Laryngeal Tremor
92-9-24 R3 郭彥君
1. Definition
Tremor :An involuntary , approximately rhythmic, roughly sinusoidal
movement.
1983 Mardsden et al: 4 types of human action tremor
a. Enhanced physiologic tremor: fast(8-12 hz), fine, postural
b. Classical essential tremor: lower frequency, greater amplitude
c. Classical essential tremor with disabling in degree
d. Symptomatic essential tremor: associated with other neurologic
disorders
Vocal tremor tremor: tremulous voice,wavy voice,quavering speech
Rapid decrease and increase in loudness and pitch or incomplete
phonation stoppages
2.Long-term phonatory instability accompanying vocal tremor
A.Essential tremor:
◆Prevalence: 4-60 per 1000 people, elderly persons, upper limbs
and head most involved, 4-20 % with vocal tremor
◆Family history (+),AD ,cause unknown (suggest olivocerecellar
tract abnormal by PET*)
◆ Absent at rest, maximal during maintenance of posture,
attenuated during movement, accentuated at the termination of
movement
◆ Pitch beaks and voice arrest(similar to SD) ; vertical oscillations
in the larynx , predominant involvement in TA muscles
◆ Greater with emotional stress and fatigue
◆ Treatment: propranolol, clonazepam+propranolal+diszepam,
thalamotomies, chronic electrical stimulation of the thalamic
nucleus , speech therapy ,injection of botulism toxin (reduce
laryngeal airway)
B.Parkinson’s disease
◆Cell death in substantia nigra
◆ Resting tremor (5-7 Hz),muscle rigidity,bradykinesia,loss of
postual reflex , “pill-rolling” tremor
◆ Sluggish articulation, monotone voice,decreased loudness(vocal
fold: adynemic and bowed
◆ Treatment: Levodopa
Fundamental frequency↑, jitter, soft phonation(noise) index↓
Speed quotient, shimmer↓, SPL↑
C.Spasmodic dysphonia
◆Action-induced laryngeal motion disorder(focal dystonia ,not a
spasmodic disorder) , irregular tremor, imply psychologic etioligy
◆ Increasing vocal fatigue, spasmodic constriction of throat
muscles, pain around the larynx ,crescendo onset prior and
during phonation,drcrascendo with offset of voicing
◆ 1985 Aroson: Adductor involved(spastic dysphonia) ,abductor
involved (whispering dysphonia) <pseudo-abductor spasmodic
dysphonia>
◆ Treatment: Botulism toxin injection
D. Palatophryngeal myoclonus
◆slow form of tremor(1-4 hz) nonsinosoidal periotic tremor
◆ Involve pharynx,larynx,diaphragm,eye muscles ,rhythmic
movement occur in both phonation and rest
◆ Tremulous voicemvoice arrest,clicking or popping sound in the
ear
◆ Disorder interrupt the central tegmental tract, usually due to
brainstem infarct or idiopathic degeneration
◆ Treatment :serotonin precursors,carbamazepine,clonazepam but
usually resist to treatment
E.Cebeller lesion
◆vocal strain (like SD), dysarthria, scaning speech
◆ Combined with intention tremor, dysmetria, dysdiadochokinesia,
ataxia, nystagmus
3. Acoustic characters of vocal tremor
☆Higher pitch phonation rapid rate for both amplitude and
frequency modulation
☆Louder phonation amplitude modulation is faster
☆Low-pitched phonation  decreased the extent of amplitude
tremor
4. Hypotheses of tremor :
(1) Central oscillator hypothesis : similar EMG activity across muscles
affected by tremor , stable frequency of tremor
( vocal tremor is not consistency to EMG activity in pairs of laryngeal
muscles)4
(2) Peripheral oscillator hypothesis: change in frequency of tremor
increase muscle load , entrainment of tremor frequency to the
frequency of imposed muscle ,reflex response to stretch
(3) Originate from multiple regions of brain : not a single frequency
(4) Abnormal enhancement of normal physiologic tremor: essential
limb tremor is produced by central oscillator but enhanced by the
connected reflex
Reference:
1. Diagnosis and treatment of voice disorder /John S Rubin 1995 [et al.]
2. Neurologic disorder of the larynx/Andrew Blitzer[et al.]
3. Otolaryngology Head and Neck Surgery/Charles W.Cummings
4. Synchrony of laryngeal muscle activity in persons with vocal tremor.
Arch Otolaryngol Head Neck Surg. 2003 Mar;129(3):313-8. Finnegan
EM [et al.]
5. The influence of pitch and loudness changes on the acoustics of vocal
tremor.
J Speech Lang Hear Res. 2002 Oct;45(5):879-90 Dromey C [et al.]
6. The treatment of essential voice tremor with botulinum toxin A: a
longitudinal case report.J Voice. 2000 Sep;14(3):410-21. Warrick P [et
al.]
7. Botulinum toxin for essential tremor of the voice with multiple
anatomical sites of tremor: a crossover design study of unilateral
versus bilateral injection.
Laryngoscope. 2000 Aug;110(8):1366-74. Warrick P [et al.]
8. The effect of levodopa on vocal function in Parkinson's disease.
Clin Neuropharmacol. 2001 Mar-Apr;24(2):99-102. Sanabria J [et al.]