Publications – dr paresh malhotra brain anoxia

Rinne P, hassan M, fernandes C,

Han E, hennessy E, waldman A, sharma P, soto D, leech R, malhotra PA, bentley P et al., 2018, motor dexterity and strength depend upon integrity of the attention-control system., proc natl acad sci U S A, vol: 115, pages: E536-E545

Attention control (or executive control) is a higher cognitive function involved in response selection and inhibition, through close interactions with the motor system. Here, we tested whether influences of attention control are also seen on lower level motor functions of dexterity and strength-by examining relationships between attention control and motor performance in healthy-aged and hemiparetic-stroke subjects (n = 93 and 167, respectively).Brain anoxia


subjects undertook simple-tracking, precision-hold, and maximum force-generation tasks, with each hand. Performance across all tasks correlated strongly with attention control (measured as distractor resistance), independently of factors such as baseline performance, hand use, lesion size, mood, fatigue, or whether distraction was tested during motor or nonmotor cognitive tasks. Critically, asymmetric dissociations occurred in all tasks, in that severe motor impairment coexisted with normal (or impaired) attention control whereas normal motor performance was never associated with impaired attention control (below a task-dependent threshold). This implies that dexterity and force generation require intact attention control.Brain anoxia subsequently, we examined how motor and attention-control performance mapped to lesion location and cerebral functional connectivity. One component of motor performance (common to both arms), as well as attention control, correlated with the anatomical and functional integrity of a cingulo-opercular salience network. Independently of this, motor performance difference between arms correlated negatively with the integrity of the primary sensorimotor network and corticospinal tract. These results suggest that the salience network, and its attention-control function, are necessary for virtually all volitional motor acts while its damage contributes significantly to the cardinal motor deficits of stroke.Brain anoxia

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Carswell CJ, win Z, muckle K,

Kennedy A, waldman A, dawe G, barwick TD, khan S, malhotra PA, perry RJ et al., 2017, clinical utility of amyloid PET imaging with (18)F-florbetapir: a retrospective study of 100 patients., J neurol neurosurg psychiatry

BACKGROUND AND OBJECTIVE: amyloid-positron emission tomography (PET) imaging (API) detects amyloid-beta pathology early in the course of alzheimer’s disease (AD) with high sensitivity and specificity. (18)F-florbetapir (amyvid) is an amyloid-binding PET ligand with a half-life suitable for clinical use outside of the research setting. How API affects patient investigation and management in the ‘real-world’ arena is unknown.Brain anoxia to address this, we retrospectively documented the effect of API in patients in the memory clinic. METHODS: we reviewed the presenting clinical features, the pre-API and post-API investigations, diagnosis and outcomes for the first 100 patients who had API as part of their routine work-up at the imperial memory centre, a tertiary referral clinic in the UK national health service. RESULTS: API was primarily used to investigate patients with atypical clinical features (56 cases) or those that were young at onset (42 cases). MRI features of AD did not always predict positive API (67%), and 6 of 23 patients with mris reported as normal were amyloid-PET positive. There were significantly more cases categorised as non-AD dementia post-API (from 11 to 23).Brain anoxia patients investigated when API was initially available had fewer overall investigations and all patients had significantly fewer investigations in total post-API. CONCLUSIONS: API has a clear impact on the investigation of young-onset or complex dementia while reducing the overall burden of investigations. It was most useful in younger patients, atypical presentations or individuals with multiple possible causes of cognitive impairment.

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Li K, malhotra PA, 2015, spatial neglect., pract neurol, vol: 15, pages: 333-339

The syndrome of visuospatial neglect is a common consequence of unilateral brain injury. It is most often associated with stroke and is more severe and persistent following right hemisphere damage, with reported frequencies in the acute stage of up to 80%.Brain anoxia neglect is primarily a disorder of attention whereby patients characteristically fail to orientate, to report or to respond to stimuli located on the contralesional side. Neglect is usually caused by large strokes in the middle cerebral artery territory and is heterogeneous, such that most patients do not manifest every feature of the syndrome. A number of treatments may improve neglect, but there is no widely accepted universal approach to therapy. Although most patients recover spontaneously, the evidence suggests that they continue to have significant cognitive impairments, particularly relating to attention.

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