Your artclce mentions phenytoin as a treatment that has been tried in open label studies. When I began as a neurologist I'd not heard of its use but was put on to it by a senior colleague. I do use carbamazepine as first line but have found phenytoin far superior to other second line agents. I draw the interested reader to the excellent article by Hellelink and Schatman (J Pain Res. 2017; 10: 1663-6 doi: 10.2147/JPR.S141896) which puts a case for phenytoin being considered first line.
Although Rowe and colleagues make it clear that the most important purpose of their review is to cover the neglected aspect of management of Progressive Supranuclear Palsy (1) they also describe the disorder’s clinical symptoms and signs and its differential diagnosis in some detail. In this section of the article they fail to mention two simple bedside tests which I have found particularly useful over the years in making me more certain about my diagnosis. In those patients where Parkinson’s disease is the main differential diagnosis sequential finger tapping for 20 seconds is frequently informative. A progressive reduction in speed and amplitude ( ‘the sequence effect’) is a sine qua non for Parkinson’s disease but is rarely found in Progressive Supranuclear Palsy where marked reduction in amplitude of finger taps without decrement and preserved speed of movement is much more usual (2). Utilisation and imitation behaviour (3, 4) and the applause sign (5), all indicative of prefrontal lobe dysfunction, are very common in fully established Richardson’s syndrome but I have also found them to be sometimes present early on particularly when abulia or behavioural abnormalities are presenting complaints. The grasp reflex on the other hand is not commonly observed
The diagnosis of Progressive Supranuclear Palsy is difficult and uncertainty is common particularly in the early stages. To retract a diagnosis of Progressive Supranuclear Palsy is tri...
Although Rowe and colleagues make it clear that the most important purpose of their review is to cover the neglected aspect of management of Progressive Supranuclear Palsy (1) they also describe the disorder’s clinical symptoms and signs and its differential diagnosis in some detail. In this section of the article they fail to mention two simple bedside tests which I have found particularly useful over the years in making me more certain about my diagnosis. In those patients where Parkinson’s disease is the main differential diagnosis sequential finger tapping for 20 seconds is frequently informative. A progressive reduction in speed and amplitude ( ‘the sequence effect’) is a sine qua non for Parkinson’s disease but is rarely found in Progressive Supranuclear Palsy where marked reduction in amplitude of finger taps without decrement and preserved speed of movement is much more usual (2). Utilisation and imitation behaviour (3, 4) and the applause sign (5), all indicative of prefrontal lobe dysfunction, are very common in fully established Richardson’s syndrome but I have also found them to be sometimes present early on particularly when abulia or behavioural abnormalities are presenting complaints. The grasp reflex on the other hand is not commonly observed
The diagnosis of Progressive Supranuclear Palsy is difficult and uncertainty is common particularly in the early stages. To retract a diagnosis of Progressive Supranuclear Palsy is tricky and there are many instances when it is prudent to temporarily withhold judgement until the clinical picture becomes clearer.
References
1. Rowe JB, Holland N, Rittman T. Progressive supranuclear palsy: diagnosis and management. Pract Neurol. 2021;21(5):376-83.
2. Ling H, Massey L, Lees A, Brown P, Day B. Hypokinesia without decrement distinguishes progressive supranuclear palsy from Parkinson's disease. Movement Disorders. 2012;27:S384-S5.
3. Lhermitte F, Pillon B, Serdaru M. Human autonomy and the frontal lobes. Part I: Imitation and utilization behavior: a neuropsychological study of 75 patients. Ann Neurol. 1986;19(4):326-34.
4. Lhermitte F. Human autonomy and the frontal lobes. Part II: Patient behavior in complex and social situations: the "environmental dependency syndrome". Ann Neurol. 1986;19(4):335-43.
5. Dubois B, Slachevsky A, Pillon B, Beato R, Villalponda JM, Litvan I. "Applause sign" helps to discriminate PSP from FTD and PD. Neurology. 2005;64(12):2132-3.
We agree with Andrew Lees on the value of the applause sign (i.e. ask a PSP patient to clap 3 times, and they typically perseverative by clapping more than 3 times) and a lack of decrement on hypokinesia tests (e.g. sequential finger tapping or in micrographic writing, without a progressive reduction in amplitude) to differentiate Progressive Supranuclear Palsy from Parkinson’s disease. Both are very useful, easy bedside tests.
