Thalassemia and Moyamoya Syndrome: Epidemiology and long-term outcome

Moyamoya Angiopathy (MMA) is a chronic, progressive intracranial vasculopathy. Unlike Sickle-cell-disease, thalassemia-syndrome has rarely been described in association with MMA. This study was aimed to analyze the demographic, clinical, radiological features and long-term outcome (and possible factors influencing prognosis) of Moyamoya Syndrome (MMS) in the largest cohort of thalassemia-related-to-MMS.

A single-centered, observational study with longitudinal follow-up was undertaken for 12 cases of MMS-related-to-thalassemia-syndrome amongst 160 consecutive MMA patients. The baseline demographic, clinical and radiological characteristics were noted; and were longitudinally followed-up to assess disease progression (clinical or radiological). Fifteen previously reported cases of thalassemia and MMA were retrieved by literature search in PubMed and Google-Scholar using keywords "Moyamoya" AND "thalassemia".

The mean age at diagnosis of thalassemia-syndrome and diagnosis of MMS were 6.4 ± 6.55 years (mean ± SD) and 10.4 ± 8.68 years respectively in our 12 cases; 3.2 ± 2.25 years and 10.6 ± 6.1 years respectively in the previously reported 15 cases. Cerebral ischemic insult was the predominant brain lesion at base-line, noted in 91.7% of our cases and 80% of the previous cases. The mean hemoglobin, transfusion-dependency and previous splenectomy were seen in 8.7 ± 3.02 gm%, 33.3% and 8.3% of our cases respectively; 7.0 ± 3.04 gm%, 53.9% and 18.2% of previous cases. All our cases were medically managed for mean follow-up of 28.3 ± 13.9 months, none had evidence of angiographic progression, 1 of our 12 cases (8.3%) had new onset neuro-deficit and subsequent mortality, rest 11 of the 12 cases (91.7%) didn't have any appearance of silent cerebral infarction or evidence of progression of brain atrophy. Among the 15 previous cases, 5 out of 9 medically managed cases and 1 revascularized case described no further clinical recurrence.

Thalassemia-related-MMS may not be so rare. Future development of consensus guidelines in diagnosing and managing cases of MMS-associated-with-thalassemia is of essence.