1. The Role of Induced Hypertension and Hyperbaric Oxygen Therapy in Moyamoya Disease: A Case Report
Smeer Salam, MD; Lisa Pabst, MD; Sushil Lakhani, MD; Deepak Gulati, MD; Archana Hinduja, MD
The Ohio State University Wexner Medical Center, Division of Cerebrovascular Diseases and Neurocritical Care, Department of Neurology, Columbus, Ohio, United States of America
Background
Moyamoya disease (MMD) is a chronic progressive steno-occlusive cerebrovascular disease involving the terminal internal carotid arteries and an abnormal collateral network resulting in ischemic and/or hemorrhagic infarcts. Treatment of MMD involves surgical bypass revascularization for prevention of infarcts as well as antiplatelet medications. Studies looking into novel approaches to medical optimization of acute ischemic stroke management in MMD have not produced definitively positive results.
We present a case of a patient with MMD suffering large ischemic strokes in which hyperbaric oxygen therapy (HBOT) and induced hypertension were utilized with the goal of preserving the ischemic penumbra.
Figure 1: DWI sequence of admission MRI scan
Figure 6: MRI Brain DWI sequence prior to discharge
Results
Though interval perfusion imaging demonstrated an improved perfusion profile without progression of core infarct after the third session of HBOT, the patient ultimately underwent tracheostomy and PEG tube placement and was discharged on mono-antiplatelet therapy with plan for potential EDAS once medically stable. NIHSS at discharge was 21. At 3 month follow-up, modified Rankin score remained 5 with a dense L MCA syndrome.
CBF
MTT
CBV
Figure 2: CT Perfusion imaging 6 days post-admission, shortly after acute rise in NIHSS score with new deficits
Case Report
Discussion
A 33 year-old female was admitted for progressive multifocal ischemic infarcts with rapidly improving left facial droop and mild right-sided weakness (NIHSS improving from 5 to 1 on presentation).  She underwent distal cerebral angiogram which revealed bilateral ICA stenosis with loss of bilateral MCA filling, consistent with a diagnosis of MMD (Suzuki grade III).  She was placed on aspirin ahead of outpatient EDAS procedure.  However, she subsequently developed acute neurologic decline with severe aphasia and worsening right-sided weakness (NIHSS increased from 1 to 14) and was found to have new significant bilateral MCA territory core infarcts with significant mismatch on CT perfusion imaging. As salvage therapy, therapeutic hypertension was induced for 10 days with multiple vasoactive medications to increase her mean arterial and cerebral perfusion. She also underwent 10 days of hyperbaric oxygen therapy. Treatment course was complicated by heart failure, presumably due to vasopressor therapy (EF 23% that normalized by time of discharge) and by hemotympanum during HBOT initiation requiring tympanostomy placement. Extensive work-up for causes of secondary MMD (including autoimmune) was negative.
Management of ischemic stroke secondary to MMD remains limited to symptom control by preventing a rise in ICP, maintaining elevated MAP, and seizure management. Maintenance of volume status and avoidance of hyperthermia and low cerebral PCO2 levels are also warranted. Thrombolytic therapy is generally not indicated due to the increased risk of hemorrhage associated with the underlying histopathology. While aspirin is recommended as secondary prevention, few other options exist to prevent recurrent strokes in these patients as a bridge to surgical revascularization.
Though data specific for MMD is limited, hyperbaric oxygen therapy (HBOT) has been attempted for patients with acute ischemic strokes for decades. While individual trials have indicated improvement in certain functional outcomes, pooled analysis has not demonstrated a difference in case fatality rate at six months between patients receiving HBOT and control subjects. This does not exclude the possibility of benefit, as most studies to date have been underpowered without consistent methodology and design characteristics among them, undermining reliability of existing evidence. Additional large, blinded randomized controlled trials are required with more consistently aligned study criteria to better assess the potential for therapeutic benefit of HBOT.
Figure 3: MRI Brain DWI sequence 1 day after acute rise in NIHSS with new deficits, 7 days after admission
CBF
MTT
CBV
Figure 4: Repeat CT perfusion imaging 4 days after acute decline
CBF
MTT
CBV
Figure 5: CT perfusion imaging 6 days after acute decline, after day 3 of HBOT