) are all evidence of
normal cognitive function. These can be fed back to the patient to help
explain the diagnosis, in the same way that a positive Hoover's sign can
be explained to a patient with functional lower limb weakness.
We argue that most patients with suspected FCD do not need investigations
such as brain imaging or neuropsychology. These are much more likely to
produce false positives with attendant iatrogenic harm than to shed any
light on the diagnosis, particularly in younger patients where the pre-
test probability of dementia is extremely low. The authors write that
"Cerebral atrophy that is out of keeping for the patient's age ... should
prompt further investigations". We would regard lower than expected brain
volume as a non-specific finding in a patient with typical FCD symptoms.
The temptation to perform further tests to clarify non-specific findings
from a previous test demonstrates the perils of embarking on low yield
investigations in the first place. Tests for anti-VGKC and NMDA receptor
antibodies should be reserved for patients presenting with the clinical
syndromes associated with these antibodies, which are readily
differentiated from FCD on the basis of the clinical history.
We believe that routine neuropsychological assessment for the diagnosis of
FCD is clinically unnecessary, not cost-effective and potentially
misleading. For example, a neuropsychology report stating that "early
neurodegeneration cannot be ruled out" in a case where the clinician
strongly suspects FCD may reduce patients' confidence in the diagnosis.
We would virtually never consider amyloid positron emission tomography or
cerebrospinal fluid biomarkers appropriate for patients with suspected FCD
(although they may have a role in rare cases in which a diagnosis of
Alzheimer's disease needs to be changed to FCD and this is not initially
accepted by patients, family and other healthcare professionals[5]).
These tests are abnormal only in Alzheimer's disease so cannot "rule out"
dementia in any case.
We welcome Pennington's comments about the need to develop treatments for
FCD. One of us (JAC) often recommends two books to patients that
beautifully illustrate the idiosyncrasies of normal memory; Forgetting by
Daaisma and Moonwalking with Einstein by Joshua Foer. For patients with
mild FCD, normalising their symptoms e.g. by explaining how we (the
neurologist) make many of the same mistakes can be helpful. An emerging
nosology can help practitioners select an individualised explanatory model
and prioritise treatment i.e. (1) FCD in isolation, with or without
dementia-related health anxiety, (2) FCD in the context of a psychiatric
co-morbidity (most typically depression) and (3) FCD as a feature of
another functional disorder e.g. CFS, fibromyalgia (adapted from [6]).
The stability of functional neurological diagnoses is well demonstrated
and the same likely applies to FCD, as Pennington and colleagues point
out. We therefore disagree with the suggestion that it is necessary to
follow patients up to ensure that their cognitive function remains stable.
Follow-up might of course be offered for other reasons e.g. where the
clinician needs more time to explain the diagnosis.
In summary, while welcoming Pennington and colleagues important
contribution to this emerging area of neurological practice, we urge
general neurologists to have confidence in making a positive diagnosis of
FCD, particularly in younger patients. We believe that unnecessary
specialist referral, investigation and surveillance of patients with FCD
risks delaying treatment and potentially incorrect diagnoses of pre-
dementia (e.g. MCI) or dementia itself.
References
1. Pennington C, Newson M, Hayre A, et al. Functional cognitive disorder:
what is it and what to do about it? Pract Neurol 2015;15:436-444
2. Stone J. Functional neurological disorders: the neurological assessment
as treatment. Neurophysiol Clin 2014;44:363-373
3. Stone J, Reuber M, Carson A. Functional symptoms in neurology: mimics
and chameleons. Pract Neurol 2013;13:104-113
4. Jones D, Drew P, Elsey C, et al. Conversational assessment in memory
clinic encounters: interactional profiling for differentiating dementia
from functional memory disorders. Aging Ment Health 2015;
DOI:10.1080/13607863.2015.1021753
5. Coebergh JA, Wren DR, Mumford CJ. 'Undiagnosing' neurological disease:
how to do it, and when not to. Pract Neurol 2014;14:436-439
6. Stone J, Pal S, Blackburn D. Functional (Psychogenic) Cognitive
Disorders: A Perspective from the Neurology Clinic. J Alzheimers Dis
2015;48 Suppl 1:S5-S17
While reading Pennington et al's (2015) article on Functional
Cognitive Disorder, I was struck by the similarity between their
descriptions and a patient seen in clinic (patient X), with the exception
that X's symptoms appeared over the course of a few days with no
identifiable precipitating event. Extensive physical tests and brain
imaging investigations were carried out and no organic disease was found
yet symptoms we...
While reading Pennington et al's (2015) article on Functional
Cognitive Disorder, I was struck by the similarity between their
descriptions and a patient seen in clinic (patient X), with the exception
that X's symptoms appeared over the course of a few days with no
identifiable precipitating event. Extensive physical tests and brain
imaging investigations were carried out and no organic disease was found
yet symptoms were reportedly severe and having a major impact on X's
functioning. Here I discuss X's case (with identifiable information
changed in order to respect patient confidentiality) and propose that
there may be a sub-type of functional cognitive disorder with an acute
onset.
Patient X is a 48 year old house-wife and local preacher. She
presented to clinic with her husband after being referred by her GP due to
the development of severe confusion and cognitive impairment developing
from a previously high level of functioning just a few days earlier.
