Tensor Tympani and Stapedial Tendon Reconstruction for Postoperative Hyperacusis after Tendon Lysis for Middle Ear Myoclonus.

OBJECTIVE: To present a method for repair of the stapedial and tensor tympani tendons in a patient with hyperacusis after a tendon lysis procedure. PATIENTS: A 71-year-old professional musician who presented to clinic with debilitating hyperacusis following a tensor tympani and stapedial tendon lysis procedure to treat middle ear myoclonus. INTERVENTIONS: A novel procedure for reapproximation of the tensor tympani and stapedial tendons into their native insertion points using periosteal grafts and nitinol wire. MAIN OUTCOMES MEASURES: Stapedial reflex measurements, uncomfortable loudness level, and subjective patient experience. RESULTS: Postoperatively, the patient had objective improvement in hyperacusis with return of acoustic reflexes in the affected ear and durable improvements in their frequency-specific uncomfortable loudness levels. CONCLUSIONS: This case describes the debilitating complication of hyperacusis following tendon lysis and highlights the importance of maximizing behavioral and medical measures prior to undergoing surgical intervention for middle ear myoclonus.

Spinal segmental myoclonus following spinal surgery.

A 44-year-old male was admitted with L5/S1 spondylodiscitis complicated by a posterior epidural abscess that was compressing the thecal sac with severe narrowing of the canal and compression of the cauda equine. He underwent computed tomography (CT) guided drainage followed by L5/S1 decompression laminectomy and was started on a 6-week course of intravenous antibiotics with good response. He remained well and afebrile with inflammatory markers showing improvement. During this period, he developed intermittent myoclonic movements of right lower limb with severe pain over the back radiating to the gluteal region which hindered his rehabilitation potential. He was diagnosed with spinal segmental myoclonus based on clinical findings and history of recent spinal surgery. He was successfully treated with a course of clonazepam and continues to make functional improvements during his rehabilitation program.

Surgical Treatment of Upper Extremity Segmental Myoclonus in an Adolescent with Chiari Malformation and Cervicothoracic Syrinx.

BACKGROUND: Myoclonus is an involuntary movement disorder characterized by semirhythmic jerking movements of muscle groups but is rarely seen in association with Chiari malformation type I (CM-1). CM-1 is a frequently encountered clinical entity in pediatric neurosurgery characterized by caudal displacement of the cerebellar tonsils with or without syringomyelia. We report a pediatric patient who presented with upper extremity myoclonus and was found to have CM-1 and a complex septated cervicothoracic syrinx eccentric to the left. CASE PRESENTATION: A 12-year-old female presented with 6 months of headaches and upper extremity paresthesias who subsequently developed a left upper extremity segmental myoclonus after a fall. MRI demonstrated a CM-1 and a large complex cervicothoracic syrinx with a midline and left paracentral cavities. Her myoclonus was nonepileptic and refractory to clonazepam, cyclobenzaprine, and gabapentin. She underwent an intradural Chiari decompression and duraplasty. Postoperatively, she had complete resolution of her segmental myoclonus. DISCUSSION: This case demonstrates a durable resolution of posttraumatic upper extremity segmental myoclonus after surgical decompression of a CM-1 with syringomyelia. Thus, Chiari decompression should be considered in cases of myoclonus with CM-1 and syringomyelia.

Painful Myoclonus Triggered by Lateral Antebrachial Cutaneous Nerve Entrapment at the Brachioradialis Muscle.

Compression of the lateral antebrachial cutaneous nerve is a rare clinical entrapment syndrome often overlooked as an initial etiology of pain. We present a case of an episodic upper limb painful movement disorder (myoclonus) in a 16-yr-old adolescent girl with a remote history of a surgically stabilized supracondylar humeral fracture who was later found to have entrapment of the lateral antebrachial cutaneous nerve. The incidence of a painful myoclonus triggered by a peripheral nerve entrapment is unknown. Combining a history and physical examination, electromyography, nerve conduction studies, and ultrasound enabled us to make an accurate diagnosis that was confirmed by resolution of symptoms after surgical release. This study conforms to all CARE guidelines and reports the required information accordingly (see Supplemental Check list, Supplemental Digital Content 1, http://links.lww.com/PHM/A855).

Selective deep brain stimulation in the substantia nigra reduces myoclonus in progressive myoclonic epilepsy: a novel observation and short review of the literature.

We report the case of a patient suffering from pharmacotherapy-resistant bilateral progressive myoclonic epilepsy (PME) showing a beneficial response upon selective deep brain stimulation (DBS) of the substantia nigra pars reticulata. As an individual experimental therapeutic approach, we implanted DBS electrodes in the transitional zone between the subthalamic nucleus (STN) and the substantia nigra pars reticulata (SNr). Electrode placement allowed for a selective stimulation of either the STN, SNr, or both targets. Postoperatively, we observed a moderate subjective and objective improvement in positive and negative myoclonus by high-frequency DBS of the STN/SNr transitional zone. However, a systematic exploration of different stimulation settings revealed that monopolar stimulation of the substantia nigra alone was more effective than high-frequency monopolar DBS of either the motor STN (monopolar) or stimulation of both targets (STN/SNr). This observation confirms earlier findings showing that patients with PME benefit from high-frequency DBS. However, in contrast to previous reports stimulating the STN/SNr transitional zone, our patient showed the most significant effect upon selective stimulation of the SNr. We propose that in patients undergoing DBS for myoclonus, at least one electrode contact should be placed in the SNr allowing for selective monopolar stimulation of this target.

