November 17th 2010 Questions you should be able to answer after this session What is the most common movement disorder?



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Approach to Tremors

Robert Altman

November 17th 2010

Questions you should be able to answer after this session

  • What is the most common movement disorder?

  • Name 2 drugs that can enhance a physiologic tremor and 2 that can turn someone akinetic and rigid?

  • What is a first line therapy for early tremor in PD for a 45 yr old?

  • What are the 2 P’s for essential tremor treatment?

  • Which tremor is so stirkingly unilateral and disabling that the patient’s limb is deemed non-functional?

  • Tensor or levator in essential palatal tremor?



References

  • AAN Movement Disorders Syllabus, 2010 Toronto

  • AAN Continuum 2007, 2010 Movement Disorders

  • Videos courtesy of YouTube and AAN Continuum CD

  • As usual; good review articles

    • Tremor : Clinical Features, Pathophysiology, and Treatment: Neurol Clin 27 (2009) 679–695
    • Grimes DA. Tremor--easily seen but difficult to describe and treat. Can J Neurol Sci. 2003 Mar;30 Suppl 1:S59-63.
    • Gupta A, Lang AE. Psychogenic movement disorders. Curr Opin Neurol. 2009 Aug;22(4):430-6.


Contemplate...

  • Definition of tremor

  • Rational and logical categorization

    • Examples of each
    • Therapies for each
  • Focus in essential tremor

    • Definition
    • Genetics
    • Clinical
    • Pharmacological and non-pharma treatments
    • Surgical therapies (refractory cases)
    • What / where to lesion or stimulate?
  • Psychogenic Movement Disorders*



Definition: Tremor

    • Movement of a body part
    • Involuntary (even PMD)
    • Rhythmical
    • Regularly recurrent
    • Oscillatory
    • Around central plane


Categorization

  • Previously described in terms of activation condition (rest vs. movement), brain region affected (rubral), presence or absence of medical condition(hypothyroid), existence of neurological conditions (dystonia), topography (limb, head, voice), frequency.....

  • Complicated and contradictory

  • Generally not necessary to diagnose and properly treat

  • Phenomenology and a syndromic classification of tremor consensus statement Movement Disorder Society (MDS) [1998]





Treat the correct cause



TREMOR





3 golden rules in tremor assessment



Action

  • Most Common:

    • Essential tremor
    • Enhanced physiological tremor
    • Drug-Induced action tremor
    • Dystonic
  • Less Common:

    • Orthostatic
    • Cerebellar
    • Psychogenic
    • Wilsonian
    • FXTAS
    • Peripheral neuropathy-related
    • Midbrain or rubral



On history

  • Tremor causing Rx?

  • Caffeine, nicotene?

  • Diarrhea, weight loss, heat intolerenace?

  • Sudden onset?

  • Temporal course? Static or progressive?

  • What body regions?



On exam

  • Postural / sustension:

    • What joints?
    • Thumb posturing? Other abnormal postures?
    • Distractibility, entrainment, suggestibility?
  • Kinetic part:

    • Pouring, drinking, using a spoon, FNF, Archimedes spiral test
    • Intentional component (worsen as draw near target)
    • Re-emergent?
    • Dystonic postures accompanying? (thumb)


Essential Tremor

  • Most common adult-onset movement disorder

  • 5% general population

  • Genetics: AD, variable penetrance, no gene found (polygenic)

  • Central generator: thought to represent cerebellar-thalamo-cortical outflow pathology

  • Kinetic and postural, mainly arms; 4-12Hz

  • Progressive

    • Armshead (“yes-yes” vs. “no-no”)
    • Voice / vocal cord, chin, tongue
  • Unilateral  bilateral

  • Rare in LE’s

  • No parkinsonian or dystonic features.



