Safety Precautions Encephalopathy
With
Spongiform
To the Editor.\p=m-\Thearticle of Cook and Austin in the Archives (35:697\x=req-\
698,1978) contains disturbing implications, which may have far-reaching results that were obviously not the intention of the authors. The proved transmissible nature of spongiform encephalopathy (SE) led to the proposal of guidelines by Gajdusek et al.1 We
should keep in mind that the majority of cases of SE are sporadic and, therefore, clinically unsuspected, and only 10% of them are familial. Considering the likelihood that the incubation period is five times longer than that of a clinically recognizable disease, the proposed safety rules will protect us from less than 20% of all potentially infectious material. Of course, in familial cases of SE, the extension of precautions to potential victims prior to the onset of clinical symptoms will increase the margin of safety. The extension of the safety guidelines to familial Alzheimer's disease (AD) proposed by Cook and Austin compounds the problem and adds a host of new ones. Alzheimer's disease is a relatively common disease in contrast with SE. This accounts for the occasional occurrence of the spo¬ radic form in one or more members of one family. The authors quote evi¬ dence for transmission of familial AD to primates. In the case reported by Rewcastle et al,2 two family members had dementia and the condition of
only one (the donor) was diagnosed as AD on examination of a biopsy speci¬ men. This patient is still alive after 8V2 years and a possibility of coexistence
of AD and SE has not been ruled out in this case. Gajdusek1 refers to these cases as "an anomaly that the familial form of AD has, in these two instances, transmitted as though it were Creutzfeldt-Jacob disease...."
The occasionally reported coexistence of AD and SE could be considered as a possible cause of successful transmis¬ sion. The scientific evidence to date makes further research imperative, but does not warrant the application of precautionary measures. The widespread acceptance of the proposal by Cook and Austin could have practical implications too exten¬ sive to list. I will mention only a few. We are still faced with inadequate diagnosis of AD in many mental insti¬ tutions.1 This will either render all precautions useless or result in an extension to include all multiple occur¬ rences of dementia of any cause in a single family. The studies to deter¬ mine the cause of AD rely on autop¬ sies for diagnosis and research pur¬ poses. I can envision with fear the imposition of protective guidelines that cannot be met on local hospitals on which we rely to obtain autopsy material This could result in a further drop of the already disturbingly low number of postmortem examinations. The impact of the proposed precau¬ tionary measures on emergency pro¬ cedures, surgery, physician examining rooms, and numerous laboratory pro¬ cedures should be considered. In conclusion, the proposal of the authors to prevent the potential carrier of a transmissible disease from being a donor of tissue or blood is a wise one. On the other hand, imposi¬ tion of precautionary measures by those who overzealously equate a hy¬ pothesis with a real threat may have disastrous results. Leopold Liss, MD Division of Neuropathology Department of Pathology Ohio State University 473 W 12th Ave Columbus, OH 43210 1. Gajdusek DC, Gibbs CJ, Asher DM, et al: Precautions in medical care of, and in handling materials from, patients with transmissible virus dementia (Creutzfeldt-Jakob disease). N Engl J
Med 297:1253-1258, 1977. 2. Rewcastle NB, Gibbs CJ, Gajdusek DC: Transmission of familial Alzheimer's disease to primates. Read before the Eighth International
Congress on Neuropathology, Washington, DC, Sept 27, 1978. 3. Gajdusek DC: Unconventional viruses and the origin and disappearance of kuru. Science
197:943-960, 1977. 4. Liss L, Lowy J: The incidence of Alzheimer's
disease in institutionalized Assoc 1:163, 1978.
