Anti-NMDA-receptor encephalitis presenting with catatonia and neuroleptic malignant syndrome in patients with intellectual disability and autism.

We report anti-N-methyl-d-aspartate (NMDA) receptor encephalitis in two patients with autism and intellectual disability presenting with neuropsychiatric symptoms of catatonia and neuroleptic malignant syndrome. Case reports such as these help raise awareness of this clinical issue. By paving the way for earlier diagnoses they ultimately maximise the potential for curative treatments and prevention of long-term complications.

Motor and sensory conduction failure in overlap of Guillain-Barré and Miller Fisher syndrome: two simultaneous cases.

We report 2 patients diagnosed simultaneously with an overlap of Guillain-Barré syndrome (GBS) and Miller Fisher syndrome (MFS), who had anti-GT1a, anti-GQ1b, anti-GD1a and anti-GD1b antibodies. There was no identifiable specific preceding infection. Both patients presented with upper and lower limb paresthesias and severe weakness, bulbar and facial weakness, ophthalmoparesis and areflexia.

An unusual case of relapsing remitting mononeuritis multiplex.

A 50-year-old man with a past history of autoimmune disease presented with posterior uveitis followed by relapsing remitting mononeuritis multiplex and hypersensitivity to pain despite continuation of high doses of steroids and the introduction of other immunosuppressive agents. Extensive initial investigations, including high resolution chest CT, were negative apart from a raised serum angiotensin-converting enzyme (ACE). The patient was initially thought to have sarcoidosis and treated with high dose prednisolone, but developed a series of cranial nerve palsies on treatment, some of which improved without any change in treatment.

Multiple coherence of cerebral blood flow velocity in humans.

The coherence function has been used in transfer function analysis of dynamic cerebral autoregulation to assess the statistical significance of spectral estimates of gain and phase frequency response. Interpretation of the coherence function and choice of confidence limits has not taken into account the intrinsic nonlinearity represented by changes in cerebrovascular resistance due to vasomotor activity. For small spontaneous changes in arterial blood pressure (ABP), the relationship between ABP and cerebral blood flow velocity (CBFV) can be linearized, showing that corresponding changes in cerebrovascular resistance should be included as a second input variable.

Cerebral blood flow velocity during mental activation: interpretation with different models of the passive pressure-velocity relationship.

The passive relationship between arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV) has been expressed by a single parameter [cerebrovascular resistance (CVR)] or, alternatively, by a two-parameter model, comprising a resistance element [resistance-area product (RAP)] and a critical closing pressure (CrCP). We tested the hypothesis that the RAP+CrCP model can provide a more consistent interpretation to CBFV responses induced by mental activation tasks than the CVR model. Continuous recordings of CBFV [bilateral, middle cerebral artery (MCA)], ABP, ECG, and end-tidal CO(2) (EtCO(2)) were performed in 13 right-handed healthy subjects (aged 21-43 yr), in the seated position, at rest and during 10 repeated presentations of a word generation and a constructional puzzle paradigm that are known to induce differential cortical activation.

Acute stroke hypertension: current and future management.

The management of hypertension in acute stroke remains a hotly debated issue. Clinical practice varies widely between physicians, and both European and US guidelines reflect the uncertainty surrounding this question. Although there is a large amount of data that, on the whole, tends to support a connection between poststroke hypertension and hypotension and worse outcome, there have been few randomized controlled trials to clarify whether pharmacologic intervention is safe or beneficial.

Dynamic cerebral autoregulation during brain activation paradigms.

Dynamic cerebral autoregulation (CA) describes the transient response of cerebral blood flow (CBF) to rapid changes in arterial blood pressure (ABP). We tested the hypothesis that the efficiency of dynamic CA is increased by brain activation paradigms designed to induce hemispheric lateralization. CBF velocity [CBFV; bilateral, middle cerebral artery (MCA)], ABP, ECG, and end-tidal Pco(2) were continuously recorded in 14 right-handed healthy subjects (21-43 yr of age), in the seated position, at rest and during 10 repeated presentations (30 s on-off) of a word generation test and a constructional puzzle.

Assessment of cerebral autoregulation from ectopic heartbeats.

