Late-onset riboflavin transporter deficiency: a treatable mimic of various motor neuropathy aetiologies.

OBJECTIVE: Riboflavin transporter deficiencies (RTDs), involving SLC52A3 and SLC52A2 genes, have recently been related to Brown-Vialetto-Van Laere (BVVL) syndrome, a hereditary paediatric condition associating motor neuropathy (MN) and deafness. BVVL/RTD has rarely been reported in adult patients, but is probably underdiagnosed due to poor knowledge and lack of awareness of this form of disease among neurologists. In this study, we aimed to investigate the phenotype and prognosis of RTD patients with late-onset MN. METHODS: We retrospectively collected clinical, biological and electrophysiological data from all French RTD patients with MN onset after 10 years of age (n=6) and extracted data from 19 other similar RTD patients from the literature. RESULTS: Adult RTD patients with MN had heterogeneous clinical presentations, potentially mimicking amyotrophic lateral sclerosis or distal hereditary motor neuropathy (56%), multinevritis with cranial nerve involvement (16%), Guillain-Barré syndrome (8%) and mixed motor and sensory neuronopathy syndromes (20%, only in SLC52A2 patients). Deafness was often diagnosed before MN (in 44%), but in some patients, onset began only with MN (16%). The pattern of weakness varied widely, and the classic pontobulbar palsy described in BVVL was not constant. Biochemical tests were often normal. The majority of patients improved under riboflavin supplementation (86%). INTERPRETATION: Whereas late-onset RTD may mimic different acquired or genetic causes of motor neuropathies, it is a diagnosis not to be missed since high-dose riboflavin per oral supplementation is often highly efficient.

A New Evolutionary Algorithm-Based Home Monitoring Device for Parkinson's Dyskinesia.

Parkinson's disease (PD) is a neurodegenerative movement disorder. Although there is no cure, symptomatic treatments are available and can significantly improve quality of life. The motor, or movement, features of PD are caused by reduced production of the neurotransmitter dopamine. Dopamine deficiency is most often treated using dopamine replacement therapy. However, this therapy can itself lead to further motor abnormalities referred to as dyskinesia. Dyskinesia consists of involuntary jerking movements and muscle spasms, which can often be violent. To minimise dyskinesia, it is necessary to accurately titrate the amount of medication given and monitor a patient's movements. In this paper, we describe a new home monitoring device that allows dyskinesia to be measured as a patient goes about their daily activities, providing information that can assist clinicians when making changes to medication regimens. The device uses a predictive model of dyskinesia that was trained by an evolutionary algorithm, and achieves AUC>0.9 when discriminating clinically significant dyskinesia.

Unusual case of bilateral hand weakness.

A 35-year-old man presented with myalgia and bilateral hand weakness, 3 days after the onset of lethargy, fevers and rigours. The hand weakness caused functional impairment including difficulty pressing keys on his mobile phone. On examination, there was mild bilateral hand weakness with normal reflexes. His serum creatine kinase was mildly raised at 503 U/L (24-195), viral PCR throat swab was negative and electromyogram showed subtle myopathic changes in the distal forearm muscles. Nerve conduction studies found no evidence of neuropathy. Forced vital capacity was reduced on admission (1.5 L) but improved within 24 hours (2.3 L). We gave supportive intravenous fluids and his weakness improved within 48 hours. He was discharged and reported that the weakness had fully resolved within weeks. The diagnosis was viral myositis. Distal forearm myositis rarely follows H1N1 influenza in adults but is an important differential for postinfective neurological symptoms.

How to use pen and paper tasks to aid tremor diagnosis in the clinic.

When a patient presents with tremor, it can be useful to perform a few simple pen and paper tests. In this article, we explain how to maximise the value of handwriting and of drawing Archimedes spirals and straight lines as clinical assessments. These tasks take a matter of seconds to complete but provide a wealth of information that supplements the standard physical examination. They aid the diagnosis of a tremor disorder and can contribute to its longitudinal monitoring. Watching the patient's upper limb while they write and draw may reveal abnormalities such as bradykinesia, dystonic posturing and distractibility. The finished script and drawings can then be evaluated for frequency, amplitude, direction and symmetry of oscillatory pen movements and for overall scale of penmanship. Essential, dystonic, functional and parkinsonian tremor each has a characteristic pattern of abnormality on these pen and paper tests.

