Image of the Month: Agitated Patient
Image of the Month: Agitated Patient
D is Correct. Acyclovir. The patient’s clinical presentation and MRI findings are consistent with herpes simplex encephalitis (HSE). HSE is an infection involving the frontal and temporal lobes of the brain. In adults, HSE is most commonly due to herpes simplex virus type 1 (HSV-1) infection, which is present in up to 90% of the population, occurs early in life and is asymptomatic. Even though HSV-1 infection is so prevalent, very few people are diagnosed with HSE. The exact pathophysiology of HSE is not well understood but the virus is known to exist in the dorsal root ganglia and has the ability to transport in a retrograde fashion to the brain.
The signs and symptoms of HSE include: fever, headache, lethargy, irritability, confusion, focal deficits, aphasia, seizures, behavioral changes, and memory impairment. The presentation of HSE is quite variable, making timely diagnosis difficult. MRI and CSF PCR are important diagnostic tests to do in any patient where there is a clinical suspicion of HSE. HSE is often mistaken for stroke, epilepsy, delirium and psychiatric disorders.
Delayed treatment is associated with significantly worse outcomes, often resulting in neuropsychological impairment and amnesia. If untreated, mortality is close to 70%, and 97% of patients do not return to normal function. Given these devastating consequences, treatment with acyclovir should be started immediately, before CSF analysis confirms HSE. With treatment, mortality is reduced to 19%.
Discontinuation of metoclopramide (A) would be indicated if the suspected diagnosis was akathisia. Given the MRI findings, HSE is more likely. Administration of tPA (B) is indicated in acute ischemic stroke, however brain imaging did not show any acute changes consistent with stroke and the patient presented at a time out of the window for administration of tPA. IV mannitol (C) would be given to decrease intracranial pressure, however there were no signs of increased intracranial pressure on physical exam or imaging. It would be important to monitor for signs of increased intracranial pressure because HSE can cause brain edema leading to uncal herniation. Lorazepam (E) would be indicated to treat seizure activity. This patient’s presentation was not consistent with seizures, although it is important to monitor the patient for signs of seizure activity, as this is one manifestation of HSE.
Answer
D is Correct. Acyclovir. The patient’s clinical presentation and MRI findings are consistent with herpes simplex encephalitis (HSE). HSE is an infection involving the frontal and temporal lobes of the brain. In adults, HSE is most commonly due to herpes simplex virus type 1 (HSV-1) infection, which is present in up to 90% of the population, occurs early in life and is asymptomatic. Even though HSV-1 infection is so prevalent, very few people are diagnosed with HSE. The exact pathophysiology of HSE is not well understood but the virus is known to exist in the dorsal root ganglia and has the ability to transport in a retrograde fashion to the brain.
The signs and symptoms of HSE include: fever, headache, lethargy, irritability, confusion, focal deficits, aphasia, seizures, behavioral changes, and memory impairment. The presentation of HSE is quite variable, making timely diagnosis difficult. MRI and CSF PCR are important diagnostic tests to do in any patient where there is a clinical suspicion of HSE. HSE is often mistaken for stroke, epilepsy, delirium and psychiatric disorders.
Delayed treatment is associated with significantly worse outcomes, often resulting in neuropsychological impairment and amnesia. If untreated, mortality is close to 70%, and 97% of patients do not return to normal function. Given these devastating consequences, treatment with acyclovir should be started immediately, before CSF analysis confirms HSE. With treatment, mortality is reduced to 19%.
Discontinuation of metoclopramide (A) would be indicated if the suspected diagnosis was akathisia. Given the MRI findings, HSE is more likely. Administration of tPA (B) is indicated in acute ischemic stroke, however brain imaging did not show any acute changes consistent with stroke and the patient presented at a time out of the window for administration of tPA. IV mannitol (C) would be given to decrease intracranial pressure, however there were no signs of increased intracranial pressure on physical exam or imaging. It would be important to monitor for signs of increased intracranial pressure because HSE can cause brain edema leading to uncal herniation. Lorazepam (E) would be indicated to treat seizure activity. This patient’s presentation was not consistent with seizures, although it is important to monitor the patient for signs of seizure activity, as this is one manifestation of HSE.