Large motor units are selectively affected following a stroke

M Lukács*, L Vécsei, S Beniczky

*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskriftArtikelForskningpeer review


OBJECTIVE: Previous studies have revealed a loss of functioning motor units in stroke patients. However, it remained unclear whether the motor units are affected randomly or in some specific pattern. We assessed whether there is a selective loss of the large (high recruitment threshold) or the small (low recruitment threshold) motor units following a stroke.

METHODS: Forty-five stroke patients and 40 healthy controls participated in the study. Macro-EMG was recorded from the abductor digiti minimi muscle at two levels of force output (low and high). The median macro motor unit potential (macro-MUP) amplitude on the paretic side was compared with those on the unaffected side and in the controls.

RESULTS: In the control group and on the unaffected side, the macro-MUPs were significantly larger at the high force output than at the low one. However, on the paretic side the macro-MUPs at the high force output had the same amplitude as those recorded at the low force output. These changes correlated with the severity of the paresis.

CONCLUSIONS: Following a stroke, there is a selective functional loss of the large, high-threshold motor units. These changes are related to the severity of the symptoms.

SIGNIFICANCE: Our findings furnish further insight into the pathophysiology of the motor deficit following a stroke.

Sider (fra-til)2555-8
Antal sider4
TidsskriftClinical Neurophysiology
Udgave nummer11
StatusUdgivet - nov. 2008


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