Types of Beriberi.—The ordinary clinical division of beriberi is into (1) wet or dropsical beriberi and (2) dry or atrophic beriberi. At the same time, in a typical case, we find such a combination of the vasomotor disturbances which lead to the oedematous or dropsical manifestations of wet beriberi, and likewise of those of peripheral nerve involvement causing more or less development of muscular palsies or atrophies, as seen more strikingly in dry or atrophic beriberi, that it does not seem advisable to employ such a division.
In fact typical cases of wet or dropsical beriberi after a profuse diuresis may change in a short time, as Manson has so aptly stated, from a bloated carcass to little more than skin and bones and assume all the appearance of a case of dry or atrophic beriberi.
Even Vedder, who states that from a theoretical standpoint wet and dry beriberi may be considered separate pathological processes (deficiency in the anti-cardiac degeneration vitamine rather than the anti-neuritis one), is inclined to believe it inadvisable, from a clinical standpoint, to consider the one type apart from the other.
One sees cases which combine the features of dry and wet beriberi which can best be designated typical beriberi. Again we see cases where the vagal and vasomotor involvement is so marked that the patient resembles a man with acute nephritis plus all the evidence of extreme cardiac decompensation. Such cases may be designated fulminating, pernicious or better cardiac.
Again we observe cases which from the start show little if any oedema and very slight cardiac involvement, but with marked motor disturbances as shown by muscular atrophies and palsies. The sensory changes are not so marked as the motor ones. Complete anaesthesia is rarely present, it is rather paraesthesia and blunting of sensation which characterize the sensory phenomena. This is usually designated the atrophic or paraplegic type.
Rudimentary or Larval Beriberi.—Scheube recognizes a rudimentary type and it must have been the experience of every one in the tropics that these indefinite types of beriberi are quite common.
In such cases there may be nothing more than some weakness of the legs with vague manifestations of blunting of the sensation or variation of the reflexes. At times there may be marked anaesthesia in the region over the shin bones.
Many of these cases show cardiac palpitation on exertion and at times we may note slight evidences of oedema about the lower part of shin bone or dorsum of the foot. It is the frequency of such cases that causes physicians in the tropics to consider almost any affection showing neurological manifestations as of beriberi nature. A careful study of the neurological features of cases in the tropics will show that many of these cases are not beriberi but rather the common cosmopolitan diseases of the nervous system.
A Typical Case of Beriberi.—The patient first complains of weakness and heaviness of the legs, particularly after fatiguing work. There is also noted a sense of fullness and tenderness in the epigastric region. The slightest exercise brings about cardiac palpitation and more or less dyspnoea.
As the symptoms of peripheral neuritis become more prominent we have hyperaesthesia of the calf muscles so that squeezing these muscles gives rise to rather marked pain. The thenar muscles or those of the forearm may also be more or less hyperaesthetic. Attention has been called to a circumoral anaesthesia.