Fabienne Perren

VERTEBRAL ARTERY HYPOPLASIA: A PREDISPOSING FACTOR FOR POSTERIOR CIRCULATION STROKE?

We determined in 725 sequentially admitted first-ever stroke patients, using color-coded duplex flow imaging of the V2 segment, whether vertebral artery hypoplasia (VAH) (diameter ≤ 2.5 mm) was more frequent (13%) in posterior circulation territory infarction (247) than in strokes in other territories (4.6%). This difference is significant (p < 0.001), whereas all other risk factors (hypertension, hyperlipidemia, diabetes, smoking) were equally (p > 0.05) distributed. Patients with VAH may be predisposed to stroke in the posterior circulation.

The Role of Sonolysis and Sonothrombolysis in Acute Ischemic Stroke: A Systematic Review and Meta-analysis of Randomized Controlled Trials and Case-Control Studies

To assess the evidence on the safety and efficacy of sonothrombolysis in acute stroke.

Double dissociation between representational personal and extrapersonal neglect

Background: Although perceptual and representational neglect are frequently associated, the demonstration of a double dissociation between both neglect forms suggests that both rely on different central mechanisms. In addition, perceptual neglect can be selectively observed within personal space or extrapersonal space. However, it is not known whether the latter dissociation also exists in representational neglect. Methods: The authors investigated this question in two brain-damaged patients with anatomically different lesions sites, using neuropsychological tests specifically designed to assess perceptual and representational neglect in both personal and extrapersonal space. Results: Patients presented a double dissociation with respect to personal and extrapersonal space in representational neglect. Conclusions: These data suggest that the cerebral networks that process mental space representation use similar principles of space compartmentalization as those used by cerebral networks processing perceived space.

Spinal cord lesion after long-term intrathecal clonidine and bupivacaine treatment for the management of intractable pain

Long-term intrathecal drug administration using implanted pumps is increasingly used in the treatment of chronic refractory pain [Anderson and Burchiel 1999, Neurosurgery 44 (1999) 289; Krames 2002, Best Pract Res Clin Anaesthesiol 16 (2002) 619; Wallace 2002, Neurology 59 (2002) S18]. Extensive clinical experience over the last 15 years suggests that in selected cases the technique is safe, although infections, system malfunction and drug-related complications have been reported. In most cases, drug-related spinal cord injuries have resulted from the compression of a spinal inflammatory mass or abcess rather than from a direct neurotoxic effect. We report on a case of toxic spinal cord lesion occurring after more than 3 years of uneventful continuous infusion of a mixture of bupivacaine and clonidine.

The petrosquamosal sinus in humans

This article provides a comprehensive description of the morphology of the human petrosquamosal sinus (PSS) derived from original observations made on 13 corrosion casts of the cranial venous system combined with routine clinical imaging studies in two patients. The PSS is not a rare finding in the adult human. In particular, continuous developments in imaging techniques have made radiologists become increasingly aware of this anatomical entity in recent years. The role of the PSS as a major encephalic drainage pathway and its potential implication in pathological conditions such as intracranial venous hypertension are discussed.

Quantification of Internal Carotid Artery Flow with Digital Subtraction Angiography: Validation of an Optical Flow Approach with Doppler Ultrasound

BACKGROUND AND PURPOSE: Digital subtraction angiography is the reference standard technique to evaluate intracranial vascular anatomy and used on the endovascular treatment of vascular diseases. A dedicated optical flow-based algorithm was applied to DSA to measure arterial flow. The first quantification results of internal carotid artery flow validated with Doppler sonography are reported. MATERIALS and METHODS: We included 22 consecutive patients who underwent endovascular procedures. To assess the sensitivity of the algorithm to contrast agent-blood mixing dynamics, we acquired high-frame DSA series (60 images/s) with different injection rates: 1.5 mL/s (n = 19), 2.0 mL/s (n = 18), and 3.0 mL/s (n = 13). 3D rotational angiography was used to extract the centerline of the vessel and the arterial section necessary for volume flow calculation. Optical flow was used to measure flow velocities in straight parts of the ICAs; these data were further compared with Doppler sonography data. DSA mean flow rates were linearly regressed on Doppler sonography measurements, and regression slope coefficient bias from value 1 was analyzed within the 95% confidence interval. RESULTS: DSA mean flow rates measured with the optical flow approach significantly matched Doppler sonography measurements (slope regression coefficient, b = 0.83 ± 0.19, P = .05) for injection rate = 2.0 mL/s and circulating volumetric blood flow <6 mL/s. For injection rate = 1.5 mL/s, volumetric blood flow <3 mL/s correlated well with Doppler sonography (b = 0.67 ± 0.33, P = .05). Injection rate = 3.0 mL/s failed to provide DSA–optical flow measurements correlating with Doppler sonography because of the lack of measurable pulsatility. CONCLUSIONS: A new model-free optical flow technique was tested reliably on the ICA. DSA-based blood flow velocity measurements were essentially validated with Doppler sonography whenever the conditions of measurable pulsatility were achieved (injection rates = 1.5 and 2.0 mL/s).

