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Hypertrophic olivary degeneration (HOD) is a rare form of transsynaptic degeneration. It is caused by a damage at the Guillain-Mollaret triangle (GMT), which is defined by three anatomical structures: the dentate nucleus, the red nucleus, and the inferior olivary nucleus (ION). Clinically, it may be revealed by palatal myoclonus. On MRI, it appears as a unilateral or bilateral enlargement of the inferior olivary nucleus which shows a high signal intensity on T2-weighted images, with sometimes a cerebellar atrophy. Here we report 2 cases of healthy patients which present hemorrhagic brainstem cavernomas, complicated later by the development of palatal myoclonus and cerebellar ataxia, with MRI features corresponding to an (HOD) secondary to a (GMT) cavernoma. The purpose is to explain the mechanism of (HOD) subsequent to lesion in (GMT), and to describe magnetic resonance imaging features.

This article discusses a case of palatal myoclonus, a condition characterized by involuntary muscle contractions in the soft palate, in a nine-year-old boy. The boy experienced distressing clicking tinnitus, a sound emitted by the ear and surrounding structures, which was successfully treated with injections of botulinum toxin. The article emphasizes the importance of careful differential diagnosis when encountering patients with unexplained tinnitus and provides insights into the diagnosis and treatment of myoclonic-induced clicking tinnitus. The use of botulinum toxin as a treatment option for palatal myoclonus is highlighted, although further research is needed to fully understand the condition. [Extracted from the article]

Abstract Background Hypertrophic olivary degeneration (HOD), a rare form of transsynaptic degeneration, is secondary to dentato-rubro-olivary pathway injuries in some cases. We describe a unique case of an HOD patient who presented with palatal myoclonus secondary to Wernekinck commissure syndrome caused by a rare bilateral “heart-shaped” infarct lesion in the midbrain. Case presentation A 49-year-old man presented with progressive gait instability in the past 7 months. The patient had a history of posterior circulation ischemic stroke presenting with diplopia, slurred speech, and difficulty in swallowing and walking 3 years prior to admission. The symptoms improved after treatment. The feeling of imbalance appeared and was aggravated gradually in the past 7 months. Neurological examination demonstrated dysarthria, horizontal nystagmus, bilateral cerebellar ataxia, and 2–3 Hz rhythmic contractions of the soft palate and upper larynx. Magnetic resonance imaging (MRI) of the brain performed 3 years prior to this admission showed an acute midline lesion in the midbrain exhibiting a remarkable “heart appearance” on diffusion weighted imaging. MRI after this admission revealed T2 and FLAIR hyperintensity with hypertrophy of the bilateral inferior olivary nucleus. We considered a diagnosis of HOD resulting from a midbrain heart-shaped infarction, which caused Wernekinck commissure syndrome 3 years prior to admission and later HOD. Adamantanamine and B vitamins were administered for neurotrophic treatment. Rehabilitation training was also performed. One year later, the symptoms of this patient were neither improved nor aggravated. Conclusion This case report suggests that patients with a history of midbrain injury, especially Wernekinck commissure injury, should be alert to the possibility of delayed bilateral HOD when new symptoms occur or original symptoms are aggravated.

Background: Hypertrophic olivary degeneration (HOD), a rare form of transsynaptic degeneration, is secondary to dentato-rubro-olivary pathway injuries in some cases. We describe a unique case of an HOD patient who presented with palatal myoclonus secondary to Wernekinck commissure syndrome caused by a rare bilateral "heart-shaped" infarct lesion in the midbrain. Case presentation: A 49-year-old man presented with progressive gait instability in the past 7 months. The patient had a history of posterior circulation ischemic stroke presenting with diplopia, slurred speech, and difficulty in swallowing and walking 3 years prior to admission. The symptoms improved after treatment. The feeling of imbalance appeared and was aggravated gradually in the past 7 months. Neurological examination demonstrated dysarthria, horizontal nystagmus, bilateral cerebellar ataxia, and 2–3 Hz rhythmic contractions of the soft palate and upper larynx. Magnetic resonance imaging (MRI) of the brain performed 3 years prior to this admission showed an acute midline lesion in the midbrain exhibiting a remarkable "heart appearance" on diffusion weighted imaging. MRI after this admission revealed T2 and FLAIR hyperintensity with hypertrophy of the bilateral inferior olivary nucleus. We considered a diagnosis of HOD resulting from a midbrain heart-shaped infarction, which caused Wernekinck commissure syndrome 3 years prior to admission and later HOD. Adamantanamine and B vitamins were administered for neurotrophic treatment. Rehabilitation training was also performed. One year later, the symptoms of this patient were neither improved nor aggravated. Conclusion: This case report suggests that patients with a history of midbrain injury, especially Wernekinck commissure injury, should be alert to the possibility of delayed bilateral HOD when new symptoms occur or original symptoms are aggravated. [ABSTRACT FROM AUTHOR]

