Publications
130 results found
Hadi Z, Mahmud M, Seemungal B, 2024, Brain mechanisms explaining postural imbalance in traumatic brain injury: a systematic review, Brain Connectivity, Vol: 14, ISSN: 2158-0022
Persisting imbalance and falls in community-dwelling traumatic brain injury (TBI) survivors are linked to reduced long-term survival. However, a detailed understanding of the impact of TBI upon the brain mechanisms mediating imbalance is lacking. To understand the state of the art concerning the brain mechanisms mediating imbalance in TBI, we performed a systematic review of the literature. PubMed, Web of Science, and Scopus were searched and peer-reviewed research articles in humans, with any severity of TBI (mild, moderate, severe, or concussion), that linked a postural balance assessment (objective or subjective) with brain imaging (via CT, T1-weighted imaging, fMRI, resting-state fMRI, DTI, MRS, SPECT, EEG, MEG, NIRS, and evoked potentials) were included. Out of 1940 articles, 60 were retrieved and screened, and 25 articles fulfilling inclusion criteria were included. The most consistent finding was the link between imbalance and the cerebellum, however, the regions within the cerebellum were inconsistent. The lack of consistent findings could reflect that imbalance in TBI is due to a widespread brain network dysfunction, as opposed to focal cortical damage. The inconsistency in the reported findings may also be attributed to heterogeneity of methodology including data analytical techniques, small sample sizes, and choice of control groups. Future studies should include a detailed clinical phenotyping of vestibular function in TBI patients to account for the confounding effect of peripheral vestibular disorders on imbalance and brain imaging.
Lyons HS, Sassani M, Hyder Y, et al., 2024, A systematic review of optical coherence tomography findings in adults with mild traumatic brain injury, Eye (Basingstoke), ISSN: 0950-222X
Mild traumatic brain injury (mTBI) is common with many patients suffering disabling long-term sequelae, with visual symptoms frequently reported. There are no objective biomarkers of mTBI that are routinely used in clinical practice. Optical coherence tomography (OCT) has been used in mTBI research, as it enables visualisation of the neuroretina, allowing measurement of the retinal nerve fibre layer and ganglion cell layer. This systematic review aims to appraise the available literature and assess whether there are significant changes within the retinal nerve fibre layer and ganglion cell layer in subjects after mTBI. A systematic review was carried out in accordance with PRISMA guidelines and registered with PROSPERO (Number: CRD42022360498). Four databases were searched for relevant literature published from inception until 1 September 2022. Abstracts and full texts were screened by three independent reviewers. Initial screening of databases yielded 341 publications, of these, three fulfilled all the criteria for inclusion. All three studies showed thinning of the retinal nerve fibre layer, whereas there were no significant changes in the ganglion cell layer. This systematic review demonstrated that thinning of the retinal nerve fibre layer (but not of the ganglion cell layer) is associated with mTBI. It provides preliminary evidence for the use of the retinal nerve fibre layer as a potential biomarker of damage to the visual system in mTBI. Further prospective longitudinal studies ensuring uniform diagnosis and accurate phenotyping of mTBI are needed to understand the effects on the visual system and potential of OCT as a prognostic biomarker.
Li Y, Smith R, Whitney S, et al., 2023, We should be screening for benign paroxysmal positional vertigo (BPPV) in all older adults at risk of falling: a commentary on the World Falls Guidelines, Age and Ageing, Vol: 52, ISSN: 0002-0729
Benign paroxysmal positional vertigo (BPPV) is amongst the commonest causes of dizziness and falls in older adults. Diagnosing and treating BPPV can reduce falls, and thereby reduce fall-related morbidity and mortality. Recent World Falls Guidelines recommend formal assessment for BPPV in older adults at risk of falling, but only if they report vertigo/dizziness. However, this recommendation ignores the data that (i) many older adults with BPPV experience dizziness as vague unsteadiness (rather than vertigo), and (ii) others may experience no symptoms of dizziness at all. BPPV sans vertigo is due to an impaired vestibular perception of self-motion or ‘vestibular agnosia’. Vestibular agnosia is found in ageing, neurodegeneration and traumatic brain injury, and results in dramatically increased missed BPPV diagnoses. Patients with BPPV sans vertigo are typically the most vulnerable for negative outcomes associated with this disorder. We thus recommend simplifying the World Falls Guidelines: All older adults (>60 years) with objective or subjective balance problems, irrespective of symptomatic complaint, should have positional testing to examine for BPPV.
