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