Keywords poliomyelitis - post-polio syndrome - neuromuscular diseases - larynx diseases - voice
disorders.
Palavras-chave poliomielite - síndrome pós-poliomielite - doenças neuromusculares - doenças da laringe
- distúrbios da voz
Introduction
The poliomyelitis, caused by RNA enterovirus (picornavirus), is in most of the cases
little symptomatic or manifests itself with a clinical Picture similar to a cold or
flu[1 ]
[2 ]. The central nervous system involvement with paralysis or paresis occurs in 1 to
2% of the cases[3 ]. The affinity of virus by neurons of the anterior horn of the spinal results in
the loss of these cells and consequent Wallerian degeneration of nerve fibers, resulting
in muscle weakness[4 ]. After the acute phase of denervation, usually occur reinnervation of some muscle
fibers by axonal branches from others motor units not denervated, with recovering
of muscle function, in greater or lesser extent[4 ]
[5 ].
The bulbar form can follow the involvement of the members or occur in isolation. Although
any nucleus can be involved, the most frequent are the ones in the bridge, particularly
nucleus ambiguous, nucleus V, VII, XII and vestibular nucleus[1 ]. This form of the disease presents a high rate of mortality because of the vasomotor
disorders that can occur as hypertension, hypotension and shock[1 ]. The patients that recover generally are able to develop compensation of oropharyngeal
problems, making these manifestations less important than in the acute phase of the
disease[6 ].
After a long period of stability, that range from 20 to 40 years, patients with previous
history of polio, can develop a late deterioration manifested as mobility impairments,
of upper limbs functions, of respiratory capacity and activities of daily life[1 ]. The post polio syndrome (PPS) is about a new history of weakness or muscle atrophy
in clinically affected muscles by previous polio or in apparently not affected muscles[1 ]
[7 ]. The complaints often reported by patients with PPS include progressive weakness,
fatigue, muscle pain, joint pain, and limitation of mobility and psychological stress[4 ]. The involvement in pharyngeal-laryngeal, the complaints are frequent like dysphagia,
dysphonia, dyspnoea; and the therapies proposed for these cases range from phonotherapy
to tracheostomy.
Literature Review
The first described case of PPS is assigned to Raymond in 1875[8 ]. The percentage of individuals that develop the PPS is not precisely known. In a
epidemiological study performed at Mayo Clinic, was observed that 25% of the patients
that survive poliomyelitis presented late effects of the disease[9 ]. Other studies point to a 90% rate[10 ]
[11 ]. Some factors related to a acute condition of polio were associated to the development
of late symptoms of PPS: age under 10 years old, need of hospitalization, use of a
fan and paralytic involvement of the four members. In this way, the age and gravity
of initial picture seems to relate to the development of new symptoms, years later[4 ]
[5 ]
[12 ].
The PPS pathogenesis remains unknown although several mechanisms have already been
proposed: natural loss of motoneurons because of age in individuals with reduced numbers
of neurons because of the previous poliomyelitis, accelerated loss of motoneurons
because of the overload of the surviving cells, incapacity of surviving motoneurons
into keep in constant operation, large motor territories after extensive reinnervation,
changes in the brainstem producing central fatigue, autoimmunity and chronic infection
by the virus[13 ]. The most likely is that the syndrome represents a process of wear and exhaust neuronal.
Other hypothesis consider the possibility of a continuous process of denervation-reinnervation
which requires as increase of metabolic demand in the branches; with the decrease
of these reserves there may be gradual loss of axonal fibers, with consequent muscular
atrophy.
Few articles mention the dysfunction of the laryngeal muscles at PPS. The dysphagia
has been the most common symptom found in these patients[6 ]. Robinson et al[10 ] related three cases of PPS affecting the laryngeal muscles with pictures of a initial
manifestation of the disease with bulbar symptoms. The clinical findings of patients
with PPS affecting the laryngeal muscles include weakness of adduction or unilateral
or bilateral abduction and fatigue associated with a continue use of voice[10 ]. The evolution of the disease in the larynx can occur in slow motion too[10 ]. Ivanyi et al[14 ] showed no significant loss of oropharyngeal function in a period of 1 to 3 years
in patients with dysphagia.
The criteria for diagnosis include previous history of poliomyelitis, partial or total
recovering of the initial function after the primary outbreak of paralysis, clinical
stability for at least 10 years and progressive development of muscle weakness[15 ]
[16 ].
