Page 23 - Mobility Management, January 2018

protein needed for effective motor neuron function. Human chromosome 5 contains two genes (SMN1 and SMN2) at location 5q13. SMA is a genetic defect in the SMN1 gene, but all patients retain at least one copy of SMN2 (some have two to four copies). SMN2 can code small amounts (10-20 percent) of the SMN protein, explaining variations in the severity of this disease.”
Cure SMA recognizes four types of SMA, the rst three of which present at various stages of childhood. (Some health-
care organizations, such as the National Organization for Rare Disorders, have discussed an additional type — Type 0 — that is the most severe form of SMA and is typically fatal by the time an infant is 6 months old.)
“In general,” Ball said, “the clinical manifestations [of SMA] are are exia (absence of re exes) for most extremities; global muscle weakness; low tone; feeding/swallowing dif culties; tongue fasciculations; degrees of respiratory compromise; and developmental delay.”
SMA type 1, also known as Infantile or Werdnig-Hoffmann disease, “has an early onset, birth to 6 months,” Ball said. “Clinically, they present with ‘ oppy baby syndrome,’ lacking head and trunk control, completely dependent, with respiratory compromise requiring mechanical ventilation soon if not immediately following birth. Their intellect can be quite normal, with the child expressing themselves through facial changes. Life expectancy is short, usually 2 years, but 10 percent at least can live to adolescence-adulthood.”
SMA Type II, Ball said, is known as Intermediate or Dubowitz disease, and “has an onset between 6 and 18 months of age, displaying global weakness with an inability to stand or
walk, but some ability to sit independently or with assistance, respiratory compromise with or without need for mechanical ventilation, and life expectancy usually to adulthood.”
Supportive Seating & Mobility
Children with different types of SMA have very different assistive technology needs, said Darlene Hawthorne, Thomashilfen’s president of North America.
“There is a big difference in the main seating, positioning and mobility-related presentations between children with Type 1 and Type 2 SMA,” she noted. “In addition, within each group there
is a range in strength from relatively strong to very weak, so it is hard to pinpoint the main presentations for each group. Children with Type 1 often present with pronounced scoliosis that must be assessed with the child in a fully reclined position, as this is indicated by their respiratory needs. Most are completely without head control.
“Children with Type 2 can present from quite strong, with head control, and the ability to sit in an upright position. Trunk stability must be considered, as many are stabilized by a TLSO [thoracolumbosacral orthosis].”
“SMA Type 1 needs full support to maintain head, trunk and extremities upright against gravity, since they are completely dependent,” Ball said. She recommended the following for
children with Type 1 SMA:
• Supportive seat and back (hip and pelvic support) to
maintain the pelvis in a more neutral position, maintain natural spinal curves, and prevent scoliosis.
• Width- and height-adjustable lateral supports and chest vest to prevent scoliosis and maintain trunk upright against back.
• Head support, which may include anterior and lateral support to maintain head upright for functional tasks, socialization, school work.
• Foot supports with either ankle straps or ankle huggies.
• Age-appropriate system that can provide position changes (tilt in space and recline) for feeding, trach care, pressure relief, diapering, postural control for functional activities, venous return insuf ciency and that can accommodate a ventilator, battery, suction machine, and all the other respiratory essentials.
• The system should also be crash tested and approved for travel in automobiles for child safety and caregiver ease. The lighter the system, the easier for the caregiver to use it to get to multiple doctor appointments, as well as to allow inclusion in family outings.
• Power mobility can be considered at about 1 year of age
if patient health status warrants and family has necessary transportation (van with lift) to accommodate its transport. A micro joystick using mobile arm supports could possibly allow independent operation on a power wheelchair with tilt in space and minimal-shear recline.
For children with Type 2, Ball said, “Some could be independent in power mobility with an effective input device and possibly mobile arm supports or tray for upper-extremity support while accessing the joystick/input device. This system would need tilt in space and maybe recline, if the client is ventilator dependent. If the client is not vent dependent, then tilt in space would be suf cient to position for functional tasks, provide pressure relief, and position changes throughout the day to tolerate sitting long periods.”
“The top priority for children with Type 1 is for the seating equipment to fully recline while at the same time providing
the needed postural support and regular position changes,” Hawthorne said. “The equipment must be able to fully recline.
It is also helpful if the equipment can be tilted beyond at to a position that can be used for postural drainage. For children with Type 1, who must remain in the reclined position, the seating should also offer adequate contouring for comfort. It is important not to have their sight lines blocked if the child’s head is turned to one side or another.
“The top priority for children with Type 2 is seating that offers a variety of positions in order to support them from upright sitting to recline. The degenerative nature of SMA must be taken into consideration. Seating and positioning needs can change even in
a single day, as the child with Type 2 fatigues or requires different positions in order to function well at school and therapy.”
And as typical with CRT clients, Hawthorne noted the individuality of children’s abilities.
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