Spinocerebellar Ataxia

 Ataxia is a term for a group of disorders that affect co-ordination, balance and speech. Spinocerebellar ataxia (SCA) is a term referring to a group of ataxias that are characterized by degenerative changes in the cerebellum and sometimes in the spinal cord. Moreover, it is a hereditary and progressive condition.

Presentation of SCA 

There are more than 20 identified types of Spinocerebellar ataxias; SCA1, SCA2, SCA3 and SCA6 being the most common amongst all. Though each may have unique signs and symptoms, however, in general, it is difficult to differentiate among the different types, and all are presented by problems with movement that tend to get worse over time. Depending on the type of SCA, signs and symptoms can develop anytime from childhood to late adulthood. 

Affected people may experience some or all of the following: 

• Problems with coordination and balance (ataxia) 
• Uncoordinated walk (ataxic gait, also called drunkard’s gait) 
• Poor hand-eye coordination 
• Abnormal speech (dysarthria) 
• Involuntary eye movements 
• Vision problems 
• Difficulty processing, learning, and remembering information 

Cause of SCA

Mutations in many different genes are known to cause the different types of spinocerebellar ataxia (SCA). For some types, the gene known to cause it has been identified, while in others, the genetic cause is still unknown. 

Spinocerebellar ataxia can be inherited in an autosomal dominant fashion. When a person with an autosomal dominant condition has children, each child has a 50% risk to inherit the mutated copy of the gene from the affected parent. 

Diagnosis

Spinocerebellar ataxia (SCA) is often suspected when a person presents with certain signs and symptoms, such as ataxic gait and uncoordinated hand/finger movements.

Genetic testing is the best way to confirm SCA and identify the specific type, especially when a person also has family members with similar features. 

Computed tomography and/or magnetic resonance imaging (MRI scan) may be necessary to establish a diagnosis if the genetic cause for some of the types is currently unknown

Prognosis 

The long-term outlook (prognosis) for people with spinocerebellar ataxia (SCA) varies. Disease progression and severity often depend on the type of SCA but people affected by any type of SCA usually require a wheelchair by 10-15 years after the onset of symptoms. Many will eventually need assistance to perform daily tasks. 

Treatment

There are no known guidelines for the medical management of spinocerebellar ataxia (SCA). Each patient requires an individualized approach according to the severity of signs and symptoms. A team consisting of neurologist, physiotherapist, occupational therapist, speech therapist and orthotist; working in close conjunction is often required to manage the patient with the primary goal of keeping the patient as active as possible and improve the quality of life. 

Though there are no known medications for SCA but a recent study suggests dietary supplementation with docosahexaenoic acid (DHA) — an omega-3 fatty acid that is essential for brain development and function — produces symptomatic improvements in patients with spinocerebellar ataxia. Although, further research is required to establish its efficacy

Physiotherapy and Rehabilitation 

Physiotherapy comprises the most essential aspect in the management of a patient with SCA. It may not halt the disease process but it definitely helps the patient to cope up with the symptoms and improve function to a large extent. Moreover, the earlier physiotherapy is started in the course of the disease, the easier it becomes for the patient to manage his/her activities of daily living as well as vocational activities. 

The chief goals of physiotherapy are:

• Optimize function and improve quality of life.
• Prevention of falls by careful assessment of the reason of fall and the environment. Improving the strength and flexibility of muscles.
• Improving balance and co-ordination 
• Retraining the gait (walk). 

Depending on the signs, symptoms and functional limitations of each patient, a physiotherapist can schedule a treatment plan based on two approaches:

1) Compensatory approach:-

This approach helps to improve functions of daily activities by employing few changes with and around the patient. These may be as follows: 

•  A physiotherapist prescribes appropriate mobility aid such as cane, walker or wheelchair. Also, he/she trains the patient for the usage of the aid by incorporating strengthening programmed for specific muscles required for the usage of mobility aid. 

• He/she provides tailor-made advises on certain environmental modifications at home or workplace of the patient such as installing ramps, handles and bars, modifying height of bed, sofa or working chair, raising the toilet seat etc. based on the requirements and clinical presentation. 

•  He/she will teach strategies to optimize the quality and ease of daily activities.

2) Restorative approach:

 Despite of SCA being a progressive condition, some symptoms show definite improvement with regular and guided training by improving the underlying impairment. As mentioned above, the most common impairments in SCA are incoordination, weakness of muscles, impaired balance and ataxic gait. A physiotherapist can use various exercise methodologies to improve each of these. These may be few or all of the below

I. Co-ordination exercises: 

Frenkel exercises: Frenkel Exercises are a series of movements of increasing difficulty performed by ataxic patients to facilitate coordination. These are used to restore rhythmic, smooth and coordinated movements.

 The main principles of Frenkel exercises are:

• Concentration or attention 
• Precision 
• Repetition Exercises can be done in four basic positions according to the level of impairment can be used: lying, sitting, standing or walking. The exercises progress from postures of greatest stability (lying, sitting) to postures of greatest challenge (standing, walking). As voluntary control improves, the exercises progress to stopping and starting on command, increasing the range and performing the same exercises with eyes closed. Concentration and repetition are the keys to success. 

II. Strength and flexibility training:

 Flexibility of all major muscles should be maintained using stretching and self-stretching techniques. The physiotherapist can design a strength training programmer which targets all major muscle groups. He/she can employ a wide range of techniques for strengthening such as: 

• Strengthening using devices such as weight cuffs, resistance bands and tubes, dumbbells and specially designed machines for strengthening. 

• Strengthening using body weight/functional strengthening: For example; squats, lunges, standing on one leg etc. 
• Hydrotherapy 
• General fitness training 

III. Balance and gait training: 

Though improvement in co-ordination and strength improves postural control and balance to a large extent, but, specific techniques are commonly used by physiotherapists to train the balance and gait. 

• Somatosensory cues from the fingertips using light touch contact as a means of guidance by the therapist can provide a powerful reference orientation while the patient is standing or doing some activity in standing position or walking. Similarly, strong verbal cues are used in the same manner.

• Techniques such as perturbations, reaching out to specified target, balance training on foam mat and balance board are also the most commonly employed techniques to train balance. 

• Treadmill training is also an effective method to train the gait. However, the intensity and duration is tailor-made for each patient. 

Psychosocial support

 As required by patients with any neurological disorder, a strong and consistent psychosocial support from the family members, community members as well as the rehabilitation team is the foundation for successful rehabilitation of a patient with SCA. It is of utmost important for the family and rehabilitation team to have a clear understanding of the disease process. Such clarity helps to be empathetic towards the patient and also helps to formulate and chase realistic goals for the patient. Moreover, a high level of motivational support is also required to maintain consistency in the rehabilitation process. It is of primary importance to maintain the individuality and dignity of the patient by the community members despite of the functional limitations. It would really help the patient to go a long way without being disheartened