By: Richard L. Bruno,Published in: American Journal of Physical Medicine and Rehabilitation, 1998; 77: 1-6.
Nearly two-thirds of polio survivors report abnormal movements in sleep (AMS), with 52% reporting that their sleep is disturbed by AMS. Sleep studies were performed in seven polio survivors to objectively document AMS. Two patients demonstrated Generalized Random Myoclonus (GRM), brief contractions and even ballistic movements of the arms and legs, slow repeated grasping movements of the hands, slow flexion of the arms and contraction of the shoulder and pectoral muscles. Two other patients demonstrated Periodic Movements in Sleep (PMS) with muscle contractions and ballistic movements of the legs, two had PMS plus Restless Leg Syndrome (RLS) and one had sleep starts involving only contraction of the arm muscles. AMS occurred in Stage II sleep in all patients, in Stage I in some, and could significantly disturb sleep architecture even though patients were totally unaware of muscle contractions. Poliovirus-induced damage to the spinal cord and brain is presented as a possible cause of AMS. The diagnosis of post-polio fatigue, evaluation AMS and management of AMS using benzodiazepines or dopamimetic agents is described.
Despite numerous late-onset symptoms reported by polio survivors -- fatigue, muscle weakness, pain, cold intolerance, swallowing and breathing difficulties -- one symptom was totally unexpected: abnormal movements in sleep (AMS). As early as 1984 our post-polio patients were reporting muscle contractions as they fell asleep. The 1985 National Post Polio Survey included two questions about AMS: "Do your muscles twitch or jump as you fall asleep?" and "Is you sleep disturbed by muscle twitching?" (1) It was surprising that 63% of the 676 respondents reported that their muscles did twitch and jump during sleep and that 52% -- a third of the entire sample -- said that their sleep was disturbed by twitching.
These percentages are markedly elevated as compared to the incidence of AMS in the general population. In one survey only 29% of those without neurological disease who were at least 50 years old reported AMS, versus 63% of surveyed polio survivors who were 52 years old on average. (2) In another survey only 34% of those older than 64 reported AMS, slightly more than half the incidence of AMS in the younger post-polio sample. (3) Given the apparent increased prevalence of AMS in polio survivors, and with daytime fatigue the most commonly reported Post-Polio Sequelae (PPS), we were interested in objectively documenting AMS, relating them to possible disturbances in sleep architecture and identifying an effective treatment for AMS. (1)
Subjects. Seven polio survivors were referred for sleep studies to a sleep disorders center. This was a sample of convenience, in that the subjects were patients presenting with PPS who themselves knew (three patients) or whose bed mates knew (four patients) that AMS were occurring. Patients were on average 54 years old and 44 years post acute polio which occurred at age 10. The patients had had AMS for a mean of eight years which was on average 35 years post acute polio. Patients reported moderate-to-severe difficulty sleeping at night and moderate-to-severe daytime fatigue that did not respond to the treatments of choice for post-polio fatigue (i.e., pacing of activities, daytime rest periods, energy conservation and use of appropriate assistive devices. (4) In addition to fatigue, patients reported an average of two limbs having late-onset muscle weakness.
Procedure. Patients underwent a standard polysomnographic evaluation with EEG and facial EMG recorded for sleep staging. (5) Blood oxygen saturation, measured using a finger pulse oxymeter, chest and abdominal wall excursion and nasal air temperature were also recorded; video monitoring of sleep was also performed. Surface EMG was recorded from patients' legs as well as from limbs in which AMS were reported.
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México a la vanguardia en el Síndrome de Post Polio