Cortical and brainstem gaze palsy

Description of Steele-Richardson-Olszewski disease

In 1964, Canadian neurologist Richardson examined a friend of his. The patient complained of poor memory and blurred vision. The doctor described the course of the disease in detail. It later turned out that Doctors Steele and Olszewski studied the results of autopsies of patients with similar symptoms.

Important! An autopsy is a post-mortem examination of tissue samples.

Disease name: progressive supranuclear gaze palsy (PSPV), supranuclear paresis, Steele-Richardson-Olszewski pathology. All names are used in medical practice. According to ICD 10, the disease is coded as G23.1.

Interesting! The definition of “progressive” characterizes the course of the disease. Within 5-7 years, profound disability occurs. “Supranuclear” is the Latin translation of the word “supranuclear”.

When there is an illness, protein complexes are deposited in brain cells. They are called tau proteins. Normally, the neuron needs them for transport. They form microtubule structures. Under the influence of unknown factors, normal protein begins to change. Its “clumps” collect in the cage and interfere with its work. The neuron dies.

Fact! With PSPV, cells of the globus pallidus, subthalamic, red and dentate nuclei, and substantia nigra are affected. These areas respond to friendly eye movements and smooth movements.

Since several areas of the subcortex are affected, degeneration is called multisystem. The nuclei of the oculomotor nerves and substantia nigra are affected. Therefore, gaze paresis occurs in combination with parkinsonian manifestations.

Interesting! Gaze paresis is the inability to move the eyes together up, down, and to the sides.

Gaze paralysis

lack of friendly movements of the eyeballs, observed with brain damage. It manifests itself as a limitation or impossibility of simultaneous movement of both eyeballs to the right or left, up or down. Develops when the cortical center of gaze is damaged in the posterior part of the second frontal gyrus (field 8); frontal oculomotor tract, connecting the cortical center with the nuclei of the oculomotor nerves; tegmentum of the midbrain at the level of the superior colliculus of the roof of the midbrain: the posterior part of the tegmentum of the pons in the area where the nucleus of the abducens nerve is located (the so-called pontine center of gaze). It is an important topical diagnostic symptom.

If there is damage (cerebral infarction, hemorrhage) to the cortical center of gaze or the frontal oculomotor tract (in the corona radiata, the anterior limb of the internal capsule, the cerebral peduncle, the anterior part of the tegmentum of the bridge), the patient can voluntarily move the eyeballs to the side opposite to the lesion, while they reflexively find themselves turned towards the lesion (“the patient looks at the lesion”). With bilateral damage to the frontal cortex or frontal oculomotor tract (with cerebral atherosclerosis, progressive supranuclear degeneration, corticostriospinal degeneration), voluntary movements of the eyeballs are lost. Side gaze palsy is characteristic of a pathological focus (with thrombosis of the basilar artery, encephalitis, multiple sclerosis, hemorrhagic polioencephalitis, glioma) in the posterior part of the pontine tegmentum, when the process involves the area close to the nucleus of the abducens nerve. In this case, the eyeballs are reflexively turned in the direction opposite to the lesion (“the patient turns away from the lesion”) and in case of damage to the path of voluntary movements (“the patient looks at the paralyzed limbs”).

Damage (compression) of the midbrain tegmentum at the level of the superior colliculus (tumor, cerebrovascular accident, secondary upper brainstem syndrome due to an increase in brain volume due to a tumor, increased intracranial pressure, as well as hemorrhages and infarctions in the cerebral hemispheres, less commonly encephalitis, hemorrhagic polyencephalitis, neurosyphilis , multiple sclerosis) causes P. v. up, less often down (see Parinaud syndrome). P.v. with a focus in the cerebral hemisphere, it is not as long as with brainstem lesions.

Bibliography: Gusev E.I. Grechko V.E. and Burd G.S. Nervous diseases, p. 153, M., 1988: Krol M.B. and Fedorova E.A. Basic neuropathological syndromes, p. 346, M., 1966.

Gaze paralysis

lack of friendly movements of the eyeballs, which occurs when the central nervous system is damaged.

