NEUROPATHOLOGY

Two periods may be differentiated in the investigation of infantile amaurotic idiocy. During the era which may be termed the 'morphological' it was established that in this disease exclusively the ganglion-cells are damaged as they arise from the neuro-ectoderm. The meninges and blood-vessels which originate from the mesoderm are unaffected; similarly, the organs of metabolism, the spleen, the liver and the bone-marrow are not involved. For these reasons Schaffer is convinced that amaurotic idiocy is the result of an affection of the ectoderm. Other authors, however, do not agree with this view. In cases of so-called Gaucher's and Niemann-Pick's diseases, the same changes have been observed in the brain as in amaurotic idiocy. For this reason some writers suppose that all these affections are identical. In cases of Gaucher's and of Niemann-Pick's diseases definite alterations have been observed in the organs of metabolism. Kufs has said that all the contrary arguments advanced by Schaffer do not affect the conception of amaurotic idiocy as a local phenomenon of disordered metabolism of colloids and lipoids. In accordance with Kufs, Spielmeyer maintains that amaurotic idiocy is a lipoidosis of the type of Niemann-Pick's disease. Schaffer terms the second era the ' chemical era.' By chemical investigations Epstein found that in the brain of a case of amaurotic idiocy the quantity of lecithin and kephalin was diminished in comparison with that of a normal brain; while in the brain of a case of Niemann-Pick's disease the quantity of lecithin and kephalin was about double that in a normal brain. From this result Epstein concludes that cases of pure amaurotic idiocy and of Niemann-Pick's disease are different entities. Schaffer, therefore, considers that his opinion is confirmed. M.