Posts tagged immunotherapy
Articles and news from the latest research reports.
Isolated Psychiatric Episodes Rare, but Possible, in Common Form of Autoimmune Encephalitis
A small percentage of people diagnosed with a mysterious neurological condition may only experience psychiatric changes - such as delusional thinking, hallucinations, and aggressive behavior - according to a new study by researchers in the Perelman School of Medicine at the University of Pennsylvania. In addition, people who had previously been diagnosed with this disease, called anti-NMDA receptor (anti-NMDAR) encephalitis, had relapses that only involved psychiatric behavior. In an article published Online First in JAMA Neurology, researchers suggest that, while isolated psychiatric episodes are rare in anti-NMDAR encephalitis cases, abnormal test findings or subtle neurological symptoms should prompt screening for the condition, as it is treatable with immunotherapies.
Within a large group of 571 patients with confirmed Anti-NMDAR Encephalitis, only 23 patients (4 percent) had isolated psychiatric episodes. Of the 23, 5 patients experienced the onset of behavior changes as their only symptoms, without neurological changes, while 18 patients had psychiatric symptoms emerge at the outset of a relapse of Anti-NMDAR Encephalitis in which no neurological changes were identified. After being treated for the condition, 83 percent of these patients recovered substantially or completely.
"While many patients with Anti-NMDAR Encephalitis present with isolated psychiatric symptoms, most of these patients subsequently develop, in a matter of days, additional neurological symptoms which help to make the diagnosis of the disease. In the current study, we find out that a small percentage of patients do not develop neurological symptoms, or sometimes these are very subtle and transitory. Studies using brain MRI and analysis of the cerebrospinal fluid may help to demonstrate signs of inflammation," said Josep Dalmau, MD, PhD, adjunct professor of Neurology. "For patients who have been previously diagnosed with Anti-NMDAR Encephalitis and are in remission, any behavior change may present a relapse and should be tested quickly and treated aggressively."
Anti-NMDAR Encephalitis is one of the most common forms of autoimmune encephalitis, and symptoms can include psychiatric symptoms, memory issues, speech disorders, seizures, involuntary movements, and loss of consciousness. In an earlier Penn Medicine study, 38 percent of all patients (and 46 percent of females with the condition) were found to have a tumor, most commonly it was an ovarian tumor. When correctly diagnosed and treated early, Anti-NMDAR Encephalitis can be effectively treated.
"For patients with new psychotic symptoms that are evaluated in centers where an MRI, EEG or spinal fluid test may not have been administered, there is a chance that Anti-NMDAR Encephalitis may be missed,” said lead author Matthew Kayser, MD, PhD, postdoctoral fellow and attending physician in Psychiatry at Penn. "However, the likelihood of pure or isolated new-onset psychosis to be anti-NMDAR encephalitis gradually decreases if no other symptoms emerge during the first 4 weeks of psychosis."
Anti-NMDAR Encephalitis was first characterized by Penn’s Josep Dalmau, MD, PhD, adjunct professor of Neurology, and David R. Lynch, MD, PhD, associate professor of Neurology and Pediatrics, in 2007. One year later, the same investigators, in collaboration with Rita Balice-Gordon, PhD, professor of Neuroscience, characterized the main syndrome and provided preliminary evidence that the antibodies have a pathogenic effect on the NR1 subunit of the NMDA receptor in the Lancet Neurology in December 2008. The disease can be diagnosed using a test developed at the University of Pennsylvania and currently available worldwide. With appropriate treatment, approximately 81 percent of patients significantly improve and, with a recovery process that takes an average of 2 years, can fully recover.
(Source: uphs.upenn.edu)
Cats and humans suffer from similar forms of epilepsy
Epilepsy arises when the brain is temporarily swamped by uncoordinated signals from nerve cells. Research at the Vetmeduni Vienna has now uncovered a cause of a particular type of epilepsy in cats. Surprisingly, an incorrectly channelled immune response seems to be responsible for the condition, which closely resembles a form of epilepsy in humans. The work is published in the current issue of the Journal of Veterinary Internal Medicine.
There is something sinister about epilepsy: the disease affects the very core of our being, our brain. Epileptic attacks can lead to seizures throughout the body or in parts of it. Clouding of consciousness or memory lapses are also possible. The causes are still only partially understood but in some cases brain tumours, infections, inflammations of the brain or metabolic diseases have been implicated.
Epilepsy is not confined to humans and many animals also suffer from it. Together with partners in Oxford and Budapest, Akos Pakozdy and his colleagues at the University of Veterinary Medicine, Vienna have managed to identify the cause of a certain form of epilepsy in cats, in which the body’s own immune system attacks particular proteins in the cell membranes of nerve cells. The symptoms include twitching facial muscles, a fixed stare, chewing motions and heavy dribbling. Based on their clinical experience, the researchers believe that this form of epilepsy is fairly widespread in cats. Interestingly, a highly similar type of epilepsy occurs in humans: an inflammation in the brain, known as limbic encephalitis, leads to epileptic seizures that generally manifest themselves in the arm and the facial muscles on only one side of the body.
Pakozdy and his colleagues have found antibodies in the blood of epileptic cats that react to proteins in the cell membranes of nerve cells. The proteins form the building blocks of ion channels that are involved in the production of nerve signals. The same ion channels are affected in the corresponding human form of epilepsy. They control the membrane’s permeability to potassium ions based on the electric potential across the membrane, thereby helping generate the rapid nerve signals of the so-called action potential.
Immunotherapy for cats?
If the immune system attacks components of these ion channels, the production of nerve signals is disrupted. There is an increased release of neurotransmitters, which leads directly to the symptoms of epilepsy. Previous work – in another group – on human patients has shown that normal anti-epilepsy medication has hardly any effect on this form of epilepsy. However, immunotherapy has proven to be relatively effective. Pakozdy’s work now shows that “limbic encephalitis in cats has the same cause as it does in humans, where the origins have been known for years. It is important that cats with epilepsy are diagnosed early, so that the correct form of therapy can be started. We believe this will dramatically increase the chances of a successful treatment. It seems as though epileptic cats might benefit from treatment with immune preparations.”
(Image: Thinkstock)