Introduction: Wernekinck commissure syndrome (WCS) is an extremely rare midbrain syndrome, which selectively destroys the decussation of the superior cerebellar peduncle and the central tegmental tract, which commonly presents with bilateral cerebellar ataxia, dysarthria, and internuclear ophthalmoplegia. Palatal myoclonus in Wernekinck commissure syndrome is uncommon and often occurs as a late phenomenon due to hypertrophic degeneration of bilateral inferior olivary nuclei., Material and Method: A patient with WCS, admitted to our hospital from December 2023, was chosen for this study, and the syndrome's clinical manifestations, imaging features, and etiology were retrospectively analyzed based on the literature. A 68-year-old right-handed East Asian man presented with dizziness, slurred speech, difficulty with swallowing and walking, and rhythmic contractions of the soft palate. He had several risk factors for ischemic cerebrovascular diseases (age, sex, dyslipidemia, hypertension and smoking history). Brain magnetic resonance imaging showed hyperintensity of DWI and hypointensity of ADC at the caudal midbrain which was around the paramedian mesencephalic tegmentum anterior to the aqueduct of midbrain., Results: He was diagnosed with Wernekinck commissure syndrome (WCS) secondary to caudal paramedian midbrain infarction. He was started on dual antiplatelet therapy (aspirin and clopidogrel) and intensive statin therapy. Blood pressure and glucose were also adjusted. His symptoms improved rapidly, and he walked steadily and speak clearly after 7 days of treatment., Conclusions: Palatal myoclonus is known to occur as a late phenomenon due to hypertrophic degeneration of bilateral inferior olivary nuclei. However, Our case suggests that palatal myoclonus can occur in the early stages in WCS., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Hypertrophic olivary degeneration (HOD) is a rare form of transsynaptic degeneration. It is caused by a damage at the Guillain-Mollaret triangle (GMT), which is defined by three anatomical structures: the dentate nucleus, the red nucleus, and the inferior olivary nucleus (ION). Clinically, it may be revealed by palatal myoclonus. On MRI, it appears as a unilateral or bilateral enlargement of the inferior olivary nucleus which shows a high signal intensity on T2-weighted images, with sometimes a cerebellar atrophy. Here we report 2 cases of healthy patients which present hemorrhagic brainstem cavernomas, complicated later by the development of palatal myoclonus and cerebellar ataxia, with MRI features corresponding to an (HOD) secondary to a (GMT) cavernoma. The purpose is to explain the mechanism of (HOD) subsequent to lesion in (GMT), and to describe magnetic resonance imaging features., (© 2024 The Authors. Published by Elsevier Inc. on behalf of University of Washington.)

1 Video This video depicts ~2 Hz myoclonus of the patient's face and neck, including the lip, chin, and throat. Magnetic resonance imaging (MRI) of the brain showed restricted diffusion in the right superomedial cerebellum consistent with an acute infarct (Fig. Keywords: palatal tremor; palatal myoclonus; hypertrophic olivary degeneration EN palatal tremor palatal myoclonus hypertrophic olivary degeneration 104 106 3 01/05/22 20220101 NES 220101 Palatal myoclonus, also described as palatal tremor, is characterized by rhythmic continuous 0.5 to 5 Hz movements of the soft palate and pharynx.1 There are two categories described: symptomatic palatal tremor, because of a brainstem or cerebellar lesion, and essential palatal tremor, with no associated structural lesion.2,3 Palatal myoclonus can rarely be associated with synchronous myoclonus of other branchial arch muscles, the diaphragm, facial muscles, or even the extremities.2 One specific variant is termed palato-pharyngo-laryngeal myoclonus, which can result in dysphagia, dysphonia, and dysarthria.4 A 56-year-old woman awoke from sleep with new right-sided weakness and dizziness. [Extracted from the article]

