From the Guidelines
Chronic ataxia is most commonly caused by hereditary conditions, such as Friedreich's ataxia and spinocerebellar ataxias, as well as acquired conditions like cerebellar tumors and inflammatory disorders, which can lead to persistent damage to the cerebellum or its connections. The causes of chronic ataxia can be diverse and complex, involving various neuronal circuits and systems beyond the cerebellum, including the basal ganglia, cerebral cortex, spinal cord, and peripheral nerves, as well as the sensory and vestibular system 1.
Key Causes of Chronic Ataxia
- Hereditary conditions: Friedreich's ataxia, spinocerebellar ataxias, and ataxia-telangiectasia are notable examples, with a significant impact on morbidity and mortality due to their progressive nature and the potential for complications 1.
- Acquired conditions: Cerebellar tumors, brain stem gliomas, and inflammatory disorders are common causes of chronic progressive ataxia in children, emphasizing the need for early diagnosis and intervention to improve quality of life 1.
- Toxic exposures and vitamin deficiencies can also lead to chronic ataxia, highlighting the importance of environmental and nutritional factors in the development and management of the condition 1.
Importance of Imaging in Diagnosis
Imaging, particularly brain imaging, plays a crucial role in the assessment of children with suspected brain tumors and in the diagnostic workup of inherited ataxias, providing valuable insights into the progression of cerebellar hemispheric and vermian volume loss, as well as associated signal abnormalities and atrophy in other brain areas 1.
Management and Outcome
Management of chronic ataxia depends on identifying the underlying cause, with some conditions responding to specific treatments like vitamin supplementation, while others require symptomatic management through physical therapy and assistive devices to improve quality of life and reduce morbidity and mortality 1. Early diagnosis and intervention are critical in managing chronic ataxia, as they can significantly impact the patient's outcome, quality of life, and survival.
From the Research
Causes of Chronic Ataxia
The causes of chronic ataxia can be diverse and include various disease processes. According to 2, ataxia is a manifestation of different diseases, and an underlying etiology needs to be investigated. The study highlights that pure ataxia is rare in acquired ataxia disorders, and associated symptoms and signs almost always exist to suggest an underlying cause.
Acquired Ataxias
Acquired ataxias represent a large group of disorders defined by the common clinical feature of ataxia and the absence of a clear genetic basis for it, as stated in 3. These disorders can be subdivided into:
- Autoimmune causes
- Toxic causes
- Infectious causes
- Vitamin deficiency causes Cerebellar ataxia may occur as an isolated syndrome in this spectrum of disorders but is often accompanied by additional neurological manifestations.
Genetic Ataxias
Genetic ataxias are a large group of rare disorders characterized by irregular movements, decreased coordination, imbalance, kinetic tremor, wide-based stance, and dysarthria, as mentioned in 4. Evaluating ataxia can be challenging considering the volume of disorders and their complex pathologies involving diverse genetic and clinical factors. Age, time course, and family history provide initial guidance for evaluation of ataxia.
Primary Autoimmune Cerebellar Ataxia
Primary autoimmune cerebellar ataxia (PACA) is a term used to describe idiopathic ataxias suspected to be immune-mediated but remain undiagnosed due to lack of diagnostic biomarkers, as discussed in 5. The proposed diagnostic criteria for PACA are based on clinical, imaging findings, and laboratory investigations parameters. The aim is to enable clinicians to consider PACA when encountering a patient with progressive ataxia and no other diagnosis, which might have important therapeutic implications.