Biomedical subjects
Publications and source records attributed to C G Harper.
A case of cryptococcosis of the central nervous system presenting as an intracranial space occupying lesion is described. The world literature and epidemiology of this unusual disease are surveyed. Problems in the diagnosis and the use of modern diagnostic techniques are discussed. The authors suggest that cryptococcosis should be included in the differential diagnosis of an intracranial space occupying lesion.
This paper reviews 216 consecutive neurosurgical biopsies examined by the immediate smear technique, and the smear diagnoses are compared with the final diagnoses made on paraffin processed sections of the same material. Ninety three percent (93%) of the diagnoses were correct. The majority of errors were due to the incorrect classification of malignant tumours. The diagnosis of malignancy, however, was clearly established in all of these cases. The smear technique is suitable for application to material obtained at craniectomy, laminectomy, and also the small, soft pieces of tissue obtained by needle biopsy through a burr hole.
Malignant gliomas of the optic pathways are uncommon in adults and are rarely diagnosed in life. In three cases of such tumors, the diagnosis was not suspected during life. Neuropathological examination showed involvement of the optic nerves, chiasm, and tracts with extensive involvement of contiguous structures in all of the cases. In view of the consistent clinical features, it is stressed that in adults with progressive visual failure, malignant gliomas of the optic pathways be included in the differential diagnosis.
Clinical interest in spinal compression and resultant paraplegia due to metastases has mounted in recent years. This has stimulated attention to the neuropathology of the condition. 14 cases of spinal cord compression due to vertebral metastases are compared with over 100 traumatic cases. In the traumatic lesions there is central haemorrhagic necrosis leading to cavitation and gliosis with nerve root regeneration in the late stages. In the metastatic cases, lesions are often peripheral, pie-shaped and are related to vascular factors. The neuropathology of cord necrosis due to metastatic spinal disease is therefore different from that caused by trauma. These observations have clinical importance in planning treatment.
The clinical and neuropathological consequences of either ethanol consumption or thiamin deficiency or both were examined in Wistar rats aged nine weeks divided into five groups and fed one of the following diets: a thiamin-replete (control) diet (A): a thiamin-fortified diet with water (B) or 15% ethanol (C); or a thiamin-deficient diet with water (D) or 15% ethanol (E). Rats fed diets A, B or C for 35 weeks showed no clinical signs of neurological disease at any stage and no significant brain pathology when harvested. Rats fed diets D and E progressed through a common sequence of clinical signs of neurological disease typical of acute thiamin deficiency, viz loss of coat condition, ataxia, opisthotonus and ultimately death within 10-23 weeks. The onset and progression of these stages of neurological disease were significantly earlier and faster (p less than 0.001 for proportion of opisthotonic and ataxic animals at weeks 10 and 15) in the thiamin-deficient rats that received ethanol than in those that did not. At death, the brain pathology in these two groups was limited and similar.
OBJECTIVE: To determine the usefulness of cytology in the intraoperative diagnosis of central demyelinating disorders. STUDY DESIGN: Smears of three multiple sclerosis (MS) plaques and two progressive multifocal leukoencephalopathy (PML) lesions prepared intraoperatively were examined and compared. The cytologic features were contrasted with those of infiltrating astrocytomas. RESULTS: The preparations of demyelinating lesions revealed normal or reactive astrocytes and large numbers of foamy macrophages, the key diagnostic finding. The preparations of the lesions of PML contained virally infected oligodendrocytes. The specific cell types were identified easily because cytoplasmic margins could be distinguished. CONCLUSION: Cytologic preparations of lesions of PML and MS permitted rapid identification of the diagnostic features and distinguished them from infiltrating astrocytomas, the most important lesion in the differential diagnosis. The findings demonstrated the utility of cytology in the diagnosis of central demyelinating diseases.