Cerebellar ataxia

Cerebellar ataxia is a general term for impaired coordination of movements due to diseases and damage to the cerebellum and its connections. Cerebellar ataxia is manifested by specific abnormalities of the gait (cerebellar dysbasia), balance, discoordination of limb movements (actually ataxia), impaired speech smoothness (cerebellar dysarthria), various types of cerebellar tremor, muscle hypotonia, and oculomotor dysfunction, dizziness. A large number of special tests are available for the detection of cerebellar dysfunction and a variety of individual symptoms that it can manifest.

A huge number of diseases capable of affecting the cerebellum and its extensive connections make it difficult to create a convenient classification of cerebellar ataxia. Unified classification has not yet been created, although there are a lot of such attempts in the literature and they are all built on different principles.

From the point of view of a practical physician, it is more convenient to rely on such a classification, which is based on this or that important clinical sign. We have stopped our attention on the classification based on the features of cerebellar ataxia (acute ataxia, subacute, chronic and paroxysmal). This classification is further supplemented by etiologic classification of cerebellar ataxia.

[1], [2]

Classification of cerebellar ataxia

Ataxia with acute onset

1. Strokes and volumetric processes with psedoinsultnym current.
2. Multiple sclerosis
3. Guillain-Barre syndrome
4. Encephalitis and postinfectious cerebellitis
5. Intoxication (including drug: lithium, barbiturates, diphenine)
6. Metabolic disorders
7. Hyperthermia
8. Obstructive hydrocephalus

Ataxia with subacute onset (within a week or several weeks)

1. Tumors, abscesses and other voluminous processes in the cerebellum
2. Normotensive hydrocephalus
3. Toxic and metabolic disorders (including those associated with impaired absorption and nutrition).
4. Paraneoplastic cerebellar degeneration
5. Multiple sclerosis

Chronically progressing ataxia (for several months or years)

1. Spinocerebellar ataxia (usually with an early onset)

• Friedreich ataxia
• Nefridreihovskaya ataxia with early onset with preserved reflexes, hypogonadism, myoclonus, and other disorders

2. Cerebro-cerebellar ataxia

• Cortical atrophy of the cerebellum Holmes
• The late cerebellar atrophy of Marie-Foix-Alajuanin

3. Cerebellar ataxia with late onset, involvement of brainstem structures and other structures of the nervous system

• OPCA
• Dentato-rubro-pallid-Lewis atrophy
• Machado-Joseph disease
• Other degenerations involving the cerebellum
• Cerebellar dysgenesis

Paroxysmal episodic ataxia

In childhood:

• Autosomal dominant hereditary periodic ataxia (type 1 and type 2, differing in the duration of seizures).
• Other ataxia (Hartnup disease, insufficiency of pyruvate dehydrogenase, maple syrup disease)

Episodic ataxia in adults

• Medicinal
• Multiple sclerosis
• Transient ischemic attacks
• Compression processes in the region of the large occipital opening
• Intermittent obstruction of the ventricular system

[3], [4], [5], [6], [7]

Cerebellar ataxia with acute onset

Stroke, apparently, is the most common cause of acute ataxia in clinical practice. Lacunar infarctions in the region of the variolium bridge and supratentorial can cause ataxia, usually in the picture of atactic hemiparesis. Ischemia in the region of the thalamus, posterior knee of the inner capsule and corona radiata (the zone of blood supply from the posterior cerebral artery) can manifest as cerebellar ataxia. At the same time, the "mute" lacunar infarcts are often found in the cerebellum. Cerebellar infarction can also be manifested by isolated vertigo. Cardiac embolism and atherosclerotic occlusion are the two most common causes of cerebellar stroke.

Hemiataxia with hemi-hypesthesia is characteristic for strokes in the thalamus region (branches of the posterior cerebral artery). Isolated atactic gait occurs occasionally when the penetrating branches of the basilar artery are affected. Hemiataxia involving certain cranial nerves develops when the upper sections of the variolium bridge (upper cerebellar artery), the lower lateral sections of the bridge and the lateral segments of the medulla oblongata (anterior lower and posterior lower cerebellar arteries) are affected, usually in the picture of stem alternating syndromes.

Extensive cerebellar infarctions or hemorrhages are accompanied by the rapid development of generalized ataxia, dizziness and other stem and cerebral manifestations often in connection with the development of obstructive hydrocephalus.

Tumors of the cerebellum, abscesses, granulomatous and other voluminous processes sometimes manifest sharply and without gross symptoms (headaches, vomiting, mild ataxia when walking).

Multiple sclerosis sometimes develops sharply and rarely occurs without cerebellar symptoms. Usually there are other signs (clinical and neuroimaging) of multifocal lesion of the brainstem and other parts of the nervous system.

