Stroke mimics and chameleons Moulin, Solène; Leys, Didier
Current opinion in neurology,
02/2019, Letnik:
32, Številka:
1
Journal Article
Recenzirano
A stroke mimic is a situation in which a diagnosis of stroke at admission is not confirmed, and a stroke chameleon is a situation in which a stroke is revealed by clinical symptoms that are not usual ...in stroke. The objective of this review is to identify the most frequent clinical situations in which stroke mimics and chameleons are encountered and consequences for the patient.
The safety profile of intravenous thrombolysis (IVT) in patients who have stroke mimics is excellent, and intracranial hemorrhages are rare. Modern neuroimaging techniques help identifying most mimics. For stroke chameleons the role of imaging may be less important, especially when the clinical presentation is not suggestive of a brain disorder that request immediate neuroimaging. Education of health providers to identify such situations is crucial.
Stroke mimics account for up to 25% of admissions for probable strokes. The proportion of patients with stroke mimics decreases with use of MRI at baseline. Mimics cannot always be ruled out in emergency. The problem with mimics is that stroke facilities are not properly used, and patients may receive IVT. However, thrombolysis is usually well tolerated in mimics and we should not spend much time in all patients to improve diagnostic accuracy, knowing that the time lost is harmful in all patients, and will only prevent treating one mimic out of 100 patients. The problem with chameleons is more serious, because patients are not identified, and are not properly treated.
An algal photoenzyme converts fatty acids to hydrocarbons Sorigué, Damien; Légeret, Bertrand; Cuiné, Stéphan ...
Science (American Association for the Advancement of Science),
09/2017, Letnik:
357, Številka:
6354
Journal Article
Recenzirano
Odprti dostop
Although many organisms capture or respond to sunlight, few enzymes are known to be driven by light. Among these are DNA photolyases and the photosynthetic reaction centers. Here, we show that the ...microalga Chlorella variabilis NC64A harbors a photoenzyme that acts in lipid metabolism. This enzyme belongs to an algae-specific clade of the glucose-methanol-choline oxidoreductase family and catalyzes the decarboxylation of free fatty acids to n-alkanes or -alkenes in response to blue light. Crystal structure of the protein reveals a fatty acid–binding site in a hydrophobic tunnel leading to the light-capturing flavin adenine dinucleotide (FAD) cofactor. The decarboxylation is initiated through electron abstraction from the fatty acid by the photoexcited FAD with a quantum yield >80%. This photoenzyme, which we name fatty acid photodecarboxylase, may be useful in light-driven, bio-based production of hydrocarbons.
Summary Background Dementia occurs in at least 10% of patients within 1 year after stroke. However, the risk of dementia after spontaneous intracerebral haemorrhage that accounts for about 15% of all ...strokes has not been investigated in prospective studies. We aimed to determine the incidence of dementia and risk factors after an intracerebral haemorrhage. Methods We did a prospective observational cohort study in patients with spontaneous intracerebral haemorrhage from the Prognosis of Intracerebral Haemorrhage (PITCH) cohort who were admitted to Lille University Hospital, Lille, France. We included patients aged 18 years and older with parenchymal haemorrhage on the first CT scan. Exclusion criteria were pure intraventricular haemorrhage; intracerebral haemorrhage resulting from intracranial vascular malformation, intracranial venous thrombosis, head trauma, or tumour; haemorrhagic transformation within an infarct; and referral from other hospitals. Median follow-up was 6 years. We studied risk factors (clinical and neuroradiological MRI biomarkers) of new-onset dementia as per a prespecified subgroup analysis, according to intracerebral haemorrhage location. Dementia