Pierre Marie’s hereditary cerebellar ataxia is a genetically determined steadily progressive lesion of the cerebellum associated with its degenerative changes. Develops after 20 years. In the clinical picture, cerebellar ataxia is combined with hyperreflexia, ophthalmological disorders and a decrease in intelligence. The diagnostic algorithm provides for neurological and ophthalmological examination, MRI of the brain, ultrasound or MRA of cerebral vessels, genetic counseling. Radical therapy has not been developed, symptomatic treatment with antidepressants, muscle relaxants, sedatives and nootropics is being carried out. Physical therapy, vitamin therapy and hydrotherapy are recommended.
General information
Pierre Marie’s hereditary cerebellar ataxia was described in detail by Pierre Marie in 1893. as a nosological form differing from Friedreich’s ataxia known at that time. Indeed, Pierre-Marie’s ataxia has a different type of inheritance, an older age of manifestation and its own clinical differences. In this regard, despite some common morphological substrate of these diseases in the form of degeneration of cerebellar tissues and its pathways, in modern neurology, their separation into independent nosological units has finally been established.
As a rule, Pierre Marie’s hereditary cerebellar ataxia manifests at the age of 20 to 45 years. Men and women get sick equally often. The prevalence of pathology is 1 case per 200 thousand people. Morphological changes in hereditary cerebellar ataxia predominate in the tissues of the nuclei and cortex of the cerebellum, less pronounced damage to the spinocerebellar pathways and lateral cord of the spinal cord, degeneration processes can be observed in the nuclei of the bridge and the medulla oblongata.
Causes
Pierre Marie’s hereditary cerebellar ataxia has a dominant inheritance mechanism, i.e. it develops when receiving a defective gene from one of the parents. Often, exogenous causes act as triggers that provoke the onset of the disease and aggravate its course. Such factors include: various infections (typhoid fever, typhoid fever, brucellosis, salmonellosis, dysentery, yersiniosis, bacterial pneumonia, pyelonephritis, etc.), pregnancy, injuries (TBI, chest injuries, pelvic fractures, severe burns), intoxication.
Pierre Marie’s hereditary cerebellar ataxia is characterized by a constant and steadily progressive increase in pathological symptoms. Isolation of periods of exacerbation of the disease and its remission is not observed. Under the influence of infectious diseases and other exogenous influences, Pierre-Marie ataxia can change the nature of its course, which significantly complicates its diagnosis. So, after an infection, there is a sharp deterioration in the patient’s condition, followed by partial recovery, simulating an improvement in the disease.
Symptoms
The leading symptom complex of the disease is cerebellar ataxia. It includes gait disorders with a deviation of the body to the sides, static disorder (in the Romberg pose there is a fall to the side or backward), discoordination of movements (hypermetry, dysdiadochokinesis, blundering when performing a finger-nasal test), sweeping macrography, dysarthria with intermittent and slow speech, intentional tremor. The manifestation of symptoms usually occurs with mild gait disorders, sometimes the first manifestations are pain in the lower back and legs, according to the description of the patients themselves, having a “shooting” character. Then there is ataxia in the hands, often accompanied by tremor. Involuntary muscle twitching may occur in the limbs, face and torso. In many cases, there is a decrease in muscle strength. Sensitivity, as a rule, is preserved.
Typical cases of the disease are accompanied by visual impairment and oculomotor disorders. The first include narrowing of the visual fields and a drop in visual acuity caused by gradually progressive atrophy of the optic nerve. The latter are represented by incomplete ptosis, insufficient convergence, strabismus due to paresis of the abductor nerve. Nystagmoid eye twitching is possible. Trying to reduce the phenomenon of ptosis, patients raise their eyebrows, which gives their face a surprised expression. The clinic is complemented by mental disorders, a decrease in mental functions and memory, the development of depressive neurosis.
Diagnostics
In the presence of a typical clinic and tracing it in several generations, the diagnosis does not pose any particular difficulties for a neurologist. Sporadic cases of the disease require a more in-depth examination of the patient and thorough differential diagnosis with other types of cerebellar ataxia, multiple sclerosis, neurosyphilis.
If necessary, the exclusion of acquired organic pathology is carried out: cerebellar tumors (medulloblastomas, astrocytomas, hemangioblastomas), cerebellitis, vascular disorders, compression of the cerebellum with hematomas or abscesses of the brain, occlusive hydrocephalus. To do this, CT and MRI of the brain, ultrasound and MRA of cerebral vessels are used.
The diagnosis of ophthalmological disorders is carried out by an ophthalmologist. The examination includes visual acuity testing, convergence examination, ophthalmoscopy, perimetry, strabismus angle measurement, etc. For more accurate verification of the diagnosis, a geneticist’s consultation may be required.
Differential diagnosis
Neurological examination allows to exclude other types of ataxia (vestibular, sensitive) and to establish its cerebellar character. Unlike Friedreich’s ataxia, characterized by hyporeflexia and a decrease in muscle tone, the neurological status of patients with Pierre-Marie ataxia shows an increase in tendon reflexes and muscle hypertension. Spastic tone in the legs is especially typical, caused by clonus of the feet. There are no pronounced skeletal deformities common for Friedreich’s disease.
The symptoms of hereditary cerebellar ataxia and multiple sclerosis may be very similar. A distinctive feature of the first is the gradual steady progression without periods of remission, however, various infectious diseases and injuries can change the nature of its course, causing significant difficulties in diagnosis. In such cases, it is important to thoroughly study the anamnestic data, to identify a typical symptom complex for multiple sclerosis: clearer pyramidal symptoms (usually lower paraparesis of spastic type with significant hyperreflexia and pathological reflexes) disappearance of abdominal reflexes, pelvic disorders (imperative urges), paleness of optic nerve discs from the temporal side.
Treatment
Ophthalmologists and psychiatrists take part in the treatment of patients along with neurologists. Since etiotropic therapy has not yet been developed, symptomatic treatment is used. These are mainly antidepressants (amitriptyline, fluoxetine, citalopram, tetrindol), sedatives (valerian, peony, magnesium sulfate), nootropics (gamma-aminobutyric acid, piracetam, gingo-biloba extracts), drugs that reduce muscle tone (melictin, baclofen, condelfin). Recommended vitamins gr. B, vit. PP and vit. C; balneotherapy, physical therapy. It is not unimportant to observe the correct working regime, the exclusion of physical and psychological overloads.
Forecast
The prognosis regarding recovery is unfavorable. The symptoms of the disease are constantly aggravated and lead to disability. However, the systematic use of symptomatic treatment, regular implementation of a special complex of physical therapy and other recommendations make a favorable prognosis for the patient’s life.