We also agree that there are cases where one is unsure. A diagnosis of Progressive Supranuclear Palsy is not to be given lightly, as for any other disease. But, patients with Progressive Supranuclear Palsy have suffered disproportionately from delays and diagnostic hesitation, often long past any reasonable doubt. It does not help a patient or family to live with a wrong diagnosis, or no diagnosis, for a large part of their illness. Across many countries, the diagnosis of PSP is made at around three years from symptom onset (Murley et al, 2021; Cosseddu et al 2017; Mamarabadi et al, 2018). In other words, halfway from onset to death. This is unnecessarily long. Greater awareness and simple clinical skills can reduce the diagnostic delay by more than a year (Mamarabadi et al, 2018). Through our article, we hope our colleagues can become more confident, early and accurate in making the diagnosis of PSP as a gateway to better care.
We agree with Andrew Lees on the value of the applause sign (i.e. ask a PSP patient to clap 3 times, and they typically perseverative by clapping more than 3 times) and a lack of decrement on hypokinesia tests (e.g. sequential finger tapping or in micrographic writing, without a progressive reduction in amplitude) to differentiate Progressive Supranuclear Palsy from Parkinson’s disease. Both are very useful, easy bedside tests.
We also agree that there are cases where one is unsure. A diagnosis of Progressive Supranuclear Palsy is not to be given lightly, as for any other disease. But, patients with Progressive Supranuclear Palsy have suffered disproportionately from delays and diagnostic hesitation, often long past any reasonable doubt. It does not help a patient or family to live with a wrong diagnosis, or no diagnosis, for a large part of their illness. Across many countries, the diagnosis of PSP is made at around three years from symptom onset (Murley et al, 2021; Cosseddu et al 2017; Mamarabadi et al, 2018). In other words, halfway from onset to death. This is unnecessarily long. Greater awareness and simple clinical skills can reduce the diagnostic delay by more than a year (Mamarabadi et al, 2018). Through our article, we hope our colleagues can become more confident, early and accurate in making the diagnosis of PSP as a gateway to better care.
James Rowe, Tim Rittman and Negin Holland
References
Mamarabadi M, Razjouyan H, Golbe LI. Is the Latency from Progressive Supranuclear Palsy Onset to Diagnosis Improving? Mov Disord Clin Pract. 2018 Nov 8;5(6):603-606. doi: 10.1002/mdc3.12678. PMID: 30637280; PMCID: PMC6277372.
Murley AG, Rouse MA, Coyle-Gilchrist ITS, Jones PS, Li W, Wiggins J, Lansdall C, Vázquez Rodríguez P, Wilcox A, Patterson K, Rowe JB. Predicting loss of independence and mortality in frontotemporal lobar degeneration syndromes. J Neurol Neurosurg Psychiatry. 2021 Jul;92(7):737-744. doi: 10.1136/jnnp-2020-324903. Epub 2021 Feb 9. PMID: 33563798; PMCID: PMC8223632.
Cosseddu M, Benussi A, Gazzina S, Manes MA, Dell'Era V, Cristillo V, Turrone R, Alberici A, Borroni B. Natural history and predictors of survival in progressive supranuclear palsy. J Neurol Sci. 2017 Nov 15;382:105-107. doi: 10.1016/j.jns.2017.09.043. Epub 2017 Sep 30. PMID: 29111000.
I read your article (Neurology and clinical neurophysiology: an artificial divide. Kieran MC. Pract Neurol 2021;21:274-275) with interest.
Clinical neurophysiology is primarily a diagnostic specialty concerned with recording electrical activity from the nervous system to aid the diagnosis, classification and management of neurological disease (clinical neurophysiology curriculum: www.jrcptb.org.uk/specialties/c;inical-neurophysiology). One of the attractions of the specialty is precisely this: the breadth of the specialty and the interaction with a wide variety of specialties. Although nerve conduction studies (NCS) and electromyography (EMG) form a big part of our work, most clinical neurophysiologists, at least in the UK do a lot more. We record and report electroencephalography (EEG) studies including long term recordings and video EEG telemetry, a variety of evoked potential studies (EPs), electroretinography (ERG) studies and sleep studies, among others. The specialty is about more than NCS and EMG. Even within the area of NCS/ EMG, although a proportion of our referrals are from neurology teams, we frequently see patients referred by orthopaedic, oncology and rheumatology teams.
I suppose there could be a world in which neurologists perform NCS / EMG as well as EPs, EEGs, sleep studies on all their patients; hand surgeons and shoulder specialists perform NCS /EMG on their patients...
I read your article (Neurology and clinical neurophysiology: an artificial divide. Kieran MC. Pract Neurol 2021;21:274-275) with interest.
