Other Hyperkinesias:Tics & Tremor

Victor FungMovement Disorders Unit, Department of Neurology,

Westmead Hospital & University of Sydney, Sydney, Australia

• Transient tic disorder in up to 20% of school age children

• 3-50/1000 Chronic motor tic disorder

• 4-8/1000 Tourette syndrome

Hughlings Jackson

• Negative features• loss of function

• secondary to destruction of brain tissue

• Positive features• abnormal or retained function

• due to function of remaining brain

• Hierarchical organisation• “gradations from the most voluntary to the most automatic”

• Spontaneous movements occur in subjects instructed simply to sit

in a chair, keep eyes open and stay away for 1 hour

• A Bereitschaftspotential (BP) usually present for spontaneous

movements, but smaller than for repetitive, instructed movements

• Spontaneous movements could be goal-directed but could also be

meaningless

• 17yo

Courtesy Padraic Grattan-Smith

• Each tic stereotyped,

but often a repertoire

• Onset in childhood

• Eye twitches or blinks

a frequent early

manifestation

• Sniffing

• Vocalisations

• Upper GIT

• Can interfere with gait

• Suggestibility

• Temporarily

suppressible with

rebound

• Can cause self-injury

• 65yo, onset involuntary twitches in late teens. Varied in

severity throughout life, worse especially in past 10 years.

Occasional vocalisations, mild OCD. +FH with son affected.

• Mainly NTSC

(neurexin trans-

synaptic connexus)

pathway genes

implicated. NTSC

pathway regulates

neuronal circuitry

development, synaptic

connectivity and

neurotransmission

• Some evidence

implicating

mitochondrial function

Hypothesis – some involuntary movements occur due to disordered “gating” of motor behaviour• Chorea – fragments of movements escape

• Tics – meaningless movement sequences escape (together with abnormal gating of internal sensory stimuli)

• Stereotypies – meaningless repetitive and more complex movement sequences escape

• Utilisation behaviour / environmental dependency syndrome –meaningful, complex behaviours escape triggered by environmental cues and executed devoid of context

• In normality, these motor actions all “bubble” under the surface, waiting for the appropropriate context in which to appear

75 yo, 15 year h/o right UL tremor and mild bilateral upper limb

akinesia/rigidity, treated with levodopa/carbidopa.

• Pathological diagnosis: Vascular parkinsonism

Mevawalla et al, Mov Disord 2009

56 yo, gradual onset aged 34 of L UL resting > postural

tremor and akinesia, extremely dopa-responsive, no motor

fluctuations after 20 years

R L L R L R

Ann Neurol 1997

Bradykinesia Rigidity Tremor

r = -0.64 r = -0.53

76 yo with 13 yr h/o tremor with delayed onset

2 years after stroke

Myorhythmia (Holmes tremor)

R Elble, AAN teaching course 2000

Models of Parkinsonian tremor• In PD, there is involvement of multiple anatomical and

neurochemical systems, which obscures clinico-pathological correlations

• In a primate lesioning model, bilateral SN nigra lesions alone did not produce (postural) tremor or rigidity. An additional lesion of the rubro-olivo-cerebello-rubral loop was required.

• Dopamine deficiency is a prerequisite for the development of rest tremor in humans, but:

• does not determine tremor severity

• may not be sufficient in isolation without additional pathology

20 yo, 18/12 h/o bilateral postural & action tremor, FH

tremor in mother, maternal uncle, maternal granduncle

42 yo with 12 yr h/o right upper limb tremor

42 yo with 12 yr h/o right upper limb tremor

Dystonic tremor

60 yo with h/o lip & chin tremor since her 30’s,

right upper limb tremor for 12 months

60 yo with h/o lip & chin tremor since her 30’s,

right upper limb tremor for 12 months

Dystonic tremor syndrome

20 yo, 18/12 h/o bilateral postural & action tremor, FH

tremor in mother, maternal uncle, maternal granduncle

Acknowledgements• Movement Disorders Unit

• Sangamithra Babu

• Florence Chang

• Ainhi Ha

• Mariese Hely (Emeritus)

• Samuel Kim

• Neil Mahant

• Andrew Martin

• Hugo Morales Briceño

• John Morris (Emeritus)

• Matthew Silsby

• Nigel Wolfe

– Russell Dale

– ShekeebMohammad

– Dale Marchant

– Michael Tchan

• Fellows

– Alessandro Fois

– Sophie Waller

– Laura Williams

• Nurses

– Sarah Bray

– Donna Galea

– Jane Griffith

– David Tsui