Basal Ganglia Dysfunction Flashcards
Pathways BG
Direct pathway - overall inhibition of primary motor cortex
Indirect pathway - inhibits the direct pathway - overall excitiation of the primary motor cortex
Path of information BG
Premotor cortex - supplementary motor cortex - sensory cortex - thalamus - basal ganglia - thalamic nuclei - primary motor cortex
BG Function
regulates voluntary movement and learning motor skills
stores movement patterns to allow for automaticity of movement
sequencing and execution of learned movements
remembers encoded instructions for initiation, control and cessation of regularly made movements
preparation for movement
postural movement, automatic and skilled volitional movement of the trunk and limbs
Hyperkinesia - Impairments
Chorea - continuous, rapid, irregular, jerky, twitching movements that are involuntary
Hemiballismus - dysfunction of the subthalamic nuclei, causing large flinging movements of the arm/leg, usually ipsilateral
Athetosis - slow, writhing movements
Dystonia - frequent, fluctuating contractions of muscles resembling hypertonia
Wilson’s Disease
hyperkinetic disorder
liver unable to metabolise copper in bed = build up, causes damage to the lenticular nucleus
- tremor of upper extremities
- slow movement
- changed temperament - argumentative and more emotional
- discolouration ring around cornea
Managed medically to get rid of excess copper
Tourette’s Syndrome
Unknown cause, typically begins in childhood
- tics - frequent, irregular movements of head, neck and shoulders
- involuntary vocalisation
- coprolalia - explosive, involuntary cursing
medical management or behavioural intervention
Huntington’s Disease
genetic disorder - symptoms onset 30s-40s progressively worsens cognitive decline chorea, loss of normal movement atrophy of caudate nucleus and putamen
Parkinson’s Disease - pathology
Degeneration of substantia nigra - causes reduced level of dopamine
Disrupts the dopeminergic pathway between the substantia nigra and striatum
causes hypokinetic movement - constant down regulating of motor plan to motor cortex
PD Impairments
flexed posture
Akinesia - difficulty initiating and ceasing movement (freezing)
Bradykinesia - slowness and stiffness of movement
Rigidity - mild hypertonia that affects the agonists and antagonists
- increased resistance to movement in all directions and throughout entire range
Tremor - resting tremor, occurs only at rest and disappears with voluntary movement
Postural Instability - loss of equilibrium and protective reactions, increased incidence of falling
Clinical Picture
Dyskinesia - presents as dystonia, wriggling and writhing Gait Disturbances - slow, shuffling and festinating - narrow BOS - reduced step length, arm swing, trunk and pelvic rotation - increased cadence - hesitance in initiations Decreased fine motor control - micrographia - hand writing very small Facial/Oculomotor Features - mask like face - reduced blinking - dysphagia Speech Disturbances - dysphonia - monotone - imprecise articulation - vocal tremor Adaptive Responses - muscle weakness - reduced joint ROM - reduced muscle length - fixed posture - reduced aerobic capacity Postural Hypotension - side effect of medication Peak dose dyskinesia - temporary hyperkinesia - only after taking medication - eventually settles to normal movement
PD Medical Management
levodopa madopar dopamine replacement therapy dopamine agonists type B inhibitors anticholinergics
PD Physio Management
education and training in use of movement strategies to improve function and strategy
LSVT BIG
intense exercise
improve and maintain balance
maintain CV fitness
strengthening and maintaining postural allignment
modify the environment
PD Methods of Exercise Intervention
LSVT BIG
- encourage large movement to combat bradykinesia
- high intensity and effort
- movement needs to be large enough to challenge the system
Strength Training - start 60-70% 1RM - max 80% 1RM 8-12 reps, 3 sets progressively increase load and volume
Forced Pace Exercise
- cycling/treadmill/exercise at fast pace than comfortable
increases function and gait
PD Prognosis
depends on age of onset
progressive without remission
likely to produce significant disability within 10-15 years
