Part 2 — CHAPTER LII NEUROLOGICAL CONSIDERATIONS IN TROPICAL DISEASES

There is a great tendency in the tropics to ascribe neurological manifestations to beriberi or malaria. It must be acknowledged, however, that various sensory and motor phenomena, which may show themselves from time to time, in those who have suffered from beriberi, are common and prove sources of confusion in diagnosis. Tropical sunlight with its ultra-violet rays had a vogue which held sway for a brief period as explaining most nervous conditions in Europeans in the tropics. At present we are inclined to believe that excesses in eating and drinking and late hours may be more potent in the production of nervous breakdowns than are factors less cosmopolitan.

While syphilis is rampant in many parts of the tropical world the usual views are that the luetic neurological manifestations, so common in temperate climates, are more or less nonexistent. At the same time it would seem advisable with this point in view to study the cases attributed to other causes along the line of laboratory investigations of the cerebro-spinal fluid.

Clinically there are many points of difference between syphilis as seen in the native races of tropical regions and as observed in Europeans at home, and it would seem advisable to do more work along the line of spinal fluid examinations. The examination of the spinal fluid for syphilis should include a Wassermann test using several concentrations ranging from 0.2 to 1.0 cc., a globulin estimation, cell count and Langes colloidal gold reaction,—the last not being necessary however, unless positive findings are obtained in one or more of the other tests. Of course the most important test is the Wassermann of the spinal fluid and every one should bear in mind the marked complement fixation power of the spinal fluid of paretics. In such a fluid we almost always obtain a positive reaction where quantities of 0.2 cc. or less are employed, while with locomotor ataxia or cerebro-spinal lues amounts of 0.5 to 1 cc. are generally required to give a positive test. It is not necessary to inactivate spinal fluid.

These tests can only be carried out in a well equipped laboratory and the same is true of the colloidal gold one. The tests for cell increase and globulin increase, however, can be made by anyone prepared to do ordinary clinical laboratory work.

The normal spinal fluid is as clear as water, has a specific gravity of about 1.010 and is under a pressure of about 5 to 7 mm. of mercury or 60 to 100 mm. of water. The sugar content is about 0.07% and the proteid content about 0.03 to 0.04%.

Cerebro-spinal Fluid Examinations

To withdraw spinal fluid for bacteriological examination or cytodiagnosis we use a sterile needle about 4 inches long for an adult, preparing the skin as described for blood cultures from a vein (see page 516). The patient is placed on the left side with knees drawn up and head and shoulders carried forward to give the greatest possible space between the spinous processes by arching the spine. A line at the level of the iliac crests passes between the third and fourth lumbar vertebrae. Select a point midway between the spinous processes of these lumbar vertebrae and enter the needle two-fifths of an inch to the right of this point, pushing the needle inward and upward. Collect the material in two or three sterile test tubes, to avoid contamination of the entire sample by a drop of blood which may come out in the first portion. The presence of blood in very slight amount interferes with cytodiagnosis and globulin tests and, if present in more than a trace, it makes the colloidal gold test practically worthless. Make cultures on blood serum at the earliest possible moment. Centrifugalize a portion of the fluid at high speed and examine the sediment for bacterial content. After the puncture the patient should drink a glass or so of water and remain in bed for a day, preferably with the head lower than the feet.

In general terms, excluding syphilis, it may be stated that:

1. A lymphocytosis indicates a tuberculous or poliomyelitis process. With these diseases, the fluid will probably be clear.

2. An abundance of polymorphonuclear and eosinophilic leucocytes indicates an infection with pyogenic organisms, in which cloudy fluid is the rule.

Meningism shows very few cells.

Trypanosomiasis gives a cellular increase very similar to syphilis. In the work of the French Sleeping Sickness Commission five cells per cubic millimeter was taken as normal.

Not only may trypanosomes be found in the spinal fluid, when they mark the setting in of the “sleeping sickness” stage of trypanosomiasis, but a case has been reported of the presence of Trichinella embryos in the spinal fluid. Recently a few cases have been reported of anthrax meningitis, in which anthrax bacilli have been found in the spinal fluid.

Cell Count.—A method of examination considered by neurologists as of differential diagnostic value is to count the number of cells in a cubic millimeter of the cerebro-spinal fluid. The technic is to use a gentian-violet-tinged 3% solution of acetic acid. This is drawn up to the mark 0.5, and the cerebro-spinal fluid is then sucked up to 11. After mixing, the cell count is made with the haemacytometer.

