Limbic encephalopathy-case report and review of the literature

Abstract

A 60 year old male with a long history of low -grade depression and a 12 month history of dysarthria, dysphasia, weakness and altered cognitive function was admitted to Bethlehem Hospital for terminal care. A preadmission diagnosis of Motor Neuron Disease had been made by a private neurologist. He was treated with due care but died of clinical bronchopneumonia 1 month after admission. At autopsy the brain was heavy (1400 gm) and macroscoplcally unremarkable. The lungs showed evidence of congestive cardiac failure but no bronchopneumonia. The left kidney was of small size, showed reduced cortical thickness, dilated pelvicalyceal system and had three cortical masses between 5 and 35 mm in diameter. A fourth Intra-cortical area of yellowish discolouration 3 mm in length was also present. These areas represent renal cortical neoplasms of the proximal tubules which are histologically and macroscopically at the boundary between benign and malignant neoplasms of the renal cortex. No evidence of metatstatic disease was noted. The brain showed sponginess and gliosis of the medial temporal cortex bllaterally. There was also some mild loss of motor neurons in the spinal cord. Only two other cases of renal carcinomas and limbic encephalopathy were found in the last 16 years, one of which was also associated with an oat cell carcinoma of lung. Limbic encephalopathy is a para-neoplastic syndrome, which in its pure form as seen In this case, is exceedingly uncommon. It Is usually in association with bulbar, cord and posterior root ganglia lesions and Is most commonly seen in cases of primary lung carcinomafoat cell carcinoma).