Extensive planning came to fruition last month when 55 clinicians and researchers from 14 different countries assembled in Santa Cruz, CA. Participants included neurologists specializing in motor neuron disease, those with expertise in neuroimaging or electrophysiology, neuropathologists, statistical geneticists and basic scientists. In other words, a group of experts in a wide range of subspecialties related to motor neuron disease. The meeting was funded through generous support of PLS Friends and Families, the Les Turner ALS Foundation, and the National Institute of Neurological Diseases and Stroke and the National Institutes of Health's office of Rare Disorders. Additional funding was provided by the Spastic Paraplegia Foundation and the Muscular Dystrophy Association.

The conference began Friday evening with a presentation by Lewis Rowland, MD, a preeminent neurologist widely acknowledged as a leader in the field of motor neuron diseases, who gave an overview of PLS, reviewing its definition from Charcot to Pringle, and outlining the work to be done the following days. He set the tone for the conference in his comprehensive, thoughtful presentation.

Saturday consisted of over eight hours of 10-30 minute presentations by experts in the fields of clinical neurology, neurophysiology (electrical studies such as electromyography and nerve conduction velocities), neuropathology (the study of nervous system tissue such as brain and spinal cord), imaging (such as MRIs, CT scans), and genetics.

Each presenter gave his or her opinion as to what should be considered and included in PLS diagnostic criteria for that area of specialization. This was an extremely thought-provoking day with a large amount of information put on the table for consideration. Lively discussion ensued over dinner and into the evening.

Saturday was a perfect set-up for Sunday. The morning addressed future research considerations in PLS, particularly in genetics, imaging, animal modeling, and patient identification. The remainder of the day was spent in small break-out groups organized according to the participant's expertise: clinical practice, neurophysiology, imaging, neuropathology and genetics. Each group was charged with developing criteria for diagnosis of PLS which focused solely on their area of expertise. It was heart to see these experts (many with strong opinions) come to a consensus within their groups.

The clinical criteria (the signs and symptoms of a PLS patient, what a PLS patient should look like) was the most contentious and difficult to negotiate because they need to be broad enough to identify everyone with PLS, but narrow enough to set them apart from other motor neuron diseases. By definition PLS is a disease affecting motor neurons (UMN), so symptoms demonstrating their involvement must be present. Duration of symptoms was a key element hotly debated. It was finally agreed UMN signs must be present for 3 years, without progression to LMN signs,  for a diagnosis of  "pure PLS."

Despite the enormous amount accomplished at this meeting, the criteria need fine-tuning. Drafts are being compiled and will be published after review by the attendees, hopefully by early next year. Then they will be circulated to the larger community of neurologists via the American Academy of Neurology and World Federation of Neurology websites population of motor neuron disease neurologists and specialists for comment and revision.

A follow-up PLS Symposium was held at Northwestern University in Chicago on June 26, 2004 to present a summary of the International PLS Conference for patients and families. The day was success, with a combination of information and social interaction. It was orchestrated by four women affectionately known as the "Fab 4" for their tremendous efforts in PLS: Thurza Campbell, Angela Dixon, Linda Gentner and Jennifer Thomson, founders of PLS Friends and Families.