Ciocca M, Seemungal BM, Tai YF, 2023, Spinal Cord Stimulation for Gait Disorders in Parkinson's Disease and Atypical Parkinsonism: A Systematic Review of Preclinical and Clinical Data, NEUROMODULATION, Vol: 26, Pages: 1339-1361, ISSN: 1094-7159
Murdin L, Seemungal BM, Bronstein AM, 2023, Assessment of dizziness in neurology, Medicine (United Kingdom), Vol: 51, Pages: 540-544, ISSN: 1357-3039
Dizziness and vertigo are common symptoms. In acute vertigo, expert clinical assessment is critically important in discerning stroke from non-stroke causes because the results of stroke-protocol brain magnetic resonance imaging, including diffusion-weighted imaging, can be falsely negative in the first 24 hours. It follows that acute medical services must have access to clinicians expert in assessing acute vertigo. Expertise in clinical examination and interpretation of the findings requires appropriate training, but here we outline the basic diagnostic and therapeutic approach to patients with dizziness. Appropriate early management of these conditions is part of the prevention of disabling chronic functional dizziness conditions. Furthermore, the availability of effective treatments for other vestibular disorders means it is always important to make an accurate diagnosis.
Davies HJ, Williams I, Hammour G, et al., 2023, In-ear SpO2 for classification of cognitive workload, IEEE Transactions on Cognitive and Developmental Systems, Vol: 15, Pages: 950-958, ISSN: 2379-8920
The brain is the most metabolically active organ in the body, which increases its metabolic activity, and thus oxygen consumption, with increasing cognitive demand. This motivates us to question whether increased cognitive workload may be measurable through changes in blood oxygen saturation. To this end, we explore the feasibility of cognitive workload tracking based on in-ear SpO2 measurements, which are known to be both robust and exhibit minimal delay. We consider cognitive workload assessment based on an N-back task with randomised order. It is shown that the 2-back and 3-back tasks (high cognitive workload) yield either the lowest median absolute SpO2 or largest median decrease in SpO2 in all of the subjects, indicating a measurable and statistically significant decrease in blood oxygen in response to increased cognitive workload. This makes it possible to classify the four N-back task categories, over 5 second epochs, with a mean accuracy of 90.6%, using features derived from in-ear pulse oximetry, including SpO2, pulse rate and respiration rate. These findings suggest that in-ear SpO2 measurements provide sufficient information for the reliable classification of cognitive workload over short time windows, which promises a new avenue for real time cognitive workload tracking.
Smith R, Burgess C, Vassilios T, et al., 2023, Why are patients with acute traumatic brain injury not routinely assessed or treated for vestibular dysfunction in the UK? A qualitative study, BMJ Open, Vol: 13, ISSN: 2044-6055
Objectives: Vestibular dysfunction is common in patients with acute traumatic brain injury (aTBI). Persisting vestibular symptoms (ie, dizziness and imbalance) are linked to poor physical, psychological and socioeconomic outcomes. However, routine management of vestibular dysfunction in aTBI is not always standard practice. We aimed to identify and explore any healthcare professional barriers or facilitators to managing vestibular dysfunction in aTBI.Design: A qualitative approach was used. Data were collected using face to face, semi-structured interviews and analysed using the Framework approach.Setting: Two major trauma centres in London, UK.Participants: 28 healthcare professionals participated: 11 occupational therapists, 8 physiotherapists and 9 surgical/trauma doctors.Results: Vestibular assessment and treatment were not routinely undertaken by trauma ward staff. Uncertainty regarding responsibility for vestibular management on the trauma ward was perceived to lead to gaps in patient care. Interestingly, the term dizziness was sometimes perceived as an ‘invisible’ and vague phenomenon, leading to difficulties identifying or ‘proving’ dizziness and a tendency for making non-specific diagnoses. Barriers to routine assessment and treatment included limited knowledge and skills, a lack of local or national guidelines, insufficient training and concerns regarding the practical aspects of managing vestibular dysfunction. Of current trauma ward staff, therapists were identified as appropriate healthcare professionals to adopt new behaviours regarding management of a common form of vestibular dysfunction (benign paroxysmal positional vertigo). Strategies to support this behaviour change include heightened clarity around role, implementation of local or national guidelines, improved access to training and multidisciplinary support from experts in vestibular dysfunction.Conclusions: This study has highlighted that role and knowledge barriers exi
