574 e-Letters

published between 2016 and 2019

  • A response from Noble et al. to e-letter by the Psychology Task Force of the International League Against Epilepsy

    Dear Editor,
    Re: A response from Noble et al. to e-letter by Psychology Task Force of the International League Against Epilepsy
    Cognitive behavioural therapy (CBT) has been recommended for treating depression in people with epilepsy (PWE).[1, 2] The clinical significance of the effects of CBT for PWE has though, not been considered. We therefore systematically searched the literature for randomised controlled trials of CBT for PWE [3] and used Jacobson’s criteria [4] to empirically determine whether PWE made clinically reliable improvement. We compared this to that seen in the control arms of these trials.
    Our main findings were that the likelihood of statistically reliable improvement in symptoms of depression was significantly higher for those PWE randomised to CBT compared to control conditions. The overall proportion of PWE achieving reliable improvement was low – 30% compared to 10% in the control arms. For most PWE, symptoms were unchanged.
    The proportion of PWE who improve following CBT is limited. It should serve as a clarion call for the development of more effective treatments. Indeed, our review may have inflated CBT’s benefit since some trials included PWE without clinical distress at baseline and so it was not possible to apply Jacobson’s second, more stringent criterion and calculate for what proportion CBT also resulted in recovery.
    The Psychology Task Force of the International League Against Epilepsy submitted a response to ou...

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  • Paradoxal increased incidence of post-traumatic stress disorder in non-mechanically ventilated Guillain-Barré syndrome patients: the role of resilience?

    Dear Editor,

    We read with interest the study presented by Berg et al [1] that showed that prolonged mechanical ventilation (more than 2 months) in Guillain-Barre syndrome (GBS) was associated with poorer outcome and more residual deficits compared to non-ventilated GBS patients.

    We recently found very similar results in the same population of patients. Nevertheless, it should be precised that despite this, we could not found any difference in quality of life compared to the general French population [2]. Berg et al. also found that ventilated patients were less likely to have residual fatigue symptoms compared to non-ventilated GBS patients, respectively 20% versus 54% (p=0.007). Among 13 prolonged mechanically ventilated GBS, we could show that 22% of patients displayed DSM IV criteria for long-term post-traumatic stress disorder (PTSD) [2]. Since one of our main hypothesis was that PTSD symptoms were mainly related to the mechanical ventilation, we assessed long-term PTSD in 20 non-ventilated GBS patients (Table). Unexpectedly, 65% of these non-ventilated patients had PTSD as compared to 22% in the ventilated group found in our previous study (Table). As for fatigue, we would have expected a correlation between the severity of the disease (especially mechanical ventilation), and the incidence of PTSD.

    One explanation of these unexpected results could be that the acute stress induced by the temporary paralysis, the traumatic aspects of intubation an...

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  • Reply to “The eye of the beholder and risks of eminence based medicine”

    We appreciate Dr. Laura S. Boylan’s interest in our article. However, her viewpoint rather strikingly exemplifies the behaviors that she mistakenly believes we were guilty of in our report, beginning with the “eminence based” statements “in my view” occurring twice in the first paragraph and her conclusion with a personal “old saw I use in teaching”. We strongly disagree with her misinterpretation about our application of “cognitive bias” in the selection of our patients for this case-control study. In fact, most patients with Parkinson’s disease (PD) had functional complications ascertained after several visits –requiring a diagnostic revision once they fulfilled the appropriate positive criteria.1 The diagnostic “delay” in part may have highlighted the absent recognition of functional comorbidities in PD prior to our study, forcing a conservative approach before ascertaining what may be considered a “second” diagnosis in these patients. Furthermore, in contrast to Dr. Boylan’s suggestion, we did not select patients on the basis of comorbid depression, anxiety, cognitive symptoms, pain, nausea, or fatigue. Instead these features segregated more commonly among cases than controls after the patient selection had been completed. She argues that we considered them “supportive” for a diagnosis of functional movement disorder, but we did not. We have instead emphasized the potentially misleading influence of both history and psychiatric features and argued in favor of a diagnos...

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  • Sleep apnoea and nocturnal hypoventilation in patients with amyotrophic lateral sclerosis

    Boentert et al. investigated the prevalence of sleep apnoea and nocturnal hypoventilation (NH) in 250 patients with non-ventilated amyotrophic lateral sclerosis (ALS) by considering gender and severity of bulbar dysfunction (1). Prevalence of NH and apnoea-hypopnoea index (AHI) >5/hour was 40.0% and 45.6%, respectively, and 22.3% of patients had both NH and sleep apnoea. Sleep apnoea was significantly more common in male patients and negatively associated with bulbar function. I have some concerns with this study.

