Long-term cognitive and neurovascular changes after carotid endarterectomy.

BACKGROUND: Carotid endarterectomy (CEA) has been associated with both cognitive decline and improvement, but the underlying neurovascular mechanisms are unclear. The aim of this study was to investigate the relationship between neurovascular indices and cognitive changes after CEA. METHODS: We studied 55 patients with severe (≥70%) symptomatic or asymptomatic carotid stenosis before and six months after CEA. A wide array of neuropsychological tests was arranged in eight cognitive domains and cognitive functions specific to hemisphere ipsilateral to operation. Differences in cognitive performance between patients and 38 matching healthy controls were studied with linear mixed models. Neurovascular functioning and microembolic signals were assessed with transcranial Doppler ultrasound of the middle cerebral artery. Associations between neurovascular indices and cognitive change were assessed with linear regression analyses. RESULTS: On group level, the CEA patients improved more than controls in working memory, whereas no cognitive deterioration was detected. Also on individual level, improvement was most frequently observed in working memory. Worse preoperative cerebrovascular reactivity was related with improvement in cognitive functions of the ipsilateral hemisphere. Low preoperative pulsatility index was associated with improvement in executive functioning and ipsilateral cognitive functions. Poorer preoperative blood flow velocity associated with improvement in complex attention. Microembolic signals were rare. CONCLUSION: The present findings suggest that CEA may have beneficial long-term effects on cognition. These effects may specifically involve patients with impaired preoperative circulatory adaptive mechanisms.

Retinal vessel diameters and microvascular abnormalities in patients with carotid stenosis before and 6 months after carotid endarterectomy: A prospective study.

PURPOSE: To assess retinal findings in patients with severe carotid stenosis (CS) before and after carotid endarterectomy (CEA) compared to those in controls. METHODS: This study is based on 70 patients (male 81%, mean age 69) scheduled for CEA in Helsinki University Hospital and 41 healthy nonmedicated controls (male 76%, mean age 68). Our examinations included fundus photographs. Semi-automated software (Vesselmap, Imedos) served for evaluation of central retinal arterial equivalent (CRAE) and venular equivalent (CRVE), and arterio-venous ratio (AVR) in both eyes. We assessed fundus photographs to subjectively grade microvascular abnormalities in the ipsilateral eyes including focal arteriolar narrowing and irregularities, arteriolar wall reflex, arterio-venous crossing signs and arteriolar and venular tortuosity in the macula. RESULTS: CRAE was similar in the ipsi-and contralateral eyes of our patients, and similar to that of the controls both pre- and postoperatively. Preoperatively, we observed higher CRVE in the patients' ipsilateral than in their contralateral eyes (222 vs. 217 µm, p = 0.009), and likewise higher than in controls' eyes (222 vs. 214 µm, p = 0.024). CRVE decreased postoperatively in the patients' ipsilateral eyes (222 vs. 217 µm, p = 0.037). Among the microvascular abnormalities, arteriolar and venular tortuosity in the macula showed higher grades in the patients than in the controls preoperatively (p = 0.035 and p = 0.043), but not postoperatively (p = 0.15 and p = 0.10). CONCLUSIONS: CRVE decreased after CEA, showing that venules constrict after the mechanical hindrance of blood flow is removed. Higher grades in arteriolar and venular tortuosity in the macula, a potential ocular biomarker of CS, subsided after CEA.

Flicker-induced retinal vascular dilation in ipsi- and contralateral eyes of patients with carotid stenosis before and after carotid endarterectomy: a prospective study.

PURPOSE: Retinal vascular function was assessed in patients with carotid stenosis (CS) before and six months after carotid endarterectomy (CEA) and in controls at a six-month interval. METHODS: We studied 68 patients (81% male, mean age 69) and 41 healthy non-medicated controls (77%, 68) from March 2015 to December 2018. Our ophthalmological examination included flicker-induced arteriolar and venular measurements with a Dynamic Vessel Analyser in both eyes. RESULTS: At baseline, flicker-induced arteriolar and venular dilation was reduced in the ipsilateral eyes of the patients compared with dilation in the controls (arteriolar 1.0% versus 2.6%, p = 0.001 and venular 2.2% versus 2.8%, p = 0.049). These differences subsided after CEA. In patients' ipsilateral eyes, flicker-induced arteriolar dilation was borderline postoperatively (preoperative 1.0% versus postoperative 1.6%, p = 0.06), whereas venular dilation increased (2.2% versus 2.8%, p = 0.025). We found various tentative associations with the change in flicker-induced dilations after CEA, but not with the preoperative dilations. CONCLUSIONS: Postoperative recovery of the reduced flicker-induced arteriolar and venular dilatation in the ipsilateral eye shows that, after CEA, the activity-dependent vascular reactivity of haemodynamically compromised retinal tissue can improve.

Ocular signs of carotid stenosis in ipsi- and contralateral eyes before and after carotid endarterectomy: a prospective study.