Rajesh S, Wonderling D, Bernstein I, et al., 2023, Head injury: assessment and early management—summary of updated NICE guidance, BMJ: British Medical Journal, Vol: 381, ISSN: 0959-535X
What you need to knowConsider an intravenous tranexamic acid bolus within 2 hours of injury in people with suspected moderate or severe traumatic brain injury, even when no extracranial bleeding is evidentShared decision making can inform a decision not to conduct a computed tomography head scan in people taking anticoagulant or antiplatelet medication if there are no signs or symptoms of traumatic brain injuryAny severity of head injury can cause symptoms of pituitary dysfunction. Consider investigations or referral for hypopituitarism in those with persistent symptoms consistent with hypopituitarismConsider referring people who have persisting symptoms following a head injury to appropriate clinicians or a multidisciplinary team
Hadi Z, Mahmud M, Pondeca Y, et al., 2022, The human brain networks mediating the vestibular sensation of self-motion, Journal of the Neurological Sciences, Vol: 443, Pages: 1-11, ISSN: 0022-510X
Vestibular Agnosia - where peripheral vestibular activation triggers the usual reflex nystagmus response but with attenuated or no self-motion perception - is found in brain disease with disrupted cortical network functioning, e.g. traumatic brain injury (TBI) or neurodegeneration (Parkinson's Disease). Patients with acute focal hemispheric lesions (e.g. stroke) do not manifest vestibular agnosia. Thus, brain network mapping techniques, e.g. resting state functional MRI (rsfMRI), are needed to interrogate functional brain networks mediating vestibular agnosia. Hence, we prospectively recruited 39 acute TBI patients with preserved peripheral vestibular function and obtained self-motion perceptual thresholds during passive yaw rotations in the dark and additionally acquired whole-brain rsfMRI in the acute phase. Following quality-control checks, 26 patient scans were analyzed. Using self-motion perceptual thresholds from a matched healthy control group, 11 acute TBI patients were classified as having vestibular agnosia versus 15 with normal self-motion perception thresholds. Using independent component analysis on the rsfMRI data, we found altered functional connectivity in bilateral lingual gyrus and temporo-occipital fusiform cortex in the vestibular agnosia patients. Moreover, regions of interest analyses showed both inter-hemispheric and intra-hemispheric network disruption in vestibular agnosia. In conclusion, our results show that vestibular agnosia is mediated by bilateral anterior and posterior network dysfunction and reveal the distributed brain mechanisms mediating vestibular self-motion perception.
Mahmud M, Saad AR, Hadi Z, et al., 2022, Prevalence of stroke in acute vertigo presentations: A UK tertiary stroke centre perspective, Journal of the Neurological Sciences, Vol: 442, Pages: 1-7, ISSN: 0022-510X
Mahmud M, Hadi Z, Prendergast M, et al., 2022, The effect of galvanic vestibular stimulation on postural balance in Parkinson's disease: a systematic review and meta-analysis, Journal of the Neurological Sciences, Vol: 442, Pages: 1-10, ISSN: 0022-510X
People with Parkinson's disease (PD) develop postural imbalance and falls. Galvanic Vestibular Stimulation (GVS) may potentially improve postural balance in humans and hence reduce falls in PD. This systematic review and meta-analysis investigate the effects of GVS on postural balance in PD.Six separate databases and research registers were searched for cross-over design trials that evaluated the effects of GVS on postural balance in PD. We used standardized mean difference (Hedges' g) as a measure of effect size in all studies.We screened 223 studies, evaluated 14, of which five qualified for the meta-analysis. Among n = 40 patients in five studies (range n = 5 to 13), using a fixed effects model we found an effect size estimate of g = 0.43 (p < 0.001, 95% CI [0.29,0.57]). However, the test for residual heterogeneity was significant (p < 0.001), thus we used a random effects model and found a pooled effect size estimate of 0.62 (p > 0.05, 95% CI [− 0.17, 1.41], I2 = 96.21%). Egger's test was not significant and thus trim and funnel plot indicated no bias. To reduce heterogeneity, we performed sensitivity analysis and by removing one outlier study (n = 7 patients), we found an effect size estimate of 0.16 (p < 0.05, 95% CI [0.01, 0.31], I2 = 0%).Our meta-analysis found GVS has a favourable effect on postural balance in PD patients, but due to limited literature and inconsistent methodologies, this favourable effect must be interpreted with caution.
