Non-obstructive carotid atherosclerosis and patent foramen ovale in young adults with cryptogenic stroke.

BACKGROUND AND PURPOSE: Up to 50% of ischaemic strokes in young adults are classified as cryptogenic despite extensive work-up. We sought to evaluate the prevalence of non-obstructive carotid atherosclerosis (NOCA) and its association with patent foramen ovale (PFO) in young adults with cryptogenic stroke (CS). METHODS: Patients aged 18-54 years, consecutively treated for first-ever CS in an academic stroke service, were included. NOCA was assessed using carotid ultrasound examination and was defined as carotid plaque with <50% stenosis. PFO was diagnosed with transesophageal echocardiography. RESULTS: A total of 164 patients [mean age (SD) = 43.7 (8.5) years; 104 men] were included. A PFO was found in 79/164 (48.2%) patients. NOCA was demonstrated in 41/164 (25%) patients. NOCA was more common in patients without PFO [37.6% vs. 11.4%, P < 0.001; adjusted odds ratio (95% confidence interval), 0.24 (0.10-0.56)]. Older age (P = 0.046) and subcortical location of cerebral infarct (P = 0.015) were also associated with the absence of PFO, whereas hypertension, diabetes and smoking were not. CONCLUSIONS: This study demonstrates that NOCA is common in young adults with CS. NOCA is negatively associated with PFO. Detecting NOCA is an important component of stroke investigation in young adults.

Transcranial color-coded sonography to predict recurrent transient ischaemic attack/stroke.

BACKGROUND AND PURPOSE: Patients with transient ischaemic attack (TIA) with a high risk of imminent stroke can be identified with the ABCD(2) score and findings on MRI and CT angiography. The predictive value of transcranial color-coded sonography (TCCS) has not been evaluated in this setting. METHODS: A retrospective analysis was conducted of patients consecutively treated for TIA or minor stroke in a TIA clinic within 24 h of symptom onset. Agreement between TCCS and MRI three-dimensional time-of-flight images for the diagnosis of proximal (internal carotid artery, vertebral artery, basilar artery, circle of Willis and main stem of the middle cerebral artery) >50% stenosis or occlusion of the intracranial symptomatic artery was evaluated. The sensitivity, specificity, predictive values and likelihood ratio of TCCS for predicting recurrent TIA/stroke at 7 days were calculated. RESULTS: Of 159 patients with a TIA or minor stroke within the last 24 h, 142 had a readable acoustic temporal bone window (89.3%). TCCS and MRI were performed within 4 h of each other in 116 patients. MRI showed a symptomatic proximal intracranial steno-occlusive lesion in six patients. Agreement between MRI and TCCS was perfect (κ coefficient = 1). Recurrent TIA/stroke occurred in 10 patients (eight TIA and two minor strokes). All recurrences occurred within 24 h of symptom onset. A symptomatic proximal intracranial steno-occlusive lesion was found on TCCS in 4/10 patients with recurrence and 3/132 patients without recurrence [sensitivity 40%; specificity 97.7%; likelihood ratio 18.1; odds ratio (95% CI) adjusted for ABCD(2) score 31.5 (4.5-218.6)]. CONCLUSION: Our study shows that TCCS can be used to guide triage of patients with TIA.

Autonomic neuropathy is associated with impairment of dynamic cerebral autoregulation in type 1 diabetes.

HYPOTHESIS: The mechanisms underlying impairment of dynamic cerebral autoregulation in diabetes are not well known. Cardiovascular autonomic neuropathy (CAN) could contribute to dynamic cerebral autoregulation impairment. In this study, we assessed the association between CAN and impairment of dynamic cerebral autoregulation in patients with type 1 diabetes. METHODS: We evaluated dynamic cerebral autoregulation (DCA) in patients with type 1 diabetes and no history of cerebrovascular disease. DCA was assessed with transcranial Doppler using the correlation coefficient index Mx method. Mx was calculated from slow changes in mean cerebral blood flow velocity and mean arterial blood pressure. Increase in Mx indicates weaker DCA, with a threshold for impaired DCA above 0.3. Moderate CAN was defined as reduced heart rate variability (HRV) on the following tests: deep controlled breathing, Valsalva maneuver or initiation of active standing. Severe CAN was defined as reduced HRV associated with orthostatic hypotension. RESULTS: 60 patients were included (M/F: 33/27; mean age ± SD: 46 years ± 11.5). 23 patients had moderate CAN and 15 patients severe CAN. DCA was impaired in 37 patients. CAN was associated with impaired DCA (p = 0.005). Impairment of DCA was more pronounced in patients with severe CAN (p = 0.019). Glycosylated haemoglobin (HbA1c) was associated with impaired DCA in univariate analysis (p = 0.05). In multivariate analysis, only CAN was associated with impaired DCA (p = 0.007) whereas HbA1c was not (p = 0.161). CONCLUSIONS: CAN was associated with impaired DCA in type 1 diabetes. The magnitude of DCA impairment increased with the severity of CAN.