Alternating syndromes: causes, symptoms, diagnosis

The nuclei of the cranial nerves and their roots, as well as long ascending and descending tracts, are closely packed in the brainstem. Therefore, lesions in the brainstem usually affect both segmental formations (cranial nerves) and long conductors, which leads to characteristic combinations of symptoms in the form of ipsilateral damage to the cranial nerve and contralateral hemisyndrome (alternating syndromes). Foci in the brain stem are more often unilateral and rarely involve in the process certain nuclei of the cranial nerves, which greatly simplifies the definition of the level of lesion.

There are also important structures in the brain stem such as the gaze control system; an ascending activating reticular system providing a level of wakefulness and consciousness of the person (oral sections of the trunk); vestibular nuclei and conductors; system of postural control and regulation of muscle tone; descending oculosympathetic fibers, systems providing vital functions (respiration, circulation, swallowing). Here is the system of the ventricles of the brain (partially).

Damage to the brain stem is manifested not only by alternating, but also by many other syndromes: pupillary and oculomotor disorders, various impaired eyes (combined vertical paralysis of the gaze, paresis of the eye, paresis of the eye, internuclear ophthalmoplegia, horizontal paralysis of the gaze, global paralysis of the gaze, and a half syndrome) , disturbances of consciousness and wakefulness (hypersomal and coma states); "Back" syndrome of akinetic mutism; syndrome of the "locked man"; syndrome of the bridge-cerebellar angle; bulbar and pseudobulbar syndrome; trunk vestibular symptom complex; syndrome of tethal deafness; syndromes of respiratory disorders (in a patient in a coma); sleep apnea syndrome; Hyperkinetic syndromes of stem origin (facial myocci, opsoklonus, bicycle-palatinous myoclonus, strartle syndromes); acute failure of postural control (drop-attack); syndromes of stem nystagmus; syndromes of compression of the brain stem with infringement of the temporal lobe in the opening of the cerebellum or in the large occipital foramen); Bruns's syndrome; obstructive hydrocephalus (for example, with the compression of the Sylvian aqueduct) with the corresponding clinical manifestations; syndromes of dysbinesia (Arnold-Kiari syndrome; Dandy-Walker syndrome); syndrome of the large occipital foramen.

Next, we will focus primarily on those syndromes of the brain stem that have been poorly covered in the previous sections of the book, namely, the syndromes most typical for ischemic stroke in the brainstem.

A. Syndromes of damage to the medulla oblongata:

• I. Medullary syndrome.
• II. Lateral medullary syndrome.
• III. Combined syndrome (medial and lateral) syndrome or hemimedullary syndrome.
• IV. Lateral ponto-medullary syndrome.

B. Syndromes of damages of the varioly bridge:

• I. Ventral Pontine Syndromes
• II. Dorsal Pontine Syndromes.
• III. Paramedian Pontine Syndrome.
• IV. Lateral Pontine Syndromes.

C. Syndrome of universal dissociated anesthesia.

D. Syndromes of damage to the mesencephalon:

• I. The ventral syndrome of the root of the third cranial nerve.
• II. Dorsal root syndrome III of the cranial nerve.
• III. Dorsal mesencephalic syndrome.
• IV. Upper basilar syndrome.

[1], [2], [3], [4]

A. Syndromes of lesions of medulla oblongata

Damage to conductors at this level of the brainstem can lead to monoplegia, hemiplegia, alternating (cross) hemiplegia, and a variety of sensory disorders. There may be lower paraplegia or decerebral rigidity. The involvement of efferent fibers from both nuclei of the vagus nerve or their compression can lead to profound violations of cardiac and respiratory functions, blood pressure and death.

Damage to the medulla oblongata can be acute, subacute or chronic and have a diverse etiology. These can include tumors, tuberculosis, sarcoidosis, vascular lesions (hemorrhages, thrombosis, embolism, aneurysms, malformations), polyoencephalitis, poliomyelitis, multiple sclerosis, syringobulbia, progressive bulbar paralysis (BAS), congenital anomalies, infectious, toxic and degenerative processes. Extramedullary syndromes can be caused by trauma, fractures of the skull base bones, skeletal malformations, acute and chronic inflammation of the membranes, and sudden increase in intracranial pressure, which results in infringement of the medulla oblongata in the large occipital orifice. A cerebral tumor can lead to a close picture.