Symptoms began to appear on the Sunday evening and peaked on the Tuesday,
with no change between then and the clinic assessment (Thursday). X
reported completely 'losing track of time' and reported severe memory loss
which her husband had first noticed. During the assessment, she claimed
inability to answer any of our questions herself and repeatedly looked to
her husband for answers. When asked why she could not answer the
questions, she said that she 'could not remember' and described problems
with attention, concentration and executive function. This appeared
inconsistent with her performance in daily life as she had managed to
maintain her previous social roles, although we had no objective baseline
for comparison.
X had no previous psychiatric history and no significant medical
history. She was not taking any regular medications except for the oral
contraceptive pill. She reported a normal upbringing. The only
identifiable recent stressor was that X had recently started a new
university course, part of which involved looking at different personality
types, which she said had 'confused' and 'worried' her.
It was first thought that she may have organic disease as her
symptoms came on suddenly, however she returned to psychiatry clinic
following extensive tests as no physical cause could be found. Could this
be a case of functional cognitive disorder with acute onset? Further
assessment and follow-up of patient X and others like her could unravel a
subgroup of patients who fall into this category.
The outlined model of cooperative and integrative services for
pregnant women with neurological conditions is warmly welcomed (and not a
little envied!). While such services are provided the English centres
mentioned, it is sad that such high quality provision remains patchy and
incomplete. This nettle-grasping should no longer be quiet, but should be
loudly heralded and made the norm. The recently updated SIGN guideline...
The outlined model of cooperative and integrative services for
pregnant women with neurological conditions is warmly welcomed (and not a
little envied!). While such services are provided the English centres
mentioned, it is sad that such high quality provision remains patchy and
incomplete. This nettle-grasping should no longer be quiet, but should be
loudly heralded and made the norm. The recently updated SIGN guidelines
recommend a joint approach from all corners, and disparate organisations
such as the ILAE, the ABN, the Medical Royal Colleges, and the RCOG need
to come together to make such synergy routine. Only then can we ensure
that complications of epilepsy during pregnancy and the first post-partum
year follow other obstetric complications in decreasing incidence.
Dear Editor,
The only thing that I can disagree with in Jonathan Schott and Martin Rossor's article on the palmomental reflex in the December issue of Practical Neurology is their plea that I should stop scraping. I have found that the palmomental reflex can be made more specific for detecting brain damage by applying the orange stick or car key to the hypothenar rather than the thenar eminence. A positive palmomen...
Dear Editor,
We were interested to read the recent case study presented by Rodrigues and Wild in the current edition of Practical Neurology where they discussed "Psychogenic non-epileptic seizures in early Huntington's disease"[1]. The authors gave an in-depth account of the clinical profile of a 51-year-old male with early Huntington's disease (HD) who presented with repeated episodes of repetitive, purposeless, c...
Dear Editor,
In his recent Neuromythology article1 on the Babinski sign, Professor Kiernan repeats the oft quoted recommendation regarding the best method for testing the plantar response, which is to:
'Run a car key (figure 1; or as some have suggested, a most expensive motor car key...) along the lateral border of the sole.'
It will not surprise many readers of Practical Neurology to learn th...
This sensitive review is very welcome, as in our experience, most patients with functional disorders are told by specialists what they do not have. I would be much more inclined to refer patients if this kind of approach was more common. It is one reason why relatively few of the patients we see in primary care are referred for specialist attention. Specialists are seeing only the tip of the primary care functional iceb...
Title: Romberg's test has stood up to the test of time and should remain standing (Neuromythology: Letter to the Editor)
I was Interested to read Professor Martin Turner's article entitled Romberg's test no longer stands up. In the article Professor Turner describes the test as "the process of standing unsupported with the eyes closed and feet together for 30 s" and asserts that "the positive result is the p...
Sir, I read with much interest the review by Weerasinghe and Lueck on the diagnosis of optic neuritis. The authors provide an extensive and detailed analysis on the differential diagnoses and the management of the disease. The importance of retinal electrophysiology is also acknowledged when differentiating retinal disorders that can mimic optic neuritis. Surprisingly, however, the diagnostic role of pattern-reversal Visua...
We welcome debate around this emerging condition. We all recognise a situation when as clinicians we have had a strong feeling that a patient has a functional complaint from early on in the consultation. However, the differential diagnosis for Functional Cognitive Disorder is neurodegenerative dementia which itself affects behaviour and personality and could, therefore, influence many of the cues clinicians pick up on wh...
Pennington and colleagues review of Functional Cognitive Disorder (FCD) [1] is very welcome to guide practice in a complex condition that is presenting increasingly to general and cognitive neurology clinics. However, in our view Pennington's presumption towards specialist assessment, investigation and surveillance is unnecessary and misses an opportunity to provide patients with a prompt diagnosis, explanation and reas...
While reading Pennington et al's (2015) article on Functional Cognitive Disorder, I was struck by the similarity between their descriptions and a patient seen in clinic (patient X), with the exception that X's symptoms appeared over the course of a few days with no identifiable precipitating event. Extensive physical tests and brain imaging investigations were carried out and no organic disease was found yet symptoms we...
The outlined model of cooperative and integrative services for pregnant women with neurological conditions is warmly welcomed (and not a little envied!). While such services are provided the English centres mentioned, it is sad that such high quality provision remains patchy and incomplete. This nettle-grasping should no longer be quiet, but should be loudly heralded and made the norm. The recently updated SIGN guideline...
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