Count all the cells appearing in the entire ruled area (9 large squares) and add one-sixth of this number to find the approximate total number of cells per cubic millimeter of spinal fluid examined as above. It is advisable to make the cell count of the fluid as soon after obtaining it as possible, the cells tending to degenerate or adhere to the glass of the tube. The latter can be minimized by vigorous shaking before withdrawal of the fluid for counting. Normally we have only two to ten cells per cubic millimeter, but in tabes and general paresis this is increased to 50 or 100 cells, greatest at onset of disease.

Pleocytosis.—Miller gives the following table as to pleocytosis:—

Average Incidence of Lymphocytosis in the Spinal Fluid (Plaut, Relim and Schottmuller)

Clinical diagnosis Frequency, per cent. Remarks

Cerebro-spinal lues 85-90 Counts often over 100—may reach 1000 per c.mm.

Tabes dorsalis 90 Counts usually under 100.

General paresis 98 Counts average 30-60 cells per c.mm.

Secondary lues 30-40 Moderate increase as a rule.

Multiple sclerosis 25 Border-line counts.

Cerebral haemorrhage { Frequency

Cerebral tumors { is Cellular increase is apt to be a very moderate one.

Sinus thrombosis { variable

Globulin Increase Tests.—Noguchi’s butyric acid test is very satisfactory, but because of the objectionable odor of the butyric acid, we use the Ross-Jones and Pandy tests routinely in our laboratory.

For the Ross-Jones method, one cc. of saturated solution of ammonium sulphate is placed in a small test tube and one cc. of spinal fluid placed on top of this column. If globulin increase is present a turbid ring appears within a few seconds at the junction. Normally there is no sign of a ring. This test is a modification of Nonne’s Phase 1 reaction. For Pandy’s test, prepare a saturated solution of carbolic acid crystals in distilled water. Place 1 cc. of this reagent in a small test-tube and add 1 drop of spinal fluid. In a normal fluid, only the faintest opalescence is observed; but in a fluid with globulin increase a smoke-like white cloud develops instantly where the drop comes in contact with the reagent.

Colloidal Gold Test (Lange’s).—It is now generally accepted that this test is more diagnostic of general paresis than any other single test. The color changes in the first five tubes (1-10 : 1-160) are so constant that the term “paretic curve” is applied to such findings. Of less diagnostic value are the so-called cerebro-spinal lues curves where the color changes, though of less intensity than the paretic ones, are most marked in the third, fourth, fifth and sixth tubes (1-40 to 1-320). In various types of meningitis, other than luetic, the color changes are at times more marked in the tubes with the higher dilutions of spinal fluids (from 1-320 to 1-2560).

The paretic curve of the colloidal gold test generally runs parallel with a spinal fluid Wassermann and globulin increase. This agreement does not exist at all constantly for positive blood serum Wassermann tests and increased cell counts.

It may be stated that this test is of more importance in paresis than any single one of the four reactions of Nonne, viz.: (a) blood serum Wassermann; (b) spinal fluid Wasserman; (c) globulin increase, and (d) increased cell count of spinal fluid (pleocytosis). Of course, all of these tests should be carried out.

Test.—The test is carried out by preparing a series of ten test tubes containing dilutions of spinal fluid in 1 cc. of normal saline, ranging from 1-10 to 1-5120, and adding 5 cc. of the colloidal gold reagent to each tube and to a control tube containing salt solution alone. The successful application of the test is dependent upon (a) care in the preparation of the reagent; (b) absolute cleanliness of all glassware used, and, (c) on the entire absence of blood from the spinal fluid. Before using a new colloidal gold solution, it should be tested with spinal fluid of known reaction, so that it may be discarded if too sensitive or not sufficiently so. The color changes usually start almost immediately and if there is no change evident in half an hour, there will probably be none later. The maximum change occurs after several hours, so that readings are made after the tubes have stood overnight at room temperature. The proper color of the control in tube 11 should be salmon-red or old rose and the fluid should be perfectly transparent. When the color is changed in tubes containing dilutions of the spinal fluid we record one showing a bluish tint as 1. When the change is to a lilac we record it as 2. A distinct blue is marked as 3 and a pale blue as 4. When decolorization is complete there is the highest color change, which is noted as 5.