Transforaminal Doppler: An alternative to transtemporal approach for right-to-left cardiac shunt assessment

BACKGROUND Paradoxical thrombotic embolism via right-to-left shunt is a risk factor for ischemic stroke, especially in younger subjects. Transtemporal Doppler shows a sensibility and specificity in the detection of patent foramen ovale comparable to that of transesophageal echocardiography, but even younger patients may not have a sufficient acoustic temporal bone window (up to 10%). METHODS AND RESULTS We thus studied prospectively in 74 patients subsequent to a recent stroke of undetermined origin whether transforaminal (foramen magnum) Doppler is an alternative to transtemporal Doppler in the detection and quantification of right-to-left cardiac shunt. We found a highly significant correlation between the two methods. CONCLUSIONS We conclude that transforaminal Doppler may be a complement and alternative to transtemporal Doppler and thus improve its value as a screening method for right-to-left cardiac shunt due to patent foramen ovale.

Combined IV–intra-arterial thrombolysis: A color-coded duplex pilot study

The authors compared the transcranial color-coded duplex pattern of the middle cerebral arteries (MCAs) before and after IV and combined IV–intra-arterial (IV–IA) thrombolysis in consecutive first-ever stroke patients. Patients receiving combined IV–IA thrombolysis showed greater improvement in flow signal and higher incidence of complete MCA recanalization vs those receiving IV thrombolysis, especially when the MCA was occluded or had only minimal flow.

Unruptured intracranial aneurysm follow-up and treatment after morphological change is safe: observational study and systematic review

Background The management of small unruptured incidentally discovered intracranial aneurysms (SUIAs) is still controversial. The aim of this study is to assess the safety of a management protocol of SUIAs, where selected cases with SUIAs are observed and secured only if signs of instability (growth) are documented. Methods A prospective consecutive cohort of 292 patients (2006–2014) and 368 SUIAs (anterior circulation aneurysms (ACs) smaller than 7 mm and posterior circulation aneurysms smaller than 4 mm without previous subarachnoid haemorrhage) was observed (mean follow-up time of 3.2 years and 1177.6 aneurysm years). Factors associated with aneurysm growth were systematically reviewed from the literature. Results The aneurysm growth probability was 2.6±0.1% per year. The rate of unexpected aneurysm rupture before treatment was 0.24% per year (95% CI 0.17% to 2.40%). The calculated rate of aneurysm rupture after growth was 6.3% per aneurysm-year (95% CI 1% to 22%). Aneurysms located in the posterior circulation and aneurysms with lobulation were more likely to grow. Females or patients suffering hypertension were more likely to have an aneurysm growing. The probability of aneurysms growth increased with the size of the dome and was proportional to the number of aneurysms diagnosed in a patient. Conclusions It is safe to observe patients diagnosed with SUIAs using periodic imaging. Intervention to secure the aneurysm should be performed after growth is observed.

Prognosis of aphasia in stroke patients early after iv thrombolysis.

OBJECTIVE Stroke patients with aphasia have a high long-term morbidity. Intravenous rt-PA (iv) thrombolysis is given more deliberately to these patients. Early outcome data is lacking. Aim of this study was to determine early benefit from rt-PA in patients with aphasia. METHODS Data of stroke patients treated by iv thrombolysis was scrutinized for the presence of aphasia defined as ≥1 point for aphasia on the National Institute of Health Stroke Scale (NIHSS). Improvement was defined as a gain of ≥1 point within 24h. Cranial computed tomography (CT) scans were evaluated regarding early ischemic changes (EICs), infarct volume and localization. RESULTS Fifty patients with aphasia were included. 16 (32%) of patients improved (4 (36%) minor, 7 (41%) moderate, 5 (23%) major stroke patients), while 44 (62%) remained unchanged. Of 28 patients with EICs, 10 (36%) improved compared to 7 out of 22 (32%) patients without (p=0.773). Aphasia outcome was significantly associated with infarct volume at admission and at 24h (Kruskal-Wallis, p=0.033, p≤0.001, respectively). CONCLUSION EICs are not predictive of aphasia outcome and patients with improvement showed smaller infarct volumes. One third improved within 24h, while two thirds remained unchanged. This might justify a closer follow-up of aphasia in stroke patients at the acute stage.