Transfer function analysis of spontaneous fluctuations in BP (blood pressure) and CBFV (cerebral blood flow velocity) has been widely used to study dynamic CA (cerebral autoregulation). The inverse Fourier transform and its integral, giving the impulse and step responses, have been used to gain perspective of the state of dynamic CA from the frequency and time domains respectively. The occurrence of ectopic heartbeats in the data has usually been treated as an artefact.

Bendrofluazide fails to reduce elevated blood pressure levels in the immediate post-stroke period.

Introduction: Blood pressure (BP) levels, beat-to-beat blood pressure variability, dynamic cerebral autoregulation and cardiac baroreceptor sensitivity are frequently abnormal following acute stroke and are associated with an adverse short- and long-term prognosis. Thiazide diuretics are effective antihypertensive agents in preventing primary and secondary stroke, but their hypotensive and cerebral autoregulatory effects in the immediate post-stroke period have not been studied.

Methods: Thirty-seven hypertensive neuroradiologically proven ischaemic stroke patients were randomized in a double-blind, placebo controlled, parallel group study to bendrofluazide 2.

Cerebral and systemic hemodynamic changes during cognitive and motor activation paradigms.

Cognitive and/or sensorimotor stimulations of the brain induce increases in cerebral blood flow that are usually associated with increased metabolic demand. We tested the hypothesis that changes in arterial blood pressure (ABP) and arterial Pco(2) also take place during brain activation protocols designed to induce hemispheric lateralization, leading to a pressure-autoregulatory response in addition to the metabolic-driven changes usually assumed by brain stimulation paradigms. Continuous recordings of cerebral blood flow velocity [CBFV; bilateral, middle cerebral artery (MCA)], ABP, ECG, and end-tidal Pco(2) (Pet(CO(2))) were performed in 15 right-handed healthy subjects (aged 21-43 yr), in the seated position, at rest and during 10 repeated presentations of a word generation and a constructional puzzle paradigm that are known to induce differential cortical activation.

The systemic haemodynamic and cerebral autoregulatory effects of bendrofluazide in the subacute post-stroke period.

Introduction: Little data exist on the efficacy in terms of blood pressure reduction or outcome measures for the various antihypertensive agents in patients post-stroke. In this study the effects of bendrofluazide on blood pressure levels and variability, dynamic cerebral autoregulation and cardiac baroreceptor sensitivity were assessed in the sub-acute stroke period.

Methods: A total of 36 hypertensive ischaemic stroke patients were randomized to oral bendrofluazide 2.

Influence of controlled breathing patterns on cerebrovascular autoregulation and cardiac baroreceptor sensitivity.

Transfer function analysis has become one of the main techniques to study the dynamic relationship between cerebral blood flow and arterial blood pressure, but the influence of different respiratory rates on cerebral blood flow has not been fully investigated. In 14 healthy volunteers, middle cerebral artery blood flow velocity, recorded using transcranial Doppler ultrasound, non-invasive beat-to-beat Finapres blood pressure, ECG and end-tidal CO(2) ( P ECTO(2)) levels were recorded with subjects resting supine and breathing spontaneously or at controlled rates of 6, 10 and 15 breaths/min. Transfer function analysis and impulse and step responses were computed at each respiratory rate.

Cerebral autoregulation indices are unimpaired by hypertension in middle aged and older people.

Background: Hypertension is known to increase the limits of static cerebral autoregulation (CA) but its effects on other aspects of CA such as efficiency and latency are unknown. In this study we test the hypothesis that dynamic cerebral autoregulation and the efficiency of static cerebral autoregulation are impaired by untreated hypertension.

Methods: Cerebral blood flow velocity was recorded using transcranial Doppler ultrasound, along with noninvasive beat-to-beat blood pressure (BP), electrocardiogram, and transcutaneous carbon dioxide levels, with subjects at rest and during isometric hand grip, thigh cuff, and the Valsalva maneuver.

Cardiac baroreceptor sensitivity predicts long-term outcome after acute ischemic stroke.

Background And Purpose: The baroreceptor reflex arc is important in the short-term regulation of the cardiovascular system, and small studies have reported impaired cardiac baroreceptor sensitivity (BRS) after acute stroke. However, the prognostic significance of impaired BRS is uncertain.

Methods: One hundred twenty-four patients underwent simultaneous ECG and noninvasive beat-to-beat blood pressure (BP) monitoring within 72 hours of neuroradiologically confirmed acute ischemic stroke.