diagnosis was based on the National Institute on Aging-Alzheimer's Association criteria for all-cause dementia. We did multivariable analyses using competing risk analyses, with death during follow-up as a competing event. Findings From the 560 patients with spontaneous intracerebral haemorrhage enrolled in the PITCH cohort between Nov 3, 2004 and March 29, 2009, we included 218 patients (median age 67·5 years) without pre-existing dementia who were alive at 6 months follow-up. 63 patients developed new-onset dementia leading to an incidence rate of 14·2% (95% CI 10·0–19·3) at 1 year after intracerebral haemorrhage, and incidence reached 28·3% (22·4–34·5) at 4 years. The incidence of new-onset dementia was more than two times higher in patients with lobar intracerebral haemorrhage (incidence at 1 year 23·4%, 14·6–33·3) than for patients with non-lobar intracerebral haemorrhage (incidence at 1 year 9·2%, 5·1–14·7). Disseminated superficial siderosis (subhazard ratio SHR 7·45, 95% CI 4·27–12·99), cortical atrophy score (SHR per 1-point increase 2·61, 1·70–4·01), a higher number of cerebral microbleeds (SHR for >5 cerebral microbleeds 2·33, 1·38–3·94), and older age (SHR per 10-year increase 1·34, 1·00–1·79) were risk factors of new-onset dementia. Interpretation There is a substantial risk of incident dementia in dementia-free survivors of spontaneous intracerebral haemorrhage; our results suggest that underlying cerebral amyloid angiopathy is a contributing factor to the occurrence of new-onset dementia. Future clinical trials including patients with intracerebral haemorrhage should assess cognitive endpoints. Funding French Ministry of Education, Research, and Technology, Adrinord, Inserm U1171.
OBJECTIVE:To determine whether higher neutrophil counts before IV recombinant tissue plasminogen activator (rtPA) administration in ischemic stroke (IS) patients are associated with symptomatic ...intracerebral hemorrhages (sICH) and worse outcomes at 3 months.
METHODS:Blood samples for leukocyte, neutrophil, and lymphocyte counts were drawn before IV rtPA administration in IS patients included in the cohorts of Lille and Helsinki. The primary endpoint was sICH (European Cooperative Acute Stroke–II definition). Secondary endpoints were death and excellent (modified Rankin Scale mRS score 0–1 or equal to prestroke mRS) and good (mRS score 0–2 or equal to prestroke mRS) outcomes at 3 months.
RESULTS:We included 846 patients (median age 71 years; 50.8% men). The neutrophil count and neutrophil to lymphocyte ratio (NLR) were independently associated with the 4 endpointssICH (adjusted odds ratio adjOR for an increase of 1,000 neutrophils = 1.21 and adjOR 1.11, respectively), death (adjOR 1.16 and adjOR 1.08), and excellent (adjOR 0.87 and adjOR 0.85) and good (adjOR 0.86 and adjOR 0.91) outcomes. The total leukocyte count was not associated with any of the 4 endpoints. The best discriminating factor for sICH was NLR ≥4.80 (sensitivity 66.7%, specificity 71.3%, likelihood ratio 2.32). Patients with NLR ≥4.80 had a 3.71-fold increased risk for sICH (95% confidence interval adjOR1.97–6.98) compared to patients with NLR <4.80.
CONCLUSIONS:Higher neutrophil counts and NLR are independently associated with sICH and worse outcome at 3 months. The identification of mediators of this effect could provide new targets for neuroprotection in patients treated by rtPA.
BACKGROUND AND PURPOSE—We aimed to determine incidences and predictors of major vascular events in intracerebral hemorrhage (ICH) survivors.
METHODS—We did a prospective observational cohort study in ...patients with spontaneous ICH from the Prognosis of Intracerebral Hemorrhage cohort in Lille, France. We studied incidences and predictors of long-term vascular events (cerebral and extracerebral, ischemic and hemorrhagic) in patients alive at 30 days with a prespecified subgroup analysis according to ICH location. We performed multivariable analyses (competing risk analyses, with death during follow-up as a competing event).
