Quantitative analysis of MR T2 relaxation times in neck muscles.

T2 relaxation times (T2 times) are different between resting and exercised muscles and between muscles of healthy subjects and subjects with muscle pathology. However, studies specifically focusing on neck muscles are lacking. Furthermore, normative neck muscle T2 times are not well defined and methodology used to analyse T2 times in neck muscles is not robust. We analysed T2 times in key neck muscles and explored factors affecting variability between muscles. 20 healthy subjects were recruited. Two circular regions of interest (ROIs) were drawn in two mutually exclusive regions within neck muscles on T2 weighted images and values averaged. ROI measurements were performed by a co-investigator, supervised by a neuro-radiologist. For the first ten subjects, measurements were done from C1-T1. For the remaining subjects, ROIs were drawn at two pre-determined levels. Two MRIs were repeated at 31 degrees acquisition to evaluate the effect of muscle fibre orientation. ROI values were translated into T2 times. Results showed semispinalis capitis had the longest T2 times (range 46.88-51.42 ms), followed by splenius capitis (range 47.37-48.33 ms), trapezius (range 45.27-47.46 ms), levator scapulae (range 43.17-45.63 ms) and sternocleidomastoid (range 38.45-42.91 ms). T2 times did not vary along length of muscles and were unaffected by muscle fibre orientation (P > 0.05). T2 times of splenius capitis correlated significantly with age at C2/C3 and C5/C6 levels and trapezius at C7/T1 level. Gender did not influence relaxation times (P > 0.05). In conclusion, results of normative neck muscle T2 time values and factors influencing the T2 times could serve as a reference for future MR analysis of neck muscles. The methodology used may also be useful for related studies of neck muscles.

Prevalence and factors associated with advanced care directives in a motor neuron disease multidisciplinary clinic in Australia.

OBJECTIVES: Motor neuron disease (MND) is a neurodegenerative disorder leading to functional decline and death. Multidisciplinary MND clinics provide an integrated approach to management and facilitate discussion on advanced care directives (ACDs). The study objectives are to analyse (1) the prevalence of ACD in our MND clinic, (2) the relationship between ACD and patient demographics and (3) the relationship between ACD decision-making and variables such as NIV, PEG, hospital admissions and location of death. METHODS: Using clinic records, all patients who attended the MND clinic in Liverpool Hospital between November 2014 and November 2019 were analysed. Data include MND subtypes, symptom onset to time of diagnosis, time of diagnosis to death, location and reason of death. ACD prevalence, non-invasive ventilation (NIV) and percutaneous endoscopic gastrostomy (PEG) requirements were analysed. RESULTS: There were 78 patients; M:F=1:1. 44 (56%) patients were limb onset, 28 (36%) bulbar onset, 4 primary lateral sclerosis and 2 flail limb syndrome presentations. 27% patients completed ACDs, while 32% patients declined ACDs. Patients born in Australia or in a majority English-speaking country were more likely to complete ACDs compared to those born in a non-English-speaking country. There was no significant correlation between ACD completion and age, gender, MND subtype, symptom duration, NIV, PEG feeding, location of death. CONCLUSION: One-quarter of patients completed ACDs. ACDs did not correlate with patient age, gender, MND subtype and symptom duration or decision-making regarding NIV, PEG feeding or location of death. Further studies are needed to address factors influencing patients' decisions regarding ACDs.

Pseudochoreoathetosis secondary to progressive spondylotic cervical myelopathy.

Pseudochoreoathetosis is a rare movement disorder associated with loss of proprioception. Culprit lesions may occur at any point between the cerebral cortex and the peripheral nerve. Seldom is the underlying cause reversible or prone to improvement. An elderly man presented to our tertiary centre with choreoathetoid movements secondary to spondylotic subaxial cervical myelopathy. His myelopathy fulminated and he was emergently treated with posterior decompressive neurosurgery. Unexpectedly, his choreoathetoid movements improved significantly post-operatively. There are a multitude of reports of pseudochoreoathetosis secondary to lesions of various aetiologies; however, few have reported this disorder secondary to cervical spondylosis. To our knowledge, there is only one other report in the medical literature. Herein, we report a second case, for the purposes of raising awareness of this disorder, and to highlight relevant clinical pearls for clinicians who encounter this rare pathology.

Clinical characteristics and diagnostic clues to Neurometabolic causes of dystonia.

Neurometabolic causes of dystonia are heterogenous and can be challenging to diagnose, yet many of these disorders are potentially treatable. The first step in the workup is to clinically phenotype the underlying condition, followed by ordering selected diagnostic tests based on the clinician's judgement and clinical suspicion. In this review, we highlight the diagnostic clues to various disorders, including lysosomal storage diseases, mitochondrial cytopathies, metal storage disorders, organic acidurias, disorders in carbohydrate metabolism, neurotransmitter diseases and vitamin and cofactor deficiencies. We discuss key diagnostic clues to the presence of these conditions, as well as currently available treatments. We highlight that recognition and characterization of these secondary causes of dystonia facilitate their management, including possible treatment of the underlying neurometabolic disorder.

Myasthenia gravis and concurrent myositis following PD-L1 checkpoint inhibitor for non-small cell lung cancer.

BACKGROUND: There are increasing reports of myasthenia gravis (MG) following oncological treatment with immune checkpoint inhibitors (ICIs). METHODS AND RESULTS: A 66-year-old man with stage 3A lung adenocarcinoma was treated with second weekly infusions of durvalumab, a programmed cell death ligand-1 inhibitor, at a dose of 10 mg/kg. After the fourth infusion, he developed diplopia, dyspnoea and constitutional symptoms including headache, weakness and anorexia. 1 month later, he developed dysphagia and dysphonia. Examination showed proximal limb weakness with fatigability. An ice pack test was positive. Blood tests revealed a raised creatine kinase and positive PM-Scl75 antibody. Antititin antibody was strongly positive in the serum and cerebrospinal fluid. Antibodies for acetylcholinesterase receptor and antimuscle-specific kinase were negative. Electromyography showed myopathic changes. The patient was treated with steroids, pyridostigmine, mycophenolate mofetil and intravenous immunoglobulin. Eight weeks after treatment initiation ptosis, eye movements and limb strength were markedly improved and repeat creatine kinase was normal. CONCLUSION: Clinicians using ICIs should have a high index of suspicion for ICI-induced MG and concurrent myositis as disease can be severe and is associated with high mortality rates.

Neurological and Sleep Disturbances in Bronchiectasis.

Bronchiectasis unrelated to cystic fibrosis is a chronic lung disease that is increasingly recognised worldwide. While other common chronic lung conditions such as chronic obstructive lung disease have been associated with cardiovascular disease, there is a paucity of data on the relationship between bronchiectasis and cardiovascular risks such as stroke and sleep disturbance. Furthermore, it is unclear whether other neuropsychological aspects are affected, such as cognition, cerebral infection, anxiety and depression. In this review, we aim to highlight neurological and sleep issues in relation to bronchiectasis and their importance to patient care.

Relationship between Sleep Duration and Risk Factors for Stroke.

Stroke is a leading cause of death and disability worldwide. While various risk factors have been identified, sleep has only been considered a risk factor more recently. Various epidemiologic studies have associated stroke with sleep such as sleep duration, and laboratory and clinical studies have proposed various underlying mechanisms. The pathophysiology is multifactorial, especially considering sleep affects many common risk factors for stroke. This review aims to provide an outline of the effect of sleep duration on common stroke risk factors. Appropriate sleep duration, especially in patients who have stroke risk factors, and increasing awareness and screening for sleep quality may contribute to primary prevention of stroke.