IPLab:Lab 8:HSV Encephalitis
This 30-year-old white male experienced a generalized tonic-clonic seizureA tonic-clonic seizure involves loss of consciousness followed by tonic, then clonic, convulsions. and was subsequently started on a course of Dilantin. He did well, but later developed a headache lasting over a week, which was associated with tonic-clonic seizuresA tonic-clonic seizure involves loss of consciousness followed by tonic, then clonic, convulsions., fever, and--toward the end of this period--ataxia. The patient improved and returned to work, but the headache returned. A lumbar puncture was then performed which showed 22 cells/mm³A normal number of cells in CSF is <4 lymphocytes per mm³. (all lymphocytes), protein of 88 grams/LA normal protein level for CSF should be < 0.4 grams/L., and a glucose level of 49 mg/dLA normal CSF glucose level should be approximately 70% of the patient's serum glucose level. (with a simultaneous serum glucose of 83 mg/dL). These findings were compatible with a viral infection. Despite therapy, the patient had another seizure and again developed fever. At that time, a brain biopsy was performed which showed herpetic encephalitis. Despite aggressive antiviral therapy the patient died.
This is a high-power photomicrograph of the previous section. At this power it is easier to see the blood vessel with the perivascular hemorrhage and mild perivascular lymphocytic cuffing (1). In addition, the areas of edema and loss of neurophil (2) can be better appreciated. Red shrunken neurons and glia with pyknotic nuclei (3) are also evident at this power.
HSV-1 (labialis) produces encephalitis in any age group but is most common in children and young adults. Only about 10% of the patients have a history of prior labial herpes.
- What type of injury is produced by herpetic encephalitis, what areas of the brain are affected, and what are the most common clinical presenting signs/symptoms?
Encephalitis usually involves the inferior and medial regions of the temporal lobes and the orbital gyri of the frontal lobes. The infection is grossly necrotizing and often hemorrhagic with perivascular inflammatory infiltratesAn infiltrate is an accumulation of cells in the lung parenchyma--this is a sign of pneumonia. and Cowdry intranuclear viral inclusion bodies in both neurons and glia. The most commonly observed clinical presenting symptoms are alterations in mood, memory, and behavior.
- eMedicine Medical Library: Herpes Simplex
- eMedicine Medical Library: Herpes Simplex in Emergency Medicine
- eMedicine Medical Library: Herpes Simplex Encephalitis
- Merck Manual: Herpes Simplex Virus (HSV) Infections
- Merck Manual: Encephalitis
- Edlow JA, Panagos PD, Godwin SA, Thomas TL, Decker WW; American College of Emergency Physicians. Clinical policy: critical issues in the evaluation and management of adult patients presenting to the emergency department with acute headache. Ann Emerg Med 2008 Oct;52(4):407-36.
- Thomson RB Jr, Bertram H. Laboratory diagnosis of central nervous system infections. Infect Dis Clin North Am 2001 Dec;15(4):1047-71.
Related IPLab Cases