therapist and to mimic or perform functional ADL and self- care activities in the context of therapy may be influenced by apraxia. If apraxia appears to be a factor in the management of a particular client after allowing a reasonable time for the client to carry out a movement or skill in response to instruction, gesture, Tone issues Paratonia is a unique presentation of hypertonia characterized by involuntary variable resistance to passive movement that increases with the progression of dementia (Hobbelen, Koopmans, Verhey, Van Peppen, & de Bie, 2006; Vahia, Cohen, Prehogan, & Memon, 2007). The diagnosis of paratonia is based on the presence of all of the following: ● Involuntary variable resistance during passive movement. ● Absence of clasp-knife phenomenon (an upper motor neuron sign of initial resistance followed by freedom of movement in an extremity, reminiscent of the closing of a pocket knife). ● Resistance to passive movement in any direction. ● Resistance felt in one limb in two movement directions or in two different limbs. ● Degree of resistance that correlates with speed of movement (e.g., less resistance to slow movement, greater resistance to fast movement). These criteria make up the Paratonia Assessment Instrument, which has been deemed valid and reliable in individuals with dementia (Hobbelen, Koopmans, Verhey, Habraken, & de Bie, 2008). One objective of this tool is to differentiate paratonia from rigidity and spasticity. Paratonia, sometimes referred to as Gegenhalten tone or “motor negativism,” may be present in any of the dementias, and risk factors may include vascular etiology of dementia and diabetes mellitus (Hobbelen, Tan, Verhey, Koopmans, & de Bie, 2011). As it progresses, paratonia can complicate the ability to assist functional movements and can ultimately lead to immobility and contractures. Passive ROM is ineffectual in impacting paratonia (Hobbelen, Tan, Verhey, Koopmans, & de Bie, 2012). Mobilizing individuals with advanced AD and paratonia can be extremely difficult; however, movement and function may be facilitated more easily by exploiting the presence of this unique tone. For example, in assisting a client to move forward in a chair in preparation for standing, the therapist may intuitively assist by “pulling” the individual forward with hands placed on the posterior aspect of the shoulders. A client with paratonia will respond by “pushing” backward into the cue of the hands so he or she is pushing back into the chair rather than moving the upper body forward; in effect, the therapist and client are fighting each other. If the therapist modifies his or her hand placement to be on the Typical motor learning There are two major memory and learning systems that function in the context of motor learning: declarative/explicit and procedural/implicit (Shumway-Cook & Woollacott, 2017; Vidoni & Boyd, 2007). Declarative/explicit learning requires awareness and attention, is reliant on recall, and is enhanced by the ability to reflect upon and articulate the process being learned. Procedural/implicit learning comes in various forms: (a) nonassociative learning, such as habituation and sensitization; (b) associative learning, such as operant and classical conditioning; and (c) skill (and habit) learning. Figure 5 depicts these mechanisms of motor learning. The neuroanatomical home for each of the memory and learning processes is distinct. When the nervous system is functioning normally, different strategies of motor learning occur both in tandem and independently, depending on the situation and goals. Declarative/explicit learning requires functioning of the hippocampus and surrounding medial temporal lobe structures, whereas procedural/implicit learning requires functioning of the basal ganglia and cerebellum (Harrison, Son, Kim, & Whall, 2007; Shumway-Cook & Woollacott, 2017; Vidoni & Boyd, 2007).
or demonstration, an alternate method of instruction may be indicated. Tactile guidance is a constructive therapeutic strategy to manage apraxia, with the goal of tapering the guidance with repetitive task efforts.
anterior aspect of the client’s shoulder, the client with paratonia will respond by “pushing” into the pressure of the hands, facilitating movement in the proper direction to achieve forward weight shift in preparation for mobility (Figure 4). This counterintuitive yet useful technique can be taught to families and caregivers to facilitate mobility in individuals with AD. Strategic use of hand placement with directional force can be equally effective to assist supine-to-sit or sit-to-stand transitions—hands should be placed giving pressure into the patient such that if the individual responds by pushing/moving his body into the pressure, the resultant movement will be in the desired direction (i.e., pushing down into the patient when you want the patient to move their body up). This strategy is not universally effective, but when it does work, it can significantly lessen caregiver burden.
Figure 4: Clinical Impact of Paratonia: Hand Placement to Facilitate Mobility
The stimulus of hands on the posterior shoulders (left) causes the client to push backwards into the stimuli; hands on the anterior shoulders (right) will facilitate the client’s anterior weight shift. Note . Illustrations copyright 2014 by Scout Ries. Used with permission.
MOTOR LEARNING PRINCIPLES AND ALZHEIMER’S DISEASE
In rehabilitation, both types of learning are often integrated. Declarative learning is used when patients are asked to reflect on performance, sequence multiple activities within a task, remember and build on previous performance, or articulate their movement processes. Procedural learning is used when therapeutic programs are designed with repetitive practice of skills without encouraging conscious awareness or reflection on task performance. With purposeful use of therapeutic strategies, physical therapists have the ability to drive neuroplastic changes in the brain. Kleim & Jones (2008) authored a seminal article summarizing the principles of experience-dependent neural plasticity, highlighting evidence that supports the ability of rehabilitation professionals to impact central nervous system recovery with skillfully designed and implemented treatments. Specificity, repetition, intensity, and salience of training were highlighted as critical considerations in therapeutic interventions.
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