Movement Disorders PDF

Movement Disorders General Basal Ganglia - Pyramidal tract: - Group of nuclei in the deep white matter of the brain. è Responsible for initiating of movement....

Movement Disorders General Basal Ganglia - Pyramidal tract: - Group of nuclei in the deep white matter of the brain. è Responsible for initiating of movement. è Caudate nucleus. è Weakness. è Putamen. è Sub-thalamic nuclei. - Extrapyramidal tract: è Globus pallidus: divided into globus pallidus è Responsible for coordination/modifying of movement. externa (GPe) and globus pallidus interna (Gpi). è Movement disorders: result from structural or functional è Substantia nigra: divided into the pars compacta problems in basal ganglia. and the pars reticulata. Classification of Phenomenology - Involved in movement of: è The trunk and extremities. - Hyperkinetic: è Extra-ocular muscles. è Tremor. è Cognition and emotion. è Chorea/ballism. è Sometimes the cerebral cortex. è Athetosis. è Dystonia. Parkinsonism è Tics. è Myoclonus. - A syndrome of clinical features caused most commonly by è Ataxia. Parkinson’s disease. - 4 cardinal features: - Hypokinetic: è Bradykinesia: the main cardinal clinical feature. è Bradykinesia/akinesia. è Resting tremor: the MC feature to start. è Rigidity. è Postural instability: è Freezing. P Recurrent falls. è Stiff muscles. P Clinically diagnosed by retropulsive pull test. P Usually a late feature in Parkinson’s disease. P Not less than 2 yrs from the onset of the features in Parkinson’s disease. P If it starts earlier, then the cause isn’t Parkinson. è Rigidity.  Movement Disorders Spasticity Rigidity Parkinson’s Disease Lesion: occurs in pyramidal tract Lesion: occurs in basal ganglia lesions lesions (commonest: internal - A progressive neurodegenerative disease. capsule) - Affects between 100 and 200 per 100,000 people over 40. Velocity and amplitude dependent Velocity and amplitude independent More tone in the initial movement Cogwheel (continuous) or lead pipe - Prevalence is 0.3%. (clasp knife) (interrupted) - Common age of onset is in the 60s. More resistance in one direction Same resistance in all directions è Early onset: If presents earlier (before 50y). Commonly present in: CP, stroke Commonly present in Parkinson è Look for gene mutations for familial and genetic forms of Parkinson. Weakness of muscles is present No weakness (atrophy) - Age is the MC RF. Only antagonists are involved Both agonists and antagonists are involved - Pathophysiology: è Substantia nigra pars compacta has most of the - Causes: è Primary: dopaminergic neurons. è Function of dopamine depends on the receptor they bind. P Parkinson’s disease: MC. è Thalamus: P Others. P Excites the cortex. § Have atypical features, have red flags. P Inhibited by globus pallidus interna and substantia § Atypical parkinsonism. § Parkinsonian plus syndromes: early postural nigra reticulata. instability. v Progressive supranuclear palsy. è Direct basal ganglia pathway: P Excitatory. v Corticobasal degeneration: alien limb P Striatum inhibits GPi and SNr. syndrome. P Thalamus is excited. v Multiple system atrophy: symmetrical rigidity with urinary incontinence. v Dementia with Lewy bodies: symmetrical è Indirect basal ganglia pathway: P Inhibitory. rigidity with dementia. P Striatum inhibits GPe. P GPe’s normal function is to inhibit subthalamic è Secondary Parkinsonism: P Drug-Induced parkinsonism mainly antipsychotics. nucleus, but now no inhibition. P STN is excited, excites GPi and SNr. P Post encephalitis: influenza virus, West Nile virus, P Thalamus is inhibited. Japanese encephalitis, prion disease.  Movement Disorders è In Parkinson: § Dramatic response in the early part of the disease. P Loss of the dopaminergic neurons in SNc. § With time, the patient will need higher doses with more § Less dopamine binding D1. frequency→ buildup of dopamine→ dyskinesia. v Less excitation to striatum. § Dyskinesia: hyperkinetic movement (usually a v No inhibition to GPi and SNr. combination of chorea and dystonia). v More inhibition to the P Levodopa-induced dyskinesias and or clinical course thalamus. of 10 or more years. § Less dopamine binding D2. v No inhibition to striatum. è Motor symptoms (other than cardinal): v More inhibition to the P Hypomimia (masked facial expression). thalamus. P Decreased spontaneous eye blink rate. P Total inhibitory effect, seen clinically as bradykinesia. P Speech & swallowing impairment. P Neurodegeneration starts years before the onset of P Shuffling, short-stepped gait, festination, freezing. motor symptoms as it takes years to lose 70% of the P Micrographia. dopaminergic neurons in SNc. P Abnormal posture. - Clinical presentation: è Non-motor symptoms: è Bradykinesia with either: P Early: P Resting tremor: § Olfactory dysfunction: the earliest symptom. § The earliest motor sign. § Gastrointestinal dysfunction: constipation. § Very characteristic of Parkinson. § Mood disorders: depression, anxiety, and apathy/abulia. § Usually absent in Parkinson plus syndrome. P Late: P Rigidity. § Cognitive dysfunction and dementia. P Postural instability. v Accepted if started at least 1y after motor symptoms. v If happens early think of dementia with Lewy bodies. è At least three of the following features: § Psychosis and hallucinations. P Unilateral onset. P Others: P Resting tremor. § Sleep disturbances: REM sleep behavior disorder P Progression over time. (acting their dreams): usually early. P Persistent asymmetry. § Fatigue. P Response to levodopa.  Movement Disorders § Autonomic dysfunction. P SEs: v Not prominent a lot. § Dizziness, nausea. v Orthostatic hypotension, urinary symptoms. § Headache, arrythmia. § Pain and sensory disturbance. § Dyskinesia: most important, mainly chorea. § Psychosis. - Etiology: If presents earlier or positive family history: look for underlying genetic cause. è Dopamine agonists (Non-erogot): - Histological findings: P Pramipexole, ropinirole: orally. è Depigmentation of SN. P Ritogotine: transdermal patch. è Degeneration of melanin and P Apomorphine: injection. dopamine containing neurons. P Used as monotherapy. è Lewy bodies in SN. P Preferred in young patients. - Medications: è Monoamine oxidase type B (MAO B) inhibitors: è Levodopa “L-Dopa”: GOLD STANDARD. P Rasagiline, selegiline, safinamide. P Precursor of dopamine. P Initially given as monotherapy. P Crosses the BBB where it is converted to dopamine by P Usually added on to L-Dopa or dopamine agonist to decarboxylation. prolong the action of dopamine. P Usually combined with carbidopa (sinemet). § Blocks conversion of levodopa to dopamine è Catechol-O-methyl transferase (COMT) inhibitors: outside CNS by inhibiting peripheral decarboxylase. P Entacapone, opicapone, tolcapone. § The more the destruction of L-Dopa in periphery, P Added on to L-Dopa more than dopamine agonists. the more the side effects: nausea, vomiting, P Prolongs the action of dopamine. hypotension. P Used as monotherapy.  Movement Disorders è Amantadine: Tremor P An antiviral. P A weak antiparkinsonian used for dyskinesia. - The MC movement disorder. - An involuntary, rhythmic, and oscillatory movement of a body part. è Anticholinergics: - It is caused by either alternating or synchronous contractions of P Used for tremor. antagonistic muscles. P Used in caution and for limited time due side effects. - Types on clinical exam: è Resting tremor. è Deep Brain stimulation: for refractory cases. è Action tremor. P Postural tremor. - Progression: P Kinetic tremor: examined by finger-nose-finger test: è On state: features improve. § Simple kinetic tremor: during purposeless è OFF state: features reappear. è Honeymoon: voluntary movements. § Goal-directed tremor: during target reaching; P Good response to medications. P 5 years in average. historically, labelled as intention tremor. § Task-specific tremor: a rare form only occurring - Red Flags suggesting a diagnosis other than Parkinson: during the performance of specific highly skilled, è Early onset of dementia. goal-oriented tasks such as handwriting or è Early onset of postural instability. speaking. § Position-specific tremor: a rare form only occurring è Early onset of hallucinations or psychosis (on low doses of Tx). during the maintenance of certain postures. § Isometric tremor: occurs during a voluntary muscle è Ocular signs such as impaired vertical gaze. è Pyramidal tract signs not explained by previous stroke or contraction that is not accompanied by any spinal cord. movement. è Early autonomic symptoms. è Prominent motor apraxia. è Alien limb phenomenon. è Truncal symptoms more than appendicular symptoms. è Marked symmetry early on the disease. Lewy Body Dementia Early postural instability (