Abstract Background Wernekink commissure syndrome causes a peculiar combination of internuclear ophthalmoplegia, dysarthria, and delayed-onset palatal myoclonus. Palatal myoclonus is thought to be secondary to delayed hypertrophic degeneration of the bilateral inferior olivary nuclei secondary to involvement of bilateral dentatoolivary tract. We describe a case of a patient with early-onset palatal myoclonus. Case presentation A 53-year-old Caucasian man with several vascular risk factors presented to our emergency room with slurred speech, double vision, difficulty with swallowing and walking, and rhythmic contractions of the soft palate. Brain magnetic resonance imaging showed an acute infarct of the right caudal midbrain and an old infarct of the right medulla. We hypothesize that the cause of early palatal myoclonus in our patient was a two-hit mechanism with degeneration of the right olivary nucleus resulting from prior right medullary lacunar stroke with the new infarct affecting the dentato-rubro-olivary tract on the left side, causing bilateral dysfunction initiating palatal myoclonus. Conclusions Wernekink commissure syndrome with palatal myoclonus at onset suggests the presence of a prior ischemic insult in the medulla. Careful examination is important to identification of this presentation.

Palatal myoclonus (PM) is a rare disease that may induce dysphagia. Since dysphagia related to PM is unique and is characterized by myoclonic movements of the involved muscles, specific treatments are needed for rehabilitation. However, no study has investigated the treatment effectiveness for this condition. Therefore, the aim of this case report was to describe the benefit of combining behavioral treatment with valproic acid administration in patients with dysphagia triggered by PM. The two cases were treated with combined treatment. The outcomes evaluated by videofluoroscopic swallowing studies before and after the treatment showed significant decreases in myoclonic movements and improved swallowing function. We conclude that the combined treatment was effective against dysphagia related to PM.

Abstract Palatal myoclonus can be primary or secondary. In primary palatal myoclonus, no obvious structural brain lesions can be found within the triangle of Guillain and Mollaret. Common causes of secondary myoclonus include stroke, demyelination, infections, trauma, and neurodegeneration.

Background: Hypertrophic olivary degeneration is a rare condition caused by damage within the triangle of Guillain and Mollaret. We discuss the anatomical, radiological, and clinical history of this rare condition. Case Description: A 32-year-old lady presented with sub-acute headache, photophobia, and dizziness. She also described facial tingling and itching over her nose, and a thirty-minute episode of slurred speech. Magnetic resonance imaging revealed a 12.1 × 11 × 7.3 mm lesion arising from the floor of the fourth ventricle [Figure 1]. Postoperative imaging confirmed complete resection of the tumor, but changes consistent with hypertrophic olivary degeneration [Figure 2a and b]. Conclusion: An awareness of this complication is of importance to all clinical neuroscience to prevent misdiagnosis with the occurrence of new symptoms. [ABSTRACT FROM AUTHOR]

Background and purpose: Hypertrophic olivary degeneration (HOD) is a rare transsynaptic degeneration that usually appears at around 3–4 weeks following an injury to the Guillain–Mollaret triangle, resulting in three possible patterns. Our purpose was to describe those MRI features linking them to their corresponding neurological manifestations and possible prior location of brain insults based on our own experience compared to the review of the literature. Methods: Six patients with clinically evident new neurological symptoms not explained by the initial brain insult were included. All patients were subjected to complete neurological assessment by neurologist or neurosurgeon accordingly. Review of their prior and recent MRI studies as well as CT if available was carried out by two neuroradiologists who picked up the different but classical patterns of HOD on the latest imaging studies. Results: The 6 patients had old brain insults including old hematomas (1 patient), old infarctions (3 patients) and hemorrhagic vascular malformation (2 patient) involving the afferent components of the Guillain–Mollaret triangle with development of new movement disorders including ataxia (4 patients), palatal myoclonus (4 patients), tremors (1 patient) and nystagmus (2 patients). MRI clearly showed the nature of the initial lesions. High T2 signal intensity was noticed at the inferior olivary nucleus (ION) in all patients representing olivary degeneration. The size of the ION was enlarged with rounded configuration in 5 cases thus considered hypertrophic, while the size of the ION was shrunken in one case and considered atrophic. The examined ION showed no restricted diffusion excluding recent infarction, blooming on T2∗ excluding hemorrhage or post contrast enhancement excluding inflammation or neoplasm. Unilateral HOD was seen in 3 cases involving the contra-lateral ION while bilateral HOD was seen in 3 cases. Conclusion: HOD is an infrequent neurological pathology, sequel to Guillain and Mollaret triangle affection that involves a wide range of symptomatology. It manifests as enlargement of the ION with high T2 and FLAIR signal without enhancement, restricted diffusion or blooming on T2∗ or SWI.