I. Medial medullary syndrome (anterior bulbar syndrome Dejerine (Dejerine)

1. Ipsilateral paresis, atrophy and fibrillation of the tongue (caused by the defeat of the XII nerve). The deviation of the language towards the hearth. Rarely the function of the XII nerve can be preserved.
2. Contralateral hemiplegia (due to the involvement of the pyramid) with the preserved functions of the facial muscles.
3. Contralateral decrease in the musculo-articular and vibrational sensitivity (due to involvement of the medial loop). Since the spinalotal tract, located more dorsolateral, remains uninvolved, the pain and temperature sensitivity are preserved.

If the lesion is spreading dorsally, affecting the medial longitudinal fascicle, nystagmus may appear "hitting up". Sometimes the medial medullary syndrome develops from two sides (bilateral), leading to quadriplegia (with preserved functions of the VII nerve), bilateral plection of the tongue and a decrease in the musculo-articular and vibrational sensitivity in all four limbs.

The syndrome is caused by occlusion of the anterior spinal artery or vertebral artery. The anterior spinal artery supplies the ipsilateral pyramid, the medial loop and the XII nerve with its nucleus.

Involving the anterior spinal artery or trauma can sometimes lead to cross-hemiplegia (pyramid cross-over syndrome) with contralateral spastic paresis of the leg and ipsilateral spastic paresis of the hand. At the same time there is also a flaccid paresis and atrophy of the ipsilateral cervical and trapezius muscles and, sometimes, the ipsilateral half of the tongue. More extensive lesions over the cross may lead to spastic tetraplegia.

The variant of medial medullary syndrome is the Avellis syndrome.

Medial medullary infarction is difficult to diagnose without an MRI.

II. Lateral medullary syndrome Wallenberg (Wallenberg) - Zakharchenko.

1. Ipsilateral reduction of pain and temperature sensitivity on the face (due to the involvement of nucleus tractus spinalis digemini). Sometimes there is ipsilateral facial pain.
2. Contralateral decrease in pain and temperature sensitivity on the trunk and extremities, caused by damage to the spinotalamic tract.
3. Ipsilateral paralysis of the soft palate, pharynx and vocal cords with dysphagia and dysarthria due to the involvement of the nucleus ambiguus.
4. Ipsilateral Gorner's syndrome (due to the involvement of descending sympathetic fibers).
5. Dizziness, nausea and vomiting (obscured by the involvement of the vestibular nuclei).
6. Ipsilateral cervical signs (in connection with the involvement of the lower leg of the cerebellum and partly the cerebellum itself).
7. Sometimes hiccups and diplopia (the latter is observed in the case of involvement of the lower sections of the bridge of varioly).

The syndrome is caused by damage to the lateral medullary region and the lower parts of the cerebellum. It most often develops with occlusion of the intracranial part of the vertebral artery or the posterior inferior cerebellar artery. Other causes: spontaneous stratification of the vertebral artery, cocaine abuse, medullary tumors (usually metastases), abscesses, demyelinating diseases, radiation damage, hematoma (with vascular malformation), manipulation during manual therapy, trauma.

In this syndrome, a variety of eye and vision impairments are described: oblique deviation (due to the elevation of the contralateral eyeball), ipsilateral tilt of the head with eyeball titration (ocular tilt reaction) with complaints of doubling or tilt of visible surrounding objects, various kinds of nystagmus, nystagmus century "and other ocular phenomena.

To the variants of this syndrome, some researchers refer to the syndrome of Sestan-Chenee (Chestan-Chenais) and the Babinsky-Najotta syndrome (strongabinski-Nageotte) as a combined medial and lateral infarction.

At the same time, such symptom complexes as Jackson's syndrome and Schmidt's syndrome (as well as the syndromes of Tepia, Berne, Villara, Kolle-Sikara and others) are attributed mainly to "neural" syndromes (cranial nerve syndrome), in which brain substance involvement is rarely observed .

Regarding the alternating Avellis syndrome (X-pair lesions (ipsilateral paralysis of the soft palate and the vocal cords), as well as the spinotalamic tract and descending oculosympathetic fibers (contralateral hemianesthesia and ipsilateral Gorner syndrome), it appears to refer to such rarities, which recently ceased to be mentioned in neurological monographs and manuals.

III. Hemimedullary syndrome.

Rarely can there be a combined syndrome (medial and lateral medullary syndromes (hemimedullary syndrome), usually caused by occlusion of the intracranial vertebral artery.

In general, the clinical picture of medullary infarcts is very heterogeneous and depends on the extent of ischemia in the medulla oblongata; sometimes they extend the lower parts of the variolium bridge, the upper parts of the spinal cord and the cerebellum. In addition, they can be one-sided and two-sided.

