MONDAY, Oct. 13 (HealthDay News) -- Quick tumor removal and immunotherapy can reverse the progress of a newly recognized neurological disease called anti-NMDA-receptor encephalitis (ANRE), a new study says.

ANRE can occur when a tumor causes the immune system to produce antibodies that disrupt NMDA receptors, which play a crucial role in brain function. The disease mainly affects women -- about 90 percent of cases -- but is also found in men and children.

The first patients identified were young women with ovarian tumors. They had serious psychosis or memory problems, rapidly progressing to multiple serious neurological problems requiring intensive care, said study lead author Dr. Josep Dalmau, of the University of Pennsylvania department of neurology, and colleagues.

Of the 100 patients in a study, ages 5 to 76, 91 were women. All the patients had psychiatric symptoms or memory problems, 76 had seizures, 88 had decreased consciousness, 86 had involuntary movements frequently involving the face, 69 had autonomic nervous system instability, and 66 had hypoventilation (abnormally slow and shallow breathing).

Of 98 patients tested for cancer, 58 had tumors -- most commonly ovarian teratomas. Patients who received quick tumor treatment and immunotherapy had better outcomes and fewer neurological relapses than other patients, the study said. Patient improvement was associated with a decrease in anti-NMDA receptor antibodies. Seventy-five of the patients recovered or had mild neurological deficits, while 25 had severe deficits or died.

The researchers noted that "ANRE can also, in about 40 percent of patients, develop without the presence of a tumor. We believe that some of these patients may have a microscopic tumor, but we also acknowledge that most have been followed for many months or years without developing a tumor. Nevertheless, given that the neurologic disease usually develops before the presence of a tumor is known, all patients with this disease should first be examined for a tumor."

The study was published online Oct. 13 in The Lancet Neurology and is to appear in the December print issue of the journal.

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