Neurology-Extrapyramidal Disorders



Neurology-Extrapyramidal DisordersWhat would be expected in Hxx of pt with an extrapyramidal disorder?Slow progressive onset, Often starts unilateral progresses to become bilateral. Responds to medication initially.What would you expect to see from observation of a pt with an extrapyramidal disorder?Movement disorders,: twitches, jerks,Hemiballismus (rare movement disorder caused by brain lesion involves involuntary flinging motions of the extremities)What would the tone be like? (resistance to passive movement)Cog-wheel rigidity is highly indicative of an extra-pyramidal conditionWould there be changes to power?No reason for it to cause power change unless pt immobilisedWould the reflexes be different in extrapyramidal conditions?Tendon reflexes-Can be slightly increased, if tone is very high can be reduced. But not clonic.Superficial cutaneous reflexes-normal so down going plantar response!Would sensation be affected?No it would be normal-NB limbs may feel different because of different tone (‘my leg feels like wood’ etc)Would coordination be affected?Affects coordination itself, as in movement initiation and smooth, accurate executionDifferentiate between Pyramidal vs. Extrapyramidal structures + functionsPyramid tract- Both the corticospinal and corticobulbar tracts. The corticospinal tract is a collection of axons that travel between the cerebral cortex of the brain and the SC. It contains mostly motor axons. It consists of 2 separate tracts in spinal cord: lateral corticospinal tract and anterior corticospinal tract. An understanding of these tracts leads to an understanding of why one side of the body is controlled by the opposite side of the brain. The corticobulbar tract is also a pyramidal tract, carrying information to motor neurons of the cranial nerve nuclei, rather than the spinal cord.Extrapyramidal - part of motor system that causes involuntary reflexes and movement, and modulation of movement (i.e. coordination). The system is called "extrapyramidal" to distinguish it from the tracts of the motor cortex that reach their targets by traveling through the "pyramids" of medulla. Tracts are Vestibulospinal Tracts, Rubrospinal Tract, Reticulospinal System, Tectospinal Tract and Descending Autonomic System.Give an overview of their part in the control of movement and gaitPyramidal pathways- corticospinal and some corticobulbar tracts, may directly innervate motor neurons of SCor brainstem (anterior (ventral) horn cells or certain cranial nerve nuclei), whereas the extrapyramidal system centers around modulation and regulation (indirect control) of anterior (ventral) horn cells. Extrapyramidal tracts-chiefly found in reticular formation of the pons and medulla, and target neurons in SC involved in reflexes, locomotion, complex movements, and postural control. These tracts are in turn modulated by various parts of the CNS, including the nigrostriatal pathway, the basal ganglia, the cerebellum, the vestibular nuclei, and different sensory areas of the cerebral cortex. All of these regulatory components can be considered part of the extrapyramidal system, in that they modulate motor activity without directly innervating motor neurons.Predict possible sources of confusion between UMNL and extrapyramidal dysfunction. UMNL tendon reflexes are hyper-reflexic, brisk, at worst ‘clonic’ (hit tendon and produce clonus) whereas extrapyramidal tendon reflexes can be slightly increased, if tone is very high can be reduced. But not clonic Superficial reflexes are not affected in extrapyramidal dysfunction; if superficial reflexes are affected in UMNL they will be reduced or infantile. The tone in UMNL changes to clonus/’stiff/wooden/leaden’ but in extrapyramidal tone changes to cog-wheel rigidity. What part of the brain is affected by Parkinsonism?De-pigmentation and loss of neurones in the substantia niagra and depletion of dopamine-producing cells. Describe the Clinical Presentation of Parkinsonism.Slurring or hesitation of speech; excess salivation, infrequent blinking, loss of facial expression and infrequent smiling,What should you ask the pt if you suspect Parkinsonism?Have you noticed anything different about handwriting? Writing would be small (micrographia)Can you turn over in bed?Partner may recall being wokenDo you have difficulty walking?Pt may report being stuck to the floor, may have noticed walk better on uneven ground as here must be a deliberate ‘pyramidal function’. Describe signs of Parkinson’s.Pill rolling tremor, mms rigidity (cog wheel). Bradykinesia (Slowed ability to start and continue movements, and impaired ability to adjust the body's position) affecting face and axial mms first. Loss of postural reflexes. How