Mastic Test.—The mastic test as devised by Cutting is apparently of value as an aid in the diagnosis of syphilis of the nervous system. The test is made by treating six dilutions of spinal fluid in test tubes with an alcoholic extract of pure gum mastic, diluted with distilled water before using. Its great value lies in the ease of preparation from an effective gum mastic, and in the keeping qualities of the stock alcoholic extract. After standing at room temperature for twelve to eighteen hours or at 37°C., for six to twelve hours, readings are made. In positive cases (paresis) the mastic will be precipitated in the first one, two, three or four tubes (higher in strongly positive cases) leaving the supernatant fluid clear, with the mastic as a white flocculent precipitate at the bottom of the tube. In some positive reactions the opalescence of the fluid persists with a fine white precipitate at the bottom. The control tube must remain unchanged.

Showing the Average Frequency of the Various Reactions in Syphilis Of The Central Nervous System (Miller)

Paresis Tabes dorsalis Cerebro-spinal

per cent. per cent. syphilis

Blood Wassermann 98-100 70 70-80

Spinal fluid Wassermann 97 60-80 85-90

Pleocytosis 98 85-90 85-90

Positive globulin test 100 90-95 90-95

Colloidal gold test 98-100 85-90 75-80

Paretic curves Luetic type of curve Luetic curve

Other Chemical Constituents.—Normally the fluid reduces Fehling’s or Benedict’s qualitative copper solutions. It is well for one to gain experience with the degree of reduction to be normally expected as the test is but slightly marked. Quantitatively, the reducing substance is equivalent to 60-70 mg. glucose per 100 cc.

The urea is practically the same as in the blood, parallels any change in the latter, and has the same significance. Creatinine is about half that of the blood, and has apparently no clinical significance. Uric acid is present in still smaller proportion.

Delirium and Coma

It is difficult to make a sharp distinction between a disease showing delirium and one showing coma as delirious states tend to be followed by coma or such conditions may alternate.

In yellow fever the alert, suspicious mental state may give way to one of marked delirium requiring close watching to prevent the patient throwing himself from his bed.

In plague there is more of a mild delirious state in which the patient has a great tendency to wander about. The mental state is rather that of an intoxicated person with the thickness of speech and retardation of mental processes.

Typhus fever and spotted fever of the Rocky Mountains tend to produce stuporous states.

A delirious state, especially at night, is often noted in tsutsugamushi.

Rat bite fever also tends to show delirium.

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.

Liver abscess may be attended with insomnia.

Malta fever is often attended with a weariness from suffering with the various joint and nerve pains so that insomnia is often marked.

Even in trypanosomiasis insomnia may be present at first. Insomnia is also one of the early neurasthenic manifestations of pellagra.

Somnolence.—The disease in which this symptom is best known is sleeping sickness. The patient may go to sleep lying in the bright sunlight or in the midst of eating a morsel of food. These cases can be easily aroused but quickly drop off to sleep afterwards. They often deny that they were asleep. Later on in sleeping sickness the patient may sleep from 24 to 36 hours continuously and a more marked tendency to somnolence may be present by day than by night.

In the prodromal stage of leprosy somnolence is often marked and accompanied by a sensation of unaccountable weakness. Sweatings and accessions of fever may also be noted at this time.

In plague the rather stuporous state of the patient may give the impression of somnolence.

Cephalalgia, Rachialgia and Other Pains

Yellow fever is marked by pains in the lumbar region, the coup de barre of the French. It is as if the patient had been beaten over the small of the back with a bar of iron. The headache is rather orbital and is often excruciating. There are also frequently heavy, dull pains of the extremities.

Blackwater fever also has marked pains in the lumbar region giving expression to the kidney damage done by the haemoglobin detritus plugging the tubules.

In all forms of malaria, but especially in the paroxysms of malignant malaria, there are severe headaches and pains in the extremities. Intermittent neuralgia is often regarded as malarial.

Dengue gives rise to a marked post-orbital soreness rather than pain. There is also a marked rachialgia with pains in the limbs often referred to the regions of the joints, which, however, are not swollen.

In Malta fever the neuralgias, especially sciatica, often associated with suddenly appearing, painful joint swellings, are prominent features.

In trypanosomiasis headache is often marked, together with a characteristic deep hyperaesthesia, so that the striking of a limb against a hard object gives rise to excruciating pain, there being, however, a delay in the experiencing of the painful sensation.

In relapsing fever the headache is often intense with pains in the back and bones.