Damage to caudal divisions of the brain stem can lead to neurogenic edema of the lungs.

IV. Lateral ponto-medullary syndrome.

In this case, there is a clinical picture of lateral medullary syndrome plus several bridge symptoms, including:

The ipsilateral weakness of the facial muscles (caused by the involvement of the VII nerve)

Ipsilateral noises in the ear and sometimes hearing impairment (due to involvement of the VIII nerve).

[5], [6], [7], [8]

В. Syndromes of damages of the variolium bridge (Pontine syndromes).

I. Ventral Pontine Syndromes.

1. Miyara-Gubler (Millard-Gubler) syndrome is caused by the lesion in the lower part of the bridge (more often a heart attack or a tumor). Ipsilateral peripheral paresis of facial muscles (VII cranial nerve). Contralateral hemiplegia.
2. Raymond (Raymond) syndrome is caused by the same processes. Ipsilateral paresis m. Rectus lateralis (VI cranial nerve). Paresis of the eye towards the hearth. Contralateral hemiplegia, caused by the involvement of the pyramidal tract.
3. "Pure" (motor) hemiparesis. Local lesions in the area of the base of the variolium bridge (especially lacunar infarctions) affecting the corticospinal tract can cause pure motorized hemiparesis. (Other localizations of lesions that can cause such a picture include: the posterior thigh of the inner capsule, the legs of the brain and the medullary pyramids.)
4. Syndrome of dysarthria and awkward arm.

Local lesions at the base of the bridge (especially lacunar infarctions) at the border of the upper third and lower two-thirds of the bridge can cause such a syndrome. In this syndrome, the weakness of the facial muscles and severe dysarthria and dysphagia develop along with the paresis of the arm, on the side of which there can be hyperreflexia and Babinsky's symptom (with preserved sensitivity).

(A similar picture can be observed with injuries of the knee of the inner capsule or with small deep hemorrhages in the cerebellum).

5. Atactic hemiparesis.

Local lesions at the base of the bridge (more often - lacunar infarctions) of the same localization can lead to contralateral hemiataxy and leg paresis (sometimes, dysarthria, nystagmus and paresthesia) on the same side of the body.

(This syndrome is also described for thalamocapsular injuries, processes in the posterior thigh of the inner capsule, the red nucleus, and for superficial infarctions in the paracentral area.)

6. Syndrome of "locked man" (Locked-in syndrome).

The bilateral damage of the ventral bridge (infarction, tumor, hemorrhage, trauma, central pontinous myelinolysis, less often other causes) can lead to the development of this syndrome (deferentation state). Clinical manifestations include the following manifestations:

Quadriplegia, caused by the bilateral involvement of corticospinal tracts in the base of the bridge. Afonia, caused by the involvement of corticobulbar fibers, going to the nuclei of the lower cranial nerves. Sometimes the violation of horizontal movements of the eyeballs due to the involvement of rootlets of the VI cranial nerve. Since the reticular formation of the brainstem is not damaged in this syndrome, the patients are in a state of wakefulness. Vertical eye movements and blinking are intact.

Deferentation state is also observed with purely peripheral lesions (poliomyelitis, polyneuropathy, myasthenia gravis).

II. Dorsal Pontine Syndromes

Foville syndrome is caused by injuries in the dorsal regions of the caudal bridge bridge: Contralateral hemiplegia (hemiparesis).

Ipsilateral peripheral paralysis of facial muscles (spine and / and nucleus of the VII nerve). The inability to move the eyes sympathetically to the ipsilateral side due to the involvement of the paramedian reticular formation of the bridge or the nucleus of the VI (abducens) nerve, or both.

Raymond-Sestan (Raymond-Cestan) syndrome is observed with rostral injuries of the dorsal sections of the bridge. With this syndrome observed:

Cerebellar ataxia with a coarse "rbrural" tremor, caused by the involvement of the upper leg of the cerebellum.

Contralateral reduction of all types of sensitivity due to the involvement of the medial loop and the spinotalamic tract.

With ventral proliferation of the lesion, there may be a conuralateral hemiparesis (involvement of the corticospinal tract) or a paralysis of the eye toward the focus (involvement of the paramedian reticular formation of the bridge).

