Isolation and characterization of the subacute spongiform virus encephalopathies of man: kuru and Creutzfeldt-Jakob disease

Chapter 50: history of tropical neurology

Tropical neurology began less than two centuries ago. Consumption of dietary toxins predominated at the beginning and gave birth to the geographic entity. The story moved from lathyrism through Jamaican neuropathy to cassava-induced epidemic neuropathy, which was contrasted with Konzo, also associated with cassava. Other tropical diseases enumerated with chronological details include: Chaga's diseases, kwashiorkor, Madras type of motor neuron disease, atlanto-axial dislocation, Burkitt's lymphoma and Kuru, associated with cannibalism among the Fore linguistic group in New Guinea. More recent documentation includes the Cuban neuropathy in 1991 with an epidemic of visual loss and neuropathy, Anaphe venata entomophagy in Nigeria presenting as seasonal ataxia, and neurological aspects of the human immunodeficiency virus infection complete the picture. With time, professional associations were formed and the pioneers were given prominence. The World Federation of Neurology featured Geographic Neurology as a theme in 1977 and Tropical Neurology was given prominence at its 1989 meeting in New Delhi, India. The situation remains unchanged with regards to rare diseases like Meniere's, multiple sclerosis, hereditary disorders. However, with westernization and continued urbanization, changing disease patterns are being observed and tropical neurology may depart from dietary toxins to more western world-type disorders.

A matter for debate: the risk of bovine spongiform encephalopathy to humans posed by blood transfusion in the UK

If human infection with bovine spongiform encephalopathy (BSE) were to occur, donated peripheral blood from humans that might have become infected from eating adequate quantities of food containing BSE should, until evidence is available to the contrary, be assumed to contain the human form of the disease. The chance of disease transfer to a blood recipient in 1995, which might in turn cause clinical disease with an incubation period of 20 years, is calculated. Transfusion is calculated to be a potential cause of a maximum of only 0.2% of clinical cases of Creutzfeldt-Jakob disease (CJD) in the UK population if the BSE epidemic were to spread to humans. Prospective epidemiological techniques would be unlikely to demonstrate any such minor contribution that blood transfusion might make to CJD incidence.

Levels of infectivity in the blood throughout the incubation period of hamsters peripherally injected with scrapie

Viremia is found in intraperitoneally scrapie-injected hamsters. The absence of a viremic peak before the beginning of scrapie replication in the brain suggests either that the spread of the agent to the brain is not via the blood or that early after infection, circulating monocytes carry the agent to the brain where it remains silent until the neural cells start replicating it.

Creutzfeldt-Jakob disease. An autopsy case of the panencephalopathic type and a review of the literature

This is a case report of a purported panencephalopathic type of Creutzfeldt-Jakob (C-J) disease in a 61-year-old Japanese farmer. He died nine months after the onset of clinical symptoms. This variety of C-J disease was named and reported in 1981 by Mizutani. The characteristic feature is extensive degeneration of cerebral white matter not related to cortical damage in addition to the spongiform changes in the cortical gray matter. The case was diagnosed clinically and at post mortem marked neural loss, astrocytic macrogliosis, and degeneration of subcortical white matter were found. Senile plaques and neurofibrillary tangles were virtually absent. Degeneration of the white matter is uncommon in C-J disease, and when it occurs is usually mild, and limited in distribution.

[Virologic studies in patients with amyotrophic lateral sclerosis]

The effects of intracerebral inoculation of cerebrospinal fluid in mice from 9 patients with amyotrophic lateral sclerosis are reported. There were 704 animals inoculated. The results were considered positive when the animals presented difficulties in walking and equilibrating. Cases 1, 2, 6, 7 and 9 were positives in the first passage. In case 1, the positivity was reached from first to fourth passage and in case 6, to third passage. At sight of this results, the possibility of that disease to be caused by slow-virus is discussed.

Limbic lobe involvement in presenile dementia

Limbic lobe involvement in presenile dementia was studied from a neuropathological and neuropsychiatric viewpoint. The material consisted of seven cases of Alzheimer's disease, four cases of Pick's disease, and four cases of Jacob-Creutzfeldt's disease. These three groups showed different patterns of distribution of the degeneration characteristic for each group, in particular for the first two. Among the groups, these patterns differed with regard to involvement both of nonlimbic and limbic areas. Thus the Alzheimer group had a mainly temporoparieto-occipital and posterior cingulate gyrus involvement. The Pick group in many respects showed an inverse distribution with frontotemporal and anterior cingulate gyrus accentuation of the damage. Basal temporal limbic areas were involved in both groups. The Jacob-Creutzfeldt group had a less schematic lesion pattern, without involvement of limbic areas. From a neuropsychiatric aspect, these differences were reflected in symptoms that could be referred both to areas spared and those more pronouncedly destroyed by the degenerative process. Thus the Alzheimer group long retained emotional qualities that were lost early in the Pick group. The possible relationship between neurotransmitters and regional accentuation of the degeneration is discussed.

Viremia in experimental Creutzfeldt-Jakob disease

Inoculation of the buffy coat of blood from guinea pigs infected with Creutzfeldt-Jakob disease resulted in passage of this disease to recipient animals. This demonstrates that there is a viremia in experimental Creutzfeldt-Jakob disease. These findings suggest that the hematogenous route may be implicated in the human infection and that the disease may possibly be transmitted by blood transfusions.

Creutzfeldt-Jakob disease: further similarities with kuru

A typical case of Creutzfeldt-Jakob disease is described. Two unusual morphological features-namely, `kuru-like' plaques in the cerebellum and coarsely vacuolated neurones in the striatum-are further similarities between Creutzfeldt-Jakob disease and kuru.