Peripheral nervous system damage
Injuries or diseases of peripheral nerves supplying specific muscles can also cause muscle atrophy. This is seen in nerve injury due to trauma or surgical complication, nerve entrapment, or inherited diseases such as Charcot-Marie-Tooth disease. Medications
Some medications are known to cause muscle atrophy, usually due to direct effect on muscles. This includes glucocorticoids causing glucocorticoid myopathy or medications toxic to muscle such as doxorubicin. Endocrinopathies
Disorders of the endocrine system such as Cushings disease or hypothyroidism are known to cause muscle atrophy. Pathophysiology
Muscle atrophy occurs due to an imbalance between the normal balance between protein synthesis and protein degradation. This involves complex cell signalling that is incompletely understood and muscle atrophy is likely the result of multiple contributing mechanisms.Mitochondrial function is crucial to skeletal muscle health and detrimental changes at the level of the mitochondria may contribute to muscle atrophy. A decline in mitochondrial density as well as quality is consistently seen in muscle atrophy due to disuse.The ATP-dependent ubiquitin/proteasome pathway is one mechanism by which proteins are degraded in muscle. This involves specific proteins being tagged for destruction by a small peptide called ubiquitin which allows recognition by the proteasome to degrade the protein. Diagnosis
Screening for muscle atrophy is limited by a lack of established diagnostic criteria, although many have been proposed. Diagnostic criteria for other conditions such as sarcopenia or cachexia can be used. These syndromes can also be identified with screening questionnaires.Muscle mass and changes can be quantified on imaging studies such as CT scans or Magnetic resonance imaging (MRI).
Cognitive-behavioral treatments, a combination of the previous two treatment types, involves a strategical-metastrategical learning technique that teaches children math, language, and other basic skills pertaining to memory and learning. The first goal of the training is to teach the child to be a strategical thinker through making cognitive connections and plans. Then, the therapist teaches the child to be metastrategical by teaching them to discriminate among different tasks and determine which plan or strategy suits each task. Finally, family-oriented strategies delve into empowering the family with the skill set they need to support and encourage their child or children with an intellectual disability. In general, this includes teaching assertiveness skills or behavior management techniques as well as how to ask for help from neighbors, extended family, or day-care staff. As the child ages, parents are then taught how to approach topics such as housing/residential care, employment, and relationships. The ultimate goal for every intervention or technique is to give the child autonomy and a sense of independence using the acquired skills he/she has. In a 2019 Cochrane review on beginning reading interventions for children and adolescents with intellectual disability small to moderate improvements in phonological awareness, word reading, decoding, expressive and receptive language skills and reading fluency were noted when these elements were part of the teaching intervention.Although there is no specific medication for intellectual disability, many people with developmental disabilities have further medical complications and may be prescribed several medications.