ARACHNOIDITIS. 13 



efiusion. He considers that staggers most commonly arises from acute arach- 

 noiditis, the result of which is hydrocephalus ; that arachnoiditis may be 

 either idiopathic or symptomatic ; and that in the chronic form it has been 

 described under the appellation of serous apoplexy, and on many occasions is 

 present with that assemblage of symptoms which have been grouped together 

 under the name of immohilite. 



As the symptoms and pathological characters of idiopathic arachnoiditis, 

 M. Roupard has given, irregularity in the appetite, obscure vision, conjunc- 

 tive membranes injected, superficial veins turgid, hearing impaired, body 

 tucked up; sometimes the mouth wide open and the tongue hanging out; 

 temperature of the body now hot, now cold ; pulse slow and oppressed, or 

 else small, thready, frequent, irregular; dragging of the hind quarters; 

 thrusting the head against the rack ; rearing the fore-feet into the manger ; 

 restlessness ; flinging himself about, and even backwards ; head erected with 

 wild stare, or jerking up and down; tremor of the limbs and tail; loss of 

 vision and audition ; sweatings ; and, as death approaches, eyes fixed with 

 convulsions. Autopsy. — Belly tympanitic; no traces of inflammation within 

 the abdomen : pulmonary tissue crepitous ; cerebral mass less consistent than 

 in health ; cerebral sinuses and superficial vessels filled with deep-coloured 

 blood ; lateral ventricles dilated from containing more or less limpid serosity, 

 slightly citrine-coloured ; the portion of choroid plexus floating in this fluid 

 discoloured and sodden-like ; the arachnoid rose-tinted, and displaying very 

 perceptibly reddish spots. 



In the above account the practitioner of experience cannot fail 

 to recognise the characters of staggers : indeed, it tends to confirm 

 the view here taken of the pathology of that disease, that it is 

 essentially, in its acute and violent form, a membranous affection, 

 the brain being but symptomatically or secondarily deranged. 



D'Arboval held the same opinion : — " De toutes les phlegma- 

 sies cerebrales celles qui se trouvent le plus souvent re-unies et qu'il 

 est le plus difficile de distinguer, pour les considerer isolement, sont 

 I'encephalite et la phrenesie. Celle-ci, — qui serait mieux nommee 

 arachnoidite, est inflammation de la ?ne??i6ra?ie sereuse du crane ; 

 a laquelle se joint souvent celle de la meninge qui la recouvre, 

 et celle de la substance encephalique elle-meme. CettejDhlegmasle, 

 ainsi etendue, est ce qui repond a ce que les veterinaires et les hip- 

 piatres ont designt sous le nom de VERTIGE ESSENTIEL, pour le 

 distinguer du vertige abdominal, que n' est que symptomatique." — 

 (Vol. ii, p. 175.; 



Vatel, in observing that inflammation of the brain is ordinarily 

 accompanied by iiiflanunation of the arachnoid membrane, and ac- 



