Episodic undulating hyperkinesias of the tongue associated with brainstem ischemia

Teaching Video NeuroImage: Isolated Undulating Tongue Hyperkinesia Following a Basilar Stroke

An 82-year-old man with a history of hypertension and coronary revascularization presented with sudden-onset right hemiparesis and disorientation lasting 5 hours. On admission, he was intubated because of gasping and a Glasgow Coma Scale of 3. Hemorrhagic stroke was suspected, but ruled out by the initial head CT, which revealed old cerebellar lacunae. The following day, the comatose, now unsedated patient exhibited tetraparesis; fixed, nonreactive pupils; and corneal reflex, but no oculocephalic reflex. Rhythmic undulating tongue movements without palatal or limb involvement were first observed (Video 1). EEG revealed no epileptiform activity. Follow-up head CT showed acute ischemic lesions in the thalamocapsular region, midbrain, and pons while angiotomography revealed distal basilar artery occlusion (Figure). Involuntary tongue movements, though rare, have been associated with various conditions such as stroke, trauma, and epilepsy.1,2 These movements may result from disinhibition within the inhibitory reticular formation projecting to hypoglossal neurons, suggesting the pontine reticular formation as a central pacemaker.2.

A Case Series of Patients With MYBPC1 Gene Variants Featuring Undulating Tongue Movements as Myogenic Tremor

Myosin-binding protein C1 (MYBPC1) encodes myosin-binding protein C, slow type (sMyBP-C), an accessory protein that regulates actomyosin cross-linking, stabilizes thick filaments, and modulates contractility in muscle sarcomeres and has recently been linked to myopathy with tremor. The clinical features of MYBPC1 mutations manifesting in early childhood bear some similarities to those of spinal muscular atrophy (SMA), such as hypotonia, involuntary movement of the tongue and limbs, and delayed motor development. The development of novel therapies for SMA has necessitated the importance of differentiating SMA from other diseases in the early infancy period. We report the characteristic tongue movements of MYBPC1 mutations, along with other clinical findings, such as positive deep tendon reflexes and normal peripheral nerve conduction velocity testing, which could help in considering other diseases as differential diagnoses.

[Case of an elderly woman with dementia showing episodic involuntary movement of the tongue]

We report a 93-year-old woman with dementia who developed generalized convulsion and involuntary movement of her tongue. She could independently walk and eat meals until 8 months ago, however she turned into bedridden. When she was admitted to our emergency room due to status epilepticus, her tongue intermittently moved from the midline to the left. She could not eat or speak during this episodic tongue movement. MR imaging study revealed brain atrophy in the bilateral mesial temporal lobe, consistent with senile dementia of Alzheimer type. Despite her tongue movements seemingly developing to the generalized convulsion, EEG study did not indicate epileptiform discharges corresponding to this movement. Although antiepileptic drug therapy was effective, we needed polytherapy to control this movement. Paroxysmal tongue movements were previously reported in cases of epilepsy, brain tumor, and stroke, observed bilaterally in most cases. This episodic tongue movement would be rare in terms of the clear laterality. The etiology of this movement was presumed as focal seizure, palatal tremor, dyskinesia or others, but was undetermined. Episodic movements involving tongue decrease the quality of daily life especially in the elderly. Therefore, we should pay more attention to it and try to treat it earlier.

Unusual focal dyskinesias

This chapter reviews focal dyskinesias that affect a restricted region of the body in isolation. Focal dyskinesias often affect body parts not commonly involved in isolation by movement disorders and are not readily classified into one of the major categories of movement disorders or peripheral nerve excitability syndromes. The clinical features and phenomenology of these "unusual focal dyskinesias" are discussed according to the region affected (ear, lip, chin, jaw, tongue, abdomen, and diaphragm (belly dancer's dyskinesias), back, scapula, and limbs). The phenomenology and origin of the unusual focal dyskinesias remain the subject of debate. Most are characterized by slow semirhythmic jerky movements at variable (usually slow) frequencies superimposed on sustained postures, consistent with dystonic movements. However, the body parts affected and pattern of occurrence (in repose rather than during action) are different to those usually seen in primary dystonia. Many of the unusual focal dyskinesias are associated with trauma and pain to the affected region, prompting the suggestion that the movements follow central sensorimotor reorganization occurring spontaneously or secondary to changes in the peripheral nervous system. In other cases, inconsistent signs and spontaneous recovery suggest a psychogenic origin.

New device to control combined lingual and palatal myoclonus

Lingual myoclonus is a poorly understood disorder that may occur in isolation or combined with palatal myoclonus. In this report, we present the case history of a 21-year-old patient with a therapy-resistant essential lingual and palatal myoclonus where a simple dental device was able to control symptoms. The use of this device will be highlighted and compared to previously described methods. Cases of previously recorded lingual and palatal myoclonus will be reviewed and compared to the case of our patient.

Tongue tremor in brainstem pilocytic astrocytoma

An isolated tremor of the tongue developed in a 22-year-old female patient in a minimally conscious state. The patient was diagnosed with brainstem pilocytic astrocytoma. A widespread lesion of the brainstem and cerebellum was evident on cranial magnetic resonance imaging. The pathophysiology of isolated tongue tremor is discussed with the magnetic resonance findings and the relevant literature.

Isolated continuous rhythmic involuntary tongue movements following a pontine infarct

Isolated involuntary tongue movements are rare and poorly understood. The anatomical substrate and pathogenesis underlying involuntary tongue movements remain elusive. We describe a patient who developed isolated continuous rhythmic involuntary tongue movements after pontine infarct without evidence of hypertrophy of inferior olivary nucleus on follow-up magnetic resonance image. We discuss the rhythmic involuntary tongue movements as a prototype of involuntary hyperkinetic movement released by a central pacemaker.

Isolated tongue tremor after gamma knife radiosurgery for acoustic schwannoma

We describe a patient who had an isolated tongue tremor with an audible click after gamma knife radiosurgery for acoustic schwannoma. The nature of the tongue tremor was clearly demonstrated by videofluoroscopy. The possible pathogenic mechanisms are discussed.

Tongue tremor in a patient with coma after electrical injury

We report on the case of a patient with transient tongue tremor and coma after electrical injury, probably due to a reversible brainstem dysfunction. We then reviewed the differential diagnosis of abnormal involuntary movements of the tongue as well as movement disorders related to electrocution.