An Update on Myoclonus Management.

INTRODUCTION: Myoclonus is a hyperkinetic movement disorder characterized by sudden, brief, lightning-like involuntary jerks. There are many possible causes of myoclonus and both the etiology and characteristics of the myoclonus are important in securing the diagnosis and treatment. Myoclonus may be challenging to treat, as it frequently requires multiple medications for acceptable results. Few randomized controlled trials investigating the optimal treatment for myoclonus are available, and expert experience and case series guide treatment. Areas Covered: In this article, the authors review the basics of myoclonus and its classification. The authors discuss the current management of myoclonus and then focus on recent updates in the literature, including both pharmacologic and surgical options. Expert opinion: Myoclonus remains a challenge to manage, and there is a paucity of rigorous clinical trials guiding treatment paradigms. Furthermore, due to the etiological heterogeneity of myoclonus, defining the appropriate scope for high-quality clinical trials is challenging. In order to advance the field, the myoclonus study group needs to be revived in the US and abroad so that interested investigators can collaborate on multicenter clinical trials for myoclonus treatments.

Progressive Encephalomyelitis with Rigidity and Myoclonus Resolving after Thymectomy with Subsequent Anasarca: An Autopsy Case.

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is an autoimmune disorder involving the brainstem and spinal cord and is sometimes associated with thymoma. We encountered a 75-year-old woman with typical PERM features, glycine receptor antibody, and thymoma. Her neurologic symptoms improved after thymectomy, but she unexpectedly developed anasarca with massive pleural effusions and hypoalbuminemia and finally succumbed to death. The autopsy showed edema and mononuclear infiltration in the pleura but no neuropathological findings typical of PERM. Effective treatment of PERM can reverse the neuropathological signs of encephalomyelitis. The autoimmune nature of anasarca is possible but not proven.

Middle ear myoclonus cured by selective tenotomy of the tensor tympani: strategies for targeted intervention for middle ear muscles.

OBJECTIVE: To describe a case of middle ear myoclonus that was successfully cured by selective transection of the tensor tympani (TT) without sectioning the stapedius tendon (ST) and to review previously reported cases, elucidating precipitating factors for interventions targeting middle ear muscles. DATA SOURCES: One case we encountered and a recent systematic review published in 2012. STUDY SELECTIONS: In addition to our case, 23 cases identified by the previous systematic review regarding middle ear myoclonus in which surgical interventions were conducted. DATA SYNTHESIS: Outcomes for selective tenotomy of TT or ST were analyzed focusing on the following 6 preoperative factors: 1) history of facial palsy, 2) provoking factors for tinnitus, 3) auscultation of the ear, 4) movement of the ear drum, 5) complication with palatal myoclonus, and 6) confirmation of myoclonus during surgery. Among these, the first 2 factors represented significant factors for selective tenotomy of ST (p < 0.05 and p < 0.01, respectively). Furthermore, no auscultation of the ear was significant for selective tenotomy (p < 0.01), specifically for ST. Confirmation of muscle contraction during surgery contributed significantly (p < 0.01) to targeted intervention, but selective tenotomy of TT was successfully performed in 3 cases without such confirmation by confirming variations in compliance with tympanometry CONCLUSION: Assessment of the history of facial palsy, provoking factor of tinnitus, auscultation of the ear, and confirmation of myoclonus during surgery appear helpful in predicting which middle ear muscle is undergoing myoclonus. Furthermore, long-time-based tympanometry offers objective information for planning targeted intervention for middle ear muscles and clarifying clinical outcomes.

Stepwise synchronization through the corpus callosum is one cause of myoclonic jerks.

BACKGROUND: Epileptic myoclonus is generally treated by valproate monotherapy, and this therapy has confirmed efficacy. However, almost 30% of patients with juvenile myoclonic epilepsy (JME) are valproate-resistant. CASE DESCRIPTION: A 23-year-old man with a diagnosis of JME had resistance to multiple antiepileptic drugs (AEDs). Stepwise synchronization of bilateral spikes on electroencephalography (EEG) was found shortly before the clinical myoclonus. The anterior two thirds of the corpus callosum were divided. Desynchronization of spikes by the corpus callosotomy arrested the patient's myoclonus. CONCLUSIONS: Interhemispheric recruitment of epileptic spikes through the corpus callosum may induce synchronization of spikes and myoclonus.

Clinical and neurophysiological improvement of SGCE myoclonus-dystonia with GPi deep brain stimulation.

