Brainstem auditory evoked potential response in pernicious anaemia.

During our study of recording auditory evoked potentials in protein-calorie malnutrition in infants and young children (1), we came across a few cases of anaemia. The heamatological investigationsincluding haemogram, showed that, of the five cases, two had megaloblastic anaemia, two had microcytic hypochromic and one had severe aplastic anaemia. Such neurological complications of various types of anaemias have not been documented except for pernicious anaemia, where classical subacuate combined degeneration of the spinal cord was first reported by Russell et al (2). Thereafter associated affection of the cerebral white matter and, more rarely, of the peripheral nerves have been amply documented. Direct relationship between optic nerve changes in the form of atrophy to the pernicious anaemia was documented by Cohen (3). However it is widely held that optic tract involvement in pernicious anaemia is rare (4-6). Patchy demyelination with affection of axis cylinders in the optic tracts has been reported in two cases of subacute combined degeneration (7). Identical changes have been found in experimental animals with induced B12 deficiency (8). Recently, Troncoso et al (9) have reported changes in visual evoked potentials in pernicious anaemia patients, suggestive of impairment of conduction in visual pathways. Now we repor: involvement of auditory pathways in our two permdous anaemia cases using. evoked potential recording procedure. However of the remaining three cases, two with microcytic hypochromic anaemia and one with severe aplastic anaemia, auditory brainstem evoked responses did not show any gross change and thus were normal.