Palsy and Other Neuromuscular Conditions

Fig. 40.1

(a) Ambulatory patient with spastic diplegia requires only a stick or pole for balance. (b) In contrast, a boy with spastic quadriplegia is barely able to crawl and requires complete support for activities of daily living. (c) Transportation is a challenge for many rural non-ambulatory patients, and the child in this example is carried in the traditional Nepalese doko

In contrast to economically developed countries where CP is commonly associated with prematurity and low birth weight, most cases in the developing world are due to inadequate antenatal care, unsupervised home deliveries, and a lack of access to emergency obstetric interventions such as cesarean section. Postnatal infections (encephalitis, meningitis) and kernicterus (neonatal jaundice) are also important causes.

Evaluating patients with CP requires a detailed birth history, identifying delays in neurologic development and documenting upper motor neuron findings including clonus and hyperreflexia. While the neurologic impairments are static, secondary musculoskeletal abnormalities progress with growth and include myostatic muscle contractures and torsional deformities of the femur and tibia, as well as foot deformities such as equinus, equinovarus, and equino-planovalgus. One may frame the neurologic impairments as positive, too much, or negative, too little. Positive signs include excessive muscle tone and/or excessive movement. Negative signs include muscle weakness, deficiencies in selective motor control, and balance abnormalities.

Spasticity is defined as a rate-dependent increase in muscle tone and is due to abnormalities in the pyramidal system that present as excessive stretch reflexes, resulting in a loss of motion at a joint (dynamic contracture). A fixed shortening of a muscle tendon unit is known as a myostatic contracture and also results in loss of motion. Dyskinetic CP involves hyperkinetic movements due to impairments in the extrapyramidal system (basal ganglia, thalamus). These include slow writhing movements of the fingers or uncontrolled movement of an entire limb. Patients with predominantly dyskinetic involvement rarely develop fixed musculoskeletal deformities. Often patients will have elements of both, with one type predominating.

Treatment Principles

Priorities for treatment include improving the patient’s communication skills and activities of daily living and only later improving mobility. While a host of physical impairments may be identified, the disability will depend on the patient’s environment, the extent of financial and emotional support from family and community, and cultural and religious perceptions. Traditional beliefs and the family’s opinions influence the perceived causes of the condition, the treatment sought, and expectations. Realistic goals must be established, and all treatment should aim to improve function or participation in activities, rather than to correct specific impairments.

One of the most distressing aspects when asked to see such a child is the sense of impotence in the face of the family’s hopes. However, the orthopedic surgeon has an important role, starting with a full, recorded history with a sympathetic and knowledgeable interpreter as a guide. A careful medical examination can identify underlying and associated functional conditions that might point to a treatable diagnosis. The musculoskeletal and neurological exams must be thorough, remembering that testing motor strength and passive range of motion are unreliable in the face of spasticity. In ambulators, the physical examination focuses on passive range of motion, degree of spasticity, muscle strength and selectivity, bony alignment, and observational gait analysis. In non-ambulators, the assessment focuses on passive range of motion, trunk balance, and spinal alignment.

An appropriate question is whether the patient will be able to walk with or without an assistive device if their orthopedic deformities are addressed. Assessment of the current level of function, the relative strength and motor control in the lower extremities, and the strength of their trunk and upper extremities will help answer this. Additional information includes the patient’s cognitive/behavioral function, ability to participate in rehabilitation, and access to or willingness to use orthoses and/or assistive devices.

It often falls on the visitor’s shoulders to explain to the family that some conditions have no cure and the problem is in the central nervous system, not the limbs. A delicate balance between realism and fatalism needs to be reached, requiring cultural sensitivity, best approached in tandem with a local counterpart. A community-based, family-centered strategy should be promoted. When family members are educated and encouraged to participate in the ongoing treatment, realistic goals can be set. In turn, trained family members can help influence and modify others’ perceptions about the associated disabilities.

Surgical treatment should be individualized and is generally aimed at complications of spasticity such as contractures and deformities. The goals are to improve function. Orthotics is often an essential component of the treatment and should be available and acceptable to the patient and family. Counseling is essential to set goals, establish priorities, and instill appropriate expectations. While short muscles can be lengthened and rotational abnormalities corrected, abnormal tone and movements, muscle weakness and imbalance, and deficiencies in the selectivity of motor control will all persist.

Patients who require an assistive device for balance preoperatively will likely need one postoperatively (Fig. 40.2). While orthoses may improve biomechanical function, they are often poorly tolerated in cultures where shoes are not worn. When setting functional goals, the patient’s current functional level can be assessed by the Gross Motor Functional Classification System (GMFCS), as follows: