Encephalitis Symptoms Masked as Worsening Parkinson’s Disease, Case Report Shows

Parkinson’s disease can sometimes mask the symptoms of other neurological disorders, according to a case report.

The report, titled “NMDAR encephalitis presenting as akinesia in a patient with Parkinson disease,” documents the case of a 71-year-old woman who was eventually diagnosed with encephalitis, the symptoms of which were first thought to be caused by a worsening of her Parkinson’s.

It was published in the Journal of Neuroimmunology.

The patient, who had a two-year history of Parkinson’s, had initially experienced some difficulty moving her left arm, a condition called bradykinesia, but was generally responding well to levodopa, a mainstay of Parkinson’s treatment.

Then, at the end of 2017, her symptoms started to worsen. Her bradykinesia increased to the point that she was unable to move her arm at all, defined as akinesia. In April 2018, she was admitted to a hospital due to difficulty moving and swallowing.

She stopped responding to levodopa treatment, and her condition continued to decline. She eventually became unresponsive; the authors described her state as being nearly catatonic.

Because the disease was continuing to progress and wasn’t responding to treatment, the doctors decided to examine her cerebrospinal fluid, the liquid that surrounds the brain and spinal cord.

After taking a sample of the patient’s cerebrospinal fluid and running a series of tests, they found antibodies against N-methyl-D-aspartate receptor (NMDAR). These antibodies are a hallmark of encephalitis, which occurs when there is inflammation in the brain — essentially, the body’s immune system attacks cells in or near the nervous system, which is not conducive to proper neurological function.

Typically, encephalitis presents as a severe disease with rapidly worsening symptoms. In this particular case, this was still true — but because the patient had Parkinson’s, which shares some similar symptoms, she was believed to be experiencing worsening Parkinson’s, and not an altogether separate disease.

“Our case should alert neurologists that NMDAR-E [encephalitis associated with antibodies against NMDAR] onset in PD [Parkinson’s] patients could manifest mainly as worsening of PD,” the researchers wrote.

After the correct diagnosis was made, appropriate treatment was swiftly given, and the patient responded well. She gradually regained her function and had completely recovered within three months, her symptoms returning to just bradykinesia of her left arm.

As is often the case in acute encephalitis, the patient has no memory of what occurred during the worst parts of the disease.