LETHARGIC ENCEPHALITIS

Otaki Mail, Volume 26, 13 June 1919, Page 4

LETHARGIC ENCEPHALITIS

Issued by direction of tlie Minister of Public Health, the Hon. G. W. Bussell.

Deferences have recently appeared in the New 7 Zealand Press reporting a now disease which appeared first at Auckland/ The attention o| the Chief Health Officer was drawn to the disy oase on the Ist May by the District Health Officer at Wellington, and on/ ths sth May the District Health Officer at Christchurch reported a case at Ohoka, Canterbury. Steps were at once taken ■to circularise all health officers. In consequence of the replies received, it has been determined by-the Minister to make the disease —lethargic

encephalitis—notifiable. The literature of the ISS9-90 pandemic shows that apparently this same . disease was noted in certain districts of Europe, more especially northern Italy, where the name “nona” (possibly a corruption of the medical term “coma”) was given to the disease, and the Germans attached to it the words “Schlaf Krankhcit” (sleeping sickness). The earliest record appear* te be an outbreak at Tubingen in 1712, which was called “sleeping sickness.” j The disease was noticed in England during Just year, and recently it has appeared in America as an 'aftermath !of the influenza. The infectivity would appear to be low. The Minister for Public Health has directed that the following article j from the British “Public Health Bc- ; ports,-” of the 21st February, 1919, be ! published for public information. T. H. A. VALIXTJXE, r Chief Health Officer. 1 Lethargic Encephalitis: A Notifiable > Disease in England. The attention of .health officers is invited to the following instructive'description of a new epidemic disease rej eently observed in Europe. It is desir- | able t,o know whether any such cases Mfave been observed in this country, f and, if so, to what extent the disease | prevails.

At a meeting of the Vienna Psychiatric Society held in April, 1917, Von Economo described a group of cases of a disease occurring in epidemic form to which he gave the name “encephalitis lethargies. ” A discussion concerning the same disorder was held the following month by the Paris Academy of Medicine, and Profesior Hotter there expressed the opinion that the disease was not a form of acute poliomyelitis. Ho also quoted some evidence in support of the view that the disease occurred at the end of the seventeenth ami beginning of the eighteenth century in Germany* and more definite evidence that it occurred in upper Italy and Hungary in 1690. Very suggestive cases occurred in nearly all the countries of Europe and in the United States in the spring of 1595. From the data presented by Von Economo it is evident that the disease occurred in Vienna in tire winter of 1916-17.

The first case noted in England occurred 11th February, 191 S, in Bermondsey, and the largest number, of cases in one week was,eighteen, in the last week in April. The number of cases declined thereafter, and the epidemic, which never attained large proportions, came, at least temporarily, to an end in June.

The disease has been made notifiable in England and Wales under the name of •'lethargic encephalitis.” Early lest year the Local Government Board, with the assistance of the Medical liesearcli Committee, instituted clinical and pathological investigations. The results ,of these have now been published in a report (X.S. 121) issued by HAL Stationery Office, London. The following data are abstracted from ti review of the Government report published in a recent'number of the “British Medical Journal,” to which acknowledgments are hereby extended.

The disease is an acute affection due te a specific virus, which, like that of acute anterior poliomyelitis, probably finds entrance through -the nasopharynx, and which, like it. has a special affinity for the nervpus system, though for different areas and elements. Pathologically, lethargic encephalitis belongs to the class of polioer.cepheliric diseases which are inflammatory in nature, Bacteriological investigations did not yield any positive .results.

.Clinically the disease is a general infectious disease characterised by manifestations originating in the central nervous system, of which the most frequent and 'characteristic are progressive lethargy or stupor and lesion in or about the nuclei of the third pair of cranial nerves. Although a rise in temperature was not observed in all the 164 cases of the disease, of which notes were obtained, there scents to be little doubt that there is always a certain amount of fever in an early stage,although occasionally it. may not be observed for several days after the onset of symptoms. The .common range is between loldeg. F. and 102 deg. F.; but temperatures up to FJfdeg. IVarc not very uncommon, and in a feu ..-ases a temperature between lOf deg. F. ami 10-sdeg. !*- has been reached. The pyrexia usually lasts from two to five days, but may continue for ten or even j fourteen. It may fall suddenly or | gradually with oscillations. A period, of subnormal tempralure not infre- [ quently follows. - -

In the majority of eases a prodromal period may be recognise/), but it is not very well defined, the symptoms 'being the early stage of those of the developed disease. Usually the first symptom is simple catarrhal conjunctivitis, and in a smaller number o£ cases tonsilitis, simple sore- throat, and bronchial catarrhs were observed; but the salient svmptom observed in 6i) per cent.- of the eases at this stage was progressive lethargy. It might be ushered in suddenly by a fainting attack or fit. but the onset was more often gradual; the patient became dazed or/ stupid, slept a

great deal, and was drowsy by day. In marked cases the lethargy, was accompanied by heaviness of the eyelids, pain in the eyes, blurred vision, and photophobia, ami, in a well-marked case, gradually passed into stupor. Headache was common, and giddiness was a highly characteristic early symptom. and in some cases was accompanied by diplopia. Mental hebetude was often associated with a highly emotional state, and the patient might exhibit, without apparent cause, symptoms which might be labelled hysterical. In other instances the mental depression was so great that melancholia was suspected. In a few cases only was the patient restless and irritable. The patient may be indisposed to speak —sometimes has distinct difficulty in articulation. The most frequent and characteristic signs in the prodromal period may be summed up as lethargy, asthenia, vertigo, headache, diplopia, and some alteration in the mental state.