severe is Parkinson’s and what is the prognoses? Not fatal but tremor, bradykinesia and rigidity deteriorate simultaneously affecting every aspect of the patient’s life. 50% suffer from depression, 80% develop dementia after 20 years if they survive. Describe signs, symptoms, severity and management of choreo-athetosisChorea is irregular, repetitive, jerking movements. Can be hereditary (huntingtons), or caused by drugs, infection or immunological causes such as SLE. The pathology is neuronal loss in the stratium with reduction on projections into other basal ganglia structures. Athetosis is irregular, repetitive writing movements; picture shows hand movements that occur.Describe hemibalismus. Involuntary flinging motions of the extremities, and random and can involve proximal and/or distal muscles on one side of body. The more a patient is active, the more the movements increaseWhat could cause hemibalismus?Damage to basal ganglia from stroke, traumatic brain injury, neoplasm (basal ganglia are a collection of nuclei that connects to several other areas of the brain. Due to the diverse nuclei that they contain, the basal ganglia are involved in numerous functions, including motor control). Hemiballismus caused by lesions in the subthalamic nucleus is more severe than other forms of disorderDescribe tics (picture shows facial tic)Involved with the dopaminergic system in basal ganglia. Sudden, repetitive, nonrhythmic motor movement or vocalization involving discrete muscle groups. Tics can be invisible to the observer, such as abdominal tensing or toe crunching. Common motor and phonic tics are, respectively, eye blinking and throat clearingWhat can osteopathy do about Parkinson’s?Gait re-education, improvement of balance and flexibilityEnhancement of aerobic capacityImprovement of movement initiationImprovement of functional independence, including mobility and activities of daily livingProvision of advice regarding safety in the home environment (from NICE guidelines on Physiotherapy ttt of Parkinson’s)What is pyramidal pattern weakness?Anti-gravity muscles (extensors of the lower limb & flexors of the upper limb) are spared. Pt can develop posture of flexed & pronated arms with clenched fingers & extended & abducted legs w plantar flexion of the feet - Turner Clinical features of extrapyramidsl diseaseGenerally seen as disorder of movement can be divided into 2 categories:Decreased Movement Postural disturbance: failure to make quick postural adjustments. Patient often falls. Flexion of limbs and trunk is associated with thisBradykinesia: a loss or slowness of voluntary movementMask like faceReduced blinkingReduced adjustments of posture when sittingIncreased MovementMyoclonus (shock like jerks)Rigidity – stiffness of limbs (During passive movement can be felt throughout the ROM & equally in flexors & extensors = Plastic/Lead Pipe Rigidity)TremorBallisimus (explosive, violent movements)Chorea (repetitive, irregular, jerking movements)Dystonia (slow, sustained, abnormal voice)What can hemibalismus be caused by?Infarction or haemorrhage in the conralateral subthalamic nucleus - turnerVascular diseaseMultiple SclerosisPredict possible sources of confusion in relation to UMNLDamage to the descending motor pathways anywhere along the trajectory from the cerebral cortex to the lower end of the spinal cord gives rise to a set of symptoms called the "Upper Motor Neuron Syndrome".The UMN neurons pass through both the pyramid and extra pyramidal tracts UMN lesions occurring within the pyramidal tracts of brain or spinal cord create patterns of pyramidal weakness (loss of power in extensors of arms and flexors of legs. Anti-gravity muscles are spared.)The rigidity that occurs in Extrapyramidal disorders could be confused with a UMNLPyramidal SystemWhere are the pyramids of the brain?Anterior potion of the medulla oblongataPyramidal System. What is its structure?The?pyramidal tract?(aka Corticospinal) travels between the cerebral cortext of the brain & the spinal cord (via the pyramid of the medulla). –wiki & lawrenceWhat is it function?The Corticospinal tract is concerned specifically with discrete voluntary skilled movements, especially of the?distal parts of the limbs. – Wiki“motor system which is used to make conscious movement. Largely centered around the corticospinal tract which passes through the pyramids of the medulla oblongata - LawrenceWhat is pyramidal pattern weakness?Anti-gravity muscles (extensors of the lower limb & flexors of the upper limb) are spared. Pt can develop posture of flexed & pronated arms with clenched fingers & extended & abducted legs w plantar flexion of the feet - Turner ................
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