Objective: To present cases of atypical palatal tremor (PT) and showcase the variable phenomenology of this condition. Study Design: Retrospective case series. Results: PT, or palatal myoclonus, is a movement disorder characterized by brief, involuntary rhythmic muscular contractions of the soft palate. Variants of PT have been described and include synchronous tremors in other branchial arch derivatives including the larynx, pharynx, neck, face, jaw, ocular and also respiratory and trunk muscles. We present 3 cases, including clinical videos, of atypical PT with extra‐palatal manifestations, in addition to a brief discussion of the pathophysiology and management of this condition. Conclusion: Variations of PT are of interest to the practicing otolaryngologist as the clinical spectrum of this condition is wide and can present with laryngeal, pharyngeal, respiratory and other head and neck manifestations. [ABSTRACT FROM AUTHOR]

Palatal myoclonus is one of the rare causes of tinnitus characterized by rhythmic involuntary contraction of muscles of soft palate as well as pharynx. Among the two types, the essential palatal myoclonus, which is idiopathic as no cause can be identified in children, is rarely reported in literature. In this case report, we present a 12-year-old girl who complained of hearing abnormal sound in her ears, which could be perceived by the examiner also. She had myoclonus of soft palate and uvula for which no obvious cause could be identified. Hence, it was diagnosed as essential palatal myoclonus and was successfully treated with clonazepam.

Wernekink commissure syndrome secondary to caudal paramedian midbrain infarction (CPMI) is a rare midbrain syndrome involving the decussation of the superior cerebellar peduncle in the caudal paramedian midbrain tegmentum. The central characteristics are constant bilateral cerebellar dysfunction, variable eye movement disorders, and rare delayed palatal myoclonus. Following is a description of the case of a 60-year-old man who presented with dizziness, slurred speech, and difficulty walking. Neurological examination revealed bilateral cerebellar dysfunction and bilateral internuclear ophthalmoplegia (bilateral INO). Serial magnetic resonance imaging (MRI) revealed a lesion in the caudal paramedian midbrain with a “heart-shaped” sign on fluid-attenuation inversion recovery images and a “V-shaped” appearance on diffusion-weighted imaging (DWI). An acute CPMI with a “heart or V” appearance sign was diagnosed. Upon follow-up evaluation 3 months later, a palatal tremor accompanied by involuntary head tremor was discovered. Hypertrophy and increased signal of the bilateral inferior olivary nucleus, compatible with hypertropic olivary degeneration (HOD) were revealed during a subsequent MRI study.

Introduction: Palatal myoclonus is a rare condition presenting with clicking sound in ear or muscle tremor in pharynx. There are two varieties: essential and symptomatic. Various treatment options exists ranging from watchful observation to botulinum toxin injection. We have not found any reported case of palatal myoclonus from our country. Here we present a case of essential palatal myoclonus managed with clonazepam. Case report: A young female presented in Ear Nose and Throat clinic with complain of auditory click and spontaneous rhythmic movement of throat muscles for eight months. On examination, there was involuntary, rhythmic contraction of bilateral soft-palate, uvula, and base of tongue. Neurological, eye, and peripheral examination were normal. A diagnosis of essential palatal myoclonus was made. It was managed successfully with clonazepam; patient was still on low dose clonazepam at the time of making this report. Conclusion: Essential palatal myoclonus can be clinically diagnosed and managed even in settings where MRI is not available or affordable.

Background: Palatal myoclonus (PM) is the hallmark of hypertrophic olivary degeneration (HOD); however, little is known regarding the association of thalamic lesions and PM. Case presentation: Here, we report a case of deteriorative PM after an acute small ventrolateral thalamic hemorrhage in a female Chinese patient with HOD. The sudden and severe deterioration of PM was preceded by at least 10 days of an occasionally occurring PM, which was related to an acute cerebellar hemorrhage 8 months earlier. A computed tomography scan upon admission showed a small intracerebral hematoma in the left ventrolateral thalamus, and a magnetic resonance imaging scan revealed the typical signs of HOD as well as a remote lesion in the dentate nucleus. Symptoms of PM were controlled by carbamazepine and clonazepam. Conclusion: These findings indicated that the damaged dentatothalamic tract might be due to a unique pathogenic mechanism involving a lesion of the ventrolateral thalamus and Guillain-Mollaret triangle.