Clinical neurophysiology is primarily a diagnostic specialty concerned with recording electrical activity from the nervous system to aid the diagnosis, classification and management of neurological disease (clinical neurophysiology curriculum: www.jrcptb.org.uk/specialties/c;inical-neurophysiology). One of the attractions of the specialty is precisely this: the breadth of the specialty and the interaction with a wide variety of specialties. Although nerve conduction studies (NCS) and electromyography (EMG) form a big part of our work, most clinical neurophysiologists, at least in the UK do a lot more. We record and report electroencephalography (EEG) studies including long term recordings and video EEG telemetry, a variety of evoked potential studies (EPs), electroretinography (ERG) studies and sleep studies, among others. The specialty is about more than NCS and EMG. Even within the area of NCS/ EMG, although a proportion of our referrals are from neurology teams, we frequently see patients referred by orthopaedic, oncology and rheumatology teams.
I suppose there could be a world in which neurologists perform NCS / EMG as well as EPs, EEGs, sleep studies on all their patients; hand surgeons and shoulder specialists perform NCS /EMG on their patients with entrapment neuropathies and brachial plexopathies; hip surgeons assess electrodiagnostically their patients with leg weakness following hip replacement; ophthalmologists record and report electroretinographies in patients with possible degenerative retinal diseases and paediatricians record and report EEGs in children presenting with episodes likely to be seizures.
I agree that neurophysiological investigations are extensions of the clinical assessments of patients and the findings should always be interpreted within the clinical context. Clinical neurophysiologists should receive rigorous training, not only in the technical aspects of the specialty but also in the clinical areas (neurology, adult and paediatric epilepsy, ophthalmology, psychiatry etc. as well as in the art of communication with the different referring specialties). The clinical neurophysiologists and the referring clinicians need to work together and communicate clearly about the needs of the patients and the clinical and electrophysiological findings. It is in the patients’ best interests that we work together in functioning multidisciplinary teams.
I think modern medicine has a place for well-trained neurologists and competent and enthusiastic clinical neurophysiologists (and our clinical physiologist colleagues) to work side by side to deliver a quality service to our patients.
We were delighted to read the article on orbital myositis heralding herpes zoster ophthalmicus (HZO) [1], highlighting the importance of considering an underlying infectious aetiology in cases of painful complex ophthalmoplegia.
Infections are a common cause of neurological complications in our setting, although unique cases continue to remind us about broader differentials. We encountered a case of a 55-year-old female with an unremarkable past medical history who was on holiday in Mombasa but presented to a local ophthalmologist with acute-onset diplopia and a painful swollen left eye. She was commenced on oral and topical antibiotics for a presumed pre-septal orbital cellulitis, but did not improve so was transferred urgently to our tertiary regional referral centre in Nairobi. Further social and travel history were non-revealing. On physical examination her blood pressure and temperature were normal, and she had no signs of thyroid disease. On full neurological examination she only had a left lateral rectus palsy with no other signs, and mild left peri-orbital swelling with erythema.
Comprehensive investigations (including metabolic, inflammatory, auto-immune, vasculitic and infective blood tests panels) as well as magnetic resonance imaging (MRI) of the brain with venography and angiography were all normal except for modestly raised C-reactive protein of 13 mg/dL (normal range 0-5). MRI of the orbits revealed enlargement of the left lateral rectus with...
We were delighted to read the article on orbital myositis heralding herpes zoster ophthalmicus (HZO) [1], highlighting the importance of considering an underlying infectious aetiology in cases of painful complex ophthalmoplegia.
Infections are a common cause of neurological complications in our setting, although unique cases continue to remind us about broader differentials. We encountered a case of a 55-year-old female with an unremarkable past medical history who was on holiday in Mombasa but presented to a local ophthalmologist with acute-onset diplopia and a painful swollen left eye. She was commenced on oral and topical antibiotics for a presumed pre-septal orbital cellulitis, but did not improve so was transferred urgently to our tertiary regional referral centre in Nairobi. Further social and travel history were non-revealing. On physical examination her blood pressure and temperature were normal, and she had no signs of thyroid disease. On full neurological examination she only had a left lateral rectus palsy with no other signs, and mild left peri-orbital swelling with erythema.
Comprehensive investigations (including metabolic, inflammatory, auto-immune, vasculitic and infective blood tests panels) as well as magnetic resonance imaging (MRI) of the brain with venography and angiography were all normal except for modestly raised C-reactive protein of 13 mg/dL (normal range 0-5). MRI of the orbits revealed enlargement of the left lateral rectus with contrast enhancement. We diagnosed idiopathic orbital myositis (IOM) and commenced oral corticosteroids which resulted in marked improvement within 48 hours.