Source: Medical Encyclopedia on Gufo.me

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Pathogenesis

PSPV refers to tauopathies. Typically, in these degenerative diseases, tau proteins are the cause of neuron death. These proteins are normally part of the neuron. The axon, the conducting part of the cell, has microtubules. Their stability is maintained by tau proteins.

But when you get sick, something happens to the tau protein. By the way, scientists still have not figured out the cause of the phenomenon. The protein changes its shape. The tubes fall apart. After all, they no longer have support. And the neuron dies.

This is just one mechanism of degeneration. There is another one. In this case, altered tau protein enters healthy synapses and makes them difficult to function. Eventually, the death of many brain cells leads to the appearance of all the symptoms of the disease.

Types of Degenerative Diseases

Progressive neuronal death is characteristic of many pathologies. As a rule, they are divided into several large groups:

Tauopathies;
Synucleopathies;
TDP-43 proteinopathy;
Fusopathy;
Trinucleotide diseases;
Prion pathologies;
Motor neuron diseases;
Axon dystrophies.

So, Parkinson's belongs to synucleopathies. It is caused by a breakdown of the enzyme. It “cuts” the membrane protein alpha-synuclein into two soluble parts. If the system breaks down, then one part of the protein becomes insoluble. It forms “plaques” in the intercellular substance, disrupting the functioning of microglia (protection). As a result of the disease, neurons of the basal ganglia and the “substantia nigra” are destroyed.

Addition! The substantia nigra is part of the extrapyramidal system. It regulates muscle tone and coordination of movements. In addition, it controls breathing, heart function and vascular tone.

Alzheimer's dementia is a tauopathy. However, all the mechanisms of the disease are not fully understood. The main question remains the time during which the disease progresses. Why does Alzheimer's disease take many years to develop? And supranuclear gaze palsy leads a person to death within 5-7 years.

Trinucleotide diseases include Huntington's chorea . This severe hereditary pathology is formed when the HTT gene breaks down. The result is a broken down huntingtin protein. It causes symptoms characteristic of the disease.

Another hereditary pathology with a trinucleotide mutation is Friedreich's ataxia . Here the damaging factor is the protein frataxin. It is known that the disease affects not only neurons. The heart muscle suffers, hormonal levels are disrupted.

The motor neuron disease is called amyotrophic lateral sclerosis. In this case, the anterior horns of the spinal cord are affected. ALS is extremely rare. Its incidence is 5 cases per 100,000 population.

Cortical and brainstem gaze palsy

The movements of the eyeballs are carried out in a friendly manner. When looking to the right, the right eye is rotated by the external rectus muscle (innervated by the abducens nerve - VI pair), and the left - by the internal rectus muscle (innervated by the oculomotor nerve - III pair). Such coordinated interaction of different nerves is possible due to the fact that their nuclei have associative connections with each other. This connection is carried out by fibers of the medial longitudinal fasciculus . This bundle originates from the following brainstem nuclei:

· Darkshevich nucleus (medial);

nucleus of Cajal (intermediate).

The medial bundle passes through the entire brain stem, uniting a number of nuclei of the cranial nerves (III, IV, VI pairs, Deiters' nucleus (vestibular) - one of the nuclei of the VIII pair - vestibular-cochlear nerve, nucleus of the XI pair - accessory nerve) with each other and other structures . Passing in the anterior cords of the spinal cord, the bundle ends on the motor neurons of the anterior horns of the cervical segments, which provides communication between eye movements and head rotation.

Voluntary eye movements are carried out by a portion of the cerebral cortex of the frontal lobes. This area is located in the posterior part of the middle frontal gyrus. It is the so-called anterior cortical adversive center for turning the eyes and head in the opposite direction . Front, because there is also a posterior adversive center located in the cortex of the parietal lobe (more specifically, in the inferior parietal lobule). Adversive (from Latin adversio - turn) - manifested by turning to the side. From this center, fibers begin that pass through the internal capsule, are directed to the tegmentum of the midbrain and the pons, in its anterior sections they cross with fibers from the opposite hemisphere and end in the opposite nucleus of the abducens nerve (VI pair). This nucleus represents the stem center of gaze . In short: fibers coming, for example, from the right cortical gaze center end in the left pontine gaze center (the left nucleus of the abducens nerve).