Guillain-Barre syndrome occurs in the form of a rare form of lesion involving cranial nerves and ataxia. But here even a weakly expressed hyporeflexia, an increase in protein in the cerebrospinal fluid, is revealed. The syndrome of Miller Fisher proceeds acutely with the development of ataxia, ophthalmoplegia and areflexia (other symptoms are optional), followed by a good restoration of impaired functions. These manifestations are very specific and sufficient for clinical diagnosis.

Encephalitis and postinfection cerebellitis often flow with the involvement of the cerebellum. Cerebellitis in mumps is especially common in children with premorbid cerebellar abnormalities. Chickenpox can cause cerebellitis. The Epstein-Bar virus causes infectious mononucleosis with secondary acute cerebellar ataxia. Acute post-infection ataxia is especially common among the consequences of childhood infections.

Intoxications are another common cause of acute ataxia. As a rule, there is an atactic gait and nystagmus. If ataxia is detected in the limbs, it is usually symmetrical. The most common causes: alcohol (including Wernicke's encephalopathy), anticonvulsants, psychotropic drugs.

Metabolic disorders such as insulinoma (hypoglycemia causes acute ataxia and confusion) are fairly common causes of acute ataxia.

Hyperthermia in the form of prolonged and intense heat stress (high fever, heat stroke, malignant neuroleptic syndrome, malignant hyperthermia, hyperthermia with lithium intoxication) can affect the cerebellum, especially in the area of the rostral sections around the worm.

Obstructive hydrocephalus, which developed sharply, manifests itself as a whole complex of symptoms of intracranial hypertension (headache, drowsiness, stunning, vomiting), among which often there is acute cerebellar ataxia. With the slow development of hydrocephalus, ataxia can occur with minimal cerebral disorders.

[8], [9], [10]

Ataxia with subacute onset

Tumors (especially medulloblastomas, astrocytomas, ependymomas, hemangioblastomas, meningiomas and schwannomas (bridge-cerebellar angle), as well as abscesses and other voluminous formations in the cerebellum can clinically appear as subacute current or chronically progressing ataxia. In addition to the increasing cerebellar ataxia, the symptoms of involvement of neighboring formations, appear relatively early signs of increased intracranial pressure. Diag nosis help neuroimaging.

Normotensive hydrocephalus (Hakim-Adams syndrome: progressive ventricular enlargement at normal CSF pressure) is clinically manifested by a characteristic triad of symptoms in the form of dysbasia (apraxia walking), urinary incontinence and subcortical type dementia that develop within a few weeks or months.

The main causes: the consequences of subarachnoid hemorrhage, suffered meningitis, craniocerebral trauma with subarachnoid hemorrhage, brain surgery with bleeding. Idiopathic normotensive hydrocephalus is also known.

Differential diagnosis is carried out with Alzheimer's disease, Parkinson's disease, Huntington's chorea, multi-infarct dementia.

Toxic and metabolic disorders (insufficiency of vitamin B12, vitamin B1, vitamin E, hypothyroidism, hyperparathyroidism, intoxication with alcohol, thalium, mercury, bismuth, overdose of difenine or other anticonvulsants, and lithium, cyclosporine and some other substances) can lead to progressive cerebellar ataxia.

Paraneoplastic cerebellar degeneration. Malignant neoplasm may be accompanied by a subacute (sometimes acute) cerebellar syndrome, often with tremor or myoclonus (as well as opsonone). Often it is a tumor of the lungs, lymphoid tissue or female genital organs. Paraneoplastic cerebellar degeneration is clinically sometimes ahead of the immediate manifestations of the tumor itself. Unexplained subacute (or chronic) cerebellar ataxia sometimes requires a targeted oncological search.

Multiple sclerosis should be confirmed or eliminated in subacute cerebellar ataxia, especially in individuals younger than 40 years. If the clinical picture is not typical or questionable, then MRI and evoked potentials of different modalities usually resolve this issue.

[11], [12], [13], [14], [15]

Chronically progressing cerebellar ataxia (for several months or years)

In addition to slow growing tumors and other voluminous processes, this group is characterized by:

Spinocerebellar ataxia (with early onset)

Spinocerebellar ataxia is a group of diseases, the list of which is not rigidly fixed and includes, according to different authors, various hereditary diseases (especially in childhood).

Friedreich ataxia (typical symptoms: cerebellar ataxia, sensory ataxia, hyporeflexia, Babinsky symptom, scoliosis, "pess cavus stop", cardiomyopathy, diabetes mellitus, axonal polyneuropathy).

Spinocerebellar degenerations of the "nephridreyich type". In contrast to Friedreich's ataxia, an earlier onset of the disease, preserved tendon reflexes, hypogonadism is characteristic here. In some families - the lower spastic paraparesis or other signs of primary lesion of the spinal cord.