patients. J Am Aging
Neurological Sequelae of Massive Hydrogen Sulfide Inhalation To the Editor.\p=m-\Inthe August 1978 issue of the Archives (35:517-521), De Reuck and Vander Eecken characterized focal subcortical lesions resulting from severe hypoxic cerebral insults. We would like to describe an unusual case of cerebral hypoxia and add comments on the pathogenesis of focal brain lesions. A 45-year-old man was accidentally
exposed
to
high-pressure hydrogen
sulfide (H2S) gas and was immediately rendered unconscious. Respiratory assistance was instituted, and spontaneous respiration soon resumed. However, the victim remained comatose, exhibiting increased tonus with extensor spasms and Babinski's signs. Computerized tomography (CT) of the head revealed bilateral symmetrical lucent lesions within the cerebral hemispheres. He remained in a chronic vegetative state and died approximately five weeks after exposure to the gas. An autopsy was not
permitted. Superimposition of a corresponding normal brain slice
on
the CT
scan
image strongly suggested that the lucent lesions represented necrotic areas involving the lentiform nucleus bilaterally (Figure). No undue enlargement of the ventricular system the subarachnoid space cerebral convexity was strated. or
Downloaded From: http://archneur.jamanetwork.com/ by a Karolinska Institutet University Library User on 06/02/2015
the demon¬
over
With
Spongiform
To the Editor.\p=m-\Thearticle of Cook and Austin in the Archives (35:697\x=req-\
698,1978) contains disturbing implications, which may have far-reaching results that were obviously not the intention of the authors. The proved transmissible nature of spongiform encephalopathy (SE) led to the proposal of guidelines by Gajdusek et al.1 We
should keep in mind that the majority of cases of SE are sporadic and, therefore, clinically unsuspected, and only 10% of them are familial. Considering the likelihood that the incubation period is five times longer than that of a clinically recognizable disease, the proposed safety rules will protect us from less than 20% of all potentially infectious material. Of course, in familial cases of SE, the extension of precautions to potential victims prior to the onset of clinical symptoms will increase the margin of safety. The extension of the safety guidelines to familial Alzheimer's disease (AD) proposed by Cook and Austin compounds the problem and adds a host of new ones. Alzheimer's disease is a relatively common disease in contrast with SE. This accounts for the occasional occurrence of the spo¬ radic form in one or more members of one family. The authors quote evi¬ dence for transmission of familial AD to primates. In the case reported by Rewcastle et al,2 two family members had dementia and the condition of
only one (the donor) was diagnosed as AD on examination of a biopsy speci¬ men. This patient is still alive after 8V2 years and a possibility of coexistence
of AD and SE has not been ruled out in this case. Gajdusek1 refers to these cases as "an anomaly that the familial form of AD has, in these two instances, transmitted as though it were Creutzfeldt-Jacob disease...."
The occasionally reported coexistence of AD and SE could be considered as a possible cause of successful transmis¬ sion. The scientific evidence to date makes further research imperative, but does not warrant the application of precautionary measures. The widespread acceptance of the proposal by Cook and Austin could have practical implications too exten¬ sive to list. I will mention only a few. We are still faced with inadequate diagnosis of AD in many mental insti¬ tutions.1 This will either render all precautions useless or result in an extension to include all multiple occur¬ rences of dementia of any cause in a single family. The studies to deter¬ mine the cause of AD rely on autop¬ sies for diagnosis and research pur¬ poses. I can envision with fear the imposition of protective guidelines that cannot be met on local hospitals on which we rely to obtain autopsy material This could result in a further drop of the already disturbingly low number of postmortem examinations. The impact of the proposed precau¬ tionary measures on emergency pro¬ cedures, surgery, physician examining rooms, and numerous laboratory pro¬ cedures should be considered. In conclusion, the proposal of the authors to prevent the potential carrier of a transmissible disease from being a donor of tissue or blood is a wise one. On the other hand, imposi¬ tion of precautionary measures by those who overzealously equate a hy¬ pothesis with a real threat may have disastrous results. Leopold Liss, MD Division of Neuropathology Department of Pathology Ohio State University 473 W 12th Ave Columbus, OH 43210 1. Gajdusek DC, Gibbs CJ, Asher DM, et al: Precautions in medical care of, and in handling materials from, patients with transmissible virus dementia (Creutzfeldt-Jakob disease). N Engl J
Med 297:1253-1258, 1977. 2. Rewcastle NB, Gibbs CJ, Gajdusek DC: Transmission of familial Alzheimer's disease to primates. Read before the Eighth International
Congress on Neuropathology, Washington, DC, Sept 27, 1978. 3. Gajdusek DC: Unconventional viruses and the origin and disappearance of kuru. Science
197:943-960, 1977. 4. Liss L, Lowy J: The incidence of Alzheimer's
disease in institutionalized Assoc 1:163, 1978.
patients. J Am Aging
Neurological Sequelae of Massive Hydrogen Sulfide Inhalation To the Editor.\p=m-\Inthe August 1978 issue of the Archives (35:517-521), De Reuck and Vander Eecken characterized focal subcortical lesions resulting from severe hypoxic cerebral insults. We would like to describe an unusual case of cerebral hypoxia and add comments on the pathogenesis of focal brain lesions. A 45-year-old man was accidentally
exposed
to
high-pressure hydrogen
sulfide (H2S) gas and was immediately rendered unconscious. Respiratory assistance was instituted, and spontaneous respiration soon resumed. However, the victim remained comatose, exhibiting increased tonus with extensor spasms and Babinski's signs. Computerized tomography (CT) of the head revealed bilateral symmetrical lucent lesions within the cerebral hemispheres. He remained in a chronic vegetative state and died approximately five weeks after exposure to the gas. An autopsy was not
permitted. Superimposition of a corresponding normal brain slice
on
the CT
scan
image strongly suggested that the lucent lesions represented necrotic areas involving the lentiform nucleus bilaterally (Figure). No undue enlargement of the ventricular system the subarachnoid space cerebral convexity was strated. or
Downloaded From: http://archneur.jamanetwork.com/ by a Karolinska Institutet University Library User on 06/02/2015
the demon¬
over
