"Asymptomatic" Moyamoya Angiopathy: Is it Truly Asymptomatic?

INTRODUCTION

An ambiguous definition of "asymptomatic" Moyamoya Angiopathy(aMMA) of absence of ischemic/hemorrhagic episodes in MMA patients, has led to its variable adaptation in the limited past-studies.

OBJECTIVE

To observe the clinic-radiological characteristics and prospective follow-up of apparently "asymptomatic" MMA, and to determine if it is truly asymptomatic or not.

MATERIALS AND

METHODS

An observation, cohort study of 122 angiographically proven MMA over 6 years was undertaken from a single, tertiary-care-center to observe the clinico-radiological characteristics, prospective follow-up of apparently aMMA. Amongst them, 6 had an initial diagnosis of aMMA following evaluation by atleast one post-graduate doctor, which were further scrutinized by 3 different neurologists for epidemiological, clinical, radiological characteristics and subsequent follow-up. Data were analyzed using descriptive statistics.

RESULTS

Mean age was 23.7 ± 13.14 years. 3 of 6 underwent brain-imaging for evaluation of non-migraine-like headache, 1 for dizziness, 2 as part of familial screening for MMA. 4 of 6 patients had specific-triggers for aggravation of symptoms. Brain-imaging revealed old vascular insults and ivy sign in 5 of 6 each (83.3%), mean suzuki staging was 3.6±0.82. 4 of 6 underwent cerebral perfusion study, all had hypoperfusion. Revascularization surgery was done in 2 of 6, rest were managed conservatively. None had any new-onset neurological deficit or radiological progression over a mean follow-up period of 22.3 ± 20.22 months.

CONCLUSIONS

Apparently aMMA may not be truly asymptomatic and often have subtle "paroxysmal events" precipitated by specific-triggers, indicative of transient ischemic symptoms. Thus, warrants for a more precise definition to avoid misclassification of aMMA.