After this prodromal period, if it occurs, the symptoms of a general infectious disease become manifest; the febrile reaction has already been mentioned. The patient lies in bed on the back, often unable to make. any voluntary movement on' account of great muscular weakness; the face is quite expressionless and masklike, and there may be definite double facial paralysis. The severest cases lie like a log in bed, resembling a tfaxen image in the lack of expression and mobility, and this may be accompanied by catalepsy. L’he patient is in a condition of stupor, although true sleep is often not obtained. Delirium'usually nocturnal, is not uncommon, and in addition to the muscular trouble there is distinct rigidity in a considerable proportion of cases.- The voice becomes nasal and monotonous, sentences are uttered very slowly, and words slurred into one an other. Occasionally, however, once started to speak, the patient chatters sentences with so great, rapidity that he is often unintelligible. Irregular non-rhythmic spontaneous movements of The face, trunk, and limbs, resembling those seen in clioera or thalamic infections, are not infrequent. Cases occur which present the general symptoms of the disease—pyrexia, lethargy, asthenia—without localising signs, and as a- rule can only be diagnosed from the general surrounding circumstances. The commonest localising sign is ophthalmoplegia, recognised in 75 per cent, of the. cases examined. Ptosis is the commonest form of tliird-ncrvo paralysis, anil is usually at some stage bilateral. Finally, paralysis is usually bilateral, or becomes so, but is almost invariably more intense on one side than tire other.

Dr. MaeXalty recognises seven types of eases: (a) A clinical affection of the third pair of nerves; (b) affections of the brain stem and bulb; (c) affections of the long tracts; (d) the taxic type; (c) affections of the cerebral cortex; (f) cases with evidence of spinal-cord involvement; and (g) the polyneuritic type in which affection of the peripheral nerves is suspected. The prognosis is better than the alarming state of the patient, in the fully developed stage would suggest. Among 16S cases

37 deaths were recorded. The duration - .of the stupor is very variable: occasionally it lasts two or three days, more often two to five weeks, and in one ease, which eventually recovered, it continued for eight weeks. It is too soon to speak positively of aftereffects, but ceriain manifestations have persisted after the expiration of three months from the date of onset; these are an alteration in the mental condition, persistent cranial nerve palsy, the appearance of paralysis (apparently of spinal-cord origin), and athetosis. The diagnosis may be very difficult: the lethargy and the progressive character of the eranial nerve paralysis arc the most characteristic signs. The. frequency of ptosis, paralysis, of the ocular muscles, diplopia, facial paralysis, ami ocular in«o-ordination are the cranial nerve signs: optic neuitis does net occur save in very occasional cases. Diagnosis, The most common error in diagnosis is to attribute the condition to tuberculous meningitis; in many uases a differential diagnosis from cerebro-spinal meningitis cannot be made with an examination of the cerebro-spinal fluid, which is little, if at all. altered in the majority of cases of lethargic eneephaliti*. • r- ■■ Some of the other difficulties encountered have already been mentioned, but the essential difficulty is to separate lethargic encephalitis from the rare , cases of the cerebral form of infantile paralysis. The resemblance is very close, and it seems probable that some of the cases reported in The past as cerebro-spinal poliomyelitis may have been examples of the disease now newlv recognised in this country (England). Dr. MaeXalty has arranged the chief criteria for diagnosis in a table which is too long and detailed for reproduction here. The main points to be noted seem to be that though the chief symptoms of lethargic encephalitis have been described in cases reported as cerebral poliomyelitis, they are slishr. of much briefer duration, ar.d not so constant: lethargic encephalitis. on the other hand, has a very definite clinical syndrome, characterised ov progressive stupor or coma, alternating' delirium, headache, giddiness, asthenia. mental and emotional changes, and, in the majority of eases, hv paralysis of the third pair of eranial nerves. * Paralysis, when present in lethargic encephalitis, is usuallt bilateral and restricted to cranial nerves, but has commonly cleared completely or is less in degree two months after recovery. In these respects it presents « marked contrast, to acute poliomyelitis.

There are c-linieal indications that in the present outbreak both poliomyelitis and lethargse encephalitis have occurred, but not in association with each other.

Dr. Mc-Xalty consider? that the question of the identity or non-identity of the two diseases is stili open, but suggests that the idgtioa between them

may perhaps be comparable to that know! to exist between typhoid and paratyphoid fever.

Treatment. With regard to treatment, no specific method has been devised, and the best that can be done is to put the patient to bed and provide him with good nursing; cold sponging is often beneficial during the pyrexial period, and tends to diminish the delirium. In many instances transient or permanent relief, with diminution of stupor, followed the withdrawal of cerebro-spinal fluid by lumbar puncture, especially when the fluid was under pressure. For the pain, numbness, and tingling of the limbs warmth is the best remedy, and the bedding should be raised on frames. Constipation is obstinate and often difficult to overcome, except by enemata, followed by such drugs as liquid paraffin or phenolphthalien. No hypnotics and no morphine or other preparation of opium should be given, and Dr. MaeXalty deprecates the administration of liexaminc in large and repeated doses; if it is prescribed, the urine should be carefully watched for albumin. Daily cleansing of the mouth, and antiseptic complications systematically looked for. Finally, the patient should be given to understand that his •onvalesccnce will last for at least six months after the beginning of the illness.