EPILEPSY. 391 



supply of blood, merely from the improper character of its nutriment 

 and from the admixture of certain materials in the blood. It must 

 also be admitted that the medulla may be thrown into an irritated 

 condition by the transmission of a morbid impression from remote re- 

 gions of the nervous system, whether central or peripheral. It is well 

 known that neuromata and cicatrices, or tumors pressing upon periph- 

 eral nerves, have sometimes occasioned epilepsy (although, indeed, 

 such instances are not common), and that the epilepsy has ceased 

 after section of the affected nerve or after removal of the cause. Per- 

 haps, also, cerebral tumors and other diseases of the brain and spinal 

 marrow may induce epilepsy in a similar manner by gradual transmis- 

 sion of a morbid irritability to the medulla oblongata. This supposi- 

 tion has received strong support from the result of recent experiments 

 by JBrown-Sequard, in which dogs, whose spinal marrows had been 

 injured, suffered from convulsions, although not immediately, but 

 some time after the receipt of the injury. It is difficult to say why 

 the morbid irritability of the motor nerves is not continuous, but mere- 

 ly occurs in paroxysms, with intervals which frequently are of very long 

 duration. Are we at liberty to suppose that it is only now and then 

 that the medulla oblongata falls into this morbid state? Is there 

 really ground for the hypothesis that the cause of epilepsy is a tran- 

 sitory spasm of the muscular fibres of the arteries, with consequent ar- 

 terial anaemia? Is it true that poisons, or the irritation of remote 

 tumors, or other agents which give rise to epilepsy, act by the occa- 

 sional provocation of the spasm of the muscles of the blood-vessels ? 

 May we, with Schroeder van der Kolk^ compare the ganglia of the 

 medulla oblongata to a Leyden jar, or to the electric organ of certain 

 fishes ? May an epileptic fit be likened to the spark from the Leyden 

 jar, or to the discharge of the electric organ of the electric fish ? and 

 do the ganglia reload themselves, as it were, for a fresh explosion 

 during the intervals ? Or, finally, is the morbid state of the medulla 

 constant, but requiring the additional stimulus of some new transitory 

 irritant transmitted to it from some remote point in the brain, the spi- 

 nal cord, the peripheral nerves, or the intestines, in order that the 

 fit may occur ? Of all these conditions we as yet have no accurate 

 knowledge, and it were idle to advance other hypotheses in explana- 

 tion of the foregoing ones. 



Equally inexplicable is the constant coexistence of irritability of 

 the spinal marrow with palsy of the cerebral hemispheres. The arrest 

 of sensation and consciousness has sometimes been regarded as a sec- 

 ondary condition, resulting from the convulsions. It has been attrib- 

 uted in part to venous engorgement of the brain, arising from com- 

 pression of the cervical veins by the contraction of the cervical mus 

 75 