The coordination of vertical eye movements is carried out by the nucleus of the medial fasciculus, which is the coordination center of vertical gaze .

In total, in order to turn the eyes, for example, to the right, impulses arise in the anterior left adversive field, they reach the right nucleus of the abducens nerve (pontine center of gaze). Next, from the right nucleus of the abducens nerve, part of the impulses is sent to the external rectus muscle of the right eye (it turns the right eye to the right side), and the other part of the impulses is sent to the right magnocellular nucleus of the oculomotor nerve, some of the fibers from which pass to the opposite side (to in this case to the left) to innervate the internal rectus muscle, which turns the left eye to the right.

· Damage to the cortical gaze center or the pathways connecting the cortical and pontine centers - gaze paralysis away from the focus. For example, damage to the left adversive field entails disruption of the innervation and weakening of the tone of the external rectus muscle of the right eye and the internal rectus muscle of the left eye. Because the tone of the muscles of the eyes turning them to the left side is preserved (the function of the right adversive field is not impaired); they, without encountering resistance from the above-mentioned muscles, turn the eyes in their direction, i.e. to the left. In this case, they say that “the eyes look at the hearth.”

· Irritation of the cortical center of gaze - clonic-tonic convulsions of the muscles of rotation of the eyes and head in the direction opposite to the focus.

· Damage to the stem center of gaze in the pons – paresis of gaze towards the lesion. In this case, they say that “the eyes look from the hearth” or “the eyes look at the paralyzed limbs.” Movement disorders in the limbs on the opposite side arise due to the involvement in the pathological process of the pyramidal tracts (corticospinal tract), which pass in the brain stem in the caudal direction and pass to the opposite side at the border of the medulla oblongata and the spinal cord.

Prevalence of the disease

Progressive supranuclear gaze palsy is the most common type of atypical parkinsonism. It occurs in 5.3 cases per 100,000 population. It can be compared to ALS in terms of prevalence in the population. Progressive disease begins at 60-65 years of age. Death occurs within 6-7 years from the onset of symptoms. The cause is cardiac and respiratory disorders.

Vertical paresis

The structures responsible for vertical gaze lose function with age. Paresis of upward and downward gaze usually develops due to tumors and infarctions affecting the midbrain. If paresis occurs upward, dilated pupils remain.

Important! Typically, in case of vertical disorders, tumors of the epiphysis .

Less commonly, the cause is infarction of the pretectal region. Due to the fact that vertical disturbances are much less common, the study of the structures responsible for them is still minimal. But it is clear that movements are activated by impulses along two paths from:

vestibular impulse center along the longitudinal fasciculus;
hemisphere to hemisphere through the pretectal zone with the 3rd cranial nerve.

Paresis affecting both eyes is an acute neurological symptom that requires careful diagnosis and consultation with neurologists, neurosurgeons and other specialists. This condition cannot be treated, since the cause is usually acute pathologies that require immediate intervention.

Possible causes and symptoms

Possible reasons include:

Alcohol intoxication;
Tumor diseases of the brain;
Poor environmental conditions;
Taking medications and drugs;
Acute and chronic cerebral ischemia.

Unfortunately, scientists do not know how degenerative processes are formed. It is not known why some people develop them after 40, while others only develop them in old age. Perhaps by studying these questions it will be possible to prevent these diseases.

Symptoms of the disease develop quickly. Either parkinsonism or gaze paresis comes first. We list the possible manifestations of the disease:

Muscle tension;
Tremor;
Loss of stability when walking;
Vertical gaze paresis;
Mild dementia;
Speech disorders;
Difficulty swallowing.

Features of the disease . The patient cannot fully look up. The limit is more than 50%. A sick person cannot look down (at his feet, at the stairs). This results in frequent trips and falls. The horizontal gaze is also disrupted.