Rust HM, Smith RM, Mahmud M, et al., 2022, Force-dependency of benign paroxysmal positional vertigo in acute traumatic brain injury: a prospective study, Journal of Neurology, Neurosurgery and Psychiatry, Vol: 93, Pages: 1232-1234, ISSN: 0022-3050
Parkinson M, Curtis F, Dani M, et al., 2022, MTBI PREDICT: A PROSPECTIVE BIOMARKER STUDY TO PREDICT OUTCOMES IN MILD TRAUMATIC BRAIN INJURY, Association-of-British-Neurologists (ABN) Annual Meeting, Publisher: BMJ PUBLISHING GROUP, ISSN: 0022-3050
Mahmud M, Hadi Z, Prendergast M, et al., 2022, The effect of galvanic vestibular stimulation on postural balance in Parkinson’s Disease: A systematic review and meta-analysis, Publisher: Cold Spring Harbor Laboratory
People with Parkinson’s disease (PD) experience postural imbalance, leading to considerably increased risk of falls. Galvanic Vestibular Stimulation (GVS) is postulated to modulate postural balance in humans and improve it in PD. This systematic review and meta-analysis investigate the effects of GVS on postural balance in PD. Six separate databases and research registers were searched for cross-over design trials that evaluated the effects of GVS on postural balance in PD. We used standardized mean difference (Hedges’ g) as a measure of effect size in all studies. We screened 223 studies, evaluated 14, of which five qualified for the meta-analysis. Among n = 40 patients in five studies (range n= 5 to 13), using a fixed effects model we found an effect size estimate of g = 0.43 (p < 0.001, 95% CI [0.29,0.57]). However, the test for residual heterogeneity was significant (p < 0.001), thus we used a random effects model and found a pooled effect size estimate of 0.62 (p > 0.05, 95% CI [– 0.17, 1.41], I2 = 96.21%). Egger’s test was not significant and thus trim and funnel plot indicated no bias. To reduce heterogeneity, we performed sensitivity analysis and by removing one outlier study (n = 7 patients), we found an effect size estimate of 0.16 (p < 0.05, 95% CI [0.01, 0.31], I2 = 0%). Our meta-analysis found GVS has a favourable effect on postural balance in PD patients, but due to limited literature and inconsistent methodologies, this favourable effect must be interpreted with caution.
Hadi Z, Pondeca Y, Calzolari E, et al., 2022, The human brain networks mediating the vestibular sensation of self-motion, Publisher: Cold Spring Harbor Laboratory
Vestibular Agnosia - where peripheral vestibular activation triggers the usual reflex nystagmus response but with attenuated or no self-motion perception - is found in brain disease with disrupted cortical network functioning, e.g. traumatic brain injury (TBI) or neurodegeneration (Parkinson’s Disease). Patients with acute focal hemispheric lesions (e.g. stroke) do not manifest vestibular agnosia. Thus brain network mapping techniques, e.g. resting state functional MRI (rsfMRI), are needed to interrogate functional brain networks mediating vestibular agnosia. Whole-brain rsfMRI was acquired from 39 prospectively recruited acute TBI patients with preserved peripheral vestibular function, along with self-motion perceptual thresholds during passive yaw rotations in the dark. Following quality-control checks, 25 patient scans were analyzed. TBI patients were classified as having vestibular agnosia (n = 11) or not (n = 14) via laboratory testing of self-motion perception. Using independent component analysis, we found altered functional connectivity in the right superior longitudinal fasciculus and left rostral prefrontal cortex in vestibular agnosia. Moreover, regions of interest analyses showed both inter-hemispheric and intra-hemispheric network disruption in vestibular agnosia. In conclusion, our results show that vestibular agnosia is mediated by bilateral anterior and posterior network dysfunction and reveal the distributed brain mechanisms mediating vestibular self-motion perception.
