A nervous disorder that had arrived at so high a degree of development must have been long in existence, and doubtless had required an elaborate preparation by the concurrence of general causes.
The symptoms which followed the bite of venomous spiders were well known to the ancients, and had excited the attention of their best observers, who agree in their descriptions of them.

It is probable that among the numerous species of their phalangium, the Apulian tarantula is included, but it is difficult to determine this point with certainty, more especially because in Italy the tarantula was not the only insect which caused this nervous affection, similar results being likewise attributed to the bite of the scorpion.

Lividity of the whole body, as well as of the countenance, difficulty of speech, tremor of the limbs, icy coldness, pale urine, depression of spirits, headache, a flow of tears, nausea, vomiting, sexual excitement, flatulence, syncope, dysuria, watchfulness, lethargy, even death itself, were cited by them as the consequences of being bitten by venomous spiders, and they made little distinction as to their kinds.

To these symptoms we may add the strange rumour, repeated throughout the middle ages, that persons who were bitten, ejected by the bowels and kidneys, and even by vomiting, substances resembling a spider's web.
Nowhere, however, do we find any mention made that those affected felt an irresistible propensity to dancing, or that they were accidentally cured by it.

Even Constantine of Africa, who lived 500 years after Aetius, and, as the most learned physician of the school of Salerno, would certainly not have passed over so acceptable a subject of remark, knows nothing of such a memorable course of this disease arising from poison, and merely repeats the observations of his Greek predecessors.
Gariopontus, a Salernian physician of the eleventh century, was the first to describe a kind of insanity, the remote affinity of which to the tarantula disease is rendered apparent by a very striking symptom.