Our case highlights that IOM can present as orbital cellulitis [2], although the latter diagnosis is more serious and needs to be recognised and treated early. Ophthalmoplegia can be due to myositis of single or multiple extra-ocular muscles as our case and the HZO case illustrate, although there are reports of lateral rectus IOM occurring without any of the other signs of orbital inflammation [3]. In the absence of other clinical and laboratory markers to support cellulitis, causes of orbital myositis need to be considered e.g. auto-immune disease, primary infections of the muscle including neuroborreliosis [4], or post-infectious sequelae even including after COVID-19 infection [5].
We hope our case adds further diagnostic considerations to those wonderfully illustrated by our colleague when confronted with a patient complaining of acute-onset painful diplopia.
REFERENCES
[1] Chen T. Orbital myositis with herpes zoster ophthalmicus. Practical Neurology. Published Online First: 28 January 2021. doi: 10.1136/practneurol-2020-002870
[2] Lee NC, Loyal J, Berkwitt A. More Than Meets the Eye: Idiopathic Orbital Inflammation Mimicking Orbital Cellulitis. Cureus. 2021 Jan 12;13(1):e12655. doi: 10.7759/cureus.12655
[3] Wazir M, Faisal-Uddin M, Tambunan D, Jain AG. Idiopathic Lateral Rectus Myositis Without Signs of Orbital Inflammation. Cureus. 2019 Jun 7;11(6):e4859. doi: 10.7759/cureus.4859. PMID: 31410342; PMCID: PMC6684302.
[4] Mangan MS, Yildiz E. New Onset of Unilateral Orbital Myositis following Mild COVID-19 Infection. Ocular Immunology and Inflammation. Published Online First: 02 April 2021. doi: 10.1080/09273948.2021.1887282
[5] McNab AA. Orbital Myositis: A Comprehensive Review and Reclassification. Ophthalmic Plast Reconstr Surg, 2020; 36(2):109-117
Dr Gowell and his colleagues, in their detailed and vivid description of a young-onset case of frontotemporal dementia (FTD) associated with FUS pathology, have missed a trick. They point out the frontal atrophy that is evident in the patient’s brain MRI (figure 1), but have not commented on the bilateral caudate head atrophy that is also present. This is best appreciated in the third image from the left in the upper row of images (coronal, T1-weighted). This MRI characteristic is a tell-tale sign in FUS-associated FTD (ref). The differential for the presence of caudate head atrophy in brain MRI scans is not wide (also present in Huntington’s disease and neuroacathocytosis), so its presence in the context of progressive dementia with predominant frontal lobe dysfunction in the absence of movement disorder should alert the clinician to this possibility. Having a “second look” at the imaging is always worth doing!
Ref.
Josephs KA, Whitwell JL, Parisi JE, et al. Caudate atrophy on MRI is a characteristic feature of FTLD-FUS. Eur J Neurol 2010;17(7):969-975.
Comment on: Nathoo N, Naik S, Rempel J, et al. Superficial siderosis treated with dural tear repair and deferiprone. Pract Neurol 2021;21(1):71-72.
Dear Colleagues
Concerning “superficial siderosis” I would like to emphasize that we have to distinguish two different types regarding localization and pathophysiology: 1) The infratentorial type that was described in the case report [1]. Patients present with a triad of sensorineural hearing loss, ataxia and myelopathy [2]. Treatment is based on staunching recurrent bleeding and elimination of toxic iron deposits with deferiprone. The latter is not without some risk: neutropenia with sepsis [3]. – 2) The supratentorial type is a manifestation of cerebral amyloid angiopathy in the vast majority of cases [4], and there is no known cure. Cortical superficial siderosis – of the supratentorial type – is the cause of transient focal neurological episodes that can mimic transient ischaemic attacks, migraine auras or simple partial seizures [5].
Conflicts of interest and ethics
The author declares that there are no conflicts of interest, in particular none with a manufacturer of pharmaceutical products...
Comment on: Nathoo N, Naik S, Rempel J, et al. Superficial siderosis treated with dural tear repair and deferiprone. Pract Neurol 2021;21(1):71-72.
