Clinical forms of poliomyelitis

Depending on the localization of the principal lesions of the nervous system paralytic poliomyelitis is divided into the following forms: a) spinal, b) bulbar, c) pontine, and d) encephalitic. Mixed forms (e.g. bulbospinal) are not uncommon. The name of each of these forms largely defines its pecualiarities.

The spinal form is that most frequent and typical of paralytic poliomyelitis. It is characterized by flaccid paralysis of the limbs, trunk, neck, and diaphragm.

The bulbar form, which is fraught with the greatest danger, is accompanied with swallowing, speech, and respiratory disturbances.

The pontine form is expressed in implication of the nucleus of the facial nerve with paresis of the facial muscles.

The encephalitic form is characterized by general cerebral phenomena and symptoms of focal lesions in the brain.

In addition, paralytic poliomyelitis is divided into the following forms according to the extent of the neurological symptoms and the severity of its course: very mild or abortive, mild, moderately severe and severe.

The visceral (or abortive) form shows symptoms of the initial stage of poliomyelitis, namely, fever, nausea, vomiting, diarrhea, or catarrhal phenomena (cough, coryza, and angina). There are also signs of irritation of the nervous system: headache, adynamia, sleep disturbances, pain in the muscles of the back, paresthesia, and hyperesthesia. Sometimes there are no changes in the cerebrospinal fluid indicative of poliomyelitis. Visceral forms are very frequent; according to various authors, they account for 25 to 80% or more of the total number of poliomyelitis cases.

In the meningeal form there are the same signs as in the visceral, with meningeal symptoms in addition (headache, vomiting, rigidity of the occipital muscles, Kemig's and Brudzinsky's signs, etc.). Findings in the cerebrospinal fluid are a moderate elevation of cell count (increase of lymphocytes) and a normal or slightly elevated protein content.

In vaccinated children poliomyelitis (which is a rare occurrence) has peculiar clinical features. It pursues a very mild course, is either aparalytic or with very slight paresis (mainly monoparesis), and usually terminates in recovery without residual phenomena.

Diagnosis

Recognition of poliomyelitis is easy in the presence of typical manifestations of the paralytic form. Characteristic are an acute febrile onset, rapid development of flaccid asymmetrical paralysis, preponderant affection of the proximal parts of the extremities, and peculiar changes in the cerebrospinal fluid.

Considerable difficulty is presented in the early preparalytic stage by non-paralytic forms, and by poliomyelitis in vaccinated children. The characteristic symptoms of the initial stage must be taken into consideration, in particular signs of irritation of the nervous system, the presence of meningeal symptoms, the slightest signs of weakness in individual groups of muscles, and reduction or loss of tendon reflexes. Examination of cerebrospinal fluid and the finding of pathological shifts typical of poliomyelitis can be of great assistance.

Differentiation of poliomyelitis with lesions of n. facialis nuclei from paralysis of the facial nerve of other etiology is based on the presence of simultaneous involvement of other cranial nerves, and of flaccid paresis or loss of tendon reflexes. With otogenic paralysis of the facial nerve there is otalgia, paresthesia, and hypoesthesia in the area of the ear and face, and taste disturbances in the anterior two-thirds of the tongue. Examination of cerebrospinal fluid is also of considerable assistance here.

It is impossible to distinguish poliomyelitis with a mild course or its pontine form with any certainty from poliomyelitis-like diseases caused by Coxsackie and ECHO viruses solely by the clinical picture. But the following features peculiar to poliomyelitis-like diseases must be kept in mind in differential diagnosis: a frequently afebrile onset; mild paresis that usually disappears rapidly; frequent absence of changes in the cerebrospinal fluid; and appropriate epidemiological evidence (contact with Coxsackie or ECHO infection, summer season).

Meningeal poliomyelitis can easily be confused with various forms of meningitis, and primarily with serous forms of various etiology (due to parotitis virus, Coxsackie and ECHO viruses, etc.), to which it is very similar. The following should be taken into consideration: the presence of other clinical symptoms of these infections (in epidemic parotitis — abdominal pain, increased diastase content in the blood and urine, inflammation of the salivary glands, in Coxsackie and ECHO infections — of epidemic myalgia, herpetic tonsillitis and of epidemiological data (contact with a patient suffering from the corresponding infection: the season).

It should be remembered that poliomyelitis can be mixed with various diseases and injuries to the bones and joints, polyradiculaneuritis, polyneuritis, tick-borne encephalitis, etc.