Disability

  • Interferes with ADL’s

    • Feeding
    • Spoon, drinking from a cup
    • Writing
    • Typing
    • Personal hygiene
  • Interferes w/ occupational motor tasks



Diagnostic Criteria

  • Core

    • Bilateral action tremor of the hand and forearms
    • Absence of other neurologic signs
    • Caveat: cogwheeling*
    • May have isolated head tremor with no signs of dystonia
  • Secondary / Supportive

    • Long duration (3 yrs)
    • + family Hx
    • Beneficial response to ETOH
    • 50-90% of cases, but careful for rebound phenomenon


Non-motor ET symptoms

  • Non-motor (tremor) symptoms being recognized

  • Implications for screening, treatment plans



Archimedes Spiral Test



Treatment of ET

  • General principals

    • Treat only if bothersome
    • The longer the tremor has been there the more difficult Tx will be
    • Limb tremor responds much better than head/neck to oral Rx
  • Non-pharmacologic

    • Biofeedback
    • Weighted objects (e.g., utensils)
    • Only dampens it temporarily, not viable long term treatment option
  • Pharmacologic

    • 2 P’s ; alone or in combo. Is there concurrent HTN?
    • Primidone, propranolol (Inderal)
    • Others: benzodiazepenes, gapapentin anecdotal use but not class A evidence (see table in appendix)
    • Botox
    • Voice, head
  • DBS (not lesional)

    • ViM of VL of thalamus in refractory cases


2 P’s





Enhanced Physiologic Tremor (EPT)

  • Appears to be peripherally generated (not central like ET)

    • Based on inertial loading electrophysiological analysis
  • Faster postural and kinetic tremor than ET (7-12Hz); very low amplitude.

  • Very easily visible

  • 15-35 yo

  • Anxious phenotype

  • Mainly voice and limb

    • No head
    • May have some cogwheeling, no frank rigidity
  • Endogenous & exogenous (see next slide) causes

  • Tx



Drug Induced Action Tremor (EPT)

  • Based on history

    • Temporal onset
    • Sympathomimetics++ (ß-adrenergic bronchodilators)
    • caffeine, nicotene
    • SSRI, Li, valproate, roids!
    • Withdrawal relieves symptoms
    • Limb, never head
  • Treatment

    • Remove causative agent
    • Bb or bzdp can dampen tremor if causative Rx absolutely necessary


Dystonic Tremor

  • Tremulous muscle activity in patients with dystonia

  • Pulling or pain sensation in region affected (e.g., neck)

  • Limbs (UE>LE), head (neck) or both (limb precedes neck)

  • Voice: strangled speech, voice break

  • Postural or kinetic

  • Not rythmic, nor oscillatory, not around 1 axis

  • Exam may reveal tonic muscle activity in tremoulous or conta-tremulous limb

    • Tremulousness is directional
    • Spooning of hands, fatiguing, thumb flexion or other dystonic postures
    • May have scarf hiding hypertrophied muscle (eg neck with toriticollis)
    • Dystonic tremor may be reduced by antagonistic gestures geste antagonistique
  • Commonly misdiagnosed as ET

  • Pharma treatment: anti-dystonic agents (baclofen, artane), bzdp, bb, botox (torticollis, voice)

  • Surgical (refractory): selective denervation, DBS



Orthostatic Tremor

  • Rare

  • ‘Unsteadiness’ when standing

    • Avoid situations when have to stand still (at movies)
  • o/e

    • Rapid 13-18hz, low amplitude tremor/rippling in calves only on standing
    • Visible and palpable
    • pseudodystonic
    • Confirmed with EMG
  • Rx:

    • Nothing evidence based
    • Most common =Clonazepam, sinemet


Cerebellar Tremor

  • Central cerebellar disorders (e.g.,SCA)

  • Kinetic with terminal worsening = intentional

  • May have postural component, but rest absent

  • In multiple planes

  • Slow, 3-5 hz

  • Presence of overshooting

    • Other cerebellar signs (hypermetric saccades, dysarthria, scanning speech, ataxic gait, head titubation, dyssynergia)
  • Treatment

    • DBS


Wilson’s Disease associated Tremor

  • Can be action (rest, combination)

    • Postural (possibly wing-beating)
    • Kinetic (like ET)
  • Young (<40 yo)

  • Exam reveals multifocal and multisystemic disorder (long-tract, cognitive, neuro-psychiatric)

    • Trivia: what are the genetics? Mode of transmission? On what layer of the cornea would you look to find KF rings?
  • Tx

    • Chelation
    • Penicillamine controversial
    • Trientene
    • Tetrathiomolybate
    • Zinc once levels normalize
    • Bb for action tremor


FXTAS (fragile X tremor ataxia syndrome)

  • Multiple complaints in addition to tremor

    • Cerebellar or parkinsonian
    • Cognition, dysexectuive function
  • Male family members (grandchildren) have MR