PURPOSE: We describe hypoperfusion-related and embolic ocular signs of carotid stenosis (CS) before and six months after carotid endarterectomy (CEA) in a CS population. METHODS: We enrolled prospectively 70 CEA patients (81% male, mean age 69) and 41 non-medicated control subjects (76%, 68), from March 2015 to December 2018, assessing intraocular pressure (IOP), best-corrected visual acuity (BCVA) in logMAR units and performing a bio-microscopy examination. RESULTS: Main index symptoms included amaurosis fugax (Afx) (29, 41%) and hemispheric TIA (17, 24%), and 17 (24%) were asymptomatic. Of the 70, 17 patients (24%, 95% CI 16-36) showed ocular signs of CS. Of four embolic (Hollenhorst plaques) findings, one small macular plaque disappeared postoperatively. Four had hypoperfusion, that is ocular ischaemic syndrome (OIS), requiring panretinal photocoagulation: one for multiple mid-peripheral haemorrhages, two for iris neovascularization and one for neovascular glaucoma (NVG); only the NVG proved irreversible. Nine (de novo in three) showed mild OIS, that is only few mid-peripheral haemorrhages, ranging pre- /postoperatively in ipsilateral eyes from one to eleven (median two)/ one to two (median one), and in contralateral eyes from three to nine (median five)/ one to six (median three). Pre- and postoperative median BCVA was 0 or better, and mean IOP was normal, except in the NVG patient. Temporary visual impairment from 0 to 0.3 occurred in one eye soon after CEA due to ocular hyperperfusion causing macular oedema. CONCLUSIONS: Ocular signs of CS are common in CEA patients, ranging from few mid-peripheral haemorrhages to irreversible NVG. Clinicians should be aware of these signs in detecting CS.

Subfoveal choroidal thickness in ipsi- and contralateral eyes of patients with carotid stenosis before and after carotid endarterectomy: a prospective study.

PURPOSE: To compare subfoveal choroidal thickness (SFCT) and associated clinical variables in patients with carotid stenosis (CS) before and 6 months after carotid endarterectomy (CEA). METHODS: The prospective non-randomized Helsinki Carotid Endarterectomy Study - Brain and Eye Sub-sTudy included seventy patients (81% male, mean age 69 years) and 40 control subjects (77% male, 68 years), from March 2015 to December 2018. Ophthalmological examination included SFCT measured with enhanced-depth imaging-optical coherence tomography. Carotid stenosis (CS) was more severe (≥70% stenosis in 92%) ipsilateral to the CEA than contralaterally (<50% stenosis in 74%; p < 0.001). RESULTS: At baseline, patients had thinner mean SFCT than control subjects in both eyes (ipsilateral, 222 versus 257 µm and contralateral, 217 versus 258 µm, p ≤ 0.005). At follow-up, SFCT did not change in ipsi- and contralateral eyes compared to baseline in patients (p = 0.68 and p = 0.77), or in control subjects (p = 0.59 and p = 0.79). Patients with coronary artery disease had thinner mean SFCT versus those without it in ipsilateral eyes before CEA (200 versus 233 µm, p = 0.027). In ipsilateral eyes of patients before CEA, thinner SFCT and ocular signs of CS, plaque and hypoperfusion related findings combined, were associated (p = 0.036), and the best-corrected visual acuity, measured in logMAR, increased with increasing SFCT (r = -0.25; p = 0.046). CONCLUSIONS: Subfoveal choroidal thickness (SFCT) is thinner in patients with CS without association between SFCT and the grade of CS. Unchanged SFCT after CEA suggests, that choroidal vessels in severe CS are unable to react to increased blood flow. Bilaterally thin SFCT could be considered as yet another sign of CS.

Involvement of intraocular structures in disseminated histoplasmosis.

PURPOSE: To describe ocular involvement and response to treatment in a patient with human immunodeficiency virus (HIV) infection with severe progressive disseminated histoplasmosis (PDH). METHODS: We report a 35-year-old HIV-infected patient seen in our clinics over a period of 4 years. During antiretroviral treatment (ART), the HIV load became undetectable at 3 months; however, CD4 T-cell count increased slowly and rose to 100 cells/microl. Histoplasma capsulatum was cultured from skin pustules, cerebrospinal fluid (CF) and aqueous humour. RESULTS: The patient developed central nervous system (CNS) involvement 2 months and panuveitis in both eyes 4 months after the initiation of ART. With intravenous liposomal amphotericin B followed by oral voricanozole, the chorioretinal lesions of the right eye (RE) became inactivated and magnetic resonance imaging (MRI) lesions of CNS disappeared. Relapse of the inflammation in the anterior segment of the left eye (LE) resulted in a total closure of the chamber angle and severe glaucoma. Despite medical therapy, two cyclophotocoagulations, total vitrectomy and repeated intravitreal amphotericin B injections, LE became blind. Histoplasma capsulatum was cultured from the aqueous humour after antifungal therapy of 16 months' duration. CONCLUSION: PDH with intraocular and CNS manifestations was probably manifested by an enhanced immune response against a previous subclinical disseminated infection. It seems difficult to eradicate H. capsulatum from the anterior segment of the eye in an immunocompromised patient.