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MDS-AOS Video Case Discussion Series

THAILAND March 7, 2021 MDS-AOS Video Case Discussion Series

• A 5-part event running from March through December 2021.

• Each 2-hour session will focus on a mixture of 3-4 long and short video cases discussion from two different regions within the AOS.

• Highlighting the typical and atypical clinical features, phenomenology, and diagnostic approaches of unique movement disorders cases.

• The participants can ask questions/give comments during Q&A. Session 4 : October 3, 2021 Session 1 : March 7, 2021 • COVID-19 related disorders • Phenomenology not-to-be missed • China & Central Asia • India & Thailand

Session 2 : May 9, 2021 • Uncommon presentations of com mon movement disorders Session 5 : December 5, 2021 • Middle-East & Korea • Rare and regional disorders in AOS • Philippines & Malaysia

Session 3 : July 11, 2021 • Common presentations of uncom mon movement disorders • Australia & Taiwan Phenomenology not-to-be missed Discussants Presenters

Pansiri Chairungsarit Warongporn Phuenpathom President, Thai Parkinson’s Disease and Movement Disorders Society

Sasivimol Virameteekul

Suppatta Maytharakcheep Pattamon Panyakaew Movement Disorders Consultant Chulalongkorn Center of Excellence for Movement Disorders Fellows Parkinson’s Disease and Related Disorders Chulalongkorn Center of Excellence for Parkinson’s Disease and Related Disorders Short cases 2 cases An elderly female with history of inability to close her mouth fully

• Chief Complaint : inability to close her mouth fully for 3 months. • Present Illness : • Progressive difficulty in swallowing of both solid and liquid food. • Inability to close her mouth fully especially in the evening & occasionally choked when she drank water. • She was referred for considering injection. Discussion

“Phenomenology” What further investigation would you consider? Investigations

• Nerve conduction: normal • : • No spontaneous compound muscle action potential. • Normal motor unit during open& close mouth. • Repetitive Nerve Stimulation test: Decremental response over 10% in compound muscle action potential at orbicularis oculi& masseter muscle. Investigations

• AChR Ab : positive

• CT Chest : Thymoma was found Final diagnosis

Newly diagnosis of myasthenia gravis presenting with bulbar and masseter weakness mimicking jaw-opening Conditions mimicking OMD Any OMD (including jaw-deviating, Jaw-opening Jaw-closing lingual, pharyngeal) LMN disorders with LMN disorders with LMN disorders with masticatory muscle weakness masseter weakness pterygoid weakness (antagonizing abn posture) TM joint disorders TM joint subluxation TM joint ankylosis Edentulous Hemimasticatory (hemiatrophy) Bruxism Jaw / Geniospasm Defazio G, et al. Neurol Sci 2019 Tips to DDx OMD from pseudo-OMD Positive features

Patterned and repetitive OM No movements/postures Reconsider Dx • Spontaneous or triggered by motor tasks • +/- Negative featuresYes Yes No • Fixed involuntary OM posture + Sensory trick • Masticatory muscle weakness • TM joint disease/dental problems Yes • Ability to voluntary suppress No + Adjacent Oromandibular Dystonia dystonia Defazio G, et al. Neurol Sci 2019 Conditions mimicking BEB Ptosis Eyelid Apraxia Stereotyped, bilateral, No OO No OO spasms synchronous OO spasms (Only peritarsal part) Eyebrow lowering below Eyebrow elevation above Eyebrow elevation above the superior margin of the the superior margin of the the superior margin of the orbit (Charcot sign) orbit (frontalis contraction) orbit (frontalis contraction) + Sensory trick NO sensory trick NO sensory trick Increase blinking Normal blinking Normal blinking Adjacent dystonia EOM abnormalities No dystonia

Defazio G, et al. 2013 Fabbrini G, et al Nat Clin Pract Neurol 2009 Colosimo C, et al. Mov Disord Clin Pract 2015 Learning points

• Neuromuscular disorders can mimic dystonia • Almost always look for weakness of muscle antagonizing abnormal postures in equivocal dystonia • Adjacent dystonia might be helpful

• Right diagnosis points to the appropriate treatment & good outcome A young man with history of action tremulous movements of both hands

• Chief Complaint : bilateral action tremulous movements for 2 years. • Present Illness : • Progressive action tremulous movements of bilateral hands • Increase movements with , no alcohol responsive • Feeling fatigue while playing basketball • PH and FH : no U/D, no medications use, no FH of tremor/MD Discussion

“Phenomenology & Physical Findings” Surface Polymyographic recording

Acc R digit 4 Short irregular & asynchronous EMG burst

R FDS

R EDC

Acc L digit 4

L FDS

L EDC Dx Polyminimyoclonus > tremor 500 ms Electrophysiological study

• Nerve conduction study – normal • Concentric needle EMG • Mild degree of positive sharp waves and fibrillations at right APB. • Most motor unit action potentials recruited from C7-8 innervated muscles were large and showed moderately reduced recruitment pattern of the right C7-8 myotomes.

Dx Focal disease What further investigation would you consider? Final diagnosis

Hirayama disease (focal ) presenting with polyminimyoclonus Polyminimyoclonus

• Involuntary, jerky, irregular, small amplitude tremor-like movements, most commonly seen in the fingers/hands CNS PNS Bulbospinal muscular atrophy PD Amyotrophic lateral sclerosis AD Severe neuropathy Familial myoclonic Lennox-Gastaut syndrome Indistinguishable from CNS Cerebral palsy Salazar et al., Mov Disord 2000. Bhat et al., Ann Indian Acad Neurol. 2015. Hirayama disease

• Pure motor focal amyotrophy in the distribution of C7, C8 and T1 with non-progressive course in Asian young man due to forward displacement of the posterior cervical dural sac on neck flexion.