  • MR brain

    • Classic picture
  • Tx: bb for action tremor



Peripheral neuropathy-related tremor

  • PN by history of same limb with tremor

    • Intertial loading leads to suppression of tremor proving peripheral generator
    • More common with demyelinating PN’s, also seen in HMSN1 (Levy-Roussy) and IgM dysgammaglobulinemic neuropathies
  • Temporal linkage

  • o/e

    • Peripheral neuropathy readily apparent on tremulous limb
    • Sensory impairment, weakness 4/5 MRC, altered DTR
    • Tremor present when muscle strength allows limb to maintain certain postures
    • Vanishes if weakness too severe or if limb power returns to normal
  • Tx:

    • Underlying neuropathy
    • BB for AT
    • What do you think about DBS?


Midbrain / Rubral / Holmes

  • Lesion based, central generator

  • Sudden onset focal neurological insult

    • Progressive forms can occur (tumor or expanding vascular lesion)..some say this is typical even for stroke.
  • Strikingly unilat, HB or monomelic

  • Non-rythmic, <4.5 Hz, high amplitude

  • Rest, action (postural and kinetic)

    • Severity: kinetic > postural > rest
  • Severe and disabling, limb entirely handicapped

  • Imaging confirms pontine-midbrain lesion affecting cerebellar outflow tracts and dopaminergic nigrostriatal fibers

  • Rx:

    • AT primidone, bb
    • Rest Levodopa, DA, Anti-chol
  • DBS (refratory)



Palatal “myoclonus” – actually tremor

  • Essential vs. symptomatic

  • See Chenjie’s presentation, great comparative table



Rest Tremor(s)

  • Most Common:

    • Parkinsonian
    • Drug-induced rest tremor
    • ET (with rest component; rare…15-20%)
  • Less Common:

    • Wilsonian
    • Midbrain


Critical Elements from Hx & Exam

  • History

    • Rx?
    • Change in arm swing, gait, facial expression?
    • Previous CVA, dementia?
  • Exam

    • Arms at rest (whole interview and dynamic exam)
    • ‘pill-rolling’ quality
    • Symmetry
    • Limb or hemi-body
    • Arm extension test
    • Not true postural, rather emergent (with crescendo after several seconds)


Parkinsonian Tremor

  • Classically @ rest; 3-5 Hz

  • Often HB

  • If arm

    • Pron-sup rather than flx-ext
    • Check for limb “posturing” flexion/fist formation hand, thumb flexion
  • Re-emergent tremor during arm extension or during tasks (pouring water) causes considerable misdiagnosis with ET

  • Other hallmark-cardinal features

    • Motor: asymmetric rigidity, bradykinesia, postural instability, fatiguing
    • Non-motor: RBD, hyposmia, constipation, mood, sebborhea, ANS dysfunction (orthostasis, ED, etc.), excessive daytime sleepiness, RLS, body pain .......
    • Aversion to caffeine...?


PD tremor

  • DA 1st line

  • Levodopa

  • Anticholinergics (rare)

    • Cogentin, artane, amantadine
  • Consider bzdp

  • Refractory DBS



Drug Induced

  • Temporal link with Rx

    • Antipsychotics (typical>atypical), Li
  • Can look practically identical to Parkinsonian tremor

  • Removal of medication should result in complete resolution

  • Tx:

    • Remove or diminish offending agent
    • Levodopa (even if on Da blocking agents) or anticholinergics can be tried


Psychogenic Tremor (PMD)

History

Psychogenic Movement Disorders (PMD)



PMD

  • Not a diagnosis of exclusion

  • Enough qualifiers to be included on Ddx early on

  • Should be recognized and treated rapidly to avoid stigmatization, ‘crazy’ label

    • CBT, neurologist (a movement disorder induced by internal stress), psychiatrist (somatization)


Frequency of PMD in clinical practice



Questions you should be able to answer after this session

  • What is the most common movement disorder?

  • Name 2 drugs that can enhance a physiologic tremor and 2 that can turn someone akinetic and rigid?

  • What is a first line therapy for early tremor in PD for a 45 yr old?

  • What are the 2 P’s for essential tremor treatment?

  • Which tremor is so strikingly unilateral and disabling that the patient’s limb is deemed non-functional?

  • Tensor or levator in essential palatal tremor?



Thanks!



Palatal Myoclonus saga...



Palatal Myoclonus: involvement of central tegmental tracts




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