TY - JOUR
T1 - Transient epileptic amnesia
T2 - A treatable cause of spells associated with persistent cognitive symptoms
AU - Ramanan, Vijay K.
AU - Morris, Kenneth A.
AU - Graff-Radford, Jonathan
AU - Jones, David T.
AU - Burkholder, David B.
AU - Britton, Jeffrey W.
AU - Josephs, Keith A.
AU - Boeve, Bradley F.
AU - Savica, Rodolfo
N1 - Funding Information:
The authors wish to thank the staff from the Department of Neurology at the Mayo Clinic in Rochester, Minnesota for clinical and administrative support.
Funding Information:
Conflict of Interest Statement: JG-R and KJ receive funding from the National Institutes of Health. DJ receives funding from the National Institutes of Health and the Minnesota Partnership for Biotechnology and Genomics. JB is an unpaid co-investigator for the following studies: a double-blind, randomized, placebo-controlled study to investigate the efficacy and safety of cannabidiol (GWP42003-P, CBD) as add-on therapy in patients with tuberous sclerosis complex who experience inadequately-controlled seizures; a double-blind, randomized, placebo-controlled study of IVIG in patients with voltage-gated potassium channel complex antibody-associated autoimmune epilepsy; an open label extension study to investigate the safety of cannabidiol (GWP42003-P; CBD) in children and adults with inadequately controlled Dravet or Lennox-Gastaut syndromes; and a study on the compassionate use of stiripentol in an intractable epilepsy due to Dravet syndrome and malignant migrating focal epilepsy of infancy. BB has served as an investigator for clinical trials sponsored by Axovant and Biogen; he receives royalties from the publication of a book entitled Behavioral Neurology of Dementia (Cambridge Medicine, 2009, 2017); he serves on the Scientific Advisory Board of the Tau Consortium; and he receives research support from the NIH, the Mayo Clinic Dorothy and Harry T. Mangurian Jr. Lewy Body Dementia Program, and the Little Family Foundation.
Publisher Copyright:
© 2019 Ramanan, Morris, Graff-Radford, Jones, Burkholder, Britton, Josephs, Boeve and Savica.
PY - 2019
Y1 - 2019
N2 - Objective: To characterize the clinical, EEG, and neuroimaging profiles of transient epileptic amnesia (TEA). Methods: We performed a retrospective analysis of patients diagnosed with TEA at the Mayo Clinic Minnesota from January 1, 1998 to September 21, 2017. Diagnostic criteria included the presence of recurrent episodes of transient amnesia with preservation of other cognitive functions and evidence for epilepsy [epileptiform abnormalities on EEG, clinical features of seizures, or symptomatic response to anti-seizure medications (ASMs)]. Results: Nineteen patients were identified (14 men, 5 women) with median onset age 66 years and median time to diagnosis 2 years. Thirteen patients (68%) reported persistent cognitive/behavioral symptoms, including 4 (21%) for whom these were the chief presenting complaints. EEG revealed epileptiform abnormalities involving the frontal and/or temporal regions in 12/19 individuals (63%), including activation during sleep in all of these cases. In numerous cases, sleep and prolonged EEG evaluations identified abnormalities not previously seen on shorter or awake-state studies. Brain MRI revealed focal abnormalities in only 4/19 cases (21%). FDG-PET identified focal hypometabolism in 2/8 cases where it was performed, both involving the frontal and/or temporal regions. Anti-seizure therapy, most often with a single agent, resulted in improvement (reduction in spell frequency and/or subjective improvement in interictal cognitive/behavioral complaints) in all 17 cases with available follow-up. Conclusions: TEA is a treatable cause of amnestic spells in older adults. This syndrome is frequently associated with persistent interictal cognitive/behavioral symptoms and thus can be mistaken for common mimics. In the appropriate clinical context, our findings support the use of early prolonged EEG with emphasis on sleep monitoring as a key diagnostic tool. FDG-PET may also complement MRI in distinguishing TEA from neurodegenerative disease when suspected.
AB - Objective: To characterize the clinical, EEG, and neuroimaging profiles of transient epileptic amnesia (TEA). Methods: We performed a retrospective analysis of patients diagnosed with TEA at the Mayo Clinic Minnesota from January 1, 1998 to September 21, 2017. Diagnostic criteria included the presence of recurrent episodes of transient amnesia with preservation of other cognitive functions and evidence for epilepsy [epileptiform abnormalities on EEG, clinical features of seizures, or symptomatic response to anti-seizure medications (ASMs)]. Results: Nineteen patients were identified (14 men, 5 women) with median onset age 66 years and median time to diagnosis 2 years. Thirteen patients (68%) reported persistent cognitive/behavioral symptoms, including 4 (21%) for whom these were the chief presenting complaints. EEG revealed epileptiform abnormalities involving the frontal and/or temporal regions in 12/19 individuals (63%), including activation during sleep in all of these cases. In numerous cases, sleep and prolonged EEG evaluations identified abnormalities not previously seen on shorter or awake-state studies. Brain MRI revealed focal abnormalities in only 4/19 cases (21%). FDG-PET identified focal hypometabolism in 2/8 cases where it was performed, both involving the frontal and/or temporal regions. Anti-seizure therapy, most often with a single agent, resulted in improvement (reduction in spell frequency and/or subjective improvement in interictal cognitive/behavioral complaints) in all 17 cases with available follow-up. Conclusions: TEA is a treatable cause of amnestic spells in older adults. This syndrome is frequently associated with persistent interictal cognitive/behavioral symptoms and thus can be mistaken for common mimics. In the appropriate clinical context, our findings support the use of early prolonged EEG with emphasis on sleep monitoring as a key diagnostic tool. FDG-PET may also complement MRI in distinguishing TEA from neurodegenerative disease when suspected.
KW - Amnestic spells
KW - Dementia
KW - Memory impairment
KW - Neurodegenerative disease
KW - Sleep electroencephalogram (EEG)
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UR - http://www.scopus.com/inward/citedby.url?scp=85071719365&partnerID=8YFLogxK
U2 - 10.3389/fneur.2019.00939
DO - 10.3389/fneur.2019.00939
M3 - Article
AN - SCOPUS:85071719365
VL - 10
JO - Frontiers in Neurology
JF - Frontiers in Neurology
SN - 1664-2295
IS - AUG
M1 - 939
ER -