Key points: Positional paroxysmal nystagmus-vestibular
dysfunction, vascular factor, middle ear diseases, Central pathways,
infectious factor
Key words: positional, paroxysmal nystagmus, cupulolithiasis,
labyrinthitis.
Introduction. Short-term accompanied by severe dizziness,
large-scale nystagmus, which occurs when the patient is laid on his back
with a simultaneous turn of the head to the side and tilt back, is
called positional paroxysmal nystagmus (PPN) [2,3,6]. This symptom
is an important and often the only objective sign of vestibular
dysfunction. PPN, first described by Bárány (1921), is observed in
various diseases and injuries of the inner ear, organic processes in the
posterior cranial fossa, functional disorders of the nervous system,
endocrine disorders, diseases of the cardiovascular system, lesions of
the cervical spine [1,3,5,8].
PPN is a sign of the presence of cupulolithiasis, i.e. the formation of
sediment with a high relative density in the posterior and semicircular
channel of the labyrinth. Possible causes of cupulolithiasis include
age-related degenerative changes in the vestibular part of the
labyrinth, concussion of the inner ear with skull injuries, acute and
chronic purulent otitis media, surgical interventions on the stirrups,
violations of blood supply to the inner ear [4,7].
In addition, many authors consider the presence of chronic infection in
the body to be an important reason for the appearance of PPN overlay.
disorders that occur in the practice of an otorhinolaryngologist are
often caused by the presence of an infectious focus (including acute or
chronic otitis, sinusitis, tonsillitis) or (due to the wide spread of
vascular pathology) disorders of the blood supply to the labyrinth and
its pathways and centers.
The aim of the study was to study the influence of vascular and
infectious factors on the development of positional paroxysmal
nystagmus.
Materials and methods of research. This study is devoted to a
comparative assessment of the value of infectious and vascular factors
in the Genesis of PPN. We observed 548 patients with impaired function,
including 311 women and 237 men aged 15 to 74 years, who were inpatient
treatment at the clinic No. 1 of the Samarkand medical Institute and 45
of them had foci of chronic infection: chronic tonsillitis (19), chronic
polypous sinusitis (12). chronic cholecystitis (8), chronic adnexitis
(6). PPN was observed in 101 of 548 patients. Chronic focal infection
was significantly more common in individuals who had this type of
infection (14 out of 101), but in 37 out of 101 patients, it was not
possible to link the occurrence of paroxysmal nystagmus with the
presence of foci of chronic infection in the body.
Result of discussion. We divided all the patients under our
supervision into 3 groups. Group 1 included patients with vascular
disorders: atherosclerosis (46), hypertension (50), cervical
osteochondrosis with artery syndrome (63), Meniere’s disease (84),
vegetative-vascular dystonia (115); group 2 patients with complications
of acute and chronic purulent otitis media: with various forms of the
labyrinth (109), otogenic intracranial complications (18 patients),
group 3 63 patients with combination of vascular pathology of middle ear
diseases. The data is presented in table 1.
Table 1 shows data on the frequency of paroxysmal nystagmus in patients
of the above-mentioned 3 groups. Thus, in patients of group I, PPN was
significantly more common (P<0.01) than in patients of group
2. However, this symptom was most often observed in a combination of
vascular pathology and middle ear diseases. Obviously, the occurrence in
this group of patients can be explained by a violation of the blood
supply to the ear and the impact of a pathological process located in
the middle ear on the ear labyrinth.
To determine the strength and reliability of the influence of diseases
of the SOSU: the system of pathological processes in the middle ear in
the Genesis of PPN in patients, we applied the method of analysis. Since
violations of the function of the vestibular analyzer are observed
mainly in cerebral forms of vascular pathology, we can distinguish the
following gradations of the degree of intensity of the influence of the
vascular factor the occurrence of paroxysmal nystagmus: 1) cerebral form
of hypertension, cerebral atherosclerosis, cervical osteochondrosis with
artery syndrome, vegetative-vascular dystonia with pronounced phenomena
of fundus spasm (A1); 2) cardinal and cardiocerebral forms of
hypertension, atherosclerosis with a predominant lesion of the carotid
arteries, vegetative-vascular dystonia without pronounced signs of
impaired tone of the brain vessels (A2). It is obvious that the presence
of a purulent focus, especially destructive processes in the temporal
bone, is a greater danger of damage to the inner ear and its conducting
pathways and centers than scarring changes in the tympanic cavity
(adhesive otitis, tympanosclerosis). Therefore, it is also advisable to
distinguish the following gradations or degrees of intensity of the
influence of factor (B) (features of the pathological process in the
middle ear) on the frequency of nystagmus laying:1) purulent chronic
epithympanitis (B1); 2) chronic mesotimpanitis (B2); 3) cicatricial
changes in the tympanic cavity (tympanosclerosis, adhesive otitis),
scars of the eardrums (B3). The data is presented in table 2.
Data on the influence of factors A and B on the detection rate in 63
individuals with various forms of vascular pathology combined with
diseases of the middle ear are shown in table 2, which is the basis of a
two-factor uneven dispersion complex for qualitative characteristics.
The influence of factor A and the total influence of organized factors
(A+AB+ AB) are statistically significant (P<0.01). The
influence of factor B (features of the pathological process in the
middle ear) in 63 patients suffering from vascular diseases in
combination with lesions of the middle ear was statistically
insignificant, which may depend on a relatively small number of
observations.
The data obtained by us indicate that changes in the vascular system
were the main leading factor in the origin of PPN in patients of this
group.
Based on the above, the following conclusions are obtained:
1. in the origin of PPN, vascular disorders are predominant in
comparison with the influence of foci of infection, including those
located in the temporal bone.
2. in patients suffering from positional labyrinth syndrome and PD, it
is advisable to prescribe means that regulate vascular tone and blood
supply to the inner ear.