Neurologists can identify diagnostic linguistic features during routine seizure clinic interactions: results of a one-day teaching intervention.

The diagnostic distinction between epilepsy and psychogenic nonepileptic seizures (PNES) can be challenging. Previous studies have demonstrated that experts in conversation analysis can identify linguistic and interactional features in transcripts and recordings of interviews with patients that reliably distinguish between epilepsy and PNES. In this study, ten senior neurology trainees took part in a one-day intervention workshop about linguistic and interactional differences in the conversation behavior of patients with epilepsy and those with PNES. Participants were familiarized with a 12-item questionnaire designed to capture their conversational observations immediately after talking to a patient with seizures. After the intervention, 55 initial outpatient visits of patients referred to seizure clinics were video and audio recorded. All medical diagnoses were confirmed two years after initial presentation on the basis of a chart review (including MRI and EEG findings) by a fully trained epilepsy expert. Postvisit questionnaires relating to patients confirmed to have epilepsy (n=20) or PNES (n=13) were analyzed. Doctors' mean responses to 6 of the 12 questions about linguistic and interactional observations differed significantly between the groups with epilepsy and PNES. Receiver operating curve analysis showed that a summation scale based on items demonstrating significant between-group differences correctly classified 81.8% of patients as having epilepsy or PNES. This study shows that a brief Conversation Analytic teaching intervention can enable neurologists to identify linguistic and interactional features supporting the differentiation of epilepsy and PNES as they take their patients' history in routine seizure clinic consultations, potentially improving diagnostic accuracy.

A brief conversation analytic communication intervention can change history-taking in the seizure clinic.

Question design during history-taking has clear implications for patients' ability to share their concerns in general and their seizure experiences in particular. Studies have shown that unusually open questions at the start of the consultation enable patients to display interactional and linguistic markers which may help with the otherwise challenging differentiation of epileptic from nonepileptic seizures (NES). In this study, we compared the problem presentation approach taken by trainee neurologists in outpatient encounters with new patients before and after a one-day conversation analytic training intervention in which doctors were taught to adopt an open format of question design and recognize diagnostically relevant linguistic features. We audio/video-recorded clinical encounters between ten doctors, their patients, and accompanying persons; transcribed the interactions; and carried out quantitative and qualitative analyses. We studied 39 encounters before and 55 after the intervention. Following the intervention, doctors were significantly more likely to use nondirective approaches to soliciting patient accounts of their presenting complaints that invited the patient to describe their problems from their own point of view and gave them better opportunity to determine the initial agenda of the encounter. The time to first interruption by the doctor increased (from 52 to 116 s, p<.001). While patients were given more time to describe their seizure experiences, the overall appointment length did not increase significantly (19 vs 21 min, n.s.). These changes gave patients more conversational space to express their concerns and, potentially, to demonstrate the interactional and linguistic features previously found to help differentiate between epilepsy and NES, without impacting the length of the consultations.

Cognitive impairment in Parkinson's disease.

Cognitive impairment is a significant non-motor symptom of Parkinson's disease (PD). Longitudinal cohort studies have demonstrated that approximately 50% of those with PD develop dementia after 10 years, increasing to over 80% after 20 years. Deficits in cognition can be identified at the time of PD diagnosis in some patients and this mild cognitive impairment (PD-MCI) has been studied extensively over the last decade. Although PD-MCI is a risk factor for developing Parkinson's disease dementia there is evidence to suggest that PD-MCI might consist of distinct subtypes with different pathophysiologies and prognoses. The major pathological correlate of Parkinson's disease dementia is Lewy body deposition in the limbic system and neocortex although Alzheimer's related pathology is also an important contributor. Pathological damage causes alteration to neurotransmitter systems within the brain, producing behavioural change. Management of cognitive impairment in PD requires a multidisciplinary approach and accurate communication with patients and relatives is essential.

