A case of severe anterograde amnesia in the era of smartphone technology

ABSTRACT

A.V. is a young herpes simplex encephalitis (HSE) survivor who suffered extensive bilateral damage to the medial temporal lobe (MTL) leading to a severe and pervasive form of anterograde amnesia. Structural Magnetic Resonance Imaging (MRI) revealed lesions that encompass the hippocampus and amygdala in both hemispheres and that extend more laterally in the right temporal lobe. At the same time, detailed neuropsychological testing showed that the disparity between A.V.’s preserved intellectual functioning (Full Scale IQ: 115) and severe memory deficit (Delayed Memory Index: 42) is one of the largest on record. Despite this deficit, A.V. has regained a higher level of functioning and autonomy compared to previously documented amnesic cases with major bilateral MTL lesions. As a millennial, one advantage which A.V. has over prior amnesic cases is fluency with digital technology – particularly the smartphone. The analysis of his phone and specific app usage showed a pattern that is consistent with the strategy to offload cognitive tasks that would normally be supported by the MTL. A.V.’s behavior is significant in terms of rehabilitation and may have broader implications at the societal level and for public health given the ubiquity of smartphone technology and its potential to become integrated with neural mnemonic functions.

KEYWORDS:

• Brain
• hippocampus
• medial temporal lobe
• encephalitis
• amnesia

Author contributions

J.A., R.K., L.H-A., J.S.F. contributed to the study design and reviewed the manuscript. J.A., R.K. and J.S.F wrote the main manuscript text. J.A. prepared all the figures. J.A. acquired, analyzed, and interpreted neuroimaging data. R.K., L.H-A., J.S.F. administrated and provided interpretation of neuropsychological testing.

Acknowledgments

We are deeply indebted to A.V. for making this research study possible. We also thank A.V.’s mother for checking the factual accuracy of this manuscript with respect to A.V.’s behavior and case history. Her active participation greatly improved our understanding of A.V.’s condition and the factors that contributed to his remarkable adaptation.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/13803395.2023.2254911

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

RK is supported by a Career Development Award (RK: 5IK1 RX003629) from the United States (U.S.) Department of Veterans Affairs.