Additional symptoms. “Mask on the face” - lack of emotions and facial expressions. Tremor and hyperkinesis (involuntary sweeping movements). Mild dementia and personality disorders.

Causes and mechanism of development

The disorder is a consequence of direct damage to nervous tissue or a complication of impaired trophism and oxygen delivery due to abnormalities in vascular development or blockage of the artery lumen by a thrombus. At risk are:

patients with benign or malignant neoplasms that compress nearby anatomical structures;
women from thirty to fifty years of age with a disease such as multiple sclerosis;
patients with a history of cerebral stroke;
those patients who have been diagnosed with an infectious lesion of the central nervous system or toxic poisoning with chemicals and radiation.

Displacement of the brain into the tentorial space is another cause of Parinaud’s syndrome.
Concomitant diseases of the endocrine system, metabolic disorders and disorders of the blood supply to vital organs worsen a person’s well-being.

Paralysis is polyetiological; due to the growth of the tumor, the oculomotor nerve is compressed, its functioning and nutrition are disrupted. The corresponding clinical picture is growing.

Structure and functions of the medulla oblongata and midbrain:

How is it diagnosed?

Symptoms of supranuclear palsy are noticeable to any doctor. But a neurologist must interpret the clinical picture correctly. He conducts a clinical examination. Based on the examination, a preliminary diagnosis is made.

Confirmation can be found on MRI. There are specific signs of paralysis:

Midbrain in the form of "hummingbirds or penguins";
Atrophy of the midbrain substance;
Symptom of "convolvulus flower".

Differential diagnosis is carried out with a stroke or cerebral infarction. Tumors and hypertension should be excluded. Corticobasal degeneration resembles the symptoms of PSP. But with this pathology there is no characteristic visual disturbance.

Clinical picture

In addition to complaints about the inability to look up, there is the development of nystagmus, constriction of the pupil depending on the position of the object on which the gaze is focused. Externally, there is an almost fixed position of the eyes; the upper eyelids lag behind when blinking. Rarely, the clinical picture is complemented by imbalance.

As the infection develops, intoxication, increased temperature to a febrile state, malaise, chills, headaches, weakness and fatigue, and decreased ability to work are possible.

Methods of treatment and rehabilitation

There is no adequate treatment for the disease. It is known that tremor and kinetic disturbances are not relieved by Levadopa. For severe symptoms of Parkinsonism, amantadine and other drugs for Parkinsonism are used.

An important point in treatment is rehabilitation. Classes with a speech therapist and exercise therapy instructor delay the onset of disability. An occupational therapist will help organize the life of a patient with PSP.

Disability comes quickly. Dysphagia progresses. The patient cannot swallow. Unfortunately, then doctors are forced to install a gastrostomy tube. Death occurs from respiratory complications.

Prognosis and prevention, patient care

Unfortunately, the prognosis for this disease is disappointing. When a diagnosis is made, the patient must immediately register for disability. After all, progressive paresis leaves almost no time for thinking. Prevention of the disease has not been developed. Ignorance of the cause of the disease does not provide a chance to develop measures to prevent it.

What should relatives do?

A patient with PSP becomes incapacitated within a few years. Therefore, when making a diagnosis, a disability group should be registered. It makes it possible to receive preferential medications and technical means of rehabilitation (wheelchair, functional bed). Single people have the right to see a social worker or carer.

Caring for a patient is quite difficult:

Feeding with prevention of food aspiration. Problems with swallowing prevent you from eating chunky food;
Preventing bedsores. This requires an adapted system (mattress), regular skin care;
Prevention of falls. The patient is unable to see the road he is walking on. Reliable means of support will allow you to maintain balance;
Gastrostomy tube care. Feeding the patient through a tube;
Regular breathing exercises and exercise therapy.

Caring for a loved one often causes burnout. In this case, responsibilities should be distributed. As a rule, they hire a nurse or involve other relatives. It would be useful to talk with a psychotherapist. They allow you to relieve tension and understand the patient’s behavior. Indeed, with dementia, such patients can be aggressive, swear and slander. It is important that private and state boarding homes take care of sick people.