Dear Colleagues
Concerning “superficial siderosis” I would like to emphasize that we have to distinguish two different types regarding localization and pathophysiology: 1) The infratentorial type that was described in the case report [1]. Patients present with a triad of sensorineural hearing loss, ataxia and myelopathy [2]. Treatment is based on staunching recurrent bleeding and elimination of toxic iron deposits with deferiprone. The latter is not without some risk: neutropenia with sepsis [3]. – 2) The supratentorial type is a manifestation of cerebral amyloid angiopathy in the vast majority of cases [4], and there is no known cure. Cortical superficial siderosis – of the supratentorial type – is the cause of transient focal neurological episodes that can mimic transient ischaemic attacks, migraine auras or simple partial seizures [5].
Conflicts of interest and ethics
The author declares that there are no conflicts of interest, in particular none with a manufacturer of pharmaceutical products. This manuscript is not under review by another journal, and it is based on previously published work, so no new studies in humans or animals were necessary.
References
1) Nathoo N, Naik S, Rempel J, et al. Superficial siderosis treated with dural tear repair and deferiprone. Pract Neurol 2021;21(1):71-72.
2) Wilson D, Chatterjee F, Farmer SF et al. Infratentorial superficial siderosis: classification, diagnostic criteria, and rational investigation pathway. Ann Neurol 2017;81(3):333-343.
3) Sammaraiee Y, Banerjee G, Farmer S et al. Risks associated with oral deferiprone in the treatment of infratentorial superficial siderosis. J Neurol 2020;267(1):239-243.
4) Lummel N, Wollenweber FA, Demaerel P et al. Clinical spectrum, underlying etiologies and radiological characteristics of cortical superficial siderosis. J Neurol 2015;262(6):1455-1462.
5) Vales-Montero M, Garcia-Pastor A, Iglesias-Mohedano AM et al. Cerebral amyloid angiopathy-related transient focal neurological episodes: a transient ischemic attack mimic with an increased risk of intracranial hemorrhage. J Neurol Sci 2019;406:116452.
I agree with Dhonde et al. (1) that a pair of humble 20 dioptre lens spectacle is often sufficient and less cumbersome than Frenzel glasses for routine bedside use at acute neurology and emergency wards. I have been using such glasses for more than 10 years to help distinguish peripheral from central nystagmus. Video 1 shows a lady with acute left vestibular neuronitis. Her right beating primary position nystagmus is more pronounced when visual fixation is removed using above-mentioned spectacles. Another trick is to ask the patient to gently shut the eye lids, Video 2. Some patients, like this man with acute left vestibular neuronitis, do have thin enough eyelids to discern the enhancement of nystagmus from the removal of visual fixation.
Reference:
1. Dhonde P, Khadilkar S. Frenzel glasses: an affordable alternative. Pract Neurol. 2020 Dec;20(6):504.
Legend for video:
a. VIDEO1-Peripheral nystagmus, more obvious with removal of visual fixation using modified Frenzel glasses: https://cloud.degoo.com/share/IKZ3Xj6YlnbMZ1Xe16ui0A
To address your first point, we did not carry out nerve conduction studies or electromyography. The patient was seen as a part of a hyperacute stroke service and we made the diagnosis within 48 hours of symptom onset. After finding an explanatory central lesion, we did not look further peripherally. It would seem to be highly unlikely the patient had developed a simultaneous acute stroke in a relevant area of cortex and peroneal nerve lesion. It is interesting you mention teaching medical students in your response - we teach our students about Occam's razor! As you will no doubt be aware, neurophysiology conducted this soon after symptom onset will be unlikely to contribute in any case, and we are not in the habit of recalling patients at a later date for additional investigations for purely academic value, and we are sure many would share our view this is not appropriate given the current pressure the NHS is under. A stroke diagnosis changes management in terms of secondary preventative medications, hypothetically diagnosing a co-existent compressive neuropathy does not add.
Secondly, we would argue that the location of this lesion does explain the neurological signs quite satisfactorily. As we know, the ankle dorsiflexors are in fact located in the anterior compartment of the lower leg, just below the knee and not actually in the foot itself. Furthermore, there is likely to be considerable individual var...
To address your first point, we did not carry out nerve conduction studies or electromyography. The patient was seen as a part of a hyperacute stroke service and we made the diagnosis within 48 hours of symptom onset. After finding an explanatory central lesion, we did not look further peripherally. It would seem to be highly unlikely the patient had developed a simultaneous acute stroke in a relevant area of cortex and peroneal nerve lesion. It is interesting you mention teaching medical students in your response - we teach our students about Occam's razor! As you will no doubt be aware, neurophysiology conducted this soon after symptom onset will be unlikely to contribute in any case, and we are not in the habit of recalling patients at a later date for additional investigations for purely academic value, and we are sure many would share our view this is not appropriate given the current pressure the NHS is under. A stroke diagnosis changes management in terms of secondary preventative medications, hypothetically diagnosing a co-existent compressive neuropathy does not add.
