Action palatal tremor in a patient with primary intestinal lymphoma

Oncologic causes of oculopalatal tremors: neurophysiology and treatment

Oculopalatal tremor (OPT) is an acquired pathology characterized by continuous and rhythmical soft palatal movements combined with pendular nystagmus. Aside from vascular lesions, oncological masses affecting the dentatorubro-olivary pathway can impair brainstem and/or cerebellar pathways, manifesting as dyssynchronous movement. In this review, we delve into the neurophysiology of OPT along with oncological causes and treatment options based on the most recent clinical trial data. This literature review includes medication treatment data from clinical trials enrolling individuals with features of OPT, including acquired pendular nystagmus (APN). Trials were deemed eligible for inclusion in this review if one or more participants had symptoms determined by the trial authors to be caused by OPT. Trials investigating the treatment of APN secondary to a separate cause, such as multiple sclerosis, were excluded from this review. Several early treatments failed to demonstrate a benefit for patients with APN due to OPT. Trials of anticholinergic agents were largely ineffective and poorly tolerated. Botulinum toxin A demonstrated improvement in APN symptoms. Most recently, trials including memantine and gabapentin have demonstrated success with attenuation of APN. Surgical modalities such as DBS have yet to show improvement, though with only a single case report as evidence. Oculopalatal tremor is a unique manifestation of posterior fossa tumors disrupting the Guillain-Mollaret triangle. Symptom control through medication management has had limited success attributed to poor response and medication intolerance. Surgical modalities like DBS may have an emerging role in OPT treatment by targeting dyssynchronous activity in the dentatorubro-olivary pathway.

Palatal Tremor - Pathophysiology, Clinical Features, Investigations, Management and Future Challenges

Background:

Palatal tremor is involuntary, rhythmic and oscillatory movement of the soft palate. Palatal tremor can be classified into three subtypes; essential, symptomatic and palatal tremor associated with progressive ataxia.

Methods:

A thorough Pubmed search was conducted to look for the original articles, reviews, letters to editor, case reports, and teaching neuroimages, with the keywords “essential”, “symptomatic palatal tremor”, “myoclonus”, “ataxia”, “hypertrophic”, “olivary” and “degeneration”.

Results:

Essential palatal tremor is due to contraction of the tensor veli palatini muscle, supplied by the 5^th cranial nerve. Symptomatic palatal tremor occurs due to the contraction of the levator veli palatini muscle, supplied by the 9%^th and 10%^th cranial nerves. Essential palatal tremor is idiopathic, while symptomatic palatal tremor occurs due to infarction, bleed or tumor within the Guillain-Mollaret triangle. Progressive ataxia and palatal tremor can be familial or idiopathic. Symptomatic palatal tremor and sporadic progressive ataxia with palatal tremor show signal changes in inferior olive of medulla in magnetic resonance imaging. The treatment options available for essential palatal tremor are clonazepam, lamotrigine, sodium valproate, flunarizine and botulinum toxin. The treatment of symptomatic palatal tremor involves the treatment of the underlying cause.

Discussion:

Further studies are required to understand the cause and pathophysiology of Essential palatal tremor and progressive ataxia and palatal tremor. Similarly, the link between tauopathy and palatal tremor associated progressive ataxia needs to be explored further. Oscillopsia and progressive ataxia are more debilitating than palatal tremor and needs new treatment approaches.

Speech-activated Myoclonus Mimicking Stuttering in a Patient with Myoclonus-Dystonia Syndrome

BACKGROUND

Acquired neurogenic stuttering has been considered a fairly uncommon clinical occurrence; speech-activated myoclonus is a rare entity that can mimic stuttering and is caused by a wide array of etiologies.

CASE REPORT

Here we report a patient with myoclonus-dystonia syndrome (MDS), due to an identified disease-causing mutation, who displayed speech-activated myoclonus mimicking stuttering.

DISCUSSION

In MDS, myoclonus has only infrequently been reported to affect speech. This case further expands the spectrum of conditions causing the rare clinical phenomenon of speech-activated myoclonus.

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.

Facial reflex myoclonus induced by language: a neuropsychological and neurophysiological study

We studied a 53 year old right-handed patient who presented isolated myoclonus of right facial muscles induced exclusively by language. Twitching significantly hindered speaking and reading performance. MRI and CT-scan revealed no brain lesion. Conventional EEG showed a few spike-waves predominantly in the left hemisphere. Spike-waves increased during drowsiness. An EEG-EMG polygraphic study was performed during stimulation tests which included linguistic tasks and non-verbal/non-linguistic tests. Myoclonus was triggered by speaking and writing but not by non-linguistic tasks. The severity of myoclonus was dependent on the complexity of the language task. Back-averaging of right facial EMG bursts failed to show a reliable EEG-EMG correlation. However, the facial reflex myoclonus might have originated from the left rolandicopercular cortex, as it was triggered by complex language activities. Findings in this case are compared with those reported for other forms of reflex seizure and myoclonus.