Ataxia & Weakness Management in Neuro Populations

Management of Impairments in Neurologic Populations (Part II)

• Focuses on ataxia/incoordination, weakness, and sensory impairment in neurological populations and their management.

Ataxia/Incoordination

• Clinical presentation depends on which area of the cerebellum is involved and its connections.
• Primary impairments include dysmetria, decomposition of movement, rebound phenomenon, dysdiadochokinesia, asthenia, intention tremor, and hypermetria.
• Related symptoms include titubation, postural tremor, dysarthria, staccato speech, and nystagmus.

Impact of Ataxia on Function

• Ataxic gait is associated with impaired balance and affects mobility.
• Incoordination impacts functional activities of the upper limb, such as self-care tasks like buttoning a shirt or brushing teeth, and contributes to poor balance
• Eye movement and gaze control also significantly impact reading and visual-spatial coordination for eye-hand and eye-foot activities.

Functional Anatomy of the Cerebellum

• Spinocerebellum:
  • Located in vermal and paravermal zones of the anterior lobe and part of the posterior lobe, it receives input from the spinal cord, peripheral receptors, spinal motor generators, and cerebral cortex.
  • Lesions lead to hypotonia; impaired trunk-limb coordination; dysmetria; intention tremor; and rebound effect.
• Cerebrocerebellum:
  • Located in the lateral hemispheres, receives input from pontine nuclei and the cerebral cortex; pontine nuclei.
  • Lesions result in abnormal timing of movement; decomposition of movement; and impaired independent limb coordination, like eye-hand coordination.
• Vestibulocerebellum:
  • Found in the most medial and inferior part of the cerebellum including the flocculonodular lobe, it gets input from the vestibular nuclei/apparatuses.
  • Lesions cause balance and gait impairments, nystagmus, vertigo, dizziness, nausea/vomiting, oscillopsia, and anxiety.

Lifespan Influence

• Age-related changes:
  • Incoordination can arise with aging due to decreased muscle strength.
  • Reaction time increases are due to degeneration of neural conduction, decreased range of movement, changes in posture and impaired postural control.

Diagnoses

• Conditions can cause ataxia/incoordination include hereditary/genetic disorders, metabolic disorders/disturbances, tumors, trauma, vascular disorders, somatosensory impairment, lesions from conditions like multiple sclerosis, and neuromusculoskeletal impairments from aging.

General Approaches to Intervention

• Gait, trunk control, and activity limitations can be improved with physical therapy, according to systematic reviews Martin, 2009 and Synovfzik, 2014
• Intervention response varies depending on the impairment's nature (stroke vs. degenerative disease).
• Ability to optimize function depends on the cerebellum's spared regions, neural adaptation and plasticity, and compensation processes.
• Treatment approach should be based on:
  • Underlying impairments causing postural instability.
  • Gaining central, proximal, and distal postural control.
  • Using compensatory strategies selectively.
  • Advancing from simple to complex tasks.
  • Progressing from self-selected to faster, accurate speeds.
  • Moving from symmetrical to asymmetrical postures.
• Consider underlying pathology, how impairments affect activities, the patient's health and functional status, compensatory methods in use, devices such as splints, and patient’s exertion/tiredness.

Use of Equipment as Intervention

• Treatment examples: Wii Fit, Xbox exergames, cycle ergometry, treadmill training.
• Adaptation/Compensation: weighted vests, weighted ADL tools, neck collars for head control, and adaptive ADL tools like nonskid cutting boards.

Therapeutic Techniques

• Motor learning is possible even with cerebellar damage (per Morton, 2009).
• Coordinative physiotherapy exercises:
  • Includes static and dynamic balance activities.
  • Balance during gait, treadmill or gait training.
  • Trunk-limb coordination in whole-body movements.
  • Stepping and falling strategies.
  • Mobility exercises for contracture prevention.
• Frenkel Coordination Exercises:
  • Emphasize visual feedback for adapting to sensory changes, such as loss of proprioception.
  • Limbs can be observed during exercises in semi-fowler or sitting, using a mirror if needed
  • Progress from supported limb movements to antigravity motions, and from unilateral to bilateral symmetrical and then reciprocal movements.
  • Postures with great stability improve patient stability.
• Functional activities:
  • Begin at the identified level of function and assess the patient.
  • Focus on central (trunk) stability before the proximal/distal control.
  • Integrate trunk/proximal stability into functional activities.
  • Focus on postural control to promote transfer of functions.
  • Increase motor learning and functional transfer into ADL.
  • Progress exercises in horizontal, sitting, and standing positions.