In cholera one of the most striking phenomena of the disease is the terrible cramping of the muscles, especially those of the calves and feet. These pains actually torture the patient. Cramps of abdominal muscles as well as those of extremities are often noted in heat stroke in men in firerooms.

In beriberi there is often pain in the epigastric region so that the slightest touch causes great distress. This epigastric tenderness is also a feature of yellow fever. The calf muscles are also markedly hyperaesthetic in beriberi.

In leprosy the neuralgic pains may be very severe while the nerves are being pressed upon by the connective tissue increase of the endoneurium and perineurium. Mention has been made of excruciating pains of toes, especially the big toe, even suggesting gout.

The excruciating pains of Oroya fever are connected with the changes taking place in the bone marrow. There is probably more rapid alteration in the blood picture in this disease than in any other. It might be designated a fulminating pernicious anaemia.

Pain on pressure on dorsal or lumbar spine is common in pellagra.

Plague may be associated, during the first day or two, with an excruciating headache. This may even be prodromal but tends to disappear with the rapidly developing stuporous state of the patient.

In typhus fever boring headache, oppressive rather than lancinating, is a feature of the first days. It is usually frontal or temporal.

In malignant tertian the headache is often quite intense during the prolonged hot stage. The headache of malaria is usually frontal or suboccipital.

In trench fever we may have a cutaneous hyperaesthesia over the shins. Rocky Mountain fever shows joint pains.

Tremors and Convulsions

It is in trypanosomiasis that we have the most important tremor. It is the fine tremors, which first are noticeable in the tongue and later in hands and even legs, that mark the onset of the stage of sleeping sickness with the trypanosomes in the cerebro-spinal fluid. At times an intention tremor may be noted in advanced cases of sleeping sickness. In addition we have epileptiform seizures in sleeping sickness.

In cerebral manifestations of pernicious malaria there is a type characterized by epileptiform convulsions.

In the acute stage of Brazilian trypanosomiasis we may have almost any type of cerebral or cord lesion.

Tremors of tongue and hands may be present in the second stage of pellagra.

Fibrillary tremors have been noted in the main-en-griffe of beriberi but tremors of the tongue and hands, so common in alcoholic neuritis, are rare in beriberi.

Convulsive seizures are not uncommon in the hyperpyrexial type of heat stroke.

In infantile beriberi the child often becomes rigid. There is not a true convulsion but such cases are at times thought to have meningitis.

In schistosomiasis and paragonomiasis as well as in infections with the larval stage of Taenia solium we may have brain involvement and manifestations of Jacksonian epilepsy.

Altered Reflexes Including Sensory and Motor Disturbances

Beriberi.—It is usually stated that the tendon reflexes of the lower extremity, especially the patellar reflex, are absent. While this is generally true they may at first show an exaggeration and some cases do not seem to show any decided change. There may be striking variation from day to day in the reflexes. The superficial reflexes, especially the cremasteric, are as a rule more active than normally.

The sensory changes in beriberi are less marked than those of the motor side. There is rarely complete anaesthesia but rather a blunting of sensation. Hyperaesthesia, particularly of the muscles of the calf of the leg, is well marked when the muscles are grasped with the hand.

The anaesthesia is earliest noted over the shin bone and dorsum of the foot. A loss of tactile sense is often noted about finger tips making it difficult for the patient to button his coat.

The most striking motor phenomena are the foot and wrist-drop, especially the former. The extensor muscles are more markedly involved than the flexors. There is marked muscular weakness of foot as well as hands. The weakness of the muscles of the leg is often the first symptom to be complained of. The type of palsy in beriberi is mainly paraplegic although hemiplegic and monoplegic types have been reported. The paralysis of the diaphragm is the most serious of the muscle palsies.

Contractures of the muscles of the foot or calf of the leg may occur. Contractures of the muscles of the upper extremity are more rare. Muscular atrophy of the leg muscles is often marked. In the upper extremity the muscles of the hand are most frequently atrophied.

Pellagra.—There is considerable variation from time to time in the reflexes. Some authorities attach diagnostic value to the appearance of an exaggerated reflex on one side and a diminution or absence of the corresponding reflex on the other side. Ankle clonus may be present.

Paraesthesias and in particular a burning sensation of the erythematous areas are often noted. Hyperaesthesia of the dorsal and lumbar regions is often noted. Pruritus is at times complained of in the region of the perineum. We have muscular weakness.