Lempert T, Olesen J, Furman J, et al., 2022, Vestibular migraine: Diagnostic criteria, JOURNAL OF VESTIBULAR RESEARCH-EQUILIBRIUM & ORIENTATION, Vol: 32, Pages: 1-6, ISSN: 0957-4271
Seemungal BM, Agrawal Y, Bisdorff A, et al., 2022, The Bárány Society position on 'Cervical Dizziness', Journal of Vestibular Research: Equilibrium and Orientation: an international journal of experimental and clinical vestibular science, Vol: 32, Pages: 487-499, ISSN: 0957-4271
This paper describes the Bárány Society Classification OverSight Committee (COSC) position on Cervical Dizziness, sometimes referred to as Cervical Vertigo. This involved an initial review by a group of experts across a broad range of fields, and then subsequent review by the Bárány Society COSC. Based upon the so far published literature, the Bárány Society COSC takes the view that the evidence supporting a mechanistic link between an illusory sensation of self-motion (i.e. vertigo – spinning or otherwise) and neck pathology and/or symptoms of neck pain - either by affecting the cervical vertebrae, soft tissue structures or cervical nerve roots - is lacking. When a combined head and neck movement triggers an illusory sensation of spinning, there is either an underlying common vestibular condition such as migraine or BPPV or less commonly a central vestibular condition including, when acute in onset, dangerous conditions (e.g. a dissection of the vertebral artery with posterior circulation stroke and, exceedingly rarely, a vertebral artery compression syndrome). The Committee notes, that migraine, including vestibular migraine, is by far, the commonest cause for the combination of neck pain and vestibular symptoms. The committee also notes that since head movement aggravates symptoms in almost any vestibular condition, the common finding of increased neck muscle tension in vestibular patients, may be linked as both cause and effect, to reduced head movements. Additionally, there are theoretical mechanisms, which have not been explored, whereby cervical pain may promote vaso-vagal, cardio-inhibitory reflexes and hence by presyncopal mechanisms, elicit transient disorientation and/or imbalance. The committee accepts that further research is required to answer the question as to whether those rare cases in which neck muscle spasm is associated with a vague sense of spatial disorientation and/or imbalance, is indeed li
Sahu B, Smith R, Burgess C, et al., 2021, Qualitative study exploring clinicians' experience of participating in a feasibility trial investigating benign paroxysmal positional vertigo in traumatic brain injury, 25th World Congress of Neurology (WCN), Publisher: ELSEVIER, ISSN: 0022-510X
Smith R, Burgess C, Marsden J, et al., 2021, Benign paroxysmal positional vertigo in acute traumatic brain injury patients - data from a multi-centre prospective randomised feasibility study, 25th World Congress of Neurology (WCN), Publisher: ELSEVIER, ISSN: 0022-510X
Hadi Z, Pondeca YJ, Calzolari E, et al., 2021, Vestibular Agnosia Linked to Widespread Abnormality of Functional Brain Networks, BNA 2021, Publisher: SAGE Publications, ISSN: 2398-2128
Mahmud M, Prendergast M, Hadi Z, et al., 2021, Modulating Balance with Galvanic Vestibular Stimulation in Traumatic Brain Injury Patients, EUROPEAN JOURNAL OF NEUROLOGY, Publisher: WILEY, Pages: 146-146, ISSN: 1351-5101
Calzolari E, Chepisheva M, Smith RM, et al., 2021, Vestibular agnosia in traumatic brain injury and its link to imbalance., Brain, Vol: 144, Pages: 128-143
Vestibular dysfunction, causing dizziness and imbalance, is a common yet poorly understood feature in patients with TBI. Damage to the inner ear, nerve, brainstem, cerebellum and cerebral hemispheres may all affect vestibular functioning, hence, a multi-level assessment-from reflex to perception-is required. In a previous report, postural instability was the commonest neurological feature in ambulating acute patients with TBI. During ward assessment, we also frequently observe a loss of vertigo sensation in patients with acute TBI, common inner ear conditions and a related vigorous vestibular-ocular reflex nystagmus, suggesting a 'vestibular agnosia'. Patients with vestibular agnosia were also more unbalanced; however, the link between vestibular agnosia and imbalance was confounded by the presence of inner ear conditions. We investigated the brain mechanisms of imbalance in acute TBI, its link with vestibular agnosia, and potential clinical impact, by prospective laboratory assessment of vestibular function, from reflex to perception, in patients with preserved peripheral vestibular function. Assessment included: vestibular reflex function, vestibular perception by participants' report of their passive yaw