Ataxia

Ataxia ( from Greek ἀταξία ataxia, confusion, ' irregularity ') is in medicine a generic term for various disorders of movement coordination. Ataxia can occur even if no paralysis ( paresis ) is present, ie in normal muscle strength.

Forms of ataxia

As truncal ataxia is defined as the inability to sit straight, so that those affected can sit or stand just by using a prop. Analog is called standataxie the inability to stand, so that those affected are standing and ambulatory only with assistance. People with ataxia have a legs - insecure gait. Ataxia (also called afferent ataxia ) for target movements leads to movements false scale with addition - Show ( dysmetria ), to shooting - outgoing movements ( hypermetropia ) or unflüssig - blurred motion ( asynergy ) and thus to the inability of a rapid succession of antagonistic movements ( dysdiadochokinesia ).

Causes of ataxia

Any disease that damages the involved in the motion control organ systems of the nervous system, can cause ataxia.

The most common cause of ataxia are diseases of the cerebellum. This is responsible in motor movements for the coordination of sensory information from the spinal cord, the information of the vestibular system and the other sensory impressions and their implementation, ie the planning, coordination and fine-tuning of movements.

Ataxias can therefore also occur if the incoming via the spinal cord sensitive information is missing from the peripheral sensory nerves, joints and muscles. This is missing the required targeted motor movements, fine-tuning, it comes to so-called sensitive ataxia.

Gait ataxia occurs even when hydrocephalus normalis, also called age-related hydrocephalus or NPH. Here the produced water is brain ( CSF ) not absorbed in sufficient amounts or distributed in the ventricles, there will be a temporary overpressure in the brain, this affects, inter alia, the nerves that control the movement. In addition to the ataxia often occur nor parallel to urinate and a reduction in cognitive performance, also called reversible dementia on. The simultaneous occurrence of these three symptoms is called Hakim 's triad.

Also on secondary ataxias due to the copper metabolic disorder Wilson's disease should be considered differentialdiagnosisch.

Cerebellar ataxia

Cerebellar blood flow disturbances or cerebellar hemorrhage, ie strokes of the cerebellum, throw an ataxia.

Ataxias occur not infrequently in the course of inflammatory diseases of the nervous system with damage to the cerebellum and / or spinal cord at, especially in multiple sclerosis. In rare cases occurring in the context of cancer antibodies can be a disease of the cerebellum and cerebellar ataxia so that a lead ( paraneoplastic disease). And ataxia caused by infections such as a zoster Zerebellitis or cerebellar abscess are rare. Increasingly, ataxia is a result of Lyme disease after tick bite.

Brain tumors or metastases in the cerebellum and herniation of the cerebellum as part of a diffusely increased intracranial pressure from any cause leading to ataxia, unless previously a clouding of consciousness occurs.

Ataxia can be caused by chronic poisoning in humans most commonly by an acute cerebellar dysfunction in the setting of acute alcohol intoxication (reversible ) or chronic alcoholism (poorer tendency to improvement ). As a symptom of an overdose of medication can lead to is usually rapidly reversible ataxia, especially in overdose or too rapid titration of antiepileptic drugs. Also, as a frequent side effect of medication from the group of benzodiazepines, even in small quantities, which after weaning, however, is reversible. Ataxia caused by poisoning with heavy metals (especially mercury) and pesticides are extremely rare.

Spinal or Sensitive ataxia

Here is the most common cause of chronic alcohol intoxication. Similar to the cerebellum and the spinal cord is frequently affected by multiple sclerosis. Tumors in the spinal cord or in the spine are rare. A sensitive ataxia is often caused by a collapse in the spinal cord space vertebral metastasis. In veterinary medicine, it is called a Wobbler syndrome.

A not uncommon cause a sensitive ataxia is caused by damage to the sensory spinal tracts by a vitamin B12 deficiency ( the so-called funicular myelosis ). This damage is completely reversible with appropriate treatment.

As an important infectious causes of sensory ataxia, syphilis of the nervous system are to be mentioned, and also HIV and infection with zoster virus.

Hereditary ataxias

Ataxias also occur in numerous, but overall rare genetically determined ( = hereditary ) to disease, hereditary ataxias. These are inherited as autosomal recessive or autosomal dominant ( ADCA = autosomal dominant cerebellar ataxias ). The autosomal dominant ataxias are now known mostly spinocerebellare ataxias ( SCAs ). Chromosomal localisations for a total of 28 SCAs are known, of which about half is cloned. Common to these diseases that infest the cerebellum and / or the posterior columns of the spinal cord.

Autosomal recessive ataxias

• Friedreich's Ataxia
• Ataxia Telangiectasia
• Refsum
• Abetalipoproteinemia ( Bassen - Kornzweig syndrome)
• Metachromatic leukodystrophy
• Adrenoleukodystrophy
• GM gangliosidosis
• Early onset cerebellar ataxia with preserved deep tendon reflexes

Autosomal dominant cerebellar ataxias ( ADCA )

• Spinocerebellar ataxia (SCA ) type 1-7
• Spinocerebellar ataxia type 13
• Dentato - rubro - pallido - luysianische atrophy with dementia
• ADCA with pigmentary retinal degeneration ( ADCA II)
• ADCA with pure cerebellar symptoms ( ADCA III)
• ADCA with myoclonus and deafness ( ADCA -IV)
• ADCA with mental retardation ( SCA13 )
• Episodic ataxia ( EA) Type 1-6