Thursday, October 27, 2005

Creeping nightmare... of Lewy bodies!

This is truly scary... apparently a new line of thought holds that Parkinsons disease is just the final stages of a progressive brain degeneration that works its way up the brain stem, disrupting functions as it goes. The problem is, since these disruptions cause only minor behavioral and sensory changes, the only way to know for sure that your on the road to Parkinsons is to have your brain sliced up in a hunt for Lewy bodies... clumps of the protein alpha-synuclein in the brain. Not really a practical test, although I'm sure its great fun at your autopsy to see what diseases you were in line for if you hadn't had those three bottles of Norwegian moonshine at the Christmas party.

The worrysome bit is that the 'early' symptoms caused by this gradual brain degeneration include muscle movement during REM sleep. Normally, when you sleep a part of your brain called the pons shuts off all of your muscles except for those of the eyes... people who have damage to the pons 'act out' their dreams, flailing arms and legs around as they run and jump in their dreamworld. Up from the pons is the substantia nigra, the part of the brain that gets damaged in Parkinsons disease and causes loss of muscle control. What they think happens is that first the Lewy bodies show up in the lower brainstem, work their way up through the pons, and then expand into the rest of the brain, including the substantia nigra. Only when it hits the substantia nigra are the symptoms strong enough to get attention, however... by which time Lewy bodies are all over the place.

So now I have to worry about whether I move in my sleep... am I just rolling over, or is this the first sign of a downward spiral? It could be worse though...

Sleep neurologist Brad Boeve recalls one couple who described a particularly horrendous night-time event. While they slept in their bed, the husband suddenly grabbed his wife's head, shook it around roughly, then slammed it down hard and threw up his arms. Far from being intentional, this distressing episode was the result of a disorder that sees sleeping people physically act out their dreams. In this instance, when the husband woke up he revealed that he had been playing rugby in his dream, had scored a try and then raised his arms in victory.

That fellow may not live long enough to get Parkinsons, if his wife has anything to say about it.