Palatal myoclonus is a rare condition in which there are rhythmic jerky movements of the soft palate and sometimes of the other muscles innervated by the brainstem A particularly annoying symptom is a rhythmic clicking sound in the ear due to the opening and closing of the Eustachian tube. Orofacial buccal dystonia is a focal dystonia with sustained spasms of the masticatory, facial or lingual muscles. The frequent symptoms of this disease have mainly been reported to be involuntary and possibly painful jaw opening, closing, deflecting and retruding, or a combination of the above. However, the subtle and unnoticeable involuntary movement of multiple facial muscles, which might be an infrequent symptom of orofacial buccal dystonia, makes this disease hard to diagnose. Understanding the functional orofacial anatomy that is responsible for the clinical signs and symptoms is necessary for making a proper diagnosis. Here we report on a rare case of palatal myoclonus that was associated with orofacial buccal dystonia, and such a case has not been previously reported. We describe the diagnostic approach and excellent treatment results after Botulinum toxin A (Dysport) injection and proper counseling.

Background and purpose Hypertrophic olivary degeneration (HOD) is a rare transsynaptic degeneration that usually appears at around 3–4 weeks following an injury to the Guillain–Mollaret triangle, resulting in three possible patterns. Our purpose was to describe those MRI features linking them to their corresponding neurological manifestations and possible prior location of brain insults based on our own experience compared to the review of the literature. Methods Six patients with clinically evident new neurological symptoms not explained by the initial brain insult were included. All patients were subjected to complete neurological assessment by neurologist or neurosurgeon accordingly. Review of their prior and recent MRI studies as well as CT if available was carried out by two neuroradiologists who picked up the different but classical patterns of HOD on the latest imaging studies. Results The 6 patients had old brain insults including old hematomas (1 patient), old infarctions (3 patients) and hemorrhagic vascular malformation (2 patient) involving the afferent components of the Guillain–Mollaret triangle with development of new movement disorders including ataxia (4 patients), palatal myoclonus (4 patients), tremors (1 patient) and nystagmus (2 patients). MRI clearly showed the nature of the initial lesions. High T2 signal intensity was noticed at the inferior olivary nucleus (ION) in all patients representing olivary degeneration. The size of the ION was enlarged with rounded configuration in 5 cases thus considered hypertrophic, while the size of the ION was shrunken in one case and considered atrophic. The examined ION showed no restricted diffusion excluding recent infarction, blooming on T2 ∗ excluding hemorrhage or post contrast enhancement excluding inflammation or neoplasm. Unilateral HOD was seen in 3 cases involving the contra-lateral ION while bilateral HOD was seen in 3 cases. Conclusion HOD is an infrequent neurological pathology, sequel to Guillain and Mollaret triangle affection that involves a wide range of symptomatology. It manifests as enlargement of the ION with high T2 and FLAIR signal without enhancement, restricted diffusion or blooming on T2 ∗ or SWI. [ABSTRACT FROM AUTHOR]

Palatal myoclonus is an extremely rare neurotological disorder presenting to an otolaryngologist. It presents as objective tinnitus which is due to rhythmic, involuntary movements of the soft palate causing distress to the patients. Different medical and surgical remedies have been attempted with variable success. Botulinum toxin has been reportedly used in few cases and has reproduced good results lasting for a few months with minimum morbidity. We report a case suffering from palatal myoclonus for about 15 years and injection of botulinum toxin into his tensor veli palatini muscle resolved his objectionable unilateral tinnitus. Optimum results obtained initially, waned off over the years, for which the dose had to be gradually increased to achieve the desired clinical results. [ABSTRACT FROM AUTHOR]

Hypertrophic olivary degeneration (HOD) is a rare type of neuronal degeneration involving the dento-rubro-olivary pathway and presents clinically as palatal tremor. We present a 48 year old male patient who developed Holmes' tremor and bilateral HOD five months after brainstem hemorrhage. The severe rest tremor was refractory to pharmacotherapy and botulinum toxin injections, but was markedly reduced after thalamotomy. Magnetic resonance imaging permitted visualization of HOD, which appeared as a characteristic high signal intensity in the inferior olivary nuclei on T2- and proton-density-weighted images. Enlargement of the inferior olivary nuclei was also noted. Palatal tremor was absent in that moment and appears about two months later. The delayed-onset between insult and tremor following structural lesions of the brain suggest that compensatory or secondary changes in nervous system function must contribute to tremor genesis. The literature and imaging findings of this uncommon condition are reviewed.Degeneração olivar hipertrófica (DOH) é um tipo raro de degeneração neuronal envolvendo o trato dento-rubro-olivar e se apresenta clinicamente como tremor palatal. Relatamos o caso de um homem de 48 anos que desenvolveu tremor de Holmes e DOH bilateral cinco meses após hemorragia em tronco encefálico. O intenso tremor de repouso foi refratário a farmacoterapia e injeções de toxina botulínica, mas foi enormemente reduzido após talamotomia. Ressonância magnética permitiu a visualização da DOH, que apareceu como um sinal intenso característico na oliva inferior em imagens ponderadas em T2 e densidade de prótons. Aumento do complexo olivar inferior também foi percebido. O tremor palatal era ausente naquele momento e apareceu cerca de dois meses depois. O início tardio do tremor após a lesão estrutural sugere que alterações compensatórias ou secundárias no sistema nervoso devem contribuir para a gênese do tremor. A literatura e os achados radiológicos dessa patologia incomum são revisados.