Now that poliomyelitis is a rare and sporadic disease, laboratory di agnosis has become of particular value. Even when it has a typical course diagnosis of poliomyelitis should be confirmed by virological studies. Patient's feces, and during the first week — nasopharyngeal washings, can serve as material for examination. It should be noted that attenuated (vaccinal) variants of the virus can be isolated from the feces of vaccinated children and of persons who have been in contact with them. Methods of i differentiating these strains from the causative agent of poliomyelitis have been developed. Sera obtained during the first days of the disease, and in two weeks or later are used to detect progressive increase of the antibody titre in the complement-fixation test and neutralization reaction.

Prognosis

Mortality among hospitalized poliomyelitis patients varies widely according to the various sources. It progressively increases with age, and is much higher in adults than in infants. Death usually occurs on the third to seventh day Fatal issues are usually due to complications, pneumonia in particular. A fatal outcome is most common in poliomyelitis accompanied with bulbar phenomena.

Stable paralysis with atrophy, and sometimes deformity, of the limbs develops after an attack of poliomyelitis in 25-40% of cases. In assessing further fate of affected muscles it should be remembered that the earlier functional restoration begins, the better the prognosis. The outcome largely depends on timely and persistent treatment and training.

Treatment

In the acute period of the disease (the preparalytic and paralytic stages) a regimen based on the principle of protective inhibition should be maintained. Strict physical and mental rest in bed should be enjoined for two or three weeks, and thermal procedures (hot wet packs, light baths, paraffin and ozokerite therapy, and transtheimia from the fifth or seventh day) are:_t prescribed. Mild hypnotics and bromides are given to prolong physiological, sleep. Such a regimen has a favourable effect on the course of the disease and reduces complications.

Although no specific effective methods against the poliomyelitis virus have been evolved, gamma-globulin has been suggested for this purpose. A i therapeutic effect from gamma-globulin may only be relied upon apparently - when it is given during the preparalytic stage. Antibiotics are indicated to combat complications resulting from secondary infection (pneumonia, inflammatory processes in the urinary tract, etc.).

Edema of the brain and of its meninges is relieved by intravenous injections of a 20% glucose solution. The following are recommended: ascorbic: acid (0.3 to 0.5 g twice a day); vitamin B,; vitamin B_l2. Spinal puncture is indicated in the presence of marked meningeal phenomena to reduce the, pressure of cerebrospinal fluid. In respiratory disorders lesions of the brain stem are treated with a 1% lobeline solution, 0.1% adrenalin, and oxygen.

The following thermal procedures are also widely employed during the stage of restitution: warm and hot baths, hot packs, paraffin and ozokerite

therapy, and transthermia.

Stimulants of intemeural and myoneural conduction (prosenne, dibazol) are prescribed two weeks after the onset of the disease. Prosenne, (neostigmine) is injected intramuscularly in the form of a 0.05% solution, 0.1 to 1 ml (depending on age), or per os (0.0005-0.001g) two times a day, for 10 to 15 days. Dibazol powders are given in doses of 0.001 to 0.005 g once a day for 20 to 30 days. The course may be repeated after an interval of two months.

Glutamic acid and other amino acids (leucine, sulfate tyrosine) are recommended during the stage of restitution. Glutamic acid improves metabolic processes in the nerve tissue, facilitates conduction of nerve impulses, and influences the contractility of muscle fibres. It is prescribed orally in a dose of 0.5 to 2 g daily in powder form or in glucose solution (the daily dose is divided into two to four fractional doses), for 10 to 15 days.

Massage and kinesitherapy are of particular value during the stage of restitution. They are begun as early as possible (immediately after the abatement of pain), and are continued systematically and persistently for a period of two to three years. To prevent deformities and contractures the limbs should be appropriately positioned and secured by sandbags, splints and other devices.

Prophylaxis

An important preventive measure is the earliest isolation of poliomyelitis patient and suspected cases.

In cases with clear signs of poliomyelitis immediate hospitalization in special departments is obligatory; if there is no special department, patients are placed in isolated wards of cubicles, in which the same regimen as for aerial-droplet and intestinal infections is maintained (attendants wear gauze masks; while tableware, bedpans, patient's secretions and clothes, etc. are subject to current disinfection; flies are combated). After the patient is isolated (for 21 days from the onset of the disease) final disinfection is performed in his dwelling. Contacts are observed for 20 days after isolation of the patient, but are not quarantined.

In children's institutions (creches, nurseries, kindergartens, etc.) the group in which a case of poliomyelitis has been discovered is quarantined for 20 days. All these measures are of little effect because of the wide circulation of the causative agent. The main measure to control poliomyelitis is prophylactic vaccination. The vaccination causes neither general nor local response: it can be combined with APDP-vaccination. The so-called vaccine-associated poliomyelitis (affection of the anterior horns of the spinal cord with flaccid paresis, mostly monoparesis, with a favourable course) occurs extraordinarily rare (1:1-4 million of vaccinated persons or those who had contacts with the vaccinated). The complication occurs more frequently in persons having immunodeficiency.

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