SPASTICITY - PART 3 ( BRADDOM 5TH EDITION )
EDITED BY ME
SIGNS AND SYMPTOMS
1 Muscle tightness or the limb cannot be moved
2 functional limitations -
A ) inability to release a grasped object
B ) difficulty in walking
C ) weakness
D ) difficulty in manipulating objects due to decreased hand dexterity
E ) inability to perform certain tasks
OFTEN WEAKNESS RATHER THAN SPASTICITY IS THE PRIMARY CAUSE OF LIMITATION
PROBLEM IDENTIFICATION AND GOAL SETTING
1 For this , there should be knowledge of abnormal postural pattern - are manifestations of imbalance
2 ARE THE GOALS SMART
S - specific ( well defined and targets a specific problem )
M - measurable ( either quantitatively ( technical ) or qualitatively ( functional )
A - agreed upon
R - realistic ( potential for improvement )
T - TIME BOUND
Or
SMARTER
E - EVALUATED
R - REEVALUATED
CLINICAL TESTING OR DIAGNOSIS
ASHWORTH SCORE
MODIFIED ASHWORTH SCORE
TARDIEU SCALE
REPAS SCALE ( IS BASED ON ASHWORTH AND MOD ASHWORTH TESTING ) - also kn as resistance to passive movement scale
DEFINITION
IS DEFINED AS VELOCITY DEPENDENT INCREASE IN TONIC STRETCH REFLEXES ( V IMP )
It occurs secondary to -
1 Increased non reflex intrinsic muscle stiffness
A ) Length dependent are secondary afferents whereas primary afferents are velocity dependent
B ) Velocity dependence was greater at greater muscle lengths and length was greater with faster stretches ( vice versa )
OVERALL , stretch responses are both velocity dependent and length dependent ( v imp )
NOW IT IS ALSO KNOWN THAT IT IS POSITION DEPENDENT ( VV IMP ) - PAY ATTENTION WHILE EXAMINING .
MANAGEMENT
A ) NON PHARMACOLOGICAL
1 - VV IMP - ALTHOUGH SPASTICITY IS A NEUROLOGICALLY BASED CONDITION , ITS OBVIOUS MANIFESTATION IS PHYSICAL , SO USE OF PHYSICAL MODALITIES
2 Passive stretching - effective in reducing tone and increasing ROM in patients with brain injury
3 use of splinting and casting in acute setting for sustained contractions - casting alone is sufficient to prevent contracture and to reduce spasticity if done earlier
4 electrical stimulation - only temporarily
B ) PHARMACOLOGICAL
1 APPROACH - 2 TYPES
A ) Base drug choice on the clinical presentation - no of limbs involved
B ) Determine the choice of drug on underlying pathophysiology of spasticity - according to neuroanatomical basis
DRUGS
A ) oral spasmolytics -
most commonly used are -
1 - Baclofen ( GABA B AGONIST )
2 - Tizanidine ( ALPHA ADRENERGIC AGONIST )
3 - Dantrolene ( HYDANTOIN DERIVATIVE )
4 - Benzodiazepines ( GABA A AGONIST )
5 - Gabapentin ( inhibitor of voltage gated calcium channels )
A ) These all are associated with adverse effects such as - sedation , drowsiness and weakness - vv imp ( VIVA IT OCCURS SECONDARY TO POOR ADHERENCE )
B ) THERE IS NO EVIDENCE BASED GUIDELINES - medicine choice is based on practical reasons
C ) A medicine should be allrounder or having patient related property *
Eg - use of tizanidine which also has analgesic properties along with spasmolytic activity can be used in painful nocturnal spasms - it also promotes sleep - BUT IT CANNOT BE GIVEN IN ORTHOSTATIC HYPOTENSION OR PATIENT TAKING CLONIDINE
D ) INJECTION SHOULD BE USED IN BRAIN DAMAGE PXS SINCE ORAL DOSING CAN CAUSE MORE SEDATION
OR
COMBINATION MEDICATION AT LOWER DOSE SHOULD BE USED
E ) DONOT ABRUPTLY STOP A DRUG - DONOT STOP BACLOFEN ABRUPTLY AS IT CAN CAUSE REBOUND SPASTICITY AND HALLUCINATIONS
F ) TIZANIDINE SHOULD NOT BE GIVEN WITH FLUOROQUINOLONES AS IT CAN INCREASE ITS LEVEL
G ) TIZANIDINE CAUSES DOSE DEPENDENT ANTI NOCICEPTIVE EFFECTS AS IT CAUSES INHIBITION OF SUBSTANCE P.
