Unintended changes in cognition, mood, and behavior arising from cell-based interventions for neurological conditions: ethical challenges.

The prospect of using cell-based interventions (CBIs) to treat neurological conditions raises several important ethical and policy questions. In this target article, we focus on issues related to the unique constellation of traits that characterize CBIs targeted at the central nervous system. In particular, there is at least a theoretical prospect that these cells will alter the recipients' cognition, mood, and behavior-brain functions that are central to our concept of the self. The potential for such changes, although perhaps remote, is cause for concern and careful ethical analysis. Both to enable better informed consent in the future and as an end in itself, we argue that early human trials of CBIs for neurological conditions must monitor subjects for changes in cognition, mood, and behavior; further, we recommend concrete steps for that monitoring. Such steps will help better characterize the potential risks and benefits of CBIs as they are tested and potentially used for treatment.

Cell-based interventions for neurologic conditions: ethical challenges for early human trials.

BACKGROUND: Attempts to translate basic stem cell research into treatments for neurologic diseases and injury are well under way. With a clinical trial for one such treatment approved and in progress in the United States, and additional proposals under review, we must begin to address the ethical issues raised by such early forays into human clinical trials for cell-based interventions for neurologic conditions. METHODS: An interdisciplinary working group composed of experts in neuroscience, cell biology, bioethics, law, and transplantation, along with leading disease researchers, was convened twice over 2 years to identify and deliberate on the scientific and ethical issues raised by the transition from preclinical to clinical research of cell-based interventions for neurologic conditions. RESULTS: While the relevant ethical issues are in many respects standard challenges of human subjects research, they are heightened in complexity by the novelty of the science, the focus on the CNS, and the political climate in which the science is proceeding. CONCLUSIONS: Distinctive challenges confronting US scientists, administrators, institutional review boards, stem cell research oversight committees, and others who will need to make decisions about work involving stem cells and their derivatives and evaluate the ethics of early human trials include evaluating the risks, safety, and benefits of these trials, determining and evaluating cell line provenance, and determining inclusion criteria, informed consent, and the ethics of conducting early human trials in the public spotlight. Further study and deliberation by stakeholders is required to move toward professional and institutional policies and practices governing this research.

Dementia in hippocampal sclerosis resembles frontotemporal dementia more than Alzheimer disease.

OBJECTIVE: To characterize the clinical course of pathologically diagnosed hippocampal sclerosis dementia (HSD). BACKGROUND: Dementia associated with HSD is incompletely characterized. Previous studies suggest similarities to both Alzheimer disease (AD) and frontotemporal dementia (FTD). METHODS: Case-control analysis of the clinical course of patients with HSD, FTD, and AD from a neuropathology autopsy series conducted by a university hospital. Case histories were reviewed. Cumulative prevalence of behavioral, cognitive, psychiatric, and language symptoms were compared between groups, as was time of symptom onset. Clinical diagnostic criteria for FTD and AD were applied to case histories. Sensitivity and specificity of clinical FTD diagnostic criteria (Report of the Work Group on FTD and Pick's disease) were computed. RESULTS: Cumulative prevalence of symptoms in HSD was most similar to that of FTD and differed from AD. Behavioral abnormalities such as decreased grooming and inappropriate behavior were more prevalent in HSD and FTD than AD. Hyperorality, inappropriate behavior, and decreased interest had earlier onset in HSD and FTD. Cognitive symptoms of disorientation, dyscalculia, apraxia, and agnosia were more prevalent in AD, as were psychiatric symptoms of hallucinations, delusions, and aggression. Most HSD patients met diagnostic criteria for FTD. Criteria sensitivity was 64.0% and specificity was 73.7%. CONCLUSIONS: FTD is a clinical syndrome associated with heterogeneous neuropathology. The clinical course of HSD is more similar to that of FTD than AD. These findings, together with the neuropathologic data presented in the accompanying article, support expanding the scope of FTD (Pick complex) to include HSD.

Most cases of dementia with hippocampal sclerosis may represent frontotemporal dementia.

Hippocampal sclerosis dementia (HSD) is a disease of unknown etiology and pathogenesis. To determine whether HSD cases could be reclassified as variants of frontotemporal dementia (FTD), a heterogeneous group of disorders, 18 brain autopsy cases previously diagnosed as HSD were re-evaluated. In 11 cases, ubiquitinated neuronal inclusions, similar to those of motor neuron disease inclusion dementia (MNDID), were found. Brain levels of soluble and insoluble tau were normal. Most patients with pathologic findings of HSD may actually have the MNDID variant of FTD.