RESULTS—From the 560 patients with spontaneous ICH enrolled between November 2004 and March 2009, we included 310 patients (median age, 70 years). Eighty-two patients presented at least 1 major vascular event leading to an incidence rate of 20.0% (95% CI, 15.7–24.7) at 5 years after ICH. In the overall cohort, ischemic events were more frequent than hemorrhagic events. However, the incidence strikingly differed according to ICH locationdeep ICH was associated with future ischemic events (subhazard ratio, 1.85; 95% CI, 1.01–3.40), whereas lobar ICH with hemorrhagic events (subhazard ratio, 2.38; 95% CI, 1.17–4.86). In deep ICH, the incidence of ischemic events at 5 years was 6× higher than the incidence of hemorrhagic events.
CONCLUSIONS—ICH survivors are at high risk of both cerebral and extracerebral vascular events. The ischemic or hemorrhagic risk profile varies according to the index ICH location with a stronger ischemic risk in deep ICH. Secondary prevention, tailored on ICH location, should target not only cerebral recurrences but also extracerebral vascular events.
Neuropsychiatric (NP) symptoms are prominent features of cognitive decline, but they have been understudied in patients with spontaneous intracerebral haemorrhage (ICH). In ICH survivors, we aimed at ...assessing NP symptoms prevalence and profiles, and their influence on long-term outcomes.
We analysed data from consecutive 6-month ICH survivors enrolled in the Prognosis of Intracerebral Haemorrhage study. We performed NP evaluation using the Neuropsychiatric Inventory Questionnaire. Patients underwent long-term clinical follow-up after ICH (median follow-up time 7.2 years, IQR 4.8-8.2).
Out of 560 patients with ICH, 265 survived at 6 months. NP evaluation 6 months after ICH was feasible in 202 patients. NP symptoms were present in 112 patients (55%), and in 36 out of 48 patients (75%) with post-ICH dementia. Affective symptoms were present in 77 patients (38%), followed by vegetative symptoms (52 patients, 26%) and hyperactivity (47 patients, 23%). Apathy and hyperactivity were associated with post-ICH dementia and cerebral amyloid angiopathy MRI profile (all p<0.05). Apathy and hyperactivity prevailing over affective symptoms at 6-month follow-up were associated with higher risks of developing new-onset dementia (HR 5.40; 95% CI 2.27 to 12.84), while presence or severity of NP symptoms were not.
NP symptoms were present in more than half of 6-month ICH survivors, with higher prevalence and severity in patients with post-ICH dementia. Distinctive NP profile might be associated to cognitive status and inform on long-term dementia risk.
To determine how pre-stroke cognitive impairment can be detected, its mechanism, and influence on outcome and management.
Literature search.
(i) A systematic approach with the Informant Questionnaire ...of Cognitive Decline in the Elderly is recommended; (ii) Pre-stroke cognitive impairment may be due to brain lesions of vascular, degenerative, or mixed origin; (iii) Patients with pre-stroke dementia, have worse outcomes, more seizures, delirium, and depression, and higher mortality rates; they often need to be institutionalised after their stroke; (iv) Although the safety profile of treatment is not as good as that of cognitively normal patients, the risk:benefit ratio is in favour of treating these patients like others.
Patients with cognitive impairment who develop a stroke have worse outcomes, but should be treated like others.
In this issue of Arquivos de Neuro-Psiquiatria, Ifergan et al showed that of 736 patients admitted for an acute neurological disorder who underwent a CT- or a MRI-scan in emergency over a 2-year ...period, almost half did not show brain lesions suggestive of ischaemic strokes. They considered them as having stroke mimics. One hundred and two of them had either intra-cerebral haemorrhages (ICH) or transient ischaemic attacks (TIA). If we consider that these 102 additional patients did not really meet criteria for stroke mimics, the proportion of stroke mimics is reduced at 33.8%. ICH are not stroke mimics because they are strokes. They need an accurate diagnosis in emergency, and require a treatment when appropriate. Here, Leys et al argue that neurologists should not blame emergency physicians for stroke mimics. It is more important for emergency physicians to be trained to identify chameleons because they are the only physicians on the scene at this stage and, if their diagnosis is wrong, there is really a risk to harm the patient.
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