Intravenous thrombolysis in ischemic stroke patients with isolated homonymous hemianopia

Non-invasive electric current stimulation for restoration of vision after unilateral occipital stroke

Occipital stroke often leads to visual field loss, for which no effective treatment exists. Little is known about the potential of non-invasive electric current stimulation to ameliorate visual functions in patients suffering from unilateral occipital stroke. One reason is the traditional thinking that visual field loss after brain lesions is permanent. Since evidence is available documenting vision restoration by means of vision training or non-invasive electric current stimulation future studies should also consider investigating recovery processes after visual cortical strokes. Here, protocols of repetitive transorbital alternating current stimulation (rtACS) and transcranial direct current stimulation (tDCS) are presented and the European consortium for restoration of vision (REVIS) is introduced. Within the consortium different stimulation approaches will be applied to patients with unilateral occipital strokes resulting in homonymous hemianopic visual field defects. The aim of the study is to evaluate effects of current stimulation of the brain on vision parameters, vision-related quality of life, and physiological parameters that allow concluding about the mechanisms of vision restoration. These include EEG-spectra and coherence measures, and visual evoked potentials. The design of stimulation protocols involves an appropriate sham-stimulation condition and sufficient follow-up periods to test whether the effects are stable. This is the first application of non-invasive current stimulation for vision rehabilitation in stroke-related visual field deficits. Positive results of the trials could have far-reaching implications for clinical practice. The ability of non-invasive electrical current brain stimulation to modulate the activity of neuronal networks may have implications for stroke rehabilitation also in the visual domain.

Intravenous thrombolysis in ischemic stroke with unknown onset using CT perfusion

BACKGROUND

Acute ischemic stroke patients with unclear onset time presenting >4.5 h from last-seen-normal (LSN) time are considered late patients and excluded from i.v. thrombolysis. We aimed to evaluate whether this subgroup of patients is different from patients presenting >4.5 h from a witnessed onset, in terms of eligibility and response to computed tomography perfusion (CTP)-guided i.v. thrombolysis.

METHODS

We prospectively studied consecutive acute non-lacunar middle cerebral artery (MCA) ischemic stroke patients presenting >4.5 h from LSN. All patients underwent multimodal CT and were considered eligible for i.v. thrombolysis according to CTP criteria. Two patient groups were established based on the knowledge of the stroke onset time. We compared the proportion of candidates suitable for intravenous thrombolysis between both groups, and their outcome after thrombolytic therapy.

RESULTS

Among 147 MCA ischemic stroke patients presenting >4.5 h from LSN, stroke onset was witnessed in 74 and unknown in 73. Thirty-seven (50%) patients in the first group and 32 (44%) in the second met CTP criteria for thrombolysis (P = 0.7). Baseline variables were comparable between both groups with the exception of age, which was higher in the unclear onset group. The rates of early neurological improvement (54.1% vs 46.9%), 2-h MCA recanalization (43.5% vs 37%), symptomatic hemorrhagic transformation (3% vs 0%) and good 3-month functional outcome (62.2% vs 56.3%) did not differ significantly between both groups.

CONCLUSION

Delayed stroke patients with unknown onset time were no different than patients >4.5 h regarding eligibility and response to CTP-based i.v. thrombolysis.

Visual impairment in stroke patients--a review

Approximately 30% of all stroke patients suffer from post-stroke visual impairment. Hemianopia is the most common symptom, but also neglect, diplopia, reduced visual acuity, ptosis, anisocoria, and nystagmus are frequent. Partial or complete recovery of visual disorders can occur, but many patients suffer permanent disability. This disability is often less evident than impairment of motor and speech functions, but is negatively correlated with rehabilitation outcome and can lead to a significant reduction in day-to-day functioning. To be visually impaired after stroke reduces quality of life and causes social isolation because of difficulties in navigating/orientating in the surroundings. A thorough diagnosis including targeted examination and later follow-up with eye examination and perimetry is essential in order to establish the extent of the visual impairment and to select the best rehabilitation strategy. Patients seem to profit from visual rehabilitation focused on coping strategies.

Intravenous thrombolysis in ischemic stroke patients with isolated homonymous hemianopia: analysis of Safe Implementation of Thrombolysis in Stroke-International Stroke Thrombolysis Register (SITS-ISTR)

BACKGROUND AND PURPOSE

Hemianopia can cause considerable disability. Only scarce data are available for ischemic stroke patients presenting with isolated homonymous hemianopia and being treated with intravenous thrombolysis. We analyzed outcome of such patients registered in the Safe Implementation of Thrombolysis in Stroke-International Stroke Thrombolysis Register (SITS-ISTR).

METHODS

The SITS-ISTR (n=45 079) was searched for patients who presented with isolated homonymous hemianopia. We identified 72 such patients. We report their baseline and demographic characteristics, radiological data, change in their National Institutes of Health Stroke Scale score within 7 days after thrombolysis, and their 3-month modified Rankin Scale (mRS) score. Univariate analysis of parameters associated with any improvement was performed. Hemianopia was assessed with perimetric examination.

RESULTS

Of 72 patients, 40 (56%) improved within 7 days after thrombolysis; 19 (26%) had full recovery. Those who improved had significantly lower systolic blood pressure before thrombolysis and were less often administered antiplatelet agents before index stroke. Infarction was visible on 24-hour computed tomography scan in 65% of patients who improved compared with 81.2% of those without improvement (P=0.32). No symptomatic intracranial hemorrhage occurred in patients who improved compared with 1 (3.1%) patient in the nonimproved group (P=0.08). Seventy-one percent of all patients had 3-month mRS score 0 to 2, and 51% had mRS score 0 to 1. Those who improved within 7 days had a significantly better 3-month outcome (median mRS [interquartile range], 0 [0-1] vs 2 [1-2]).

CONCLUSIONS

Relatively few ischemic stroke patients received thrombolysis because of isolated homonymous hemianopia. Thrombolysis seems to be safe in these patients. Of those treated, more than half improved and more than two-thirds had good outcome.