Secondly, we would argue that the location of this lesion does explain the neurological signs quite satisfactorily. As we know, the ankle dorsiflexors are in fact located in the anterior compartment of the lower leg, just below the knee and not actually in the foot itself. Furthermore, there is likely to be considerable individual variation in precise cortical areas where individual muscles are represented - to quote Penfield's original paper from which the homunculus is derived - "we do not know what the architectural pattern is in any particular case and how much these boundaries may vary from individual to individual", indeed they stated that between "different individuals the result will vary greatly so that any standardized chart which localizes the position of those points upon the cortex may be correct for one individual but not for all" (1).
Robin Fox and Laszlo Sztriha
Penfield W, Boldrey E. Somatic motor and sensory representation in the cortex of man as studied by electrical stimulation. Brain 1937; 60: 389-443
We read the above article (like all highly educational articles of Practical Neurology) with interest.
As the authors pointed out the clinical picture is highly suggestive of peroneal nerve lesion. There was no mention of NCS and EMG had been undertaken in this case. If NCS were carried out then it is prudent to stated that Nerve Conduction Studies excluded Common Peroneal nerve lesion, to make the case water tight and credible.
It is known that elderly would wake up with foot drop due to Peroneal nerve lesion and not necessarily indicate a stroke. In this case an ischaemic lesion was noted at the top of the motor strip and not in the depth of central sulcus where the foot is located. As the homunculus illustrates in Figure 2, the lesion is at the Knee area at best). Parasagittal meningiomas in the depth cause the foot weakness(also suggesting that the well-known ‘homunculus illustration is probably accurate’!) and we teach medical students practical neuroanatomy and localization using such examples. Thus it would be helpful for the paper to document all claims as accurately as possible.
Dr S Wimalaratna, Neurologist, Kettering General Hospital
Dr S Alagoda, Clinical Neurophysiologist, Musgrove Park Hospital, Taunton
Your artclce mentions phenytoin as a treatment that has been tried in open label studies. When I began as a neurologist I'd not heard of its use but was put on to it by a senior colleague. I do use carbamazepine as first line but have found phenytoin far superior to other second line agents. I draw the interested reader to the excellent article by Hellelink and Schatman (J Pain Res. 2017; 10: 1663-6 doi: 10.2147/JPR.S141896) which puts a case for phenytoin being considered first line.
To the editor
Although Rowe and colleagues make it clear that the most important purpose of their review is to cover the neglected aspect of management of Progressive Supranuclear Palsy (1) they also describe the disorder’s clinical symptoms and signs and its differential diagnosis in some detail. In this section of the article they fail to mention two simple bedside tests which I have found particularly useful over the years in making me more certain about my diagnosis. In those patients where Parkinson’s disease is the main differential diagnosis sequential finger tapping for 20 seconds is frequently informative. A progressive reduction in speed and amplitude ( ‘the sequence effect’) is a sine qua non for Parkinson’s disease but is rarely found in Progressive Supranuclear Palsy where marked reduction in amplitude of finger taps without decrement and preserved speed of movement is much more usual (2). Utilisation and imitation behaviour (3, 4) and the applause sign (5), all indicative of prefrontal lobe dysfunction, are very common in fully established Richardson’s syndrome but I have also found them to be sometimes present early on particularly when abulia or behavioural abnormalities are presenting complaints. The grasp reflex on the other hand is not commonly observed
Show MoreThe diagnosis of Progressive Supranuclear Palsy is difficult and uncertainty is common particularly in the early stages. To retract a diagnosis of Progressive Supranuclear Palsy is tri...
To the Editor,
We agree with Andrew Lees on the value of the applause sign (i.e. ask a PSP patient to clap 3 times, and they typically perseverative by clapping more than 3 times) and a lack of decrement on hypokinesia tests (e.g. sequential finger tapping or in micrographic writing, without a progressive reduction in amplitude) to differentiate Progressive Supranuclear Palsy from Parkinson’s disease. Both are very useful, easy bedside tests.