Myoclonus-dystonia (M-D) is characterized by early onset myoclonus and dystonia. It is thought to be subcortical in origin. Response to oral medications may be incomplete, such that deep brain stimulation (DBS) surgery to the globus pallidum interna (GPi) or ventral intermediate thalamic nucleus (VIM) may be considered. The optimal site is not known. The physiology and surgical response for a 63-year-old woman who underwent GPi DBS for M-D with onset at age 2 and related to a mutation in the epsilon-sarcoglycan gene (SGCE) is described. She showed excellent clinical and neurophysiological improvement of both myoclonus and dystonia, suggesting that modulation by DBS is effective even after long disease duration and only partial response to oral medications.

Cerebellum can be a possible generator of progressive myoclonus.

A 19-month-old girl presented with progressive myoclonic jerking of both proximal lower extremities. On her brain magnetic resonance imaging (MRI), the authors found an ill-defined mass involving cerebellar vermis and the right middle cerebellar peduncle. ( 11)C-methionine positron emission tomography (PET) showed no abnormalities, but (18)F-fluorodeoxyglucose ((18)F-FDG) PET revealed a well-defined hypermetabolic focus. Depth electrodes were inserted deep into the mass, which recorded focal slow waves associated with the clinical myoclonus. Following the removal of the tumor, the myoclonus was completely resolved with no neurological deficit. Here, the authors present a case showing progressive myoclonus associated with a cerebellar ganglioglioma with the electrophysiological data, which provides strong supportive evidence that the cerebellum can be a myoclonus generator.

Local field potentials and oscillatory activity of the internal globus pallidus in myoclonus-dystonia.

The pathophysiology of myoclonus-dystonia (M-D), an autosomal dominantly inherited movement disorder characterized by myoclonic jerks and dystonic contractions, is largely unknown. In the present study, local field potential (LFP) activities in the globus pallidus internus (GPi) from two genetically proven M-D patients are investigated. Coherence analysis between GPi LFP activity and electromyographic muscle activity (EMG) and synchronization of GPi neuronal activity using event-related spectral perturbation (ERSP) in a go-no-go paradigm were studied. Significant increased coherence in the 3 to 15 Hz frequency band was detected between GPi LFP activity and several muscles, with the LFP leading the muscles. The ERSP analysis revealed synchronization in the 3 to 15 Hz frequency band within the GPi before the imperative cue of the go-no-go task and desynchronization in the same band after the cue. The LFP recordings of the GPi in M-D show that the low-frequency band previously described in dystonia is also involved in the dystonia plus syndrome M-D. The 3 to 15 Hz synchronization in the go-no-go paradigm has not been described previously and may point to the existence of (myoclonus-)dystonia specific oscillatory activity in the GPi.

Radiofrequency ablation in the treatment of idiopathic bilateral palatal myoclonus: a new indication.

OBJECTIVES: We tested the effect of radiofrequency ablation in the treatment of palatal myoclonus refractory to other therapeutic regimens. METHODS: A 20-year-old patient who presented with palatal myoclonus and annoying rhythmic objective clicking noise was treated with a radiofrequency generator with topical and local anesthesia in an outpatient setting. RESULTS: The clicking noise was abolished within 3 to 4 days of the radiofrequency ablation. The rhythmic, jerky movements of the soft palate were confirmed to be absent 2 weeks later with electromyographic studies. The patient has been symptom-free for 6 months, and no side effects have occurred. CONCLUSIONS: As a new indication, radiofrequency ablation may effectively abolish abnormal movements of the soft palate and relieve associated tinnitus.

Treatment for severe palatoclonus by occlusion of the eustachian tube.

PURPOSE: Surgical blocking of the eustachian tube is presented as an ultimate treatment option in a 11-year-old suicidal boy with a therapy-resistant, persistent clicking tinnitus caused by myoclonus of the levator veli palatini. PATIENT: An 11-year-old boy decompensated psychologically as a result of loud and objective tinnitus. The tinnitus could be heard easily by an examiner by bringing his own ear at a distance of approximately 20 to 30 cm to the left ear of the patient. No neurologic etiology for the tinnitus could be traced. Pediatric psychiatric evaluation resulted in a recommendation to perform, as a last resort, an experimental surgical option like blockage of the eustachian tube. INTERVENTION: Treatment with Tegretol (Novartis, The Netherlands) had no effect. Treatment with Dysport (Ipsen) botulin toxin with 30 to 60 U was temporarily effective. Finally, 60 U were not effective anymore. As last refugium, a surgical blockage of the eustachian tube has been performed, first with bone cement and later by a more conventional surgical blockage of that bony tube. OUTCOME: After surgical blockage of the bony part of the eustachian tube, the objective tinnitus disappeared. Blockage of the protympanum by bone cement resulted in only 1 year of successful blocking. After recurrence of the tinnitus combined with aeration of the middle ear, a second surgical transcanal approach was successful in blocking the eustachian tube. With a grommet, the hearing level remained within 10 dB for 0.5 to 8.0 kHz.