THE NOtf-CO^TAGIOUS DISEASES. 217 



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their action ; but during inflammation messages cannot 

 be transmitted through the diseased area in the cord, 

 and this leaves that portion and all below it without a 

 brake, and the spinal nerves having escaped the control 

 of the mind, set up a spasmodic action due to the in- 

 flammation. 



At first the inflammation acts as a stimulant and the 

 nerves respond by involuntary movements. The pa- 

 tient cannot control his actions because of the con- 

 stant excitement kept up in the cord. 



In the second stage of that form of paralysis known 

 as locomotor ataxia, the feet and lower limbs escape the 

 control of the patient and fly in all directions. Later 

 the hands and arms may suffer in the same way. With 

 the destruction of the nerves, all motion is lost and 

 paralysis is complete. 



Paralysis of the lower limbs alone indicates invasion 

 of the" lower part of the spinal cord, because the nerves 

 governing them arise in the lower part. Paralysis of 

 the hands and arms indicates invasion of the cervical 

 portion, because the nerves governing them arise there. 



Chronic progressive bulbar paralysis; i. e., paralysis 

 of the muscles of the throat, tongue, lips, etc., is caused 

 by connective tissue overgrowth at the base of the brain, 

 where the nerves supplying these muscles take origin. 

 The nerves themselves are first hardened by inflam- 

 matory processes, and later degenerate. These changes 

 take place gradually; so do these forms of paralysis. 

 At first a few cells are affected, the number increases 

 until nutrition and function of the part escape nerve- 

 control, when the change takes place more rapidly. 