We also agree that there are cases where one is unsure. A diagnosis of Progressive Supranuclear Palsy is not to be given lightly, as for any other disease. But, patients with Progressive Supranuclear Palsy have suffered disproportionately from delays and diagnostic hesitation, often long past any reasonable doubt. It does not help a patient or family to live with a wrong diagnosis, or no diagnosis, for a large part of their illness. Across many countries, the diagnosis of PSP is made at around three years from symptom onset (Murley et al, 2021; Cosseddu et al 2017; Mamarabadi et al, 2018). In other words, halfway from onset to death. This is unnecessarily long. Greater awareness and simple clinical skills can reduce the diagnostic delay by more than a year (Mamarabadi et al, 2018). Through our article, we hope our colleagues can become more confident, early and accurate in making the diagnosis of PSP as a gateway to better care.
James Rowe, Tim Rittman and Negin Holland
References
Mamarabadi M, R...
Show MoreI read your article (Neurology and clinical neurophysiology: an artificial divide. Kieran MC. Pract Neurol 2021;21:274-275) with interest.
Show MoreClinical neurophysiology is primarily a diagnostic specialty concerned with recording electrical activity from the nervous system to aid the diagnosis, classification and management of neurological disease (clinical neurophysiology curriculum: www.jrcptb.org.uk/specialties/c;inical-neurophysiology). One of the attractions of the specialty is precisely this: the breadth of the specialty and the interaction with a wide variety of specialties. Although nerve conduction studies (NCS) and electromyography (EMG) form a big part of our work, most clinical neurophysiologists, at least in the UK do a lot more. We record and report electroencephalography (EEG) studies including long term recordings and video EEG telemetry, a variety of evoked potential studies (EPs), electroretinography (ERG) studies and sleep studies, among others. The specialty is about more than NCS and EMG. Even within the area of NCS/ EMG, although a proportion of our referrals are from neurology teams, we frequently see patients referred by orthopaedic, oncology and rheumatology teams.
I suppose there could be a world in which neurologists perform NCS / EMG as well as EPs, EEGs, sleep studies on all their patients; hand surgeons and shoulder specialists perform NCS /EMG on their patients...
We were delighted to read the article on orbital myositis heralding herpes zoster ophthalmicus (HZO) [1], highlighting the importance of considering an underlying infectious aetiology in cases of painful complex ophthalmoplegia.
Infections are a common cause of neurological complications in our setting, although unique cases continue to remind us about broader differentials. We encountered a case of a 55-year-old female with an unremarkable past medical history who was on holiday in Mombasa but presented to a local ophthalmologist with acute-onset diplopia and a painful swollen left eye. She was commenced on oral and topical antibiotics for a presumed pre-septal orbital cellulitis, but did not improve so was transferred urgently to our tertiary regional referral centre in Nairobi. Further social and travel history were non-revealing. On physical examination her blood pressure and temperature were normal, and she had no signs of thyroid disease. On full neurological examination she only had a left lateral rectus palsy with no other signs, and mild left peri-orbital swelling with erythema.
Comprehensive investigations (including metabolic, inflammatory, auto-immune, vasculitic and infective blood tests panels) as well as magnetic resonance imaging (MRI) of the brain with venography and angiography were all normal except for modestly raised C-reactive protein of 13 mg/dL (normal range 0-5). MRI of the orbits revealed enlargement of the left lateral rectus with...
Show MoreDr Gowell and his colleagues, in their detailed and vivid description of a young-onset case of frontotemporal dementia (FTD) associated with FUS pathology, have missed a trick. They point out the frontal atrophy that is evident in the patient’s brain MRI (figure 1), but have not commented on the bilateral caudate head atrophy that is also present. This is best appreciated in the third image from the left in the upper row of images (coronal, T1-weighted). This MRI characteristic is a tell-tale sign in FUS-associated FTD (ref). The differential for the presence of caudate head atrophy in brain MRI scans is not wide (also present in Huntington’s disease and neuroacathocytosis), so its presence in the context of progressive dementia with predominant frontal lobe dysfunction in the absence of movement disorder should alert the clinician to this possibility. Having a “second look” at the imaging is always worth doing!
Ref.
Josephs KA, Whitwell JL, Parisi JE, et al. Caudate atrophy on MRI is a characteristic feature of FTLD-FUS. Eur J Neurol 2010;17(7):969-975.
Comment on: Nathoo N, Naik S, Rempel J, et al. Superficial siderosis treated with dural tear repair and deferiprone. Pract Neurol 2021;21(1):71-72.
