Limb-shaking TIA in Moyamoya angiopathy

Background: Limb shaking TIA(LS-TIA) is an rare manifestation seen in high grade steno-occlusive carotid disease. LS-TIA is rarely recognized as a presenting manifestation of MMA and has never been previously studied prospectively in MMA cohort. Methods: Of 104 cases of MMA collected in our Indian center in last 4 years, 5 new patients had LS-TIA. MMA was diagnosed by MR angiography and LS-TIA was confirmed by three different neurologist by detailed scrutiny of history, neurological examination and EEG-recording (to rule out seizure). Seven previously reported cases of LSTIA in MMA were retrieved by literature search in PubMed using keywords "Moyamoya" AND "Limb shaking TIA", "Moyamoya" AND "Limb shaking". Subsequently all data were analyzed and compared using descriptive statistics. Results: Analysis of our 5 cases and those 7 found in the literature showed mean age at the time of diagnosis of MMA was 12.2 +/- 8.9(Mean +/- S.D.) years in our cases and 32.7 +/- 13.6 years in previous cases. The commonest precipitating factors included prolonged crying and hyperventilation(3 of 5 our cases each) and exercise (3 of 7 previous cases). CT-perfusion demonstrated frontal white matter hypoperfusion in 2 of our 5 cases, corroborative with fronto-parietal hypoperfusion in previous cases. Medical management showed decreased symptoms in 4 of our 5 cases in a follow-up of 15.8 +/- 11.6 months, while all previous patients had underwent revascularization surgery with resolution of symptoms. Conclusion: LS-TIA in MMA may not be so uncommon, especially in children. Early recognition is imperative to avoid future catastrophe. Steno-occlusive posterior circulation lesions might be an independent predictor of development of LS-TIA in MMA. In a resource-limited setting, careful avoidance of triggers and anti-platelet therapy can lead to decreased symptomatology of LS-TIA in MMA.