Precautions

• Resistance/tasks shouldn't require extreme effort.
• Compensatory strategies for postural control should be avoided unless the patient has reached his/her optimal postural control to their prognosis.
• Consider the patient's fitness level to avoid overexertion for those with ataxia as part of MS symptoms.
• Monitor patients their levels of exertion so they can adapt to the functional activity based on their ADL.
• Visual and mental fatigue can occur through cognitive control of movement.
• Task variability should only be used if a patient can and anticipate the movement.

Weakness

• Weakness is a neurological disorder that affects the function.
• Important to strength train those suffering from neurological disorders because:
  • remediates weakness deficits.
  • prevents impairments
  • promotes optimal health and wellness.
• Strength training in neurological diagnoses is supported with the evidence.
• Customize each patients exercise program.
• Weakness affects the skills and functional activity.
• Weakness range includes a range of the neurological disorders like:
  • Nonprogressive disorders in the adults and children.
  • Progressive disorders
  • Spinal Cord disorders
  • Peripheral nervous system disorders
• The degree of weakness depends on pathology and the diagnosis.
• Therapy will need to examine the deficits of the strength, severity, and nature.
• Strength training is custom based on the needs.

Post-stroke

• Weakness extents depend on the characteristics of the stroke.
• There is underlying weakness due to loss of drive unit and the muscle fibers' change.
• Evidence suggest bilateral strength training required.
• Important to associate strength training with functional activity for upper and lower limbs.

Acquired Brain Injury (ABI)

• Varies due to brain injury.
• Prolong Immobilization and Concomitant fracture contributes to muscle weakness.
• Multiple Sclerosis (MS)
  • Underlying cause is similar to a post stroke.
  • Muscle fatigue increases disability.
  • Impaired in LE force production.
  • Functional limitation is correlated.

Strength Training Benefits

• Shown for Traumatic Brain Injury (TBI), MS, Parkinson's Disease (PD), Cerebral Palsy (CP), and neuromuscular disease patients.
• Benefits of programs:
  • Moderate to high intensity to promotes neuroplasticity.
  • Reverses inactivity effects, reduces the fall risk, and stops disuse atrophy.

Evidence

• Stroke Population
  • Very effective for chronic and acute patients.
  • Intensity and strength training vary.
  • Task specific better results.
  • Training does limit spasticity, but when strength training is mixed with task functional training.
• MS Population
  • Need aerobic and strength combination.
  • Functional gains have strong evidence.
  • There is some evidence that there are no increase in exacerbations.
  • Moderate intensity submaximal strength training.
• PD population
  • Contributes to the weakness of a fall risk patient.
  • Gains in strength are linked with balance and gait.

Strength Training Interventions

• Training functional muscle synergies and very weak exercise muscles and isolations muscle training is very helpful for patients with neurological conditions.
• Some of these interventions would include Facilitation, NMES, EMG, BFB, EMG and task oriented functional strength training, isotonic and aquatic exercises.
• Design principles:
  • Overload
  • Specificity
  • Cross-training
  • Reversibility
• Prescription:
  • frequency
  • volume
  • intensity
  • duration
• Submaximal training.
• Important:
  • Warm up and cool down.
  • Intensity
  • Fatigue
  • Fatigue can improve when working a muscle to its overload gains.
  • Caution is needed from diagnoses as they can be concerned about exhaustion.

Therapeutic exercises

• Isotonic
  • Strengthen postural muscle and is effective with very weaker muscles.
• Eccentric
  • Muscle weakness that is centralized.
  • More mechanically effective than concentric.
• Concentric
  • Improve the speed of muscles by doing them faster and improving your muscles.
• Sensorimotor and Proprioceptive inputs that help with activation.

Sensory Impairment

• Is the ability to process a stimulus in a motor response, like:
  • Tactile
  • Vestibular
  • Proprioceptive
• Types:
  • Hypersensitivity
  • Hyposensitivity

Impairment

• Disruption to the registration or the body's ability in neurological functions, can lead to disruption in activities and lead patients with disabilities, also has both an external and internal experience and you should respects it.
• It is best to support with evidence the sensory processing.
• Hypo:
  • Integration therapy and recovery through sensory to improve awareness of awareness.
  • Improve the motor control through aquatic activities.
• Electro therapy and use of MIRE and home integration can improve sensation in neurological function.
• Compensation with environmental changes can help prevent injury by making adjustments or using adaptive equipment to function.
• Hyper:
  • Integration and therapy of sensory can improve quality of life, decrease defensiveness and function.
  • Vibrations may help hypersensitivity by providing proprioception.

Modify Hypersensitivity in patients:

• Modifying the stimulus.
• Provide less cluttered and quiet room by taking things away or providing the room with weight blankets and vests.
• Offer daily D and B to lower the discomfort and help them function at their greatest.