Cerebellar ataxia

Cortical atrophy of the cerebellum Holmes is a hereditary disease of adults, manifested by slowly progressing cerebellar ataxia, dysarthria, tremor, nystagmus and, rarely, other neurological signs (isolated cerebelloplegal family atrophy, type B heterodoxia). On MRI - atrophy of the cerebellum worm.

Late cerebellar atrophy of Mari-Fua-Alaugianina begins late (mean age 57 years) and progresses very slowly (within 15-20 years), largely resembling the previous form (clinically and morphologically), but without a family history (isolated cerebelloplegal atrophy of the sporadic type ). Similar pathomorphological and clinical manifestations are described in alcoholic cerebellar degeneration.

Cerebellar ataxia with late onset, involvement of brainstem structures and other structures of the nervous system

Olivopontocerebellar atrophy (OPCA)

There are various OCAA classifications. The sporadic form (Dejerine-Toma) looks like a clinically "pure" type or as a type with extrapyramidal and vegetative (progressive vegetative insufficiency) manifestations. The latter option refers to multiple systemic atrophy. Hereditary forms (approximately 51%) of OPCA (type A heterodoxia) pathomorphologically and sometimes clinically (unlike sporadic forms here are not characteristic of PTS) differ little from the sporadic forms of OPCA and today there are seven genetic variants.

The leading manifestation of any form of OPCA is cerebellar ataxia (on average more than 90% of patients), especially noticeable in walking (more than 70%); dysarthria (chant, dysphagia, bulbar and pseudobulbar disorders); Parkinsonism syndrome occurs in about 40-60% of cases; no less characteristic are pyramid signs. Some clinical variants include myoclonus, dystonia, choreic hyperkinesia, dementia, oculomotor and visual disorders; rarely - amyotrophies, fascinations and others (epileptic seizures, apraxia century) symptoms. In recent years, sleep apnea is increasingly being described in OPCA.

CT or MRI reveals the atrophy of the cerebellum and cerebral trunk, the expansion of the fourth ventricle and cistern of the cerebellar angle. Often, the parameters of auditory stem evoked potentials are disturbed.

Differential diagnosis is carried out inside various forms of multisystem atrophy (sporadic variant of OPCA, Shay-Draiger syndrome, striroid degeneration). Among the diseases with which OPCA has to be differentiated include diseases such as Parkinson's disease, progressive supranuclear palsy, Huntington's chorea, Machado-Joseph disease, Friedreich's ataxia, ataxia-telangiectasia, Marinesco-Sjogren's syndrome, abetalipoproteinemia, CM2-gangliosidosis, Refsum disease , metachromatic leukodystrophy, adrenoleukodystrophy, Creutzfeldt-Jakob disease, paraneoplastic cerebellar degeneration and, sometimes, Alzheimer's disease, Levy diffuse bodies disease and others.

Dentato-rubro-pallido-Lewis atrophy is a rare family illness, described mainly in Japan, in which cerebellar ataxia is combined with choreoathetosis and dystonia and, in some cases, includes myoclonus, parkinsonism, epilepsy or dementia. Exact diagnosis is carried out by molecular-genetic analysis of DNA.

Machado-Joseph disease (Azores disease) is a disease with an autosomal dominant type of inheritance, manifested by slowly progressing cerebellar ataxia in the adolescent or early adulthood, combined with hyperreflexia, extrapyramidal rigidity, dystonia, bulbar signs, distal motor weakness and ophthalmoplegia. The interfamilial variability of certain neurological manifestations is possible. Precise diagnosis is achieved by genetic analysis of DNA.

Other hereditary ataxia with involvement of the cerebellum. There are a large number of descriptions of hereditary cerebellar ataxia with unusual clinical features (cerebellar ataxia with atrophy of the optic nerves, pigmentary degeneration of the retina and congenital deafness, degeneration of the retina and diabetes mellitus, Friedreich ataxia with juvenile parkinsonism, etc.).

This group includes the so-called "ataxia plus" syndromes (Hippel-Lindau disease, ataxia-telangiectasia, "cerebellar ataxia plus hypogonadism", Marinescu-Sjogren's syndrome, "cerebellar ataxia plus bradyacuasia") and diseases with a known biochemical defect Refsum, Bassen-Kornzweig disease), as well as some other rare diseases (Lee's disease, Gerstmann-Strausler's Gerstmann-Straussler disease); Creutzfeldt-Jakob disease; X-linked adrenoleukodystrophy; MERRF syndrome; Thea-Sachs disease; Gaucher's disease; Nyman-Pick disease; Sandhoff's disease).

