What is Haley-Haley disease, also known as Chronic Methylmercury (Mercury) Poisoning?

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Last updated: May 25, 2025View editorial policy

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From the Research

Fatal familial insomnia (FFI) is a rare and fatal genetic disorder that should be considered in patients presenting with progressive insomnia, cognitive deficits, and gait instability, and managed with a focus on symptom management and palliative care. The disease is characterized by severe progressive insomnia, dysautonomia, neuropsychiatric changes, and gait instability, with diagnostic workup including genetic testing, EEG, MRI imaging of the brain, polysomnography, and CSF analysis 1.

Key Characteristics of FFI

  • Severe progressive insomnia
  • Dysautonomia
  • Neuropsychiatric changes
  • Gait instability
  • Diagnostic workup includes genetic testing, EEG, MRI imaging of the brain, polysomnography, and CSF analysis

Management of FFI

  • Symptom management is the primary focus of treatment
  • Palliative care services should be directed towards patients and families
  • Therapeutic approaches are centered on symptom management, predominantly for insomnia 1
  • Consideration of immunotherapy may be necessary in some cases, as seen in a case report where a patient showed initial improvement with immunosuppressive treatment 2

Importance of Genetic Testing

  • Genetic testing is crucial for diagnosis, as it can identify the D178N mutation in the PRNP gene, which is characteristic of FFI 3
  • PRNP examination is of guiding significance for the diagnosis of FFI 3

Prognosis and Quality of Life

  • FFI is a fatal disease with a poor prognosis
  • The disease typically progresses rapidly, with patients experiencing significant cognitive decline, mobility dysfunction, and mental disorders 2, 3
  • Quality of life is significantly impacted, with patients requiring palliative care services to manage symptoms and improve quality of life.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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