Most of the electrophysiological studies shows that patients that become symptomatic
years after the polio present signs of severe acute illness in the past, in other
words, decreasing of number and reorganization of motor units. These findings are
compatible with great loss of cells of the anterior horn of the spinal during the
acute outbreak[4 ]. Electromyography in these patients are observed signs of extensive denervation
and reinnervation, indicating previous poliomyelitis and action potentials of the
large motor units and reduced in numbers, consistent finding with the loss of many
motoneurons and increase of the territory of the muscle fibers innervated by neurons
remaining[10 ]. Signs of acute denervation and reinnervation can be found both in symptomatic and
asymptomatic individuals[4 ].
According to Agre et al[4 ], the effects of training programs at long-term syndrome are unknown. Alternated
exercises with period of rest seem to decrease the muscle fatigue and increase the
capacity of cover the muscle strength after the exercise. Herbison et al[17 ] claim that the exercises with brief muscle contractions, isometric or isotonic,
are more beneficial to the increase of muscle strength than the usual programs of
exhaustive exercise.
Case Report
MLC, 48 years, male, married and a salesman. The patient search for medical care with
history of slurring of words during speech, with worsening throughout the day for
9 years. The picture presented sudden onset and progressive character, coming to be
unable to speak for periods of 15 days, with spontaneous recovery. Now complaints
of tiredness to speak with worsening throughout the day, associated to voice weakness,
change of letters and omission of the last syllables of words. Refer improvement of
symptoms after sleep a few hours. Refer still tiredness in the lower limbs. Sporadically
presents chokes during swallowing solid food. The patient is a smoker of 15 cigarrets
per day for 36 years and had child paralysis at age of three years old which coursed
into left facial paralysis and lower limb motor deficit. At the time was hospitalized
for a two years period, but can't explain the reason for why such a long stay at the
hospital.
To the physical exam and otorhinolaryngological presented diversion of oral rhymes
to the right. Nasofibrolaryngoscopy showed insufficient soft palate, hyper median
constriction of vestibular folds that which worsened during the phonation and stasis
of secretions in the pyriform sinuses hyaline. Telelaryngoscopy was observed vocal
folds with preserved mobility, complete glottal coaptation and absence of lesions.
The evaluation of vocal behavior showed rough voice and strained-strangled, in a moderate
to intense degree, with laryngeal pharyngeal resonance and sound breaks. The maximum
time of phonation was inside the patterns of normality, withe average of 16 seconds.
Vocal instability was evident, with decrease of frequency of intensity, vocal attacks
alternating between abrupt and isochronous, intense use of reserve air and lack of
pneumophonic coordination. Presented a severe pitch, reduced loudness and limited
modulation. The speed of speech was adequate, although with articulation indistinguishably.
During the period of speech therapy was observed worsening of vocal fatigue and all
the items evaluated throughout the session. The vocal pattern to vocal cadence was
similar to the sustained emission. Was performed a laryngeal electromyography which
showed rarefaction of the trace in the cricothyroid and thyroarytenoid muscles bilaterally,
presence of potentials of great amplitude and duration, as synkinesis in the thyroarytenoid
left muscles ([Image 1 ]).
Image 1. Electromyography of the thyroarytenoid left muscle.
Considering the findings described above, was performed a diagnostic hypothesis of
Post Polio Syndrome and indicated Phonotherapy. The speech therapy has presented as
a objective the smoothing of the emissionm the increase of pneumophonoarticulatory
coordination and the improvement of speech intelligibility. Were performed 11 weekly
sessions about 30 minutes each. As result of the treatment, the patient showed improvement
in speech patterns, but with more significant results during the tasks of sustained
emission. The characteristics that identify the evolution of the patient in the speech
therapy are: important reduction of tension during phonation with elimination of choking,
range of pneumophonoarticulatory coordination by increasing the breaks during the
speech, elaborate articulation with bigger amplitude of movements and reduction of
speed of speech; such adjustments were capable of reduce the complaints of shortness
of breath and vocal tiredness of the patient, and allow a bigger adaptation of vocal
quality and intelligibility of speech.
The patients was also submitted to the video endoscopy of swallowing exam to evaluation
of dyphagia, being observed the closure of the coronal velopharyngeal and incomplete,
proper laryngeal elevation, without signs of salivary stasis, laryngeal penetration,
tracheal aspiration or residue after swallowing. The pharyngeal and laryngeal sensitivity
were preserved. This way, the patient received general orientations to swallow with
improvement of gasps complaints.