    First, the authors did not conduct stratified analysis by gender. As the prevalence of sleep apnoea differs by gender, the association between sleep apnoea, NH and severity of bulbar dysfunction should be analyzed by stratification with gender.

    Second, the authors conducted univariate analyses, and adjustment of independent variables cannot be made. Although the number of patients is limited, recommendation for the use of transcutaneous capnography should be based by appropriate adjustments of confounders.

    Finally, Park et al. evaluated the relationship between nocturnal hypoxia and cognitive dysfunction in patients with ALS, and patients with nocturnal hypoxia showed poor memory retention and retrieval efficiency. They speculated that patients with ALS might be exposed to repeated episodes of deoxygenation-reoxygenation during sleep, because of the weakness of the respiratory muscles. In order to evaluate the effect of desaturation on ALS...

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  • The eye of the beholder and risks of eminence based medicine

    In my view the data presented in this study (1) which are interpreted as indicating a high prevalence of functional movement disorders (FMD) in PD might also be interpreted as suggesting that diagnostic delay is common in PD, particularly among women patients who present as "high maintenance" patients. The diagnosis of functional movement disorders is a matter of expert opinion and in my view problems with study design and interpretation support rather than minimize cognitive and confirmation bias in this study.
    Subjects all met UK brain bank criteria for PD. Subjects diagnosed with FND in this study had high rates of family history of PD. They had depression, anxiety, cognitive symptoms, pain, nausea, fatigue all common complaints among the population in general and most particularly in PD. The presence of these symptoms before or after diagnosis of PD is considered by the authors as supportive for a diagnosis of FMD. However, these same symptoms are known to be associated with PD and might be considered supportive of a PD diagnosis.
    Disparities in healthcare for women are well established (2). Neurology has a long history of mistakes distinguishing the "functional" from the "organic" (e.g.3). To choose one example people with blepharospasm, mostly women, were institutionalized long-term as the disease was not recognized as neurologic. Women commonly encounter dismissal in the medical context and this can occasion missed opportuni...

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  • Leg stereotypy syndrome

    We read with great interest the research paper published recently by Lotia et al. entitled “Leg stereotypy syndrome: phenomenology and prevalence”. 1 The study brings important new information about an intriguing newly identified condition, previously designated by the same group as leg stereotypy disorder2, defined as repetitive, rhythmical, stereotypic leg movements, particularly noticeable while sitting.1,2 The authors describe the phenomenology and prevalence of leg stereotypy syndrome (LSS) by evaluating a total of 92 individuals, 57 from the general population (control group) and 35 with different movement disorders (Parkinson´s disease, restless legs syndrome, Tourette´s syndrome, and tardive dyskinesia).1 LSS was found in 7% of the control group and 17% of the movement disorders group, concluding that in terms of prevalence, this is a common condition.1 Another interesting finding was that all but one (83 %) of the patients with LSS from the movement disorders group also had a diagnosis of attention deficit hyperactivity disorder (ADHD).1 Lotia and colleagues do not believe in a relationship between ADHD and LSS1 stating in the discussion that “while certain movements or fidgetiness can be observed in individuals with anxiety or ADHD, the presence of typical stereotyped movements has not been previously described with ADHD”.1 Our group is currently studying the frequency of abnormal involuntary movements in patients with ADHD, compared a control group, and our pre...

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  • Degeneration of the locus coeruleus in premotor Parkinson's disease could predispose to functional neurological disorders

    Wissel and colleagues recently reported on a large retrospective case series of patients with functional neurological disorder (FND) and Parkinson's disease (PD) [1]. The authors only briefly touched upon the question of shared pathophysiology, noting that in principle certain structural brain diseases may predispose to FND. The study was not designed to tease out any shared or causal pathways between FND and PD, but some speculation based on the presented data could help formulate useful hypotheses concerning this interesting comorbidity. I propose that a disruption of the central noradrenergic system due to degeneration of the locus loeruleus (LC), the sole source of noradrenaline in the brain with far-reaching projections, is a good candidate for a causal link between FND and (prodromal) PD.
    In the study by Wissel and colleagues FND antedated the diagnosis of PD in 26% of cases, often by several years [1]. This is significant, because it nearly eliminates the possibility that the comorbidity is entirely a matter of symptom modelling or functional overlay in all cases. Considering the typical neuroanatomical progression of Lewy pathology in PD, this suggests that neurodegenerative effects within the lower brainstem (Braak stage 1 or 2) are likely structural candidates for a causal pathway. Early LC pathology has been associated with other premotor manifestations of Lewy pathology and PD such as REM sleep behaviour disorder and cognitive decline. A study using...

