Herpes Simplex Virus Diencephalitis Leading to Panhypopituitarism

Area of Science:

• Neurology
• Endocrinology
• Infectious Diseases

Background:

• Herpes simplex virus (HSV) is a common cause of viral encephalitis.
• Hypothalamic-pituitary dysfunction is a rare complication of HSV encephalitis, with limited data on long-term outcomes.

Observation:

• A 46-year-old male presented with delirium, fever, and polydipsia, initially with normal brain imaging and CSF.
• MRI revealed T2-hyperintensity in the hypothalamus and related structures; HSV1 DNA was detected in CSF, confirming HSV diencephalitis.
• The patient exhibited severe electrolyte imbalances and subsequently developed central diabetes insipidus and panhypopituitarism.

Findings:

• The patient was diagnosed with permanent central diabetes insipidus, central hypothyroidism, hypogonadotrophic hypogonadism, and adrenal insufficiency.
• Neurocognitive deficits, including executive function and information processing impairments, persisted months after initial recovery.
• Long-term complications included hypothalamic hyperphagia and temperature dysregulation, necessitating lifelong hormone replacement therapy.

Implications:

• This case underscores hypothalamic-pituitary dysfunction as a rare endocrine complication of HSV diencephalitis.
• It highlights the complex, long-term management challenges, including hormonal replacement and ongoing endocrine surveillance.
• Understanding these rare complications is crucial for comprehensive patient care and prognosis in HSV encephalitis.