Cerebellar dyskinesia

The malformation of Arnold-Chiari is manifested by the protrusion of the tonsils of the cerebellum into the large occipital orifice. Type I of such malformation reflects the weakest protrusion and manifests itself as headache, neck pain, nystagmus (especially beating down), atactic dysbasia and involvement of the lower cranial nerves, and also the conductor systems of the trunk. Type IV is the heaviest and is manifested by cerebellar hypoplasia with cystic enlargement of the fourth ventricle. This type overlaps with the Dandy-Walker syndrome, which can include many other brain abnormalities.

Such variants of cerebellar dyskinesia as congenital hypoplasia of a layer of granular cells are also described; agenesis of the cerebellar worm.

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

Paroxysmal (episodic) ataxia

In childhood

Family episodic (paroxysmal) ataxia exists in two forms.

Type I begins at 5-7 years of age and is characterized by short attacks of ataxia or dysarthria, lasting from a few seconds to several minutes. In the interictal period, myocardium is detected, which is usually observed in the circular muscles of the eyes and hands. Attacks are usually provoked by startle or physical exertion. In some families, seizures respond to anticonvulsants. Among other findings, joint contractures and paroxysmal dyskinesias are described. On EMG - the constant activity of motor units.

Type II episodic ataxia characterized by attacks lasting up to several days. Attacks are provoked by emotional stress and physical stress. The disease often begins at school age. In some patients, seizures are accompanied by a migraine-like headache, dizziness and nausea, that is, a picture that excludes basilar migraine. In the interictal period, the nystagmus that strikes down is typical. In some cases, progressive cerebellar ataxia may occur. MRI sometimes shows a pattern of selective atrophy of the cerebellum worm.

Hartnup disease is a rare disease with an autosomal recessive type of inheritance, consisting of a violation of tryptophan metabolism. It is characterized by intermittent cerebellar ataxia. Symptoms grow for several days and last from a week to a month. Children with this disease are characterized by increased photosensitivity of the skin (photodermatosis). Many patients have episodes of cerebellar ataxia, sometimes accompanied by nystagmus. Neurological manifestations are provoked by stress or intercurrent infections, as well as a diet containing tryptophan. The flow is favorable. Characteristic of aminoaciduria. Attacks are prevented by oral daily administration of niconitamide (25 to 300 mg per day).

Insufficiency of pyruvate dehydrogenase. Most patients show a slight lag in development in early childhood. Attacks of ataxia, dysarthria and sometimes hypersomnia usually begin after 3 years of age. In more severe forms, ataxia episodes begin in infancy and are accompanied by generalized weakness and impaired consciousness. Some seizures develop spontaneously; others are provoked by stress, infections. Attacks of cerebellar discoordination are repeated at irregular intervals and can last from 1 day to several weeks. Lactate acidosis and recurrent polyneuropathy are characteristic. The concentration of lactate and pyruvate always rises during seizures. When glucose load per os, hyperglycemia is prolonged and the concentration of lactate in the blood rises. This test can provoke the appearance of clinical symptoms.

The disease of "Maple syrup" is inherited by autosomal recessive type and consists in the violation of amino acid metabolism. Clinical manifestations become noticeable at the age of 5 months to 2 years: there are episodes of ataxia, irritability and increasing hypersomnia. Provoking factors: infections, surgical interventions and a diet rich in protein. The duration of seizures is variable; Most children experience spontaneous recovery, but some die with a picture of severe metabolic acidosis. The surviving psychomotor development remains normal. The diagnosis is based on general clinical data and the detection of a specific sweetish odor of urine. In the blood serum and in urine, amino acids leucine, isoleucine and valine are found in large quantities (they give this smell to the urine). Differential diagnosis is carried out with phenylketonuria and other hereditary anomalies of amino acid metabolism.

Episodic ataxia in adults

The drug (toxic) ataxia has already been mentioned above. Its occurrence is often due to the cumulation or overdose of such drugs as diphenin and other anticonvulsants, certain psychotropic drugs (lithium) and other drugs. Multiple sclerosis with remittent flow at the time of exacerbations (as well as pseudorecidivi) may manifest as a recurring ataxia. Transient ischemic attacks, manifested by cerebellar ataxia, are characteristic for the destruction of vertebral and main arteries (including in the picture of basilar migraine).

Compression processes in the region of the large occipital foramen may also manifest as episodes of cerebellar ataxia.

Intermittent obstruction of the ventricular system in some neurosurgical diseases, among other neurological manifestations, contains episodes of cerebellar ataxia.

The presented syndrome-nosological analysis of cerebellar ataxia concerns the main forms of neurological diseases that occur with ataxia, but it is not and can hardly be completely complete. Therefore, in addition, we present another classification of cerebellar ataxia, in which etiology (and not clinical signs) forms the basis of classification. It contains primarily a detailed list of diseases and can serve as an aid to the previous clinical classification when conducting a differential diagnosis of cerebellar ataxia.

[21], [22], [23], [24], [25], [26]