Progressive Aphasia in Alzheimer’s does not predict memory loss

Memory was preserved over time in people with primary progressive aphasia (PPA) with Alzheimer’s disease, a small study showed.

Episodic memory was preserved at the first test and did not decline 2.35 years later, at which time PPA symptoms had been present for 6.26 years, although language skills fell sharply, he reported. M. Marsel Mesulam, MD, of Northwestern University’s Feinberg School of Medicine in Chicago, and co-authors in Neurology.

“While we knew that the memories of people with primary progressive aphasia were not initially affected, we did not know whether they kept the memory working over years,” Mesulam said in a statement. can be difficult to prove as most memory tests rely on speech skills that these people have lost or are losing. “

PPA is a neurodegenerative condition characterized by obvious language problems that worsen over time. Approximately 40% of patients with PPA exhibit atypical features of Alzheimer’s disease, often with a logopenic variant of PPA.

The study included 17 PPA patients with Alzheimer’s disease compared to 14 people with normal Alzheimer’s disease. PPA participants came from the Northwestern PPA research program and had autopsy or biomarker evidence of Alzheimer’s disease and at least two follow-up visits with language and memory assessments. Alzheimer’s pathology was based on autopsy in eight participants, cerebrospinal fluid biomarkers in three, and amyloid PET in six. Ten participants were male, and 11 had logopenic PPAs. Age at the onset of symptoms ranged from 47 to 74, with an average of 59.

In the group with typical Alzheimer’s were eight men and six women from the Northwestern Alzheimer’s disease center who had Alzheimer’s disease as the primary neuropathologic diagnosis at autopsy. The average age of onset of the signal was 66. In this group, both verbal memory and language function declined over time with the same level of anxiety.

Images, made exclusively of the PPA group, showed left ventricular mediotemporal atrophy. On autopsy, both groups had bilateral neurofibrillary hippocampo-entorhinal biopsy. Compared with the normal Alzheimer’s group, the PPA group had a lower frequency of TDP-43 mediotemporal pathology and a lower frequency of APOE4 genotype.

“Perhaps the most interesting finding is that memory retention in the PPA-Alzheimer’s disease group has been seen despite a pathology that is very prevalent in temporal lobe structures in each group,” said Seyed Ahmad Sajjadi, MD, PhD, University of California Irvine note. , and co-authors in accompanying edits. “Thus, the temporal temporal lobe structures in PPA-Alzheimer’s disease patients may be considered stable, and not stable, against Alzheimer’s pathology.”

The lack of right temporal temporal lobe atrophy in the PPA group confirms this view: “It leads to disconnection of neurodegeneration and pathology in those with PPA-Alzheimer’s disease,” the editors wrote. .

“Along with the broader cortical atrophy of the left hemisphere in the PPA group, it seems reasonable to conclude that neurodegeneration, and not just the presence of pathology, is relevant to clinical presentation in those patients, “they said. “This is an important idea at a time of development of targeted therapies that are increasingly aimed at those with or without mental health problems.”

The limitations of the study include a relatively small sample size. Autopsies were not available for all PPA cases. In addition, episodic memory was assessed by different tests in both groups.