• Clinical features

• Symmetric or asymmetric muscle weakness and atrophy in C7-T1 with sparing brachioradialis à Thenar/interossei atrophy 100%, oblique atrophy 50%

• Polyminimyoclonus 40-77%

• at rest 40%

Foster M,t al. J Clin Neurosci 2015 Sonowal TN. J Evolution Med Dent Sci. 2018. Zhou B. Amyotrophic Lateral Sclerosis. 2010. Polyminimyoclonus-like in MND

Irregular, asynchronous short EMG bursts (11-40 ms) on the surface EMG channels corresponded to on the needle EMG

Polyminifasciculations

Bhat et al., Ann Indian Acad Neurol. 2015. Learning points

• Polyminimyoclonus should be distinguished from tremor.

• Motor neuron disease can present with abnormal movements. – polyminimyoclonus • Looking for signs of MND (fasciculations/atrophy) is helpful to diagnose the PNS origin of polyminimyoclonus. Spot Diagnosis 4 cases Holmes’ tremor Myorrhythmia Activation Rest < postural < kinetic Rest > postural, kinetic Distribution Hands, Unilateral Hands, cranial , Unilateral Frequency Slow 1-4 Hz Slow 1-4 Hz Regularity Irregular, jerky Semirhythmic Higher amplitude with actions Same amplitude with actions Lesions Thalamus, Almostmidbrain, always GMT orlook multiple for structuralBrainstem brain, GMT, lesion thalamus, BG Associated sign Hemiparesis, hypoesthesia, ataxia, Focal signs dystonia

Baizabal-Carvallo JF, et al. Movement Disorders 2015 Ure RJ, et al. J Neurol Neurosurg Psychiatry 2016 Raina GB, et al. Neurology 2016 Consistent with Holmes’ tremor Learning points

• Recognition of unique phenomenology

• Unilateral Holmes’ tremor • Almost always look for structural brain lesion (thalamus, brainstem, cerebellum) • Additional eye signs – helpful for localization Brainstem myoclonus

• Generalized myoclonus, beginning with the ascending order of CN (lower brainstem) à proximal limb/axial muscles (craniocaudal propagation)

Exaggerated startle reflex Reticular reflex Spontaneous jerk Not prominent Common Flexors > extensors Flexors = extensors Involving muscles (blink – face, flexion of neck, trunk, flex + (neck – face, trunk, arm) adduction of arm Sudden noise Stimuli Tapping at distal limbs Tapping at mantle area Nucleus Reticular Pontine Caudalis (pons) Nucleus Reticularis Gigantis (medulla) Source of generation Reticulospinal tract (slow) Bulbospinal tract (fast)

Kojovic A, Cordavari C and Bhatia K. Ther Adv Neurol Disord 2011 Merchant S, et al Mov Disrd Clin Prac 2020 Progressive with rigidity and myoclonus (PERM)

• Acute or subacute brainstem dysfunction (gaze paresis, bulbar, ANS dysfunction) with and rigidity • Brainstem myoclonus (exaggerated ) • Spectrum of stiff person syndrome (SPS-plus) • Autoimmune disease : Gly-R Ab (50%), GAD Ab ,DPPX Ab • Only 15% paraneoplastic disease (SCLC, thymoma)

Mckeon A, Vincent A, Handbook of Clinical Neurology 2016 Learning points

• Recognition of unique phenomenology

• (exaggerated startle reflex) • Localization = lower brainstem • Subacute onset hyperekplexia with , rigidity à points to treatable autoimmune disease Differential Dx of facial movements

Facial movement disorders Characteristics Distribution Facial dystonic tremor • Asynchronous movements of upper and • Upper and lower face (not innervated by CN7) lower face, can be bilateral • Adjacent dystonia – BEB, OMD, CD with tremor • Irregular tremor Bilateral hemifacial spasm • Intermittent clonic or tonic contractions • Initial lower eyelids and then lower face • Synchronous movements of upper and (innervated by CN7) lower face ipsilaterally • Asynchronous between sides if bilateral Facial myoclonus • Rhythmic clonic contractions • Predominant perioral > periorbital Facial myorhythmia • Rhythmic, regular, jerky slow (1-4 Hz) • Periorbital (eyelids), perinasal, lips contraction • Can be isolated but associated with limb Facial • Undulating movements under skin, • Eyelids rhythmic Facial tics • Stereotypic repetitive movements • Upper and lower face • • Neck • Can be voluntary suppressed Tardive dyskinesia • Non-repetitive flow of movements • Predominant lower face (orolingual) Fabbrini G at al., Nat Clin Pract Neurol 2009 Erro R, et al PRD 2014 Tan EK, et al J Neurol Sci 2007 Learning points

• Diagnosis of tremor in the upper/middle face is challenging • Asynchronous movements with concomitant head dystonia with tremor à Dx facial dystonic tremor How to differentiate from psychogenic MD Frontal lobe Psychogenic Violent, repetitive, stereotypic Variable movements (rocking, pedaling, pelvic thrust) Asynchronous limb movements Movements Dystonic posturing (extend one Side to side movement arm while the other flexes) Pelvic thrust Versive Vocalization Rare Occasional Self injury Yes No but may be present Onset Sudden onset Sudden onset Natural Hx Static or progressive Wax & wane, spont. remission Sleep Often occur during sleep NOT during sleep LaFrance WC, et al. Neurol Clin 2011 Take Home Message

• Phenomenology of movement disorders – challenging

• Other neurological disorders can mimic or present with MD

• Recognition of unique/typical phenomenology – helpful to Dx

• Bizarre movement is not always psychogenic MD