Leukoencephalopathy with calcifications and cysts (LCC): 5 cases and literature review

Leukoencephalopathy with calcifications and cysts (LCC) is a rare autosomal recessive cerebral angiomatous-like microangiopathy characterized by diffuse and asymmetric white-matter lesions associated with multiple calcifications and cysts. The disease is caused by SNORD118 mutations. The entire clinical spectrum of LCC is not yet fully determined.

To define the clinical spectrum of LCC, we analyzed data from recently diagnosed cases and from the litterature. Both clinical and imaging features from our five LCC cases harboring compound heterozygous SNORD118 mutations were presented and all cases reported in the litterature reviewed.

Ninety-two LCC cases including our five patients were identified. Consanguinity was rare (4%), and 97% of cases were symptomatic. Mean age of first clinical manifestations was 16.1±16.1 years (range 1 month-71 years) and was earlier in men (10.3±14.3 years) than in women (20.2±22.8 years) (P=0.02). The main inaugural symptoms were seizures (36%; mean age at onset: 5.2±9.5 years) and progressive neurological symptoms including ataxia, dystonia and spasticity (26%; 27.8±23.6 years). Intracranial hypertension was less frequently observed (14%), mostly in adults (mean age 31.5±13.2 years). Ischemic or hemorrhagic strokes were inaugural symptoms in two adults (2%). During follow-up, most patients developed progressive extrapyramidal, cerebellar and pyramidal signs (83%), cognitive decline (56%), seizures (37%), intracranial hypertension (30%) or stroke (2%).

In LCC, the clinical spectrum is largely heterogeneous and the course of the disease appears highly variable in contrast to other hereditary cerebral small vessel diseases.