We describe two cases of palatal myoclonus (PM), one essential and another secondary to a stroke. Case 1: a 64 years old female who developed clicking sounds in both ears after a stroke and three years later on noticed a progressive involuntary movement of the throat associated with rhythmic contractions of the soft palate, muscles of tongue and throat. MRI showed an ischemic area in brainstem. The patient had a partial response to the use of sumatriptan 6 mg subcutaneously. Case 2: a 66 years old female who began with ear clicking at left ear that worsed slowly associated with tinnitus and arrhythmic movements of soft palate and an audible click at left ear. Brain MRI was normal; audiometry showed bilateral neurosensory loss. She was prescribed clonazepan 1 mg daily with complete recovery. Primary and secondary palatal myoclonus share the same clinical features but probably have different pathophysiological underlying mechanisms.

Objective: Hashimoto encephalopathy (HE) is known as a steroid-responsive encephalopathy associated with autoimmune thyroiditis or nonvascular inflammation-related autoimmune meningoencephalitis. The average age of onset of HE is approximately 50 years; and it is more common in women. The onset of HE may be acute or subacute. The course of most HE cases is relapsing and remitting, which is similar to that of vasculitis and stroke. Methods: In this article, we present a previously healthy 32 years old; veterinarian male with palatal myoclonus, as a rare presentation of this disorder, and review the neurologic aspects of hashimoto encephalitis . Results: The clinical presentation of HE is characterized by progressive cognitive decline tremor, transient aphasia, seizures, abnormal gait, sleep disorder and stroke-like episodes . Myoclonus, either generalized or multifocal, and tremor, often of the bilateral upper extremities, is the most frequently observed involuntary movements in HE. Conclusion: The rapidly progressive cognitive dysfunction and encephalopathies observed.

Patients with palatal myoclonus may suffer from pulsatile tinnitus stemming from involuntary contractions of tensor veli palatini and levator veli palatini muscles. Botulinum toxin (BTX) injection to these muscles is effective in resolving pulsatile tinnitus symptom. We present a case of pulsatile tinnitus who was effectively treated with BTX injection under an electromyography guidance as an office procedure. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis To review the clinical characteristics and management of patients with palatal myoclonus and devise an algorithm for treatment with botulinum toxin based on presenting symptoms, clinical examination findings, and involved muscle groups. Study Design Retrospective chart review at two clinical research centers. Methods Between 1985 and 2011, 15 patients with a diagnosis of essential palatal myoclonus were assessed. Data were collected on patient demographics, disease characteristics, and treatment outcomes. Results Patients were more commonly female (60.0% vs. 40.0%) with average age at onset of 35.6 years. In 40.0% of patients, the myoclonus began after a viral upper respiratory tract infection. Two-thirds of patients had been previously treated unsuccessfully with oral medications. Predominant presenting symptoms included clicking tinnitus (46.7%), nonaudible awareness of palatal movements ± rhinolalia (20.0%), or both (33.3%). Clinical examination revealed co-incident involvement of pharyngeal musculature in 53.3%. Palatal site for initial botulinum toxin injection depended on the predominant presenting symptom: for tinnitus, 2.5 U were injected transorally into the tensor veli palatini muscle at the level of the pterygoid hamulus/lateral soft palate; for palatal movements, the injection was placed medially on either side of the uvula. Dose and location of subsequent injections were tailored depending on response to the toxin and location of subsequent observed maximal muscular contractions. Conclusions Palatal myoclonus can present with tinnitus or patient-perceived palatal movements. Management with botulinum toxin can be tailored to address the muscles contributing to the predominant presenting symptoms. Level of Evidence 4 Laryngoscope, 124:1164-1169, 2014 [ABSTRACT FROM AUTHOR]