rotations in the dark, objective balance via posturography, subjective symptoms via questionnaires, and structural neuroimaging. We prospectively screened 918 acute admissions, assessed 146 and recruited 37. Compared to 37 matched controls, patients showed elevated vestibular-perceptual thresholds (patients 12.92°/s versus 3.87°/s) but normal vestibular-ocular reflex thresholds (patients 2.52°/s versus 1.78°/s). Patients with elevated vestibular-perceptual thresholds [3 standard deviations (SD) above controls' average], were designated as having vestibular agnosia, and displayed worse posturography than non-vestibular-agnosia patients, despite no difference in vestibular symptom scores. Only in patients with impaired postural control (3 SD above c
Smith R, Marroney N, Beattie J, et al., 2020, A mixed methods randomised feasibility trial investigating the management of benign paroxysmal positional vertigo in acute traumatic brain injury, Pilot and Feasibility Studies, Vol: 6, Pages: 1-10, ISSN: 2055-5784
BackgroundTraumatic brain injury (TBI) is the leading cause of long-term disability in working age adults. Recent studies show that most acute TBI patients demonstrate vestibular features of dizziness and imbalance, often from combined peripheral and central vestibular dysfunction. Effective treatment for vestibular impairments post-TBI is important given its significant adverse impact upon quality of life and employment prospects. The most frequent peripheral vestibular disorder in acute TBI is benign paroxysmal positional vertigo (BPPV), affecting approximately half of acute cases. Although there is effective treatment for idiopathic BPPV, there are no high quality clinical data for post-TBI BPPV regarding its prevalence, natural history, which treatment is most effective and when is the best time to treat. In particular, observational studies suggest post-TBI BPPV may be recurrent indicating that hyperacute treatment of BPPV may be futile. Given the potential hurdles and the lack of accurate post-TBI BPPV data, the current study was designed to provide information regarding the feasibility and the optimal design of future large-scale prospective treatment studies that would compare different interventions and their timing for post-TBI BPPV. MethodA multi-centre randomised mixed methods feasibility study design was employed. We aim to recruit approximately 75 acute TBI patients across a range of clinical severities, from three major trauma centres in London. Patients will be randomised to one of three treatment arms: (1) therapist-led manoeuvres; (2) patient-led exercises; and (3) advice. Participants will be re-assessed by blinded outcome assessors at 4 and 12 weeks. Acceptability of the intervention will be obtained by patient interviews at the end of their treatment, and therapist interviews at the end of the study. Primary outcomes relate to feasibility parameters including recruitment and retention rates, adverse events, and intervention fidelity. We will al
Shaikh AG, Bronstein A, Carmona S, et al., 2020, Consensus on virtual management of vestibular disorders: urgent versus expedited care, The Cerebellum: an international journal from neurosciences to clinical perspectives, Pages: 1-5, ISSN: 1473-4222
The virtual practice has made major advances in the way that we care for patients in the modern era. The culture of virtual practice, consulting, and telemedicine, which had started several years ago, took an accelerated leap as humankind was challenged by the novel coronavirus pandemic (COVID19). The social distancing measures and lockdowns imposed in many countries left medical care providers with limited options in evaluating ambulatory patients, pushing the rapid transition to assessments via virtual platforms. In this novel arena of medical practice, which may form new norms beyond the current pandemic crisis, we found it critical to define guidelines on the recommended practice in neurotology, including remote methods in examining the vestibular and eye movement function. The proposed remote examination methods aim to reliably diagnose acute and subacute diseases of the inner-ear, brainstem, and the cerebellum. A key aim was to triage patients into those requiring urgent emergency room assessment versus non-urgent but expedited outpatient management. Physicians who had expertise in managing patients with vestibular disorders were invited to participate in the taskforce. The focus was on two topics: (1) an adequate eye movement and vestibular examination strategy using virtual platforms and (2) a decision pathway providing guidance about which patient should seek urgent medical care and which patient should have non-urgent but expedited outpatient management.