III. Paramedian Pontine Syndrome

The paramedian pontine syndrome can be represented by several clinical syndromes:

• Unilateral medio-basal infarction: coarse fasio-brachio-spherical hemiparesis, dysarthria and homolateral or bilateral ataxia.
• Unilateral medio-lateral basal infarction: mild hemiparesis with ataxia and dysarthria, atactic hemiparesis or dysarthria syndrome - an awkward arm.
• Unilateral medio-central or medio-segmental infarction: dysarthria syndrome - awkward arm; atactic hemiparesis with sensory impairment or impaired eye movements; hemiparesis with contralateral paralysis of facial muscles or m. Rectus lateralis (VII or VI nerves).
• Bilateral central-basal infarction: these patients develop pseudobulbar paralysis and bilateral sensoric-motor disorders.

The most common causes of paramedian pontine infarctions are lacunar infarctions, vertebral-basilar insufficiency with infarcts, cardiogenic embolism.

IV. Lateral Pontine Syndromes

Marie-Foix syndrome develops in lateral bridge injuries, especially if the middle legs of the cerebellum are affected, and includes:

Ipsilateral cerebellar ataxia, caused by the involvement of connections with the cerebellum. Contralateral hemiparesis (involvement of the corycospinal tract).

Variable contralateral hemihypesesthesia of pain and temperature sensitivity due to involvement of the spinotalamic tract.

C. Syndrome of universal dissociated anesthesia

Universal dissociative anesthesia is a rare syndrome described in patients with combined occlusion of the right upper cerebellar artery and the left posterior inferior cerebellar artery. The defeat of the first artery leads to lateral upper bridge infarction, the defeat of the second artery - to the left-sided lateral medullary syndrome Wallenberg-Zakharchenko. The patient has a reduction in pain and temperature sensitivity on the face, neck, trunk and all limbs, while tactile, vibrational and muscular-articular sensitivity are preserved (dissociated sensitivity decrease).

Hemorrhagic damage to the bridge is accompanied by a violation of consciousness, coma and have a slightly different clinic.

[9], [10], [11], [12], [13]

D. Syndromes of damage to the mesencephalon

I. The ventral syndrome of the root of the third cranial nerve of Weber.

Damages in the brain stem, affecting the fibers of the pyramidal tract and the spine of the third nerve, are manifested by the following picture: Contralateral hemiplegia. Ipsilateral paralysis of the muscles innervated by the nerve.

II. Dorsal root syndrome III of the cranial nerve of Benedict (Venenedikt)

It is caused by damage to the mesencephalon cover with the involvement of the red core, the upper legs of the cerebellum and the root of the third cranial nerve:

Ipsilateral paralysis of muscles innervated by the third nerve.

Contralateral involuntary movements, including intentional tremor, hemichorrhea, hemiballism, caused by the involvement of the red nucleus.

Similar clinical manifestations develop with more dorsal damage to the midbrain, which seizes the dorsal parts of the red core and the upper legs of the cerebellum and is called Claude syndrome, in which cerebellar (contralateral hemiataxy, hypotension) predominates and there is no hemiballism.

III. Dorsal mesencephalic syndrome

It is mainly manifested by neuro-ophthalmologic phenomena. Dorsal mesencephalic syndrome (syndrome of the Silvia water pipe or Parinoud syndrome) is most often detected on the background of hydrocephalus or a tumor of the pituitary region and includes all the following (or some of them) signs:

1. Paralysis gaze upward (sometimes down).
2. Pupillary disorders (usually wide pupils with dissociation of reaction to light and accommodation with convergence).
3. Convergent and retractor nystagmus when viewed upward.
4. Pathological retraction of the eyelids.
5. The lag of the eyelids.

IV. Upper Basilar Syndrome

It is caused by the occlusion of the rostral sections of the main artery (usually due to embolism), leading to a mid-brain, thalamus, and partial temporal and occipital lobes. The syndrome is also described in patients with giant aneurysm of this part of the main artery, with its vasculitis and after cerebral angiography. Variation manifestations of this syndrome include:

1. Disorders of eye movements (unilateral or bilateral paralysis of the gaze upward or downward, disruption of convergence, pseudo-abutence paralysis, convergent and retractor nystagmus, abnormalities of eyeballs, lag and retraction of upper eyelids, oblique deviation).
2. Pupillary disorders.
3. Behavioral disorders (hypersomnia, peduncular hallucinosis, memory impairment, delirium).
4. Visual impairment (hemianopia, cortical blindness, Balint syndrome (Valint).
5. Motor and sensory deficit.

[14], [15], [16], [17], [18], [19], [20]