Myocarditis and diffuse skeletal muscle oedema: new features of neuromyelitis optica spectrum disorder? A case report.

We present a case report of newly diagnosed neuromyelitis optica spectrum disorder (NMOSD) with associated myocarditis and diffuse oedema of the pelvic and anterior compartment thigh muscles on magnetic resonance imaging. Aquaporin 4 antibodies are expressed in skeletal myofibres but involvement of skeletal muscle is rarely reported in NMOSD and myocarditis has not previously been described in this context. This case highlights the need for further research into the involvement of cardiac and skeletal muscle in NMOSD.

Increased Knowledge of Adult-Onset Dystonia Amongst Medical Students via Brief Video Education: A Systematic Review and Cohort Study.

Most doctors have limited knowledge of dystonia, a movement disorder that can affect people of all ages; this contributes to diagnostic delay and poor quality of life. We investigated whether a brief educational intervention could improve knowledge of dystonia amongst medical students. We conducted a systematic review on undergraduate knowledge of dystonia and created an eight-minute video on the condition. We invited medical students at the University of Leeds, UK, to answer 15 multiple choice questions before and immediately after watching the video, and again one month later. Only one previous study specifically assessed medical students' knowledge of dystonia whilst five others tested their knowledge of movement disorders, or neurology generally, with some questions on dystonia. Of the University of Leeds medical students, 87 (100%), 77 (89%) and 40 (46%) completed the baseline, immediate-recall and delayed-recall questionnaires, respectively. The mean score for students who completed all three questionnaires increased from 7.7 (out of 15) to 12.5 on the immediate-recall questionnaire (p < 0.001), and to 10.1 on the delayed-recall questionnaire (p < 0.001). At baseline, 76% of students rated their confidence in recognising dystonia as low. After watching the video, 78% rated their confidence as a high, and none rated it low. A brief video improved their knowledge substantially, with sustained effects. This method could be incorporated into medical curricula to reduce diagnostic delays.

Geste Antagoniste Effects on Motor Performance in Dystonia-A Kinematic Study.

Background: The kinematic effects of gestes have not previously been studied. The mechanism(s) by which these sensory tricks modify dystonic movement is not well understood. Objectives: A kinematic investigation of the geste phenomenon in patients with dystonia. Methods: Twenty-three patients with dystonia associated with a geste were studied. Twenty-nine healthy controls also participated. Fifteen seconds of finger tapping was recorded by electromagnetic sensors, and the task was repeated with geste. Separable motor components were extracted using a custom-written MATLAB script. Performance with and without geste was compared using Wilcoxon signed ranks testing. Results: Speed and fluency of finger tapping is impaired in dystonia. When patients executed their geste, speed of movement (amplitude × frequency) increased (P < 0.0001), and halts decreased (P = 0.007). Conclusions: That gestes improve not only dystonic muscle contraction but also the efficiency of voluntary movement suggests a broad influence at the premotor control stage.

Acute neurological consequences of novel psychoactive substance use: a retrospective review in a large UK hospital.

BACKGROUND: Novel psychoactive substances (NPS) are a growing public health concern. We aimed to identify the acute neurological consequences of NPS. METHOD: We performed a retrospective case-note review of patients who presented to the emergency department after taking NPS. RESULTS: We identified 237 admissions from 190 patients, mostly young men. There were high rates of psychiatric comorbidity (43%), unemployment (39%), homelessness (24%) and incarceration (17%). Most reported use of synthetic cannabinoids (SC; 91%). Some took synthetic cathinones (SCath; 7%) or nitrous oxide (NOS; 2%). SC caused impaired consciousness (61%) and seizures (16%). SCath users presented with psychiatric disturbance or seizures (55%). Most patients were managed conservatively (67%) and a small proportion (14%) were referred to drug or psychology services. CONCLUSIONS: NPS users represent a vulnerable group in society. Certain clinical features may suggest the type of NPS used. Most patients require supportive management and onward referral to drug addiction services is recommended.

Significant cognitive decline in Parkinson's disease exacerbates the reliance on visual feedback during upper limb reaches.

