For me, freezing is a state of rigidity. It is all but impossible to lift my foot to take a step. Stress, such as a need to get to the bathroom, makes it much worse. I can count on it at two times of the day. One is when the meds drop off the plateau either because I forgot to take them or it is time for bed. The other is as one of those attacks enters its recovery phase. I have read that freezing is a short term problem that will pass soon. Not so for this. Once an attack begins it is going to run its two-hour course of low tone - acute urinary output - high tone - return to normal. The time of day when this is likely to happen is also part of the pattern. These tie into potassium fluctuations in response to insulin levels.

It is tempting for me to simply think of Laura and myself as anomalies. But I am not so sure. After all, sinemet messes with our insulin systems. Further, the following is from 1973 when levodopa was still new:

Levodopa has proved to -be safe despite many dose-
dependent adverse reactions at the start of treatment when
the dose is being adjusted to an optimal level. But with longterm treatment two new problems have emerged. One,
which has been termed "oscillation in performance" or the
"on-off phenomenon,"1 2 comprises rapid transient deteriora-
tion of the Parkinsonian motor deficit, which develops over
minutes and usually persist for 1-6 hours. These episodes
then clear spontaneously. Hypokinesia, tremor, and rigidity
may be exacerbated over the period of deterioration. Hypotonia is common and has also lbeen reported. These
oscillations in performance are commonest in patients
who have been on levodopa for over a year. They usually
occur in the afternoon, and they may be repeated in cycles.
Their mechanism is not understood.
The second new problem with levodopa is a group of
endocrine disturbances which have been detected by
metabolic investigation but which have not so far caused
clinical symptoms. Administration of levodopa over a year
has been found to result in a rise of growth hormone in the
plasma, an increase in serum cholesterol, a decrease in glu
cose tolerance, and a delayed but exaggerated insulin re-
sponse.3 It appears that these changes take some time to
become established, as similar investigations after shorter
periods of levodopa therapy have failed to show the same
abnormalities.4 British Medical Journal; Feb 17, 1973

I can't help but wonder if there is a part of the sinemet story yet to be told.