D iscussion
Many are the causes of motility of vocal folds. The anamnesis the complete otorhinolaryngological
exam followed by nasofibrolaryngoscopical exam, strobe video-laryngoscope and laryngeal
electromyography, lead to different diagnoses. Particularly, the clinical history
of previous poliomyelitis must warn the doctor to the possibility of PPS to cause
vocal fatigue. Is estimated that PPS affects 25 to 90% of patients with previous history
of poliomyelitis[9 ]
[18 ]. The most common symptoms are fatigue and muscle tiredness previously affected or
not[1 ]. The PPS generally becomes apparent 30 years after the initial infection by the
polio virus. It is more common the appearance during the periods of emotional stress
or physical. Also ir more common their occurrence in people affected by poliomyelitis
after 10 years old, that used mechanical ventilation and with more extensive disease[11 ]. There are few reports in literature of PPS affecting the laryngeal muscles. Robinson et al[10 ] related three cases of patients with PPS affecting the laryngeal muscles and had
presented pictures of initial bulbar manifestation of the disease.
Our patient, in particular, does not fit the profile of appearance of the disease,
having contracted her with age of three years old. However, the time of initial manifestation
of the disease and the late symptom of vocal fatigue was at 36 years and the initial
involvement was extensive, affecting both neuronal bodies and spinal, leading to deficit
of the motor lower limbs, like bulbar neurons, attending with facial paralysis, coinciding
with the findings of Robinson
[10 ]. The fact of the patient have remained in hospital by a period of two years corroborates
with the hypothesis of extensive disease and probably with the involvement of other
brain stem cores. His recovery was excellent, because presents only a small deviation
from the mouth rhymes and there are no important motor disorders in lower limbs, or
noticeable muscle atrophy walks normally. The described patient in the case made Professional
use of voice (salesman) and noted worsening of the symptom of vocal fatigue throughout
the day. The continuous use of the muscles already compromised takes to the precipitation
of the symptoms[1 ]
[4 ]. Relationship with the individual background, there was no history of diabetes mellitus,
exposure to toxic agents or family history of neuromuscular disease, as there was
signs observed in the larynx, but this sign don't often occur, unless there is extensive
involvement, as described by Agre
[1 ]. However was observed stasis in the pyriform sinus, signaling to the involvement
of pharyngeal muscles or esophagus. The electromyography of the patient larynx showed
thinning of the trace and presence of great potentials of great amplitude and length,
indicating earlier neuronal commitment, with reinnervation and increase of the territory
of remaining motor units. The presence of synkinesis in the thyroarytenoid left muscle
is another evidence of the existence of a previous process and its resolution with
abductor fibers innervating adductor muscles.
In relation to the proposed treatment to our client, there is reason to believe that
phonotherapy must be beneficial once the exercises of rehabilitation to the extremities
showed that the increase of muscle strength and elevate the maximum extraction of
oxygen[19 ]. Abaza et al[6 ] reported three cases of patients with laryngeal symptoms of PPS characterized by
respiratory difficulty, dysphagia and dysphonia with vocal fatigue, quiver, decrease
of loudness and vocal breaks. These patients were treated with success with phonotherapy
that aimed to eliminate the hyper function and compensatory muscle tension, increase
of the loudness and fatigue, with optimization of residual laryngeal muscle function.
In relation to dysphagia, the patient was only assessed effectively after the beginning
of phonotherapy through swallowing video endoscopy. Probably phonotherapical techniques
and decrease of muscle tension associate to the improvement of coordination pneumophonic
and of articulation have reflected into a better coordination to swallow, and for
that at the time of evaluation the exam did'nt showed dysphagic changes. In relation
to the complaints of sporadic gagging, the patient reported improvement after general
improvement to swallowing and phonotherapy.
Final Comments
The diagnosis of PPS depends of the high rate of suspicion and a good anamnesis, in
which the patient reports previous history of poliomyelitis. As in the most of the
cases these patients present other commemorative resulting of the syndrome, voice
alterations become less evident before the whole picture. Active searches in services
of references in treatment of PPS can show that the frequency of dysphonia and dysphagia
maybe is bigger than the ones described in the literature. Considering that the laryngeal-pharyngeal
manifestations of PPS are suitable for treatment with improvement of life quality
of the patients, is evident the importance of the diagnosis.