Sleeping Sickness.—The deep reflexes are usually exaggerated and the superficial ones diminished or absent.

There is no distinct alteration of motor or sensory function except that of deep hyperaesthesia (Kérandel’s sign). There is usually marked weakness of muscles of locomotion.

Leprosy.—The usual statement is that there is an exaggeration of the deep reflexes. Ankle clonus has been rarely reported.

Anaesthesia is the most important symptom in the diagnosis of leprosy. This loss of sensation is often for pain and temperature with retention of tactile sense (dissociation of sensation—a prominent symptom of syringomyelia). The anaesthesia is not only found in the spots but associated with the leprous neuritis which chiefly involves the ulnar, facial and peroneal nerves. Muscle palsies and atrophies are common and the main-en-griffe appearance of the hand is seen.

In lathryism we have spasticity and an exaggeration of the reflexes.

A very remarkable disease called kubisagari or paralytic vertigo has been observed in Japan. This disease is thought to affect those living in stables. The attacks only last a few minutes and at other times the patient seems normal. An attack shows ptosis and diplopia, speech disturbances and palsy of muscles of back of neck, causing the head to fall forward. There may also be some paresis of muscles of extremities. The disease is not fatal. Cases have been observed in Switzerland.

The Gait

There are no gaits in tropical diseases which can strictly speaking be regarded as special types of gait. In beriberi we often note the designation tripod gait of beriberi. This simply refers to the manner in which a case of the paraplegic type of beriberi uses a stick held by his hands to assist him in dragging along his atrophied and enfeebled legs. The legs are widely separated and the stick placed in front makes the two legs and stick resemble a tripod.

It is true that beriberics show the steppage gait of multiple neuritis as, owing to more or less foot-drop and lack of power to extend the toes, the patient lifts his foot high from the ground to avoid scraping the toes, and bends to the other side. It is as if a man were walking through a mire.

When other groups of muscles than the foot extensor ones become involved the gait is that of extreme weakness—a shuffling one.

In sleeping sickness it is a shuffling gait. It is as if one were dragging the feet along from pure muscular weakness.

In pellagra we may see a gait in which the patient separates his legs rather widely and uses a stick in front, shuffling his feet along with knees slightly bent and soles of the feet scarcely raised from the ground.

Some cases show a typical spastic paralytic gait.

We often note under dengue the designation dandyfied gait. This refers to the stilted, mincing gait of a dandy and is probably the explanation of the derivation of the word dengue. The pains about the site of the insertions of muscles with the slightest movement make these patients walk in a stiff, self-conscious manner.

Psychic and Neurasthenic States

A very remarkable fact is that in many tropical and subtropical regions where syphilis is rampant among the natives there is slight or absent incidence of general paresis and locomotor ataxia.

Jefferys and Maxwell state that the parasyphilitic manifestations were absent in thousands of cases observed by them in Formosa. In the Philippines one sees occasionally typical cases of these parasyphilitic diseases but of course standard methods of treatment of syphilis have been employed there for many years.

In China, where there is practically no treatment for syphilis, luetic ulcerations are exceedingly common and it has been suggested that insufficient treatment cures the skin lesions but adds to the effects on the nervous system. It will be remembered that skin and nerve tissue arise from similar embryological layers (epiblast) hence a suppression of toxic effect on one tissue may add to the burden on the other. It has been suggested that if the surface lesions are allowed to develop to maturity, the skin, which is the great elaborating center for antibodies, will produce enough adequately to protect the whole body; whereas, if the surface lesions are aborted, there is a diminished stimulus with consequent diminished elaboration of protective bodies. The brain is then liable to parenchymal invasion, since chemicals, owing to difference in their physical properties, cannot replace natural antibodies in controlling the disease in this location. This theory takes no reckoning of differences exhibited by variant strains of treponema in their tendencies toward selective localization. It has been noted that the form of syphilis endemic in certain regions is much less virulent than is the cosmopolitan form.

Pellagra.—Very important in diagnosis is a more or less prolonged prodromal period of neurasthenia which is apt to be more marked in the winter at a time when the skin and alimentary tract manifestations are in abeyance. Along with the anxiety and unrest of this neurasthenia we have lack of mental concentration and depression of spirits.

A melancholic state is almost always present in the psychosis of pellagra. There is not the indifferent, satisfied, more or less happy mental state of the case of general paresis. Some consider the pellagrous psychosis to belong to the toxic group, as from alcohol or cocaine, while others place it in the group of infective psychoses, as the post-influenzal one. Gregor regards it as belonging to the infective-exhaustive group. The insanity of pellagra is that of an acute confusional one.