Dear Colleagues
Concerning “superficial siderosis” I would like to emphasize that we have to distinguish two different types regarding localization and pathophysiology: 1) The infratentorial type that was described in the case report [1]. Patients present with a triad of sensorineural hearing loss, ataxia and myelopathy [2]. Treatment is based on staunching recurrent bleeding and elimination of toxic iron deposits with deferiprone. The latter is not without some risk: neutropenia with sepsis [3]. – 2) The supratentorial type is a manifestation of cerebral amyloid angiopathy in the vast majority of cases [4], and there is no known cure. Cortical superficial siderosis – of the supratentorial type – is the cause of transient focal neurological episodes that can mimic transient ischaemic attacks, migraine auras or simple partial seizures [5].
Yours sincerely,
Daniel Eschle, MD, MSc
Consultant Neurologist
Kantonsspital Uri, 6460 Altdorf (Switzerland), Telephone: ++41 41 875 51 51
E-Mail: deschle@hotmail.com or daniel.eschle@ksuri.ch
Conflicts of interest and ethics
Show MoreThe author declares that there are no conflicts of interest, in particular none with a manufacturer of pharmaceutical products...
I agree with Dhonde et al. (1) that a pair of humble 20 dioptre lens spectacle is often sufficient and less cumbersome than Frenzel glasses for routine bedside use at acute neurology and emergency wards. I have been using such glasses for more than 10 years to help distinguish peripheral from central nystagmus. Video 1 shows a lady with acute left vestibular neuronitis. Her right beating primary position nystagmus is more pronounced when visual fixation is removed using above-mentioned spectacles. Another trick is to ask the patient to gently shut the eye lids, Video 2. Some patients, like this man with acute left vestibular neuronitis, do have thin enough eyelids to discern the enhancement of nystagmus from the removal of visual fixation.
Reference:
1. Dhonde P, Khadilkar S. Frenzel glasses: an affordable alternative. Pract Neurol. 2020 Dec;20(6):504.
Legend for video:
a. VIDEO1-Peripheral nystagmus, more obvious with removal of visual fixation using modified Frenzel glasses: https://cloud.degoo.com/share/IKZ3Xj6YlnbMZ1Xe16ui0A
b. VIDEO2-Peripheral nystagmus, worse on eye closure: https://cloud.degoo.com/share/FyVfA144V6oHsULRgUOuIQ
Thank you for your interest in our case report.
To address your first point, we did not carry out nerve conduction studies or electromyography. The patient was seen as a part of a hyperacute stroke service and we made the diagnosis within 48 hours of symptom onset. After finding an explanatory central lesion, we did not look further peripherally. It would seem to be highly unlikely the patient had developed a simultaneous acute stroke in a relevant area of cortex and peroneal nerve lesion. It is interesting you mention teaching medical students in your response - we teach our students about Occam's razor! As you will no doubt be aware, neurophysiology conducted this soon after symptom onset will be unlikely to contribute in any case, and we are not in the habit of recalling patients at a later date for additional investigations for purely academic value, and we are sure many would share our view this is not appropriate given the current pressure the NHS is under. A stroke diagnosis changes management in terms of secondary preventative medications, hypothetically diagnosing a co-existent compressive neuropathy does not add.
Secondly, we would argue that the location of this lesion does explain the neurological signs quite satisfactorily. As we know, the ankle dorsiflexors are in fact located in the anterior compartment of the lower leg, just below the knee and not actually in the foot itself. Furthermore, there is likely to be considerable individual var...
Show MoreLetter to the editor; 14th February 2021
RE: Cortical foot
Fox R,Sztriha L. Pract Neurol 2021, 21:73-74
Dear Editors,
We read the above article (like all highly educational articles of Practical Neurology) with interest.
As the authors pointed out the clinical picture is highly suggestive of peroneal nerve lesion. There was no mention of NCS and EMG had been undertaken in this case. If NCS were carried out then it is prudent to stated that Nerve Conduction Studies excluded Common Peroneal nerve lesion, to make the case water tight and credible.
It is known that elderly would wake up with foot drop due to Peroneal nerve lesion and not necessarily indicate a stroke. In this case an ischaemic lesion was noted at the top of the motor strip and not in the depth of central sulcus where the foot is located. As the homunculus illustrates in Figure 2, the lesion is at the Knee area at best). Parasagittal meningiomas in the depth cause the foot weakness(also suggesting that the well-known ‘homunculus illustration is probably accurate’!) and we teach medical students practical neuroanatomy and localization using such examples. Thus it would be helpful for the paper to document all claims as accurately as possible.
Dr S Wimalaratna, Neurologist, Kettering General Hospital
Dr S Alagoda, Clinical Neurophysiologist, Musgrove Park Hospital, Taunton
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