=Acute Pernicious Beriberi.=—This is the fulminating type of beriberi in which the marked involvement of the vagus overshadows the other but less manifest phenomena of the disease. In some cases the signs of peripheral neuritis may be quite prominent before the fulminating onset of the cardiac manifestations, there being almost a total lack of disturbance of the vasomotor system. Again we may have slight if at all demonstrable motor or sensory disturbances but with marked oedema. It should be borne in mind that this development of cardiac disturbance with its fatal tendency may develop even in a case of rudimentary beriberi. It is a common experience that cases considered as mild types may, in a few hours, show cardiac involvement and terminate fatally with striking suddenness. There is apt to be marked epigastric tenderness or even distress coming on with the onset of the acute cardiac involvement. It may be so extreme that the patient dreads the slightest palpation of his epigastrium. From a marked palpitation and praecordial distress evidences of the dilatation of the right heart become prominent. Indications of tricuspid insufficiency are seen in the pulsating jugulars and cyanosis. The cardiac dullness is greatly increased to the right and various abnormalities of sounds and rhythm may be observed. There is also dyspnoea and a sensation of constriction of the chest (beriberic corset). These are the cases which give as horrible a picture of death as one ever sees. In the final struggle for breath and praecordial agony of the last stages of decompensation in old heart lesions we have a more gradual course in a more asthenic patient. Acute pernicious beriberi may run its course in a strong, vigorous patient in a few hours. In some cases we have paralysis of the diaphragm. =Paraplegic and Rudimentary Types.=—The rudimentary type has already been considered and it would be impossible to draw a line between slightly developed paraplegic cases and rudimentary ones. The paraplegic cases show the weakness of feet and hands going on to wrist and foot-drop. There is also marked blunting of sensation of feet and hands which gives one the impression of ataxia when the patient tries to button his coat. [Illustration: FIG. 83.—_A_, Mixed Beriberi. _B_, Wet Beriberi. _C_, Dry Beriberi. (From Jackson’s Tropical Medicine.)] There is atrophy of muscles so that the grip of the patient is enfeebled. This partial anaesthesia also accounts for the pseudoataxic gait in which the element of muscular weakness is prominent as opposed to the vigorous heel stamping gait of the ataxic tabetic. The patient drags the toes and leans forward on a cane when walking, thus suggesting the tripod. It is the typical steppage gait of degeneration of the lower motor neurones. It is a flaccid, atrophic paralysis of the muscles. There is no involvement of the sphincter.