2026 ECNP Congress

EP01-1066

Reactivation of bereavement following encephalitis in a patient with alzheimer’s disease: a case report

Beyza Ayçanur Akkuş — C. Çoban · Etlik City Hospital, Psychiatry Department, Ankara, Türkiye

2026 ECNP Congress

Encephalitis is characterized by inflammation in the brain parenchyma, resulting to significant neurological dysfunction. Etiologies are typically classified as infectious and immune-mediated [1,2]. Encephalitis predominantly targets limbic system structures- including the medial temporal lobes, amygdala, hippocampus and orbitofrontal cortex- often resulting in emotional disturbances by disrupting the neurotransmitter mechanisms or neural pathways dedicated to emotional regulation [3,4]. İn patients with dementia, the grieving process is already complicated by cognitive deficits that prevent the assimilation of loss. When depressive symptoms occur in these patients, they are associated with decreased quality of life, increased caregiver burden, and accelerated functional decline [5].

We present the case of an 80-year-old woman with a 3-year history of Alzheimer’s disease. Despite her cognitive impairment, she remained functional, managing daily activities and navigating her neighborhood with minimal assistance. Her husband died 2 years ago.

One year ago, she visited the emergency room with fever, acute emotional lability, psychomotor agitation, and complex hallucinations. Following intensive care stabilization and diagnostic imaging (MRI)-laboratory tests, she was diagnosed with viral encephalitis.

After successful antibiotic treatment, she returned to her baseline cognitive status and was discharged. However, one month after discharge, she experienced a sudden recurrence of grief for her husband’s death. Although she knew that her husband died two years ago, she appeared to ‘re-experience’ the loss with acute emotional intensity. She exhibited anhedonia, hopelessness and repeated speech regarding the deceased. Pharmacological interventions included titrating sertraline to 200 mg/day; however, as the patient did not show clinical benefit from the higher dose, it was reduced back to 100 mg/day. During follow-up, the acute bereavement symptoms were observed to regress spontaneously over time, independent of the medication adjustments. However, the progression of the dementing process was noted to continue.

The differential diagnoses in this case includes complicated grief (CG), progression of dementia, post-encephalitic emotional changes and major depressive disorder (MDD).

While the natural course of grieving typically leads to acceptance within two years, this case illustrates how acute brain pathology can modify the experience of bereavement, effectively “resetting” the emotional clock of a past trauma [5,6].

Research indicates that 90% of encephalitis patients report psychiatric symptoms and 21% of neurology outpatients report depressive symptoms, yet only one-third receive psychiatric follow-up [1,7,9,10]. Emotional dysregulation symptoms are common in mild cognitive impairment (MCI) and are associated with poorer outcomes and higher conversion rates to dementia [11]. The severity of emotional and memory deficits often correlates with the extent of pathology in the medial temporal regions [8,9]. In this patient, the dissociation between preserved factual memory and impaired emotional regulation suggests an organic component, possibly involving microglial activation or inflammation-induced network disruption [2].

This case highlights that encephalitis can reactivate the emotional intensity of a past loss in patients with pre-existing dementia. Recognizing these post-encephalitic psychiatric manifestations is vital, as targeted intervention and an understanding of the organic “reset” of grief can significantly improve neurorehabilitation outcomes and the overall well-being of the patient.

References

  1. Butler, M., Abdat, Y., Zandi, M., et al., 2024. Mental health outcomes of encephalitis: An international web-based study. Eur J Neurol. 2024;31:e16083. doi:10.1111/ene.16083
  2. Bean, P., Heck, A., Habis, R., Sowmitran, S., Cartaina, Z., Gupta, R., Probasco, J., Hasbun, R., Venkatesan, A., 2025. Psychiatric manifestations of encephalitis. Ann Clin Transl Neurol, 12: 405-414. https://doi.org/10.1002/acn3.52260
  3. Granerod, J., Davies, N.W.S., Ramanuj, P.P. et al., 2017. Increased rates of sequelae post-encephalitis in individuals attending primary care practices in the United Kingdom: a population-based retrospective cohort study. J Neurol 264, 407–415. https://doi.org/10.1007/s00415-016-8316-8
  4. Moscato, E.H., Jain, A., Peng, X., Hughes, E.G., Dalmau, J. and Balice-Gordon, R.J., 2010. Mechanisms underlying autoimmune synaptic encephalitis leading to disorders of memory, behavior and cognition: insights from molecular, cellular and synaptic studies. European Journal of Neuroscience, 32: 298-309. https://doi.org/10.1111/j.1460-9568.2010.07349.x
  5. Cindy, J., Grief, D., David, D. M., 2006. Bereavement in Cognitively Impaired Older Adults: Case Series and Clinical Considerations. J Geriatr Psychiatry Neurol 2006 19: 209 DOI: 10.1177/0891988706292753
  6. Arizmendi, B. J., O’Connor, M. F., 2015. What is “normal” in grief?. Australian Critical Care 28: 2: 58–62. https://doi.org/10.1016/j.aucc.2015.01.005.
  7. Harris, L., Griem, J., Gummery, A., Marsh, L., Defres, S., 2020. Neuropsychological and psychiatric outcomes in encephalitis: A multi-centre case-control study. PLOS ONE 15(3): e0230436. https://doi.org/10.1371/journal.pone.0230436
  8. Herken, J., Prüss, H., 2017. Red Flags: Clinical Signs for Identifying Autoimmune Encephalitis in Psychiatric Patients. Front. Psychiatry 8:25. doi: 10.3389/fpsyt.2017.00025
  9. Blum, R. A., Tomlinson, A. R., Jetté, N., Kwon, C. S, Easton, A., Yeshokumar, A. K., 2020. Assessment of long-term psychosocial outcomes in anti-NMDA receptor encephalitis. Epilepsy & Behavior, 108: 107088. https://doi.org/10.1016/j.yebeh.2020.107088
  10. Carson, A.J., Postma, K., Stone, J., Warlow, C., Sharpe, M., 2003. The outcome of depressive disorders in neurology patients: a prospective cohort study. J Neurol Neurosurg Psychiatry. 2003 Jul;74(7):893-6. doi: 10.1136/jnnp.74.7.893. PMID: 12810774; PMCID: PMC1738555.
  11. Ismail Z, Gatchel J, Bateman DR, Barcelos-Ferreira R, Cantillon M, Jaeger J, Donovan NJ, Mortby ME. Affective and emotional dysregulation as pre-dementia risk markers: exploring the mild behavioral impairment symptoms of depression, anxiety, irritability, and euphoria. Int Psychogeriatr. 2018 Feb;30(2):185-196. doi: 10.1017/S1041610217001880. Epub 2017 Sep 13. Erratum in: Int Psychogeriatr. 2019 Jan;31(1):157. doi: 10.1017/S1041610218000637. PMID: 28899446.