In the ordinary paroxysm of malignant tertian there is quite a tendency to flightiness during the prolonged hot stage. In the cerebral types of pernicious malaria there may be violent delirium followed by coma or the patient may be comatose from the onset of the paroxysm. Such conditions are often mistaken for sun stroke. In the comatose form of malaria we have a high temperature with sighing or stertorous breathing and at times Cheyne-Stokes respiration.
Following upon the algid stage of cholera we may have a stage of reaction without the disappearance of anuria, in which a typhoid state, with low muttering delirium or even with an acute delirious state, supervenes.
Toward the end of the sleeping sickness stage of trypanosomiasis we have a subnormal temperature with a comatose state.
Comatose states following upon the acute confusional psychoses of pellagra are not uncommon. Pellagra may show an acute collapse delirium.
In heat stroke we may have either delirium or coma. There is no more difficult problem encountered in the tropics than the one of differentiating cerebral malaria from heat stroke.
Oroya fever is frequently accompanied by delirium.
In typhus fever (tabardillo) delirious or stuporous states are to be expected about the end of the first week or even earlier. This is a disease in which the clouding of the consciousness is almost as marked as in plague. Delirium is more apt to occur at night.
In very toxic cases of bacillary dysentery there may be a mild delirium.
Insomnia.—Sleeplessness or, at any rate, a condition where the patient only dozes is often seen in dengue. This mental alertness and wakefulness may also be noted in yellow fever. In malaria, possibly connected with quinine administration, we may have marked insomnia although cases have been reported of insomnia due to malaria which has been relieved by quinine.
Just as cardiac decompensation from any cause will be attended by a distressing insomnia so is this also a feature of beriberi where cardiac involvement is marked.