Table 1
Contrasting features between Parkinson’s disease patients with and without jaw tremor.
| JAW TREMOR PRESENCE n = 39 (%) | JAW TREMOR ABSENCE n = 190 (%) | P-VALUE | |
|---|---|---|---|
| Sex (male) | 22 (56.4) | 108 (56.8) | 0.960 |
| Age (years) | 70.77 ± 11.22 | 67.17 ± 10.99 | 0.065 |
| Evolution time (years) | 8.19 ± 8.43 | 6.27 ± 6.14 | 0.100 |
| Cognitive status (MoCA) | 21.06 ± 5.36 | 21.69 ± 5.83 | 0.668 |
| MDS-UPDRS-III (subscores) | |||
| Language | 0.92 ± 1.09 | 0.96 ± 1.05 | 0.829 |
| Facial expression | 1.44 ± 1.02 | 1.09 ± 0.92 | 0.036 |
| Rigidity composite score | 9.33 ± 4.86 | 7.05 ± 4.03 | 0.002 |
| Bradykinesia composite score | 18.38 ± 9.77 | 13.02 ± 9.09 | 0.001 |
| Rising from chair (3.9) | 1.51 ± 1.62 | 1.18 ± 2.39 | 0.406 |
| Gait (3.10) | 2.08 ± 1.27 | 1.69 ± 1.16 | 0.061 |
| Freezing (3.11) | 0.79 ± 1.51 | 0.66 ± 1.24 | 0.540 |
| Postural stability (3.12) | 2.15 ± 1.25 | 1.50 ± 1.17 | 0.002 |
| Posture (3.13) | 1.59 ± 1.14 | 1.17 ± 0.95 | 0.018 |
| Postural tremor (composite score) | 2.08 ± 1.86 | 1.06 ± 1.33 | <0.001 |
| Kinetic tremor (composite score) | 1.56 ± 1.68 | 0.97 ± 1.22 | 0.010 |
| Rest tremor (composite score) | 4.97 ± 3.46 | 1.85 ± 2.31 | <0.001 |
| Tremor persistence | 3.03 ± 0.873 | 1.25 ± 1.38 | <0.001 |
| Total score | 52.56 ± 22.89 | 34.53 ± 17.52 | <0.001 |
| Hoehn-Yahr scale (modified) | 3.62 ± 0.96 | 3.17 ± 0.88 | 0.005 |
| Dyskinesia presence, n (%) | 5 (12.8) | 28 (14.7) | 0.952 cc |
| Treatment | |||
| Levodopa/carbidopa, n (%) | 24 (61.5) | 115 (60.5) | 0.966 |
| Amantadine, n (%) | 4 (10.3) | 13 (6.8%) | 0.502 |
| Dopamine agonists, n (%) | 10 (25.6) | 52 (27.4) | 0.981 |
| Anticholinergic, n (%) | 5 (12.8) | 11 (5.8) | 0.159 |
| MAOI, n (%) | 2 (5.1) | 20 (10.5) | 0.385 |
| LEDD | 458.3 ± 425.5 | 595.1 ± 632.6 | 0.101 |
[i] LEDD: Levodopa equivalent daily dose; MAOI: Monoamine oxidase inhibitor.
Table 2
Multivariate analysis of statistically significant variables in the bivariate analysis.
| VARIABLES IN THE FINAL REGRESSION MODEL | EXPB COEFFICIENT | EXPB 95% C.I. | P-VALUE |
|---|---|---|---|
| Age | 1.035 | 0.996–1.076 | 0.075 |
| MDS-UPDRS-III score | 1.029 | 1.007–1.051 | 0.009 |
| Rest tremor composite score | 1.383 | 1.197–1.597 | <0.001 |
[i] Constant: B-6.220, ExpB: 0.00, P < 0.001. Hosmer-Lemeshow: (P = 0.299). Nagelkerke R2 = 0.323. Variables not included in the final equation: Hoehn-Yahr scale, postural tremor composite score, kinetic tremor composite score, facial expression, bradykinesia composite score, rigidity composite score, postural stability and posture, scores. MDS-UPDRS-III: Movement Disorders Society Unified Parkinson’s Disease Rating Scale, part III.
Table 3
Contrasting clinical features of rhythmic repetitive lip/jaw movements.
| PARKINSON’S JAW TREMOR | ESSENTIAL JAW TREMOR | JAW CLONUS | GENIOSPASM | RABBIT SYNDROME | TASK-SPECIFIC JAW TREMOR | MYORHYTHMIA | TARDIVE PHENOMENA | |
|---|---|---|---|---|---|---|---|---|
| Etiology | PD and other parkinsonian syndromes | Essential tremor | ALS, NMO, OD | Mostly hereditary, isolated in few cases | Drug-induced by DRB | Unknow | Stroke, infections (WpD), autoimmune | Tardive dyskinesia or tremor (DRB and other drugs) |
| Prevalence within specific cause | 17–18% | 7.5 to 18% | Rare | All cases by definition | 2.3 to 4.4% | Rare | Rare | Common (dyskinesia), tremor (uncommon) |
| Type of movement | Jaw and lip rest tremor, postural and kinetic component are less common | Jaw tremor is usually postural or kinetic | Elicited by testing the jaw-jerk reflex or by jaw opening | Rhythmic or irregular twitch-like chin quivering or trembling in bouts lasting minutes to hours | Vertical mouth and lip movements, without tongue involvement | Jaw tremor triggered with a specific task (i.e., drinking water) | Continuous central facial rhythmic movements, + nystagmus, palatal, limb movements (OMM) | Repetitive masticatory movements or jaw tremor + lingual, limb or axial stereotypies |
| Movement frequency (Hz) | 3–5 Hz | 4–12 Hz | ~ 10 Hz | 5–6 Hz | ~ 5 Hz | 5–8 Hz | 1–4 Hz | 1–2 Hz |
| Clinical correlates and/or comorbid conditions | Older age, greater limb rest tremor severity, higher motor scores | Older age, presence of head and voice tremor, greater arm tremor severity, rest tremor in the arms. | Upper motor lesion above the spinal cord | Family history (Autosomal dominant pattern). RNTB | Underlying schizophrenia, bipolar disorder, Korsakoff’s sx, etc. Some have parkinsonism | Some may improve with alcohol, or alleviating maneuvers (i.e., sensory tricks) | SnGP, arthralgia, diarrhea, weight loss or focal deficits depending on the cause | Associated psychiatric disorders. Some have parkinsonism |
| Treatment | Levodopa, dopamine agonists, Achol, BoNT | Propranolol, primidone, topiramate, BoNT | Baclofen, tizanidine, BZD, BoNT | BoNT; BZD for RNTB | ↓ DRB or withdrawal, Achol | BoNT | Treat underlying cause, i.e., Abs for WpD | ↓ DRB or withdrawal, TBZ, VBZ, deuTBZ |
[i] Abs: antibiotics; Achol: anticholinergics (benzatropine, procyclidine, trihexyphenidyl, etc.); ALS: amyotrophic lateral sclerosis; BoNT: botulinum toxin; BZD: benzodiazepines; deuTBZ: deutetrabenazine; DRB: Dopamine receptor blockers; NMO: neuromyelitis optica; OD: osmotic demyelination; OMM: oculomasticatory myorhythmia; PD: Parkinson’s disease; RNTB: Recurrent nocturnal tongue biting; SnGP: supranuclear gaze palsy; Sx: syndrome; TBZ: tetrabenazine; VBZ: valbenazine; WpD. Whipple disease.