Neurology represents one of the most multifaceted, fascinating specialties in medicine. In addition to diseases such as multiple sclerosis, Alzheimer’s disease and the universally known stroke, spinocerebellar ataxias are also of immense importance. These are the generic term for a wide variety of disorders in the coordination of movements. The loss of nerve cells leads to a faulty interaction of the musculature.
What is spinocerebellar ataxia?
Spinocerebellar ataxias (SCA for short) refer to a group of neurodegenerative disorders of the human central nervous system (CNS). The neurons of the cerebellum and the spinal cord (medulla spinalis) perish progressively. Diseases from this form group are extremely rare, occurring in the United States and Central Europe with an average incidence of a single new case per one hundred thousand population.
Causes
The cause is due to the death of Purkinje cells (the largest neurons of the cerebellum), caused by autosomal dominant inheritance of pathological genes. Currently, more than twenty-five different gene loci are known. The subgroups of spinocerebellar ataxia are defined according to these causative genes and are referred to as SCA type 1, type 2, type 3, respectively SCA1, SCA2, SCA3 et cetera. Types 1, 2, 6, 7 as well as 17 belong to the group of trinucleotide diseases (such as Huntington’s disease), because the disease is caused by a mutation in the form of an unusually long triplet repeat (triplet= three consecutive nucleobases of a nucleic acid) of the codon CAG (which corresponds to the amino acid glutamine). Spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph disease (MJD), represents the most common form of this disorder within Germany, accounting for thirty-five percent of autosomal dominant inherited cerebellar ataxias.
Symptoms, complaints, and signs
The onset of the disease in most cases is between the ages of thirty and forty. The cardinal symptom is impaired coordination of movements (ataxia). Patients complain of the resulting insecurity in walking and standing as well as the clumsy grasping of objects. In addition, there is a change in speech melody (dysarthria) and a movement disorder of the eyes (nystagmus). Depending on the subgroups of spinocerebellar ataxia, symptoms also appear depending on the involvement of other brain regions, for example, muscle spasms, spasticity (pathological increase in muscle tone). Also memory impairment (dementia), sensory disturbances and insensations, dysphagia, incontinence, deterioration of vision, slowing of movements and restless legs (restless legs syndrome). Some patients exhibit Parkinson’s-like symptoms that respond well to medications used to treat PD.
Diagnosis and disease progression
Diagnosis is made from a detailed medical history, clinical neurologic examinations, and additional findings (for example, cerebrospinal fluid examination, magnetic resonance imaging, and neurophysiologic examination) to rule out other possible diseases. A molecular genetic examination is urgently needed to confirm the diagnosis. It is often difficult, sometimes impossible, to determine what type of ataxia is present because they differ only slightly. As the disease progresses, symptoms increase until (in most cases) the disease leads to the death of the patient.
Complications
Depending on which form of the disease it is, spinocerebellar ataxias can cause various complications. In general, ataxias cause muscle spasms, spastic twitching, and changes in speech melody. In addition, memory impairment may occur, which can develop into dementia as the disease progresses. The slowing of movements often represents a considerable restriction in everyday life for those affected. In conjunction with other complications, such as the typical deterioration of vision, ataxia then sometimes also causes mental suffering. Regardless of the form of the disease, the symptoms increase as the disease progresses. In most cases, spinocerebellar ataxias lead to the death of the patient. Treatment of a neurological disorder also carries risks.Drug therapy is always associated with certain side effects and interactions for those affected. The same applies to occupational therapy and physiotherapy, which are occasionally associated with tension, muscle soreness and minor injuries. Surgical procedures are rare for spinocerebellar ataxias, but can lead to infection, bleeding, rebleeding, infection and wound healing problems. If the procedure goes poorly, it may also worsen the original disorder in some circumstances.
When should you see a doctor?
As a rule, the patient always needs medical treatment by a doctor for this disease. Thereby, especially an early diagnosis with an early treatment has a very positive effect on the further course. This is the only way to prevent further complications, since this disease cannot heal itself. A doctor should be consulted if the affected person experiences discomfort in movement and coordination. Usually, patients cannot easily walk straight or reach for things properly. Cramps in the muscles or spasticity may also indicate this disease. Many affected individuals also suffer from difficulty swallowing or even incontinence, as well as other sensory disturbances. The disease can be detected by a general practitioner. However, further treatment usually requires a visit to a specialist. It can be thereby suffers also not universally predicted whether it can come to a complete healing.
Treatment and therapy
To date, there is no known causative therapy for spinocerebellar ataxias. The focus is on symptomatic treatment in the sense of preserving function to maintain the patient’s quality of life as long as possible. This includes medication, occupational therapy and physiotherapy as well as speech therapy. According to the German Neurological Society (DGN), a pilot study showed that cerebellar ataxias respond to the drug riluzole. Although research on spinocerebellar ataxias has intensified considerably in recent years, it has not yet progressed to the point where a curative therapy can be expected in the near future. During occupational and physical therapy, the mobility of the individual body parts is maintained, diminishing musculature is strengthened and synapse formation is stimulated. Activities of daily living are practiced in order to maintain the patient’s independence as far as possible. Speech therapy works on existing speech problems.
Prevention
Because it is a genetic condition, any prevention is impossible.
Follow-up care
The collective term ‘spinocerebellar ataxia’ refers to genetic disease patterns in which the nervous system is affected. Disturbed motor processes up to dementia in the late stage are typical manifestations. In contrast to other hereditary diseases, the symptoms do not occur exclusively in childhood. On average, ataxia breaks out at an age of 30 to 40 years, in some patients earlier or only from the 50th to 60th year of life. Until this time, the affected person was symptom-free. As it stands now, spinocerebellar ataxia cannot be cured. The disease is chronic and has a fatal outcome in every case. The aftercare lies in symptom relief, the patient should be enabled to lead a largely normal life. Parallel psychotherapeutic support makes sense for the person affected, as the disease can be accompanied by emotional stress. Relatives also have the opportunity to receive support from a psychotherapist. Exercises are intended to maintain the mobility of the limbs. If the speech center is affected by the neurological deficits, logopedic therapies are recommended. The aftercare measures are set for the long term, they accompany the patient from the onset to the late stage of the disease. Follow-up care is useful only if it is performed consistently for years.
What you can do yourself
In spinocerebellar ataxia, the main focus is on medical and physical therapy. Along with this, patients can do a few things to make everyday life with the condition easier. The coordination disorder considerably restricts those affected in their everyday life. Therefore, the most important measure is to compensate for the limitations and support the sufferer as much as possible.In most cases, it is necessary to move to an apartment suitable for the disabled. The increasing movement restrictions also require a walking aid for the patient. Affected persons need support in everyday life, since even simple activities can usually no longer be performed without outside help. Affected persons should read specialist literature on spinocerebellar ataxia in order to better understand and accept the disease. Accompanying discussions with other affected persons are recommended, for example in the context of a self-help group for people with Parkinson’s disease. In the later stages of the disease, outpatient and finally inpatient care is necessary. In the final stage of the disease, when movements and conversations become increasingly difficult, comprehensive therapeutic care may also be useful for the patient and his or her relatives.