In the final cachexia there is a dementia.

Sleeping Sickness.—It may be many months or even years before the mental changes follow the trypanosome fever stage. At first a change in disposition is noted, the patient becoming listless and apathetic.

There is great impairment of mental concentration and memory. There may be later on catatonic manifestations as echolalia, mutism or flexibilitas cerea. There may at times be paranoid manifestations to be succeeded by states of profound melancholia. In the terminal stage a comatose state overshadows the psychical manifestations.

Malaria.—Leaving out of account the acute delirious states which accompany cerebral malaria there have been reported cases showing various manifestations of psychic disturbances even to maniacal or melancholic forms of insanity.

It is a common practice to attribute the irritability and lack of mental concentration of those who have lived for a long time in the tropics to the damage done the cerebral cortex by the malarial parasite. It is certainly more reasonable to attribute these minor psychic disturbances to malaria rather than to actinic rays of the sun.

There is no doubt but that quinine, given either for treatment or prophylaxis of malaria, is a cause as potent as alcohol and tobacco in tropical neurasthenia.

Insolation.—It is popular to assign neurasthenic manifestations to the actinic rays of the sun or the tropical heat, as these influences operate on every resident of the tropics. It is very necessary to exclude derangements of the digestion due to errors in diet with resulting exhaustion of the pancreatic and hepatic functions.

Alcohol is a potent factor for tropical neurasthenia as the tendency is for excess in this direction in those who in temperate climates are only moderate drinkers.

Hookworm Disease.—The patients with this disease are apt to become hypochondriacal and even melancholic.

There is a correspondence between the physical and mental backwardness of children with this disease, a child of twelve, who by the Binet-Simon test will only be rated at 7 will also not seem larger or better developed physically than a child of seven years would be.

Malta Fever.—Owing to the neuralgic pains and insomnia patients with this disease are apt to become neurasthenic. They are peculiarly liable to form the morphine habit if this drug be placed in their hands for the relief of pain.

The victims of leprosy not only may show an indifference to their condition but may also exhibit a moral apathy.

Dengue often shows a rather marked neurasthenia during convalescence and this may be protracted if the patient tries to resume his active duties before his complete recovery.

In latah there is echolalia and echopraxia, the patient repeating words he hears and mimicking movements he sees. The mind is usually clear. As a matter of fact the symptoms show similarity to those of the catatonic form of dementia praecox. The disease is more common in that part of the world centering in the Malay peninsula. Suggestion is an important factor in this neurosis.

In amok, a sort of epileptiform seizure in which the patient is obsessed with a desire to kill, there may be no recollection of the running amok. After the attack the patient may be stuporous.

Lunacy in the Tropics

Van Loon, having examined over 200 cases from among 1100 insane patients in Java, found the most common types of mental disease to be dementia praecox, general paresis, various manifestations of cerebral syphilis and acute maniacal or confusional states. Not only were all forms of mental disorder known in European countries represented, but their comparative frequency and the types of conduct exhibited were, on the whole, what might be expected in the study of a group of similar cases encountered in any other part of the world.

Overbeck-Wright in his book—“Lunacy in India”—notes that 44% of cases were under treatment for various types of mania, 15.9% for melancholia, 4.8% for delusional insanity, 5.2% for idiocy, 5.7% for dementia and 6.6% for insanity following the use of Cannabis indica. It is noted that dementia praecox is not included in the statistical returns, but the author states that in his experience hebephrenia and katatonia account for a much larger proportion of cases than melancholia.

Overbeck-Wright is of the opinion that general paresis is quite common in India notwithstanding the fact that for many years the opinion has obtained that syphilis of the central nervous system and the parasyphilitic diseases were exceedingly rare among tropical natives. He regards the incidence of cerebral disease in syphilitic natives as less than with Europeans, attributing this fact to the existence of an immunity acquired through the prevalence of syphilis among these people during a period of several centuries. Cases of general paresis are generally reported under the diagnosis of chronic mania.

Van Loon also notes the mistake made in most books on tropical medicine as to the rarity of general paresis. General paresis being a disease in which we have such characteristic laboratory diagnostic tests, especially the colloidal gold test, there should be little difficulty in settling this question of its absence or relative infrequency among natives of tropical regions.