Murdin L, Seemungal BM, Bronstein AM, 2020, Assessment of dizziness in neurology, Medicine, ISSN: 1357-3039
Dizziness and vertigo are common symptoms. Because there are effective treatments for vestibular disorders, it is always important to make an accurate diagnosis. In acute vertigo, expert clinical assessment is critically important in discerning stroke from non-stroke causes because results of stroke-protocol brain magnetic resonance imaging, including diffusion-weighted imaging, can be falsely negative in the first 24 hours. It follows that acute medical services must have access to clinicians expert in assessing acute vertigo. Expertise in clinical examination and interpretation of findings requires appropriate training, but here we outline the basic diagnostic and therapeutic approach to patients with dizziness. Appropriate early management of these conditions is part of prevention of disabling chronic functional dizziness.
Harris L, Hateley S, Tsang KT, et al., 2020, Impact of anti-epileptic drug choice on discharge in acute traumatic brain injury patients, Journal of Neurology, Vol: 267, Pages: 1774-1779, ISSN: 0340-5354
BackgroundAnti-epileptic drug (AED) prophylaxis in the first-seven days post-traumatic brain injury (TBI) is known to reduce seizure frequency acutely. AED efficacy is equivalent; therefore, choice of AED may rest with their side-effects. We hypothesise that AEDs that impair balance will prolong recovery, shown by a longer hospital stay. We compared length of hospital stay (and reported dizziness) in TBI patients receiving the commonest AEDs used in our TBI patients, Phenytoin (which may cause imbalance), and Levetiracetam (which does not affect balance).MethodA retrospective observational study was performed on TBI patients admitted to a Major Trauma Unit between October 2013 and June 2018. 100 of 278 patients treated with phenytoin or levetiracetam monotherapy for seizure prophylaxis were included. The inclusion criteria of admission Glasgow Coma Score of 14 or more and length of stay less than 3 weeks minimised confounding variables such as non-ambulant patients. Length of hospital stay and incidence of dizziness were assessed.ResultsThe length of hospital stay was longer for patients on Phenytoin versus Levetiracetam, i.e., 10.74 vs. 7.58 days (p = 0.015; unpaired, two-sided t test). Dizziness reported by patients on phenytoin was 24% and levetiracetam was 8% (p = 0.018; Chi-squared test).ConclusionIn this cohort, using Phenytoin for acute TBI, seizure prophylaxis was associated with longer length of stay and more dizziness compared to Levetiracetam. Given their equivalent AED efficacy in acute TBI seizure prophylaxis, our data suggest that Levetiracetam is preferable to Phenytoin for early seizure prophylaxis in TBI. This requires evaluation in larger, prospective studies.
Lempert T, Seemungal BM, 2020, How to define migraine with brainstem aura?, Brain, ISSN: 1460-2156
Marcus HJ, Paine H, Sargeant M, et al., 2019, Vestibular dysfunction in acute traumatic brain injury, Journal of Neurology, Vol: 266, Pages: 2430-2433, ISSN: 0340-5354
Traumatic brain injury (TBI) is the commonest cause of disability in under-40-year-olds. Vestibular features of dizziness (illusory self-motion) or imbalance which affects 50% of TBI patients at 5 years, increases unemployment threefold in TBI survivors. Unfortunately, vestibular diagnoses are cryptogenic in 25% of chronic TBI cases, impeding therapy. We hypothesized that chronic adaptive brain mechanisms uncouple vestibular symptoms from signs. This predicts a masking of vestibular diagnoses chronically but not acutely. Hence, defining the spectrum of vestibular diagnoses in acute TBI should clarify vestibular diagnoses in chronic TBI. There are, however, no relevant acute TBI data. Of 111 Major Trauma Ward adult admissions screened (median 38-years-old), 96 patients (87%) had subjective dizziness (illusory self-motion) and/or objective imbalance were referred to the senior author (BMS). Symptoms included: feeling unbalanced (58%), headache (50%) and dizziness (40%). In the 47 cases assessed by BMS, gait ataxia was the commonest sign (62%) with half of these cases denying imbalance when asked. Diagnoses included BPPV (38%), acute peripheral unilateral vestibular loss (19%), and migraine phenotype headache (34%), another potential source of vestibular symptoms. In acute TBI, vestibular signs are common, with gait ataxia being the most frequent one. However, patients underreport symptoms. The uncoupling of symptoms from signs likely arises from TBI affecting perceptual mechanisms. Hence, the cryptogenic nature of vestibular symptoms in TBI (acute or chronic) relates to a complex interaction between injury (to peripheral and central vestibular structures and perceptual mechanisms) and brain-adaptation, emphasizing the need for acute prospective, mechanistic studies.
