Encephalitis, Polyethylene glycol solution (PEG) plus contrast, and long-lasting symptoms.

Encephalitis is a complex and often serious condition that affects the brain. 

It is typically caused by a viral infection, with the most common viruses being herpes simplex (which causes cold sores), varicella zoster (responsible for chickenpox and shingles), and other viruses like those causing measles, mumps, and rubella. One specific type, KLHL11 encephalitis, is characterized by rhomboencephalitis and presents with symptoms like ataxia, diplopia, dysarthria, hearing loss, tinnitus, and vertigo. In this case, hearing loss and tinnitus can precede other neurological deficits by months.

The symptoms of encephalitis are diverse and can vary in severity. Common symptoms include fever, seizures, headaches, movement disorders, sensitivity to light and sound, and neck stiffness. In more severe cases, it can lead to short-term memory loss, confusion, mood disturbances, epilepsy, psychosis, sleep disorders, and even permanent issues such as fatigue, irritability, impaired concentration, and sensory losses like hearing loss and blindness.

Autopsy Study Shows Acute Neutrophilic Vasculitis (Leukocytoclasia) In Brains Of Those Who Died From COVID-19!
https://www.thailandmedical.news/news/autopsy-study-shows-acute-neutrophilic-vasculitis-leukocytoclasia-in-brains-of-those-who-died-from-covid-19

Psychologically, encephalitis can manifest in various ways. Patients may show emotional and behavioral changes, including difficulties in managing anger and signs of major depression, sometimes exhibiting suicidal behaviors in the early stages of the illness. Unfortunately, these psychological symptoms are often underdiagnosed or misdiagnosed as standard psychological disorders like depression, aggression, and anxiety, leading to inappropriate treatments. This underdiagnosis is partly because psychological evaluations rarely include tests for encephalitis.

Pathophysiologically, encephalitis involves direct neurotoxicity such as that damages the blood-brain barrier and causes endothelial dysfunction. Risk factors for developing encephalitis include hypertension, diabetes mellitus, renal insufficiency, and the use of large volumes of contrast media, with males being at higher risk.  

Summary of a case report: Original publication: https://www.aerzteblatt.de/archiv/236513/Kontrastmittelinduzierte-Enzephalopathie?rt=e73420a6b2b56371fb0a7f4614a5aa01
The case described involves a older patient who underwent a coronary angiography using 190 mL of Ultravist 370, a contrast agent.
Based on these observations, the diagnosis of contrast-induced encephalopathy (CIE) was considered.

Contrast-induced encephalopathy is a rare but recognized complication following the use of contrast media in diagnostic imaging. Pathophysiologically, CIE is attributed to direct neurotoxic effects leading to damage to the blood-brain barrier and endothelial dysfunction. Factors that increase the risk of CIE include hypertension, diabetes mellitus, renal insufficiency, the use of a large volume of contrast medium, and male gender.

The clinical presentation of CIE can vary, but it commonly includes neurological symptoms like confusion, visual disturbances, headache, and sometimes more severe manifestations such as seizures. In most cases, the symptoms of CIE resolve spontaneously within 24 to 72 hours. To prevent recurrence, it is advisable to avoid repeat administration of contrast medium, especially if the patient has known risk factors.

Early detection and appropriate management are crucial to ensure a favorable outcome and prevent long-term neurological sequelae.

Repeated MRI or CT scans with contrast at short intervals can raise concerns about potential adverse effects, particularly in individuals with pre-existing conditions or risk factors. However, the development of encephalitis as a direct result of repeated MRI or CT scans with contrast is not a typical or well-documented outcome.

Encephalitis, which is inflammation of the brain, is most commonly caused by viral infections, but can also be triggered by other factors like autoimmune diseases or, very rarely, vaccinations. The contrast agents used in MRI and CT scans are generally considered safe for most patients, but they can have side effects, especially in individuals with kidney problems, as the kidneys are involved in clearing the agents from the body.

One rare complication related to contrast agents is contrast-induced encephalopathy (CIE), as previously mentioned. CIE is a transient and reversible condition characterized by a variety of neurological symptoms, and is different from encephalitis in its causes and manifestations. The risk of CIE can increase with the volume of contrast agent used and with certain patient-related risk factors like renal insufficiency, diabetes, hypertension, and advanced age.

Is contrast toxic to brain?

Neurotoxicity from iodinated contrast agents is a known but rare complication of angiography and neurovascular intervention. Neurotoxicity results from contrast penetrating the blood-brain barrier with resultant cerebral oedema and altered neuronal excitability. Persistent Neurological Deficit from Iodinated Contrast Encephalopathy Following Intracranial Aneurysm Coiling

In summary, while repeated imaging with contrast in short intervals should be approached with caution, particularly in at-risk populations, it does not typically lead to encephalitis. The primary concerns with frequent use of contrast agents are usually related to kidney function and the risk of CIE in susceptible individuals.

It's important to note that many of the symptoms of encephalitis may resolve once the infection is under control. Early detection and appropriate treatment are crucial for minimizing long-term effects and improving patient outcomes.