W e report an unusual case of recurrent stroke in a patient with vitamin B 12 deficiency who was also homozygous for the methylene tetrahydrofolate reductase (MTHFR) gene mutation. The patient was a 35-year-old male vegetarian with no known medical history who initially presented with global aphasia, slurred speech, right facial weakness, and right-sided hemiplegia and was found to have a stroke (NIH Stroke Scale score of 25). At that time a CT scan of the head ruled out intracranial hemorrhage and a CT angiogram of the head and neck was done. The patient was found to have occlusion of the M1 segment of the left middle cerebral artery. Because he was within the time frame for thrombolytics, systemic thrombolysis with alteplase was given without improvement. He therefore underwent a cerebral angiogram that demonstrated occlusion of the M1 segment of the left middle cerebral artery and very poor leptomeningeal collaterals from the left anterior and posterior cerebral artery territories (figure 1). He underwent mechanical thrombectomy of the left middle cerebral artery thrombus with Penumbra aspiration device (Penumbra Inc., Alameda, CA) and SOLITAIRE stentriever (Covidien, Irvine, CA) with complete recanalization of the occluded segment (figure 2). He had a remarkable early recovery as the hemiplegia resolved. During the hospital course he was placed on a statin and low-dose aspirin and was later discharged to a rehabilitation unit for treatment of his right-sided hemiparesis and residual expressive aphasia. Workup for secondary stroke prevention, including telemetry and a transesophageal echocardiogram, was unremarkable.On follow-up MRI 3 months later, a small new acute left middle cerebral artery stroke was found. At that time he underwent a workup for a hypercoagulable state. The workup was negative for the following: lupus anticoagulant, anticardiolipin antibody, factor V Leiden mutation, prothrombin gene mutation, protein C and S deficiency, and antithrombin deficiency. However, the patient was found to have a markedly elevated homocysteine level of 55.7 mmol/L (normal 5-15 mmol/L) and relatively low levels of vitamin B 12 and folate at 206 ng/L (normal 180-914 ng/L) and 5.2 mg/L (normal $4 mg/L), respectively. Serum creatinine was 0.98 mg/dL and complete blood count showed hemoglobin of 14.4 g/dL and mean corpuscular volume of 88 fL. Genetic testing revealed the presence of homozygous MTHFR 677 TT genotype.The patient was then treated with supplemental vitamin B 12 1,000 mcg daily, initially IM and then orally. He also received folic acid supplementation. Two months later, the patient's symptoms improved dramatically, with resolution of his expressive aphasia and marked improvement of his right-sided hemiparesis. Laboratory data also showed improvement, as
Practical ImplicationsIn certain patients with recurrent stroke, such as those with elevated homocysteine and MTHFR gene mutations, supplemental vitamin B 12 may be beneficial.