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  • Aiding diagnosis of suspected patients with Parkinson's Disease and functional disorders

    Dear Editor,

    I read the article entitled "Patients with Parkinson disease are prone to functional neurological disorders" by Hallett M published in the Journal of Neurology, Neurosurgery and Psychiatry (Published Online First: 16 March 2018. doi: 10.1136/jnnp-2017-317684). I want to congratulate the author for this successful article, and make some contributions.

    The article particularly mentions certain aspects of the clinical presentation, medical history and examination of patients, which should raise the suspicion of a functional disorder (1). I think it is important to remember patients with functional disorders will not always adhere to these criteria and clinicians should perhaps consider trialling suspected patients on either cognitive behavioural therapy (CBT) or physiotherapy to assess if they experience any improvement with these strategies. There is increasing evidence to show CBT and physiotherapy are beneficial for patients with functional disorders, hence they may be useful in confirming the diagnosis (2)(3).

    Furthermore, the author suggests patients with functional symptoms and no sign of Parkinson's Disease should not be pursued further for a diagnosis of Parkinson's Disease. I think a difficulty is often deciding what classifies as a sign of Parkinson's Disease. The cardinal symptoms of bradykinesia, resting tremor, muscular rigidity and postural instability are commonly subtle within patients, making...

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  • Dosing regimen of oral prednisolone and prognosis in patients with generalized myasthenia gravis

    Imai et al. examined the association between the dosing regimen of oral prednisolone (PSL) and the achievement of minimal manifestation status or better on PSL <=5 mg/day lasting >6 months in patients with generalized myasthenia gravis (1). The authors classified 590 patients into high-dose, intermediate-dose and low-dose (n=166) groups, and logistic regression analysis was applied to know the prognosis of patients in low-dose group, by splitting observational period into 1 to 3 years of treatment. The authors concluded that a low-dose PSL regimen with early combination of other treatment options was significantly associated with good prognosis. I have two concerns about their study.

    First, the dosing regimen of oral PSL should be considered with caution. Namely, the authors set the maximum dose of oral PSL in each group, and standard treatment schedule was selected after each patient was allocated. Mean daily dose of PSL does not become highest in high-dose group in the study, which happens in the study protocol. In addition, there is a possibility of higher frequency in patients with combination of other treatment options, when patients were registered into low-dose group. As the age of onset was higher and disease duration was shorter in patients with low-dose group, randomized allocation should be strictly conducted in further study.

    Second, the number of events was not enough after 1 year observation, and higher odds ratios with wide ranges of con...

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  • No laughing matter

    In their recent article on the pathogenesis of dystonia, Kaji and colleagues argue that aberrant cerebellar inputs can induce dystonic movement mediated by the basal ganglia.[1] In this framework, the sensory trick (geste antagoniste) leads to a realignment between predicted and actual sensory information, thus reduces (or overrides) the sensorimotor mismatch forwarded to the basal ganglia, and in turn alleviates dystonic contractions.
    A similar model of sensorimotor mismatch response has been implicated in the physiology of being tickled[2]. Specifically, it has been proposed that the inability to tickle oneself is related to a sensory attenuation mediated by the cerebellum during self-generated tactile sensation[3]. This attenuation is proportional to the precision of the sensory prediction[4]. Whether the same cerebellar processes are responsible for the alleviation of dystonia during a sensory trick would be an interesting question to explore experimentally. At the risk of straining the analogy, one could even describe the postures and movements one produces when being tickled as dystonic-like. Neurologists are reminded of this when interpreting ambiguous plantar responses in very ticklish patients -- a problem that can be avoided by employing the patient's cerebellar sensory attentuation[5].

    1. Kaji R, Bhatia K, Graybiel AM. Pathogenesis of dystonia: is it of cerebellar or basal ganglia origin? J Neurol Neurosurg Psychiatry. 2017 Oct 31. pii: jnnp-20...

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