NeuroCognition After Carotid Recanalization

Complete occlusion of the Internal carotid artery (ICA) by atherosclerotic disease (COICA) causes approximately 15%-25% of ischemic strokes in the carotid artery distribution. Patients treated with medical therapy have a 7%-10% risk of recurrent stroke per year for any stroke and a 5%-8% risk per year for ipsilateral ischemic stroke during the first 2 years after ICA occlusion. Internal carotid artery occlusion causes an estimated 61,000 first-ever strokes per year in the US an incidence more than twice the annual occurrence of ruptured intracranial aneurysms Additionally, 40% of subjects with COICA who present with transient ischemic attack (TIA) and 70% of COICA who present with stroke have cognitive decline with increased risk of vascular dementia and Alzheimer's' disease (AD) with time (2,3).

Symptomatic COICA subjects are at increased risk of developing cognitive impairment and progressive development of vascular dementia and AD with time. Our proposal leverages several compelling retrospective and prospective preliminary data from human to perform this exploratory trial with go/no-go criteria to proceed to a phase 3 based on the data generated

Study Design:

Prospective randomized open blinded end-point (PROBE) study

This is a phase 2 randomized single-center open label clinical trial with randomization of 1:1 to either best medical management vs. best medical management and endovascular revascularization of COICA.

Screening, Enrolling, \& Randomization:

All subjects who presents to our tertiary hospital with a diagnosis of COICA will undergo full evaluation including 1) documenting previous history of transient ischemic attack (TIA) and/or stroke; 2) cervical and brain CT angiography (CTA) to document complete occlusion; 3) CT perfusion (CTP) to assess for presence of penumbra evident by increased mean transient time (MTT) in the ipsilateral side of COICA; and 4) Montreal cognitive assessment (MoCA) score. If any subject is found to have complete occlusion of COICA, evident of abnormal/prolongation of MTT on CTP, previous history of TIA and or stroke, and MoCA \<26 or abnormal response on another neuropsychological assessment preformed in the screening battery, then further evaluation is obtained including: MRI spectroscopy to assess for presence/absence of lactate in the ipsilateral watershed area (centrum semiovale), and size of ipsilateral hippocampus and amygdala, additional cognitive testing battery, and digital subtraction angiography (DSA) to document adequately the type of COICA the subject have (type A-D).

If a subject meets all inclusion criteria (complete occlusion, MoCA \<26 and/or abnormal other neuropsychological test result, abnormal CTP) they will be randomized, after consent is obtained. If all inclusion criteria are met other than the CTP, they will be enrolled but not randomized. These subjects will only be eligible for best medical management- not surgical intervention.

If any subject does not have complete occlusion or abnormal MoCA \>26 or other neuropsychological assessment, then the subject is excluded and no further testing needed (see exclusion criteria).

If the subject meets all inclusion criteria, then a baseline of complete neurological testing, full demographics, CTA or MRA, CTP, MoCA, additional neurological testing, MRI spectroscopy and DSA are obtained and subject is randomized 1:1 to either best medical management or best medical management + endovascular balloon angioplasty and stenting. Follow up clinic visits are arranged at 6 and 12 months. Repeat testing of MoCA and additional cognitive testing battery are done at these clinical follow-up visits (6 and 12 months). MRI of the brain and is done at 6 and 12 months. DSA is performed at 1 year follow-up for intervention subjects to assess brain bio-markers and revascularization respectively.

Eligibility Criteria:
Inclusion Criteria:

* Age ≥ 21
* Complete occlusion of cervical ICA on imaging studies (MRA or CTA) and confirmed with DSA
* History of TIA or stroke
* Increased MTT and/or time to peak (TTP) on CT perfusion as defined as T Max threshold of \> 10cc \> 4 seconds in the territory of the occluded carotid specifically in the MCA territory when compared to the opposite unaffected hemisphere (not required for observational cohort)
* All occlusion is due to atherosclerotic disease
* MoCA \< 26 or abnormal result on another test in the battery (abnormal defined as 1.5 SD below age/ gender/ education matched norms).
* Baseline MoCA assessed by the neurosurgery team or neuropsychology team
* Failed best medical treatment (defined below)
* Class A and B on COICA Classification
* Study team able to gain consent from subject or legal adult representative (LAR)

Exclusion Criteria:

* Non-atherosclerotic occlusive disease that may have caused the occlusion, including moyamoya, dissection, trauma or other causes
* Tandem occlusion
* No evidence of penumbra on CT perfusion
* Severe co-morbid diseases: Chronic Kidney Disease (CKD) stages 4 or 5, end-stage renal disease, liver cirrhosis; Chronic Obstructive Pulmonary Disease (COPD) requiring home oxygen; terminal illness such as cancer; Parkinson disease or other neurodegenerative diseases; severe congestive heart failure; seizures; debilitating stroke, Modified Rankin Score (mRS) ≥ 3
* Short life expectancy due to cancer or other co-morbid diseases
* Class D on COICA classification
* Normal neuropychological battery test results
* Subject unwilling to randomized to surgical procedure
* Pregnant or risk of becoming pregnant