Abstract
Symptomatic palatal tremor is potentially the result of a lesion in the triangle of Guillain-Mollaret (1931) and is associated with hypertrophic olivary degeneration (HOD) which has characteristic MR findings. The triangle is defined by dentate efferents ascending through the superior cerebellar peduncle and crossing in the decussation of the brachium conjunctivum inferior to the red nucleus, to finaliy reach the inferior olivary nucleus (ION) via the central tegmental tract. The triangle is completed by ION decussating efferents terminating on the original dentate nucleus via the inferior cerebellar peduncle. We can demonstrate the anatomy of this anatomical triangle using a clinical case of palatal tremor presenting with bilateral subjective pulsatile tinnitus along with the pathognomonic MR findings previously described. The hyperintense T2 signal in these patients may be permanent, but the hypertrophied olive normally regresses after 4 years. The temporal relationship between the evolution of the histopathology and the development of the palatal tremor remains unknown as does the natural history of the tremor. Botox injection at the level of tensor and levator veli palatini insertion have been used to treat patients with disabling tremor synchronous tinnitus. A lesion involving the triangle can have a quite varied clinical expression.
Highlights
Palatal tremor (PT) was first described by Politzer in 1878 [1]
Symptomatic PT, known as symptomatic palatal myoclonus is a clinically, anatomically, and pathologically well-defined movement disorder characterized by a stereotypic 1–3 Hz palatal contractions that commonly appear after an injury involving the Guillain-Mollaret triangle (G-Mt) known as the dentato-rubro-olivary tract [2,3,4]
Symptomatic PT is correlated with hypertrophic olivary degeneration (HOD), a rare form of transsynaptic degeneration causing hypertrophy of the inferior olives as opposed to atrophy observed in other parts of the central nervous system [2, 4]
Summary
Palatal tremor (PT) was first described by Politzer in 1878 [1] This rare condition exists in two variations, namely, an “essential” form where it is not attributable to a structural cause and a “symptomatic” form that is secondary to pathology involving the brainstem or cerebellum [2]. Symptomatic PT, known as symptomatic palatal myoclonus is a clinically, anatomically, and pathologically well-defined movement disorder characterized by a stereotypic 1–3 Hz palatal contractions that commonly appear after an injury (e.g., haemorrhage, infarction, trauma, neoplasm, and demyelination) involving the Guillain-Mollaret triangle (G-Mt) known as the dentato-rubro-olivary tract [2,3,4]. Antemortem visualization of HOD using MRI has helped to better characterize the causative neuropathologies and associate temporal evolution of the inferior olivary nuclei (ION) [3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
