Susan Schneider Williams, widow of Robin Williams, opened up this week about the late comedian's confusing final year as he suffered the effects of Lewy body disease and was several times misdiagnosed. In an open letter to the journal Neurology, Schneider Williams details her husband's "relatively swift persecution at the hand of this disease's symptoms and pathology," in an effort to educate neurologists about the effects of the condition on patients and their spouses.

Lewy body dementia or Lewy body disease (LBD) is named for early Parkinson's researcher Frederich H. Lewy, who discovered the abnormal protein deposits in the brain that are now known as Lewy body proteins. As the Lewy Body Dementia Association explains, "LBD refers to both Parkinson’s disease dementia and dementia with Lewy bodies. The earliest symptoms of these two diseases differ, but reflect the same underlying biological changes in the brain."

Schneider Williams had been married to Williams not quite three years when he took his own life in August 2014, and she says it would be three months before an autopsy would reveal that it was likely Lewy body disease that directly precipitated his suicide.

All 4 of the doctors I met with afterwards and who had reviewed his records indicated his was one of the worst pathologies they had seen. He had about 40% loss of dopamine neurons and almost no neurons were free of Lewy bodies throughout the entire brain and brainstem.

She further recalls that Williams suffered a panic attack during the shooting of Night at the Museum 3 in Vancouver in April 2014, and was having difficulty remembering his lines on set, which was highly out of character. A doctor prescribed an antipsychotic medication to help with his anxiety, however Schneider Williams later discovered that such medications can cause extreme symptoms in those with LBD. "This loss of memory and inability to control his anxiety was devastating to him," she writes.

He would be diagnosed with Parkinson's disease on May 28, but apparently this diagnosis was not satisfying to him. Schneider Williams recalls a doctor explaining to her that LBD and Parkinson's are at opposing ends of a spectrum, and because her husband's first symptoms were primarily neurological and psychological as opposed to physical, he should have been diagnosed with diffuse LBD.

She further describes his painful final months, and says that had he been properly diagnosed it might only have "prolonged his agony."

Robin was growing weary. The parkinsonian mask was ever present and his voice was weakened. His left hand tremor was continuous now and he had a slow, shuffling gait. He hated that he could not find the words he wanted in conversations. He would thrash at night and still had terrible insomnia. At times, he would find himself stuck in a frozen stance, unable to move, and frustrated when he came out of it. He was beginning to have trouble with visual and spatial abilities in the way of judging distance and depth. His loss of basic reasoning just added to his growing confusion.

It sounds as though, deep in grief, Schneider Williams spent well over a year researching these brain diseases and trying to become an expert in them. And she cheers on researchers in this field, saying, "Do not give up. Trust that a cascade of cures and discovery is imminent in all areas of brain disease and you will be a part of making that happen."

Previously: Video: Zelda Williams Opens Up To Chelsea Handler About Life After Her Dad's Death