Breached cerebral glia limitans-basal lamina complex in Fukuyama-type congenital muscular dystrophy

We have reported breaches of glia limitans (GL)-basal lamina (BL) complex w ith protruding neuroglial tissue in Fukuyama-type congenital muscular dystr ophy (FCMD) fetus brain and suggested that some basic deficits in the GL-BL complex may have a pivotal role in formation of micropolygyria in FCMD. We therefore investigated the cerebral GL-BL complex in seven FCMD cases (12- 27 years of age), in three cases of Duchenne muscular dystrophy (17-25 year s of age) and in two non-neurological controls (28 and 33 years of age). Th e frontal lobe cortex was examined immunocytochemically using antibodies ag ainst collagen type IV and laminin in each case, and ultrastructurally in a n adult case of FCMD. In FCMD, the BL of the cortical surface was frequentl y breached with protruding neural tissue that ultrastructurally showed freq uent synapses, neurites that had parallel arranged microtubules, and astroc ytic processes. The outermost surface of this tissue was only partly lined by a BL, In the region of the gyral adhesion of micropolygyria, the perivas cular space of the apparently entrapped meningeal blood vessels was occupie d by neuroglial tissue, which is assumed to have invaded through the occasi onally seen breaches of the perivascular GL-BL complex. Electron microscopy of the intruding tissue showed frequent synapses, microtubule-containing n eurites and astrocytic processes. No breached GL-BL complex was found in an y of the non-FCMD cases. These findings indicate that in FCMD, the cerebral GL-BL complex continues to have a crucial deficit with resulting breaches through which neuroglial tissue protrudes, promoting adhesion of the adjace nt cerebral gyri during brain development before and after birth.