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August 1929


Author Affiliations


From the Institute of Neurology, Northwestern University Medical School.

Arch NeurPsych. 1929;22(2):265-281. doi:10.1001/archneurpsyc.1929.02220020081004

Orthodox physiology does not satisfactorily account for normal muscle tonus nor for the various types of hypertonus and contracture. The inadequacy of the explanations of these phenomena, which can be deduced from the conception of a single motor innervation and the all-or-none law, has led to the formulation of theories of dual innervation and a special holding mechanism. The theory which has attracted most attention is that skeletal muscle receives a tonic innervation from the sympathetic nervous system. But, fairly recently, another theory was formulated by Frank,1 namely, that tonic impulses are conveyed to the muscles antidromically over parasympathetic fibers in the dorsal roots. At the time this ingenious idea was conceived it had much in its favor. The pseudomotor phenomenon, a slow tonic contraction produced by stimulation of the dorsal roots after degeneration of the ventral root fibers, is closely allied to antidromic vasodilation and to the contracture produced

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