B ) FOCAL TREATMENT - BOTULINUM TOXIN CHEMODENERVATION
1 - it exerts its action through inhibition of acetylcholine release at NM junction
2 - it takes several days following an injection and its a complex process -
A ) internalisation of the toxin
B ) reduction and translocation of disulfide bonds holding the light and heavy chains of the toxin
C ) inhibition of acetylcholine release - cleaving of SNARE protein ( sensitive n ethylmaleimide sensitive fusion attachment receptor )
3 DOSING -
600 - 800 UNITS ARE SAFER ( Incobotulinum toxin A and onabotulinum toxin A )
4 DILUTION - high volume or end plate targeted botulinum toxin result in more profound neuromuscular blockade than low volume - its a double edge sword as it can leads to reversible paralysis of non affected area or muscle group - OPTIMAL CONCENTRATION IS REQUIRED
5 ENHANCEMENT TECHNIQUES
1 Target the muscle innervation zone not just the motor points ( v imp ) can optimise the effects of botulinum toxin innervation
2 guide injection by listening to EMG activity
3 identify motor points through electrical stimulation
4 visualising target sites by sonography
5 role of casting ( v imp - practical point of view ) enhances the effects of onabotulinum toxin A owing to prolonged stretching of spastic muscles
6 pairing with electrical stimulation - influences the activity of synaptobrevin 2 receptors - it facilitates neuronal binding and subsequent uptake of botulinum toxin ( v imp )
7 Pairing with extracorporeal shock wave therapy - recently through modulation of muscle rheology and neurotransmission
POTENTIAL REASONS FOR POOR OUTCOME ( VV IMP - VIVA VOCE )
1 PATIENT RELATED -
A ) age and size
B ) disease condition
C ) concurrent medications that can interact with spasmolytics
D ) unrealistic goals
2 - INJECTOR RELATED
A ) incorrect diagnosis
B ) incorrect muscle selection
C ) improper injection technique
3 DRUG RELATED
A ) incorrect dose
B ) incorrect preparation
C ) FOCAL PHARMACOLOGICAL TREATMENT ( NERVE BLOCK - NEUROLYSIS )
1 By phenol ( 5 - 7 % ) or alcohol ( 35 to 60 % ) - denatures proteins ( v imp ) in neural tissues leading to blockage of nerve transmission
2 causes degeneration of muscle spindles , damage to both afferent and efferent nerve fibers - is irreversible - leads to permanent control of spasticity
3 is also an anesthetic at low concentrations - less than 3 %
4 effect is immediate
5 commonly injected nerves are - pectoral , subscapular , musculocutaneous , obturator and tibial nerve
6 side effects - injection related dysesthesia , localised swelling , excessive weakness , hypotension , tremor and convulsions
D ) INTRATHECAL BACLOFEN
1 - has the advantage of direct access to GABA B receptors in spinal cord because the BBB has not to be crossed for this
2 - decreases the oral related adverse effects
3 to be used in severe spasticity OR severe dysautonomia following brain injury , when other Rx fails
4 trial should be done and is defined as 1 to 2 drop in modified ashworth score - the recommended trial dose is 50 micrograms
5 - most common drug related side effect is hypotonia , somnolence , headache , convulsions , dizziness and urinary retention
E ) SURGICAL INTERVENTION - LAST RESORT
1 is well accepted treatment option for contractures as it primarily address joint deformities rather than spasticity itself
2 includes neuroablative procedures such as rhizotomies , peripheral neurotomies and orthopaedic reconstruction procedures such as tendon lengthening and tendon transfers
3 commonly performed tendon procedures are - SPLATT ( SPLIT ANT TIBIAL TRANSFER ) , achillis tendon lengthenings for managing spastic equinovarus - specifically corrects the abnormal joint positioning by providing a new position