Publications by authors named "Ross Nortley"

Previous research suggests that emotional prosody perception is impaired in neurodegenerative diseases like Alzheimer's disease (AD) and primary progressive aphasia (PPA). However, no previous research has investigated emotional prosody perception in these diseases under non-ideal listening conditions. We recruited 18 patients with AD, and 31 with PPA (nine logopenic (lvPPA); 11 nonfluent/agrammatic (nfvPPA) and 11 semantic (svPPA)), together with 24 healthy age-matched individuals.

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Successful communication in daily life depends on accurate decoding of speech signals that are acoustically degraded by challenging listening conditions. This process presents the brain with a demanding computational task that is vulnerable to neurodegenerative pathologies. However, despite recent intense interest in the link between hearing impairment and dementia, comprehension of acoustically degraded speech in these diseases has been little studied.

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Background: Neurological COVID-19 disease has been reported widely, but published studies often lack information on neurological outcomes and prognostic risk factors. We aimed to describe the spectrum of neurological disease in hospitalised COVID-19 patients; characterise clinical outcomes; and investigate factors associated with a poor outcome.

Methods: We conducted an individual patient data (IPD) meta-analysis of hospitalised patients with neurological COVID-19 disease, using standard case definitions.

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Article Synopsis
  • This study investigated the potential link between COVID-19 and Guillain-Barré syndrome (GBS) by analyzing GBS cases in the UK before and during the COVID-19 pandemic.
  • The researchers found that GBS incidence decreased during the pandemic and did not show a correlation with COVID-19 infection rates across different regions.
  • Although some GBS cases were associated with COVID-19, there were no significant differences in clinical features between COVID-19 positive and negative cases, suggesting no strong evidence linking the virus as a cause of GBS.
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Therapies targeting late events in Alzheimer's disease (AD), including aggregation of amyloid beta (Aβ) and hyperphosphorylated tau, have largely failed, probably because they are given after significant neuronal damage has occurred. Biomarkers suggest that the earliest event in AD is a decrease of cerebral blood flow (CBF). This is caused by constriction of capillaries by contractile pericytes, probably evoked by oligomeric Aβ.

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Article Synopsis
  • * In a study of 43 patients, most were confirmed or probable COVID-19 cases, revealing five main categories of neurological disorders: encephalopathies, inflammatory central nervous system syndromes, ischemic strokes, peripheral neurological disorders, and other central disorders.
  • * Treatment outcomes varied, with many patients showing full or partial recovery, particularly those with encephalopathy and inflammatory CNS syndromes, while some experienced severe conditions like stroke or Guillain-Barré syndrome.
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Cerebral blood flow is reduced early in the onset of Alzheimer's disease (AD). Because most of the vascular resistance within the brain is in capillaries, this could reflect dysfunction of contractile pericytes on capillary walls. We used live and rapidly fixed biopsied human tissue to establish disease relevance, and rodent experiments to define mechanism.

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Many central nervous system diseases currently lack effective treatment and are often associated with defects in microvascular function, including a failure to match the energy supplied by the blood to the energy used on neuronal computation, or a breakdown of the blood-brain barrier. Pericytes, an under-studied cell type located on capillaries, are of crucial importance in regulating diverse microvascular functions, such as angiogenesis, the blood-brain barrier, capillary blood flow and the movement of immune cells into the brain. They also form part of the "glial" scar isolating damaged parts of the CNS, and may have stem cell-like properties.

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Astrocytes form an anatomical bridge between the vasculature and neuronal synapses. Recent work suggests that they play a key role in regulating brain energy supply by increasing blood flow to regions where neurons are active, and setting the baseline level of blood flow. Controversy persists over whether lactate derived from astrocyte glycolysis is used to power oxidative phosphorylation in neurons, but astrocytes sustain neuronal ATP production by recycling neurotransmitter glutamate that would otherwise need to be resynthesised from glucose, and by providing a short-term energy store in the form of glycogen that can be mobilised when neurons are active.

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We describe two women presenting with severe postpartum headache associated with hypertension but with no other signs or investigation results to suggest pre-eclampsia. In one case, the headache was associated with atypical subarachnoid haemorrhage. The variable nature of the headache and the degree of associated hypertension raised the clinical suspicion of reversible cerebral vasoconstriction syndrome, confirmed on MR angiography.

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A 54-year-old woman diagnosed with primary Sjögren's syndrome in 2007 presented with a 1-year history of visual hallucinations requiring admission to a psychiatric unit. The hallucinations resolved while on olanzapine and hydroxychloroquine but recurred when they were stopped. Despite restarting olanzapine, her visual hallucinations persisted.

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