Connor TA, Clark JM, Jayamohan J, et al., 2019, Do equestrian helmets prevent concussion? A retrospective analysis of head injuries and helmet damage from real-world equestrian accidents, Sports Medicine - Open, Vol: 5, Pages: 19-19, ISSN: 2198-9761
OBJECTIVES: To collect and analyse helmets from real-world equestrian accidents. To record reported head injuries associated with those accidents. To compare damage to helmets certified to different standards and the injuries associated with them. METHODS: Two hundred sixteen equestrian helmets were collected in total. One hundred seventy-six helmets from amateur jockeys were collected via accident helmet return schemes in the UK and USA, while 40 helmets from professional jockeys were collected by The Irish Turf Club. All helmet damage was measured, and associated head injury was recorded. RESULTS: Eighty-eight percent (189) of equestrian fall accidents returned an injury report of which 70% (139) reported a head injury. Fifty-four percent (75) of head injury cases had associated helmet damage while 46% had no helmet damage. Reported head injuries consisted of 91% (126) concussion, 4% (6) skull fractures, 1 (0.7%) subdural hematoma, 1 (0.7%) cerebral edema and 5 (3.6%) diffuse axonal injury (DAI). It is also shown that helmets certified to the most severe standard are overrepresented in this undamaged group (p <0.001). CONCLUSIONS: It is clear that despite jockeys wearing a helmet, large proportions of concussion injuries still occur in the event of a jockey sustaining a fall. However, the data suggest it is likely that helmets reduce the severity of head injury as the occurrence of skull fracture is low. The proportion of undamaged helmets with an associated head injury suggests that many helmets may be too stiff relative to the surface they are impacting to reduce the risk of traumatic brain injury (TBI). It may be possible to improve helmet designs and certification tests to reduce the risk of head injury in low-severity impacts.
Bronstein A, Bednarczuk N, Bonsu A, et al., 2019, Abnormal visuo-vestibular interactions in vestibular migraine: a cross sectional study, BRAIN, Vol: 142, Pages: 606-616, ISSN: 1460-2156
Vestibular migraine is among the commonest causes of episodic vertigo. Chronically, patients with vestibular migraine develop abnormal responsiveness to both vestibular and visual stimuli characterized by heightened self-motion sensitivity and visually-induced dizziness. Yet, the neural mechanisms mediating such symptoms remain unknown. We postulate that such symptoms are attributable to impaired visuo-vestibular cortical interactions, which in turn disrupts normal vestibular function. To assess this, we investigated whether prolonged, full-field visual motion exposure, which has been previously shown to modulate visual cortical excitability in both healthy individuals and avestibular patients, could disrupt vestibular ocular reflex and vestibular-perceptual thresholds of self-motion during rotations. Our findings reveal that vestibular migraine patients exhibited abnormally elevated reflexive and perceptual vestibular thresholds at baseline. Following visual motion exposure, both reflex and perceptual thresholds were significantly further increased in vestibular migraine patients relative to healthy controls, migraineurs without vestibular symptoms and patients with episodic vertigo due to a peripheral inner-ear disorder. Our results provide support for the notion of altered visuo-vestibular cortical interactions in vestibular migraine, as evidenced by vestibular threshold elevation following visual motion exposure.
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