While upper limb reaches are often made in a feed-forward manner, visual feedback during the movement can be used to guide the reaching hand towards a target. In Parkinson's disease (PD), there is evidence that the utilisation of this visual feedback is increased. However, it is unclear if this is due solely to the characteristic slowness of movements in PD providing more opportunity for incorporating visual feedback to modify reach trajectories, or whether it is due to cognitive decline impacting (feed-forward) movement planning ability. To investigate this, we compared reaction times and movement times of reaches to a target in groups of PD patients with normal cognition (PD-NC), mild cognitive impairment (PD-MCI) or dementia (PD-D), to that of controls with normal cognition (CON-NC) or mild cognitive impairment (CON-MCI). Reaches were undertaken with full visual feedback (at a 'natural' and 'fast-as-possible' pace); with reduced visual feedback of the reaching limb to an illuminated target; and without any visual feedback to a remembered target with eyes closed. The PD-D group exhibited slower reaction times than all other groups across conditions, indicative of less efficient movement planning. When reaching to a remembered target with eyes closed, all PD groups exhibited slower movement times relative to their natural pace with full visual feedback. Crucially, this relative slowing was most pronounced for the PD-D group, compared to the PD-MCI and PD-NC groups, suggesting that substantial cognitive decline in PD exacerbates dependence on visual feedback during upper limb reaches.

Objective assessment of bradykinesia in Parkinson's disease using evolutionary algorithms: clinical validation.

BACKGROUND: There is an urgent need for developing objective, effective and convenient measurements to help clinicians accurately identify bradykinesia. The purpose of this study is to evaluate the accuracy of an objective approach assessing bradykinesia in finger tapping (FT) that uses evolutionary algorithms (EAs) and explore whether it can be used to identify early stage Parkinson's disease (PD). METHODS: One hundred and seven PD, 41 essential tremor (ET) patients and 49 normal controls (NC) were recruited. Participants performed a standard FT task with two electromagnetic tracking sensors attached to the thumb and index finger. Readings from the sensors were transmitted to a tablet computer and subsequently analyzed by using EAs. The output from the device (referred to as "PD-Monitor") scaled from - 1 to + 1 (where higher scores indicate greater severity of bradykinesia). Meanwhile, the bradykinesia was rated clinically using the Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) FT item. RESULTS: With an increasing MDS-UPDRS FT score, the PD-Monitor score from the same hand side increased correspondingly. PD-Monitor score correlated well with MDS-UPDRS FT score (right side: r = 0.819, P = 0.000; left side: r = 0.783, P = 0.000). Moreover, PD-Monitor scores in 97 PD patients with MDS-UPDRS FT bradykinesia and each PD subgroup (FT bradykinesia scored from 1 to 3) were all higher than that in NC. Receiver operating characteristic (ROC) curves revealed that PD-Monitor FT scores could detect different severity of bradykinesia with high accuracy (≥89.7%) in the right dominant hand. Furthermore, PD-Monitor scores could discriminate early stage PD from NC, with area under the ROC curve greater than or equal to 0.899. Additionally, ET without bradykinesia could be differentiated from PD by PD-Monitor scores. A positive correlation of PD-Monitor scores with modified Hoehn and Yahr stage was found in the left hand sides. CONCLUSIONS: Our study demonstrated that a simple to use device employing classifiers derived from EAs could not only be used to accurately measure different severity of bradykinesia in PD, but also had the potential to differentiate early stage PD from normality.

Using epigenetic networks for the analysis of movement associated with levodopa therapy for Parkinson's disease.

Levodopa is a drug that is commonly used to treat movement disorders associated with Parkinson's disease. Its dosage requires careful monitoring, since the required amount changes over time, and excess dosage can lead to muscle spasms known as levodopa-induced dyskinesia. In this work, we investigate the potential for using epiNet, a novel artificial gene regulatory network, as a classifier for monitoring accelerometry time series data collected from patients undergoing levodopa therapy. We also consider how dynamical analysis of epiNet classifiers and their transitions between different states can highlight clinically useful information which is not available through more conventional data mining techniques. The results show that epiNet is capable of discriminating between different movement patterns which are indicative of either insufficient or excessive levodopa.