Snapshot A 65-year-old man is brought to his primary care physician by his wife due to "abnormal movement." She states that her husband appears depressed and has a tremor that occurs at rest. She also reports that he "moves very slowly." The patient says that he has no current concerns. Past medical history includes hypertension, which is treated with hydrochlorothiazide. On physical exam, there is a right-sided 3-5 Hz resting "pill-rolling" tremor and cogwheel rigidity of the right upper extremity. On gait testing, the patient takes short steps and has a stooped posture. (Parkinson disease) Introduction Abnormal movements can result from impairment of the upper and lower motor neurons motor cortex motor association cortex cerebellum basal ganglia e.g., Wilson's disease Movement Disorders Type Comments Tremor Essential tremor presentation most commonly affects the hands or arms typically bilateral can cause functional impairment the tremor worsens with stress and improves with alcohol β-blockers often familial with an autosomal dominant inheritance pattern treatment β-blockers (e.g.,propranolol) primidone Physiologic tremor presentation affects all people but may become visible with caffeine beta-agonists hypoglycemia anxiety excitement alcohol and opioid withdrawal thyrotoxicosis treatment dependent on etiology e.g., decrease caffeine intake Intention tremor presentation appendicular ataxia when using their extremity towards a target there is irregular and oscillating moevment associated with cerebellar disorders Resting tremor presentation tremor that occurs when the limbs are relaxed can be best observed when distracting the patient tremor improves when the patient moves their limbs can be described as"pill rolling" this is an important of Parkinson's disease Dystonia Presentation sustained or slowed abnormal positions of the limb, trunk, or face examples of dystonia include torticollis blepharospasm spasmodic dysphonia writer's cramp Believed to be due to dysfunction of the basal ganglia Treatment many cases have a good response to botulinum toxin injection Myoclonus Presentation rapid muscular jerk that can be due to multiple causes seizure e.g., juvenile myoclonic epilepsy anoxic brain injury encephalitis toxic or metabolic encephalopathy paraneoplastic syndromes Creutzfeldt-Jakob disease Chorea Presentation dance-like involuntary movement An important cause of chorea is Huntingon's disease Athetosis Presentation writhing and twisting movement of the limbs, face, and trunk that can merge with chorea to form choreoathetosis Presentation rotatory or flinging movement of the proximal limb muscles The most common type of ballismus is hemiballismus contralateral extremity flinging movement secondary to a lesion (e.g., lacunar stroke) to thesubthalamic nucleus Tics Presentation a sudden and brief movement that is preceded by an urge that is then relieved after the movement is performed The types of tics include motor tics vocal tics e.g